Honors Biology Lab Manual Unit 3: Gene Expression, Mitosis & Differentiation

Unit 4: Meiosis, Genetics & Genetically Modified Organisms Name: _______________________________________________ Teacher: _________________________ Period: ________

Honors Biology Lab Portfolio Rubric

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Lab 1*

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* If you do not mark (*) the 3 labs you wish to be graded, the first 3 labs in your binder will be graded!*

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Units 3 & 4 Learning Targets Unit 3:

1. Construct an explanation based on evidence for how the structure of DNA determines the structure of proteins which carry out the essential functions of life through systems of specialized cells.

2. Ask questions to clarify relationships about the role of DNA and chromosomes in coding the instructions

for characteristic traits passed from parents to offspring.

3. Use a model to illustrate the role of cellular division (mitosis) and differentiation in producing and maintaining complex multicellular organisms.

Unit 4:

4. Make and defend a claim based on evidence that inheritable genetic variations may result from: (1) new genetic combinations through meiosis, (2) viable errors occurring during replication, and/or (3) mutations caused by environmental factors.

5. Apply concepts of statistics and probability to explain the variation and distribution of expressed traits in

a population.

6. Analyze a major global challenge to specify qualitative and quantitative criteria and constraints for solutions that account for societal needs and wants. (bioengineering/GMO)

7. Design a solution to a complex real-world problem by breaking it down into smaller, more manageable

problems that can be solved through engineering. (bioengineering/GMO)

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Unit 3: Gene Expression,

Mitosis & Differentiation

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Constructing DNA & RNA Models Introduction: Within the nucleus of every cell are long strings of DNA, the code that holds all the information needed to make and control every cell within a living organism. DNA, which stands for deoxyribonucleic acid, resembles a long, spiraling ladder. It consists of just a few kinds of atoms: carbon, hydrogen, oxygen, nitrogen, and phosphorus. Combinations of these atoms form the sugar-phosphate backbone of the DNA -- the sides of the ladder, in other words.Other combinations of the atoms form the four bases: thymine (T), adenine (A), cytosine (C), and guanine (G). These bases are the rungs of the DNA ladder. (It takes two bases to form a rung -- one for each side of the ladder.) A sugar molecule, a base, and a phosphate molecule group together to make up a nucleotide. Nucleotides are abundant in the cell's nucleus. Nucleotides are the units which, when linked sugar to phosphate, make up one side of a DNA ladder. DNA is called the blueprint of life. It got this name because it contains the instructions for making every protein in your body . Why are proteins important? Because they are what your muscles and tissues are made of; they synthesize the pigments that color your skin, hair, and eyes; they digest your food they make (and sometime are) the hormones that regulate your growth; they defend you from infection. In short, proteins proteins determine your body’s form and carry out its functions. DNA determines what all of these proteins will be. How does a cell “read” the chemical message coded in its DNA in the form of specific base sequences? Part of the answer lies with a second molecule in the nucleus of cells called ribonucleic acid (RNA). RNA is similar to DNA in that its molecules are also formed from nucleotides. However, deoxyribose and thymine are not found in RNA. Two other molecules, ribose and uracil (U), are present. Ribose replaces deoxyribose, and uracil replaces thymine. Looking at their models, you will see certain similarities between the molecules that they replace. RNA is important in assisting in the production of proteins because it, unlike DNA, can leave the nucleus and carry instructions for protein production to the rest of the cell. Activity: The goal of this lesson is to:

● Construct a paper model of a DNA helix by making the fundamental unit of DNA (nucleotide) ● Construct a paper model of a RNA helix by making the fundamental unit of RNA (nucleotide) ● Each member of the class will make a small segment of a DNA double helix and then join them

to form a large ladder-like helix. ● Each member of the class will make a small segment of a RNA molecule and then join them to

form a large RNA molecule. DNA Modeling Procedure:

1. Cut out the DNA model segments of deoxyribose, phosphate groups, and the bases provided. Color them according to the following color-code:

● Deoxyribose: purple ● Phosphate: brown ● Adenine: blue ● Guanine: green ● Thymine: red ● Cytosine: yellow

2. Using the small circles and stars as guides, line up the bases, phosphates and sugars. 3. Now glue the appropriate parts together forming 4 total nucleotides.

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4. Select 2 nucleotides to be the left half of your DNA molecule. Using the small squares as a guide, line the 2 nucleotides up.

5. Glue the 2 nucleotides together, forming the left half of your DNA ladder. 6. Complete the right side of the ladder by adding the complementary bases. You will have to turn them

upside down in order to make them fit. 7. Glue the right side of the ladder together at the small squares and in the center where the bases meet.

Your finished model should look like a ladder. 8. Write your name on the back of your piece of DNA. Bring your pieces to the lab area and join them to

the class’ pieces to form a longer piece of DNA. RNA Modeling Procedure:

1. Cut out the DNA model segments of deoxyribose, phosphate groups, and the bases provided. Color them according to the following color-code:

● Ribose: pink ● Phosphate: brown ● Adenine: blue ● Guanine: green ● Uracil: orange ● Cytosine: yellow

2. Using the small circles and stars as guides, line up the bases, phosphates and sugars. 3. Now glue the appropriate parts together forming 4 total nucleotides. 4. Using the small squares as a guide, line the 4 nucleotides up. 5. Glue the 4 nucleotides together, forming a small segment of a RNA molecule. 6. Write your name on the back of your piece of RNA. Bring your pieces to the lab area and join them to

the class’ pieces to form a longer piece of RNA. Questions

1. Five different nucleotides make up nucleic acids. What are they? What elements make up all nucleotides?

2. The DNA molecule resembles a twisted ladder. Which 2 molecules of a nucleotide form the sides of a DNA ladder? Which molecule of a nucleotide forms the rungs of a DNA ladder?

3. What bases pair together in DNA? What bases pair together in RNA?

4. If 30% of a DNA molecule is adenine, what percent is cytosine? SHOW YOUR WORK!

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5. What 2 molecules are present in RNA nucleotides that are not found in DNA nucleotides?

6. Complete the table below comparing DNA and RNA (mark with a ✔ if the trait is present; leave the box blank if it is absent).

DNA RNA

Ribose present

Deoxyribose present

Phosphate present

Adenine present

Thymine present

Uracil present

Guanine present

Cytosine present

Double stranded

Single stranded

Remains in the nucleus

Moves out of the nucleus

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DNA MODEL SEGMENTS:

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RNA MODEL SEGMENTS:

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DNA and Mutations Webquest Answer all questions in complete sentences!

http://evolution.berkeley.edu/evolibrary/article/mutations_01 DNA and Mutations 1. What is a mutation? 2. What does DNA affect? 3. Without mutations, what would not occur? DNA: The Molecular Basis of Mutations 1. What is DNA? 2. What are the four basic units of DNA? 3. The sequence of these bases encodes _____________________. 4. Some parts of DNA are __________________ that carry instructions for making ___________________ - which are long chains of ________________________. 5. What are codons? 6. The cellular machinery uses these instructions to ____________________ a string of corresponding amino acids. 7. What do “stop” codons signify? Types of Mutations 1. What is a substitution? 2. What causes sickle cell anemia?

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3. What are 3 things that a “substitution” mutation cause?

1.

2.

3.

4. Copy the example of a substitution mutation. (left side of page) 5. What is an insertion mutation? 6. Copy the example of an insertion mutation. 7. What is a deletion? 8. Copy the deletion example. 9. What is a frameshift mutation? 10. Copy the example of the frameshift mutation. Causes of Mutations 1. DNA fails to ______________ __________________. 2. External _____________________ can create _________________________. 3. What are two examples of external influences?

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The Effects of Mutations 1. Where may mutations occur? 2. What are somatic mutations? 3. What are the only types of mutations that matter to large-scale evolution? 4. What are the effects of germline mutations?

1.

2.

3 5. While many mutations do indeed have negative effects, mutations can have major and ___________________ effects. 6. What are Hox genes? 7. What is the effect of a mutation in the Hox gene? 8. Weird Fact: What happened to the fly with a Hox mutation? A Case of the Effects of Mutation: Sickle cell mutation 1. What is sickle-cell anemia? 2. People with _________ copies of the gene have the disease. 3. What are the negative effects of the sickle cell gene? 4. What are some of the positive effects of sickle cell?

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Mutations are Random 1. Mutations can be _________________, neutral, or _________________ to the organism. 2. What are two possible explanations for “resistant” lice? 3. What is directed mutation? 4. In 1952, Esther and Joshua Lederberg performed and experiment that helped show . . . 5. What was their hypothesis? 6. What is the experimental set-up for the experiment?

1.

2.

3.

4.

5.

7. So, the penicillin-resistant bacteria were there in the ________________________ before they encountered _________________________. They did not _________________________ resistance in response to the exposure to the _____________________________.

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Virtual Gene Expression Modeling Go to the following site: http://www.zerobio.com/drag_oa/protein/overview.htm and read the overview and tips for the activity. Click the next arrow at the bottom right of the page to begin the activity. Transcription Read the introduction to transcription. Drop and drag the bases and labels to simulate the process of transcription. Once you have it correct (use the check answer button to determine this), fill in the corresponding figure below.

Questions:

1. Which base in RNA is replaced by uracil?

2. How many mRNA codons are illustrated above?

3. What is the name of the enzyme that creates the mRNA copy from DNA?

4. What is the name of the sugar in the mRNA nucleotides?

5. What is the mRNA transcript for the DNA sequence TTACGC? Click the next arrow to move on.

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Translation Read the introduction to translation. Drop and drag the bases and labels to simulate the process of translation. Once you have it correct (use the check answer button to determine this), fill in the corresponding figure below.

Questions:

1. What organelle assists tRNA in translating the mRNA in the cytoplasm?

2. The role of tRNA is to carry a(n) _______________________________.

3. Is a tRNA anticodon more similar to DNA or RNA in nucleotide sequence?

4. If the mRNA codon was CGA, the tRNA anticodon that it binds with is ____________. Click the next arrow to move on.

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Protein Synthesis 1 Read the introduction to protein synthesis 1. Drop and drag the bases and labels to simulate the process of protein synthesis. Once you have it correct (use the check answer button to determine this), fill in the corresponding figure below.

Questions:

1. How many amino acids are coded for by the DNA?

2. What protein does this DNA code for?

3. If instead of ACT, the first DNA triplet was ACG, which amino acid would be coded for?

4. What amino acid is carried by a tRNA with the anticodon GUA? Click the next arrow to move on.

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Protein Synthesis 2 Drop and drag the bases and labels to simulate the process of protein synthesis. Once you have it correct (use the check answer button to determine this), fill in the corresponding figure below.

Questions:

1. Other than UUU, what is another mRNA codon that codes for phenylalanine (PHE)?

2. What is the tRNA anticodon that binds to the codon you answered above?

3. The role of the ribosome is to help mRNA and tRNA interact. It is made of two subunits and is roughly half __________ and half protein.

4. Sickle cell anemia is a disease of red blood cells in which a genetic mutation in DNA leads to a

mutation in hemoglobin. A single base change alters the DNA sequence CTC to CAC which codes for the wrong amino acid. What amino acid is coded for by the normal DNA sequence, CTC?

5. For the question above, what amino acid is coded for by the mutated DNA sequence, CAC?

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Click the next arrow to move on. Quiz Take the quiz and record the correct answers for the questions below.

1. Transcription is the first step of protein synthesis and it occurs in the _______________________.

2. Translation is the second step of protein synthesis and it occurs in the ______________________.

3. If a DNA sequence consists of 12 nucleotides, how many RNA codons will there be? __________

4. The enzyme that creates mRNA from a DNA sequence is called __________________.

5. Each codon of the mRNA (hence each triplet in DNA) codes for one __________________________.

6. The specific amino acid carried by a tRNA is determined by its ____________________________.

7. When amino acids are brought in by tRNA, they are joined together by hydrolysis reactions to form the

growing protein. True False

8. Whenever a cell needs to, it can unzip DNA and make a transcript of a sequence so that a protein can

be made. DNA then zips up. True False

9. The same amino acid can be carried by different tRNAs. True False

10. Although not discussed in this activity translation actually takes place in 3 steps: ________________,

_______________, __________________.

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How Are Proteins Made Anyway? (Simulating Protein Synthesis)

Introduction A gene is a series of bases on a DNA molecule that codes for a particular trait, such as attached or unattached earlobes, eye color, or blood type. You inherit genes from your parents. The order of the nucleotide bases in DNA determines the sequence of amino acids in polypeptide chains, and thus the structure of proteins. In a process called transcription, which takes place in the nucleus of the cell, messenger RNA (mRNA) reads and copies the DNA's nucleotide sequences in the form of a complementary RNA molecule. Then the mRNA carries this information in the form of a code to the ribosomes, where protein synthesis takes place. The code, in DNA or mRNA, specifies the order in which the amino acids are joined together to form a polypeptide chain. The code words in mRNA, however, are not directly recognized by the corresponding amino acids. Another type of RNA called transfer RNA (tRNA) is needed to bring the mRNA and amino acids together. As the code carried by mRNA is "read" on a ribosome, the proper tRNAs arrive in turn and give up the amino acids they carry to the growing polypeptide chain. The process by which the information from DNA is transferred into the language of proteins is known as translation. In this activity, you will simulate the mechanism of protein synthesis and thereby determine the traits inherited by fictitious organisms called ZWEEBLES. A ZWEEBLE, whose cells contain only one chromosome, is a member of the kingdom Animalia. A ZWEEBLE chromosome is made up of six genes (A, B, C, D, E and F), each of which is responsible for a certain trait. Problem

1. How can the traits on a particular chromosome be determined? 2. How can these traits determine the characteristics of an organism?

Materials Colored Pencils Procedure

1. To determine the trait for Gene A of your ZWEEBLE, fill in the information in the box labeled GENE A in the Data Table. Notice the sequence of nucleotides in DNA. On the line provided, write the sequence of nucleotides of mRNA that are complementary to DNA. Then, on the line provided, write the sequence of nucleotides of tRNA that are complementary to mRNA.

2. In order to determine the sequence of amino acids, match each mRNA triplet with the specific amino acid in the codon tables (Figure 1a or 1b). Using a - (hyphen) to separate each amino acid number, record this information in the appropriate place in the Data Table.

3. Using Figure 2, find the trait that matches the amino acid sequence. Record this information in the appropriate place in the Data Table.

4. Repeat steps 1 through 3 for the remaining genes (B through F). 5. Repeat for all four zweebles (A-D). 6. Complete the analysis questions.

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FIGURE 1a

FIGURE 1b

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FIGURE 2

ZWEEBLE-A

Gene A DNA TGG CCA ATA mRNA ___________________ tRNA ___________________ Amino Acid Sequence __________________ Trait __________________

Gene B DNA TCG CTT mRNA ___________________ tRNA ___________________ Amino Acid Sequence __________________ Trait __________________

Gene C DNA AAA TTG mRNA ________________ tRNA ________________ Amino Acid Sequence _______________ Trait _______________

Gene D DNA ACA GCG GCT mRNA ___________________ tRNA ___________________ Amino Acid Sequence __________________ Trait __________________

Gene E DNA CCC TCC TTT GGG mRNA ___________________ tRNA ___________________ Amino Acid Sequence __________________ Trait __________________

Gene F DNA TAG TAG GAT mRNA ________________ tRNA ________________ Amino Acid Sequence _______________ Trait ________________

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ZWEEBLE-B

Gene A

DNA TGG AAA ATA mRNA ___________________ tRNA ___________________ Amino Acid Sequence __________________ Trait __________________

Gene B

DNA AGT TTA mRNA ___________________ tRNA ___________________ Amino Acid Sequence __________________ Trait __________________

Gene C

DNA AAA TTT mRNA ________________ tRNA ________________ Amino Acid Sequence _______________ Trait _______________

Gene D

DNA ACG GCC CTT mRNA ___________________ tRNA ___________________ Amino Acid Sequence __________________ Trait __________________

Gene E

DNA GAA TCC TTT GGA mRNA ___________________ tRNA ___________________ Amino Acid Sequence __________________ Trait __________________

Gene F

DNA TAT TAT CAC mRNA ________________ tRNA ________________ Amino Acid Sequence _______________ Trait ________________

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ZWEEBLE-C

Gene A

DNA TGT AGT AGC mRNA ___________________ tRNA ___________________ Amino Acid Sequence __________________ Trait __________________

Gene B

DNA AGA GCG mRNA ___________________ tRNA ___________________ Amino Acid Sequence __________________ Trait __________________

Gene C

DNA AAA TTT mRNA ________________ tRNA ________________ Amino Acid Sequence _______________ Trait _______________

Gene D

DNA ACA GCT TTA mRNA ___________________ tRNA ___________________ Amino Acid Sequence __________________ Trait __________________

Gene E

DNA CAA GCC TTT GGG mRNA ___________________ tRNA ___________________ Amino Acid Sequence __________________ Trait __________________

Gene F

DNA TAT TAG CAA mRNA ________________ tRNA ________________ Amino Acid Sequence _______________ Trait ________________

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ZWEEBLE-D

Gene A

DNA TGG CCA ATA mRNA ___________________ tRNA ___________________ Amino Acid Sequence __________________ Trait __________________

Gene B

DNA TCG GCT mRNA ___________________ tRNA ___________________ Amino Acid Sequence __________________ Trait __________________

Gene C

DNA AAA TTG mRNA ________________ tRNA ________________ Amino Acid Sequence _______________ Trait _______________

Gene D

DNA ACG GCG GCT mRNA ___________________ tRNA ___________________ Amino Acid Sequence __________________ Trait __________________

Gene E

DNA CCC TCC TTT GGG mRNA ___________________ tRNA ___________________ Amino Acid Sequence __________________ Trait __________________

Gene F

DNA TAG TAG GAT mRNA ________________ tRNA ________________ Amino Acid Sequence _______________ Trait ________________

Analysis Questions

1. How are transcription and translation different? 2. Where does transcription take place in the cell? _________________________________ 3. Where does translation take place in the cell? ___________________________________

4. How many tRNA nucleotides form an anticodon that will attach to the mRNA codon? _______

5. Suppose you knew the make-up of a specific protein in a cell. How could you determine the particular DNA

code that coded for that protein?

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6. Create two additional traits for your ZWEEBLE . Create a new amino acid sequence, unlike any other sequence in Figure 2. From the amino acid sequence you should be able to determine the tRNA anticodon, mRNA codon, and the initial DNA sequence.

Trait #1 (you create this) __________________ Amino Acid Sequence _____________________ (Create a code by choosing sets of numbers from Figure 1a or 1b.) tRNA anticodon ___________________________ mRNA codon ___________________________ DNA code ___________________________

Trait #2 (you create this) __________________ Amino Acid Sequence _____________________ (Create a code by choosing sets of numbers from Figure 1a or 1b.) tRNA anticodon ___________________________ mRNA codon ___________________________ DNA code ___________________________

7. Using all the inherited traits, sketch your ZWEEBLE family portrait in the space below. Don't forget to use

colored pencils.

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Mitosis – How Each New Cell Gets a Complete Set of Genes

Genes and Chromosomes You probably already know that genes can influence a person's characteristics. For example, some people have genes that result in sickle cell anemia or albinism (very pale skin and hair). In this section you will learn how genes in chromosomes influence our characteristics. Each cell in your body contains chromosomes. Each chromosome contains a long molecule of DNA. Each DNA molecule contains many genes. A gene is a segment of a DNA molecule that gives the instructions for making a protein.

Different versions of the same gene are called alleles. Different alleles give the instructions for making different versions of a protein. This table shows the alleles for two human genes. 1. In the table, circle each symbol that represents part of a DNA molecule. Underline each word that is the name of a protein.

Allele → Protein

A → Normal enzyme for producing melanin, a pigment molecule that gives color to our skin and hair

a → Defective enzyme that cannot make melanin

S → Normal hemoglobin s → Sickle cell hemoglobin

Chromosomes come in pairs of homologous chromosomes. In each pair of homologous chromosomes, both chromosomes have the same genes at the same locations. A gene may have different alleles on the two homologous chromosomes (e.g. Aa) or a gene may have the same alleles (e.g. SS). The table below shows how different genotypes (i.e. different combinations of alleles) result in the production of different proteins which in turn result in different phenotypes (i.e. different observable characteristics).

Genotyp

e → Protein → Phenotype (characteristics)

AA or Aa → Enough normal enzyme to make melanin in skin and hair → Normal skin and hair color

aa → Defective enzyme for melanin production → Very pale skin and hair color; albino

SS or Ss → Enough normal hemoglobin to prevent sickle cell anemia → Normal blood; no sickle cell anemia

ss → Sickle cell hemoglobin, which can cause red blood cells to become sickle shaped

→ Sickle shaped red blood cells can block blood flow in the smallest blood vessels, causing pain, etc.; sickle cell anemia

2. Suppose that Jim has the alleles in the pair of homologous chromosomes shown in the above circle.

Is Jim's genotype ___aaSs ___AaSs ___AaSS? Is Jim an albino? ___yes ___ no Does Jim have ___ sickle cell anemia ___ normal blood?

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3. Explain why a person with the aa genotype has very pale skin and hair color. Include the words enzyme and melanin in your explanation. 4. Fill in the blanks of the following sentences.

A chromosome contains one long ______ molecule. Each gene in this ______ molecule gives the

instructions for making a ____________________.

Both chromosomes in a pair of ______________________ chromosomes have the same genes, but the genes in these two _____________________ chromosomes may have different ____________.

Many of the genes on each chromosome give the instructions for making the large number of proteins that are needed for normal cell structure and function. Therefore, each cell needs to have a complete set of chromosomes with all of these genes.

Cell Division – How New Cells Are Made

Each of us began as a single cell, so one important question is: How did that single cell develop into a body with more than a trillion cells?

The production of such a large number of body cells is accomplished by cell division repeated many many times. First, one cell divides to form two cells; then both of these cells divide to produce a total of four cells; then these four cells divide to produce eight cells, etc. Thus, repeated cell division is needed for growth. 5. Even in an adult, some cells continue to divide. Why is cell division useful even in an adult who is no longer growing? (Hint: Think about what happens when you have an injury that scrapes off some of your skin.) Almost all the cells in our bodies are produced by a type of cell division called mitosis. In mitosis, one cell divides to produce two daughter cells, each with a complete set of chromosomes. (It may seem odd, but the cells produced by cell division are called daughter cells, even in boys and men.) 6. Before mitosis begins, a cell makes a copy of all the DNA in each chromosome. What would go wrong if a cell did not make a second copy of all of its DNA before the cell divided into two daughter cells?

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Mitosis – How Each Daughter Cell Gets a Complete Set of Chromosomes This figure shows mitosis for a cell that has a single pair of homologous chromosomes. To indicate that these two homologous chromosomes have different alleles for many of their genes, one chromosome is shown as dark or striped.

Preparation for Mitosis To prepare for mitosis, the cell makes a copy of the long DNA molecule in each chromosome; this is called DNA replication. DNA replication results in two identical copies of the DNA with the same alleles for each of the genes. Beginning of Mitosis Each copy of the long DNA molecule is wound tightly into a compact chromatid. The two chromatids in each chromosome are called sister chromatids; they are attached at a centromere. The chromosomes are lined up in the center of the cell. Mitosis continues Next, the two sister chromatids of each chromosome are separated. After they separate, each chromatid is an independent chromosome. Cytokinesis The cell pinches together in the middle and separates into two daughter cells, each with a complete set of chromosomes. Thus, each daughter cell has a complete copy of all the genes in the original cell. The DNA in each chromosome unwinds into a long thin thread.

7. Explain why the chromosomes in the second drawing have sister chromatids, but the chromosomes in the third drawing do not. What happened to the sister chromatids?

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8. This fill-in-the-blank question reviews the information from the previous page and provides some additional information about six steps that are needed for mitosis to occur.

A. In preparation for mitosis, DNA is copied; this is called DNA ______________________.

B. Each copy of the DNA is wound tightly (condensed). Now each chromosome has two compact sister ___________________. These compact chromosomes are easier to move than the long thin chromosomes in a cell which is not undergoing cell division. Spindle fibers which will move the chromosomes begin to form.

C. Spindle fibers attach to the chromosomes and line up the chromosomes in the middle of the cell.

D. Spindle fibers pull the sister ___________________ apart to form separate chromosomes which are moved toward opposite ends of the cell.

E. In a process called __________________________, the cell pinches in half, with one complete set of chromosomes in each half.

F. Two identical _________________ cells are formed. Each _________________ cell has received a complete set of chromosomes. The DNA in each chromosome unwinds into a long thin thread so that genes can become active and give the instructions for making proteins. 9. For each of the figures below, give the letter of the corresponding step described above. Draw arrows to indicate the sequence of events during cell division. (The figures show mitosis for a cell that has only 4 chromosomes (2 pairs of homologous chromosomes). The basic process is the same in a human cell which has 46 chromosomes.)

10. Circle each pair of homologous chromosomes in step C. Use an * to mark the arrow you drew which shows when sister chromatids separate to form individual chromosomes.

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Modeling Mitosis with One Pair of Homologous Chromosomes ➢ Find a pair of model homologous chromosomes, one with the a and s alleles

and the other with the A and S alleles. Both model chromosomes should be the same color, but one model chromosome will have a stripe on both chromatids to indicate that, although these two homologous chromosomes have the same genes, they have different alleles for many of their genes. The shape of the model chromosomes indicates that the DNA has already been copied and wound tightly into sister chromatids.

➢ Sit across from your partner and use your arms to represent the spindle fibers that move the chromosomes. Begin mitosis by lining up the model chromosomes in the middle of the cell (see figure below). Use string to indicate the cell membrane that surrounds the cell that contains these chromosomes.

➢ Demonstrate how the sister chromatids of each chromosome are separated into two separate chromosomes which go to opposite ends of the cell.

➢ Now the cell is ready for cytokinesis which will produce two daughter cells, each with a complete set of chromosomes. Rearrange the string to demonstrate cytokinesis and then cut the string to form the cell membranes surrounding each daughter cell.

➢ Model mitosis again and answer question 11. (To do this, you will first need to put the sister chromatids of your model chromosomes back together. This does not correspond to any biological process – it is just necessary in order to continue your modeling activity.)

11. Record the results of your modeling in this figure. Draw and label the chromosomes in the oval and in the daughter cells.

12. The original cell had the genetic makeup AaSs. What is the genetic makeup of the daughter cells?

Are there any differences in genetic makeup between the original cell and the daughter cells produced by mitosis?

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Multiple Pairs of Homologous Chromosomes Each human cell has 23 pairs of homologous chromosomes. Each of these pairs of homologous chromosomes has its own unique set of genes. For example, human chromosome 11 has the genes that can result in albinism and sickle cell anemia (as well as more than 1000 additional genes). Human chromosome 12 has different genes, including a gene that can result in alcohol sensitivity. This table shows the effects of the L and l alleles of this gene. Genotyp

e → Protein → Phenotype (characteristics)

LL or Ll → Defective enzyme that cannot dispose of harmful molecules produced by the metabolism of alcohol → Skin flush and discomfort after

drinking alcohol

ll → Normal enzyme that disposes of harmful molecules produced by alcohol metabolism → No flush or discomfort after

drinking alcohol Modeling Mitosis with Two Pairs of Homologous Chromosomes ➢ Find a second pair of model homologous chromosomes, one with the L allele and the other with the l allele.

Model mitosis for a cell with two pairs of homologous chromosomes. 13. Record the results of your modeling in this figure.

14. The original cell had the genetic makeup AaSsLl. What is the genetic makeup of the daughter cells? Are there any differences in genetic makeup between the original cell and the daughter cells produced by mitosis?

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Follow-Up Questions 15. Suppose that your partner has put the model chromosomes back together as shown in the diagram. What is wrong? Explain why, in a real cell, sister chromatids could not have different alleles.

What is wrong with these model chromosomes?

16. Each of the cells in your skin, brain, and other parts of your body has a complete set of chromosomes with the same genes and the same alleles that were present in the single cell that developed into your body. Explain how these billions of genetically identical cells were produced. Include the following terms in your explanation: chromosome, cytokinesis, daughter cell, DNA replication, genes, mitosis, sister chromatids, and spindle fibers. Some animals and plants use a combination of mitosis and splitting off to reproduce. For example, a hydra can reproduce by budding. The bud is formed by many many repetitions of mitosis, and then the bud breaks off to form a daughter hydra. (A hydra is an animal that lives in the water and uses its tentacles to catch food.) 17. Will there be any genetic differences between the mother hydra and the daughter hydra? Explain your reasoning.

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Stem Cells Webquest In Google, type “Learn.Genetics” and click on the first link. Scroll down to the bottom and click on the “Stem Cells” link. 1st – Click on “The Nature of Stem Cells” 1. What are differentiated cells? 2. Are stem cells “differentiated” cells? Explain! 3. Circle: True or False , for the first few divisions, cells remain undifferentiated. If false, explain why below. 4. What is the embryo called after one week of fertilization? 5. What is the name given to the part of the embryo will eventually form all the cells of the body? 6. Cell signals ________________ the potential of the embryo cells about two weeks after fertilization. Each layer will give rise to a __________________ set of cell types. 7. Circle: True or False , after birth, some stem cells remain. If false, explain why below. 8. What are the possible functions of stem cells in the body? 9.Circle: True or False , (adult) somatic stem cells are the same as embryonic stem cells. If false, explain why below. 10. List other tissues where (adult) somatic cells have been found.

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2nd- Go back to the “Stem Cells” home page and click on “Go Go Stem Cells.” 11. What is a stem cell niche? 12. What happens to a stem cell if it is removed from its niche? 13. Explore three of the five cell niches shown on the right side of the screen. Write three interesting facts about the cell niches that you have chosen to explore.

Cell Niche Type:_________________

Cell Niche Type:________________

Cell Niche Type:_________________

Interesting Facts: 1.

1.

1.

2.

2.

2.

3.

3.

3.

3rd- Go back to the “Stem Cells” home page and click on “Unlocking Stem Cell Potential.” 14. Define regeneration. 15.Circle: True or False , regeneration in humans is limited. If false, explain why below. 16. List three examples of regenerative medicine that scientists are currently using. 1. 2. 3. 17.How are stem cells similar to cancer?

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Regeneration in Planarians Lab

Introduction Before we begin this lab, you need to do some research about planarians and their regenerative properties. Please research and answer the following questions. About regeneration:

1. What is cell differentiation? How does this happen?

2. How is gene expression/protein synthesis related to cell differentiation?

3. What are stem cells? Why are they important?

4. What is regeneration? How is regeneration a useful process for organisms? About planarians:

1. In what environment(s) are planarians normally found in nature?

2. What is the purpose of the planarian’s photoreceptors found in the eyespots?

3. How do planarians reproduce? (there are two ways, explain both)

4. Describe how planarians regenerate when cut (use information from at least three different reliable websites).

5. Identify two ways in which planarians are being used for research. Watch the video: http://www.hhmi.org/biointeractive/planarian-regeneration-and-stem-cells

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Purpose

● To test the planarian’s ability to regenerate. ● To determine where stem cells are located in the planaria, based on the length of time it takes for the

photoreceptors in the eye spots to reappear. Hypothesis Materials · planarian culture (Dugesia dorotocephala ) · disposable scalpels · dropping pipets · petri dishes

· permanent marker · stereomicroscope/dissecting scope · spring water · paper towels

Procedure

1. Number the bottoms of three of the petri dishes 1 through 3, fill halfway with spring water, and set aside. (Marking the bottoms will prevent confusion by accidental swapping of lids.)

2. Using a plastic transfer pipette, transfer a planarian into the remaining unlabeled empty plastic petri dish.

3. Soak up excess water with a paper towel. Limiting the amount of water can reduce the mobility of the planarian and facilitate the next step. Be careful not to touch the planarian—they will stick to the paper and could then die.

4. Place the petri dish with the planarian under the dissecting microscope WITHOUT turning the light on. Focus.

5. Using a scalpel, make Cut #1 to the planarian as indicated on the diagram on the right. Planarians can move rapidly. Cutting them in a precise location can be difficult.

6. Using a transfer pipette, gently transfer the head fragment into the petri dish #1.

7. Repeat steps 5-6 for Cut #2, placing the mid-section in petri dish #2 and tail section in petri dish #3. 8. Repeat steps 2 through 7 with the remaining worms until dishes have at least three or four tail

fragments of each of the three cutting positions. 9. On the data table, record the time and room temperature when finished cutting all the planarians. 10. Monitor planarians daily, recording detailed, specific observations of their regeneration.

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Data Table Title: __________________________________________________________________________________

Day Time Temp. (°C) Segment # Photoreceptors? Observations (movement, changes, etc.)

1 1

2

3

2

1

2

3

3

1

2

3

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Day Time Temp. (°C) Segment # Photoreceptors? Observations (movement, changes, etc.)

4 1

2

3

5 1

2

3

Questions

1. After you cut your planarian, how did the mobility of the tail fragments differ from the mobility of the head fragments? Do they move the same or differently? If they move differently, why do you think this is?

2. Did you notice a difference in the mobility of the tail pieces as the head regenerated? Explain what you saw and why this might be.

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3. Describe the regeneration of piece 1 over time. Did it result in a complete (with eyespots and tail) planarian?

4. Describe the regeneration of piece 2 over time. Did it result in a complete (with eyespots and tail) planarian?

5. Describe the regeneration of piece 3 over time. Did it result in a complete (with eyespots and tail) planarian?

6. Discuss how the color of the regenerating parts changed over time? Explain why this difference in coloring may have occurred.

7. When the heads were growing back, do you think the eyespots were functional? How would you test this?

8. Did all the fragments regenerate photoreceptors at the same rate? Which were slower and which were faster? (give specific piece numbers and days)

9. What does the rate of appearance of photoreceptors in the different fragments tell you about the regeneration ability of different sections of the worm? Based on your data, where might the main stem cell niche be for the planarian? Why did you choose this area?

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Conclusion Write a formal conclusion for this lab as if it were a formal lab report. To demonstrate that you really understand the data and what it means, you should make connections between the information you learned about stem cells and the regeneration qualities of the planarian. (Use the terms stem cells, differentiation, and mitosis in your conclusion and make the connections!)

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Unit 4: Meiosis, Genetics & Genetically

Modified Organisms

Meiosis and Fertilization – Understanding How Genes Are Inherited

Almost all the cells in your body were produced by mitosis. The only

exceptions are the gametes – sperm or eggs – which are produced by a

different type of cell division called meiosis.

During fertilization the sperm and egg unite to form a single cell called the

zygote which contains all the chromosomes from both the sperm and the

egg. The zygote divides into two cells by mitosis, then these cells each

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divide by mitosis, and mitosis is repeated many times to produce the cells in an embryo which develops into a baby.

1. Each cell in a normal human embryo has 23 pairs of homologous chromosomes, for a total of 46 chromosomes per

cell. How many chromosomes are in a normal human zygote? Explain your reasoning.

2. What would happen if human sperm and eggs were produced by mitosis? Explain why this would result in an

embryo which had double the normal number of chromosomes in each cell.

A human embryo with that many chromosomes in each cell would be abnormal and would die before it could develop

into a baby. So, gametes cannot be made by mitosis.

3. Each human sperm and egg should have ____ chromosomes, so fertilization will produce a zygote with ____

chromosomes; this zygote will develop into a healthy embryo with ____ chromosomes in each cell.

4. Each sperm and each egg produced by meiosis has only one chromosome from each pair of homologous

chromosomes. When a sperm and egg unite during fertilization, the resulting zygote has ____ pairs of homologous

chromosomes. For each pair of homologous chromosomes in a zygote, one chromosome came from the egg and the

other chromosome came from the _______________.

A cell that has pairs of homologous chromosomes is diploid. A cell that has only one chromosome from each pair of homologous chromosomes is haploid.

5. Next to each type of cell in the above chart, write:

● the number of chromosomes in that type of cell

● a d for diploid cells or an h for haploid cells.

Meiosis – Cell Divisions to Produce Haploid Gametes

Before meiosis, the cell makes a copy of the DNA in each chromosome. Then, during meiosis there are two cell

divisions, Meiosis I and Meiosis II. These two cell divisions produce four haploid daughter cells.

Meiosis I is different from mitosis because each pair of homologous chromosome lines up next to each other and then

the two homologous chromosomes separate. (The figure shows Meiosis I for a cell with a single pair of homologous

chromosomes; the stripes on the chromatids of one of the chromosomes indicates that this chromosome has

different alleles than the other homologous chromosome.)

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Meiosis I produces daughter cells with half as many chromosomes as the parent cell, so the daughter cells are

haploid. Each daughter cell has a different chromosome from the original pair of homologous chromosomes.

6. In the figure for Meiosis I, label the diploid cell, the pair of homologous chromosomes in this diploid cell, and the

two sister chromatids in one of these chromosomes.

7. Do the chromosomes in the two daughter cells produced by Meiosis I have the same alleles for each gene? Explain

your reasoning.

Meiosis II is like mitosis since the sister chromatids of each chromosome are separated. As a result, each daughter cell

gets one copy of one chromosome from the pair of homologous chromosomes that was in the original cell. These

haploid daughter cells are the gametes.

8. Use asterisks to indicate the cells in this figure that represent sperm produced by meiosis.

Modeling Meiosis to Understand How Meiosis Produces Genetically Diverse Gametes

To model meiosis, you will use the same pairs of model homologous chromosomes that you used to model mitosis. A

person with these chromosomes would have the genotype AaSsLl.

9. What phenotypic characteristics would a person with this genotype have? Circle the appropriate phenotypic

characteristics in this table.

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You will begin modeling meiosis with only one pair of the model chromosomes.

➢ Use this pair of model chromosomes to model each step of meiosis. Use

string to model the cell membranes at each stage.

10. Show the results of your modeling in this figure. Sketch and label the chromosomes in each cell that is produced

by Meiosis I and by Meiosis II.

11. You have modeled meiosis, beginning with a diploid cell that has the alleles AaSs. The haploid gametes produced

by meiosis have the alleles: __ AS or as __ AASS or aass __ AaSs

Next, you will model meiosis using both pairs of model chromosomes. At the beginning of Meiosis I each pair of

homologous chromosomes lines up independently of how the other pairs of homologous chromosomes have lined

up. This is called independent assortment. As a result of independent assortment, at the beginning of Meiosis I the as

chromosome can be lined up on the same side as either the l chromosome or the L chromosome (see figure).

➢ Use your four model chromosomes to model Meiosis I and Meiosis II for both of the possible ways of lining up

the model chromosomes at the beginning of Meiosis I.

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12. Record the results of your modeling in this chart.

When a pair of homologous chromosomes is lined up next to each other during

Meiosis I, the two homologous chromosomes can exchange parts of a chromatid.

This is called crossing over.

13a. On each chromatid of the chromosomes in the bottom row of this figure,

label the alleles for the genes for albinism and sickle cell anemia.

When these chromosomes and chromatids separate during Meiosis I and II, this

produces gametes with four different combinations of alleles for the genes for

albinism and sickle cell anemia.

13b. The combinations of alleles in the different gametes are:

__AS__ _____ _____ _____

14a. Explain why different gametes produced by the same person can have

different combinations of alleles for genes that are located on two different

chromosomes.

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14b. Explain why different gametes produced by the same person can have different combinations of alleles for two

genes that are located far apart on the same chromosome

Comparing Mitosis and Meiosis

15a. In this figure, label the column that shows meiosis and the

column that shows mitosis.

15b. What are some similarities between cell division by mitosis

and cell division by meiosis?

These diagrams show mitosis and meiosis

after DNA has been replicated and wound

tightly into sister chromatids. The dotted

lines represent cytokinesis.

15c. Complete this table to describe some important differences between mitosis and meiosis.

Characteristic Mitosis Meiosis

# of daughter cells

Type of cells produced

Genetic differences or similarities between daughter

cells

# of cell divisions

16. Complete these diagrams to show how a pair of

homologous chromosomes is lined up in a cell at the

beginning of mitosis vs. the beginning of meiosis I.

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17. Match each item in the top list with the appropriate match from the bottom list.

Mitosis separates _____

Meiosis I separates _____

Meiosis II separates _____

a. pairs of homologous chromosomes

b. sister chromatids

18. Explain why sexually reproducing organisms need to have two different types of cell division. What are the

advantages of mitosis and of meiosis?

Analyzing Meiosis and Fertilization to Understand Inheritance

In this section you will learn how events during meiosis and fertilization determine the genetic makeup of the zygote

which in turn determines the genotype of the baby that develops from the zygote.

You already know that sisters or brothers can have different characteristics, even though they have the same parents.

One major reason for these different characteristics is that the processes of meiosis and fertilization result in a

different combination of alleles in each child.

You will model meiosis and fertilization for a very simplified case where there is only one pair of homologous

chromosomes per cell and only one identified gene on each chromosome.

➢ To produce the two pairs of model chromosomes shown in this figure, you will need a pair of the as and AS

model chromosomes in one color and a pair of the l and L model chromosomes in a different color. Tape

blank strips of paper on these model chromosomes to cover the S, s, L, and l alleles. Then, tape strips with the

a and A alleles to create a second pair of model chromosomes which have the a and A alleles.

Modeling Meiosis and Fertilization to Understand Inheritance

➢ One person in your group should use one pair of model homologous chromosomes to demonstrate how

meiosis produces sperm. Another person should use the other color pair of model homologous chromosomes

to demonstrate how meiosis produces eggs.

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19. For each type of sperm and egg produced by meiosis, write the allele in an appropriate white box in this chart.

➢ Use chalk to outline the rectangles of this chart on your lab table. Put a model chromosome for each type of

sperm and egg in each of the boxes on the top and on the left.

➢ Use one of the sperm to fertilize one of the eggs to produce a zygote. The resulting zygote will have one

chromosome from the egg and one from the sperm. Note the genetic makeup of this zygote in the

appropriate gray box in the chart above.

➢ Model fertilization three more times, pairing each type of sperm with each type of egg.

20. Write the genetic makeup of each type of zygote in the appropriate box in the shaded area in the chart.

21. Each person began as a zygote. Explain why each person has the same genetic makeup as the zygote he or she

developed from.

22. In the above chart, write in the phenotypic characteristic (albinism or normal skin and hair color) for the mother,

the father, and the person who would develop from each zygote. Circle the zygotes that would develop into a person

with the same phenotypic characteristic as the parents. Use an * to mark the zygote that would develop into a person

who would have a different phenotypic characteristic that neither parent has.

23a. Explain why many children have the same phenotypic characteristics as their parents.

23b. Explain how a child can have a different phenotypic characteristic that neither parent has.

Why are siblings different from each other?

Your analysis of the inheritance of a single gene showed how meiosis and fertilization can result in genetic and

phenotypic differences between siblings produced by the same mother and father. Now you will analyze the results

of meiosis and fertilization for multiple genes. You will see how meiosis and fertilization result in the many genetic

and phenotypic differences between siblings.

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Remember that AaSsLl parents can produce multiple different types of gametes with different combinations of the

alleles for the albinism gene, sickle cell gene, and alcohol sensitivity gene (see page 4). As a result of independent

assortment and crossing over, an AaSsLl parent can produce eight types of gametes: asl, ASL, asL, ASl, aSl, aSL, AsL

and Asl.

Obviously, fertilization of the eight different types of eggs by the eight different types of sperm could result in

offspring with many different genotypes. In question 24, you will describe the outcomes for fertilization of a few of

the possible types of eggs by one of the possible types of sperm.

24. Complete the following chart to describe the genetic makeup and phenotype of some of the possible outcomes of

fertilization between the different types of eggs and sperm produced by AaSsLl parents.

Alleles

in egg

Alleles

in sperm

Alleles in

zygote

Phenotype of person who will develop from this zygote (Hint: See the table in question 9 on page 38.)

ASL asl AaSsLl

ASl asl

aSl asl

This illustrates how, even when we consider only three genes with two alleles each, meiosis and fertilization can

produce zygotes with many different combinations of alleles which can develop into people with many different

combinations of phenotypic characteristics. The actual amount of genetic diversity possible in the children produced

by one couple is much greater, since each person has thousands of genes on 23 pairs of homologous chromosomes.

25. Explain why no two siblings have exactly the same combination of alleles inherited from their parents (except for

identical twins who both developed from the same zygote). Begin with the observation that each person has

thousands of genes on 23 pairs of homologous chromosomes. Include in your explanation the terms genes, alleles,

chromosomes, meiosis, independent assortment, crossing over, eggs, sperm, fertilization, and zygote.

A Mistake in Meiosis Can Cause Down Syndrome

You have seen that normal meiosis and fertilization can produce a lot of genetic variability in the different children

produced by the same parents. Additional genetic variability can result from mistakes in DNA replication (which can

cause mutations) or mistakes in meiosis. For example, when meiosis does not happen perfectly, the chromosomes are

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not divided equally between the daughter cells produced by meiosis, so an egg or a sperm may receive two copies of

the same chromosome.

26. Suppose that a human egg receives two copies of a chromosome, and this egg is fertilized by a normal sperm.

How many copies of this chromosome would there be in the resulting zygote? ____

- How many copies of this chromosome would there be in each cell in the resulting embryo? ____

When a cell has three copies of a chromosome, the extra copies of the genes on this chromosome result in abnormal

cell function and abnormal embryonic development. To understand how an extra copy of one chromosome could

result in abnormalities, remember that each chromosome has genes with the instructions to make specific types of

proteins, so the extra chromosome could result in too many copies of these specific proteins. Think about what would

happen if you added too much milk to a box of macaroni and cheese. The mac and cheese would have too much

liquid and be runny instead of creamy. Cells are much more complicated than mac and cheese, and a cell cannot

function properly when there are too many copies of some types of proteins due to an extra copy of one of the

chromosomes.

When the cells in an embryo do not function properly, the embryo develops abnormalities. For example, some babies

are born with an extra copy of chromosome 21 in each cell. This results in Down syndrome with multiple

abnormalities, including mental retardation, a broad flat face, a big tongue, short height, and often heart defects.

This figure shows a karyotype for a normal boy. A karyotype is a photograph of a magnified

view of the chromosomes from a human cell, with pairs of homologous chromosomes

arranged next to each other and numbered. In the karyotype, each chromosome has double

copies of its DNA, contained in a pair of sister chromatids linked at a centromere.

27. Label the sister chromatids in chromosome 3 in the karyotype.

- Draw in an extra chromosome 21 to show the karyotype of a boy with Down syndrome.

28. In most cases, an embryo which has an extra chromosome in each cell develops such severe abnormalities that

the embryo dies, resulting in a miscarriage. For example, an extra copy of any of the chromosomes in the top row of

the karyotype results in such severe abnormalities that the embryo always dies. In contrast, an extra copy of

chromosome 21 results in less severe abnormalities so the embryo can often survive to be born as a baby with Down

syndrome. What do you think is the reason why a third copy of chromosome 1, 2, 3, 4 or 5 results in more severe

abnormalities than a third copy of chromosome 21?

Chromosomal Mutations & Karyotyping

Purpose: to explain what a chromosomal mutation is and how a human karyotype is used to identify specific genetic disorders Introduction

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Each species has a characteristic number of chromosomes; for example, corn cells have 20 chromosomes, mouse cells have 40 chromosomes, and human cells have 46 chromosomes. In order to view the chromosomes so that they may be counted, a cell will be allowed to reproduce and colchicine is added to stop the cell division during metaphase. The resulting cells are placed in a hypotonic solution that causes the cell membranes to rupture. The chromosomes are stained and photographed. The chromosomes may then be cut out of the photograph and arranged by homologous pairs according to size, position of the centromere and the characteristic banding pattern. The resulting display is called a karyotype. See Figure I. Figure I: Karyotyping Procedure

Part I - The Normal Human Karyotype The normal human karyotype is composed of 46 total chromosomes. The first 22 pairs (chromosomes 1-22) are known as autosomes (code for general human traits); the 23rd pair is known as the sex chromosomes (X and Y). Females have two X chromosomes (XX) and males have one X chromosome and one Y chromosome (XY). 1. Observe the normal human karyotype chart found in FIGURE II (next page). Figure II – Normal Human Karyotype Chart

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Q1. What is the total number of chromosomes found in this cell? ______________________________ Q2. How many autosomal chromosomal pairs are visible in the above karyotype? ________________ Q3. What are the THREE chromosome characteristics used to organize the karyotype? Q4. What is the sex of the above individual? _____________ Q5. Could two individuals have the same karyotype? Explain. Part II – Identifying Genetic Disorders

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Karyotypes can be used to identify a number of chromosomal mutations. Chromosomal mutations can result in changes in the number of chromosomes in a cell or changes in the structure of a chromosome. Unlike a gene mutation which alters a single gene or larger segment of DNA on a chromosome, chromosome mutations change and impact the entire chromosome. Nondisjunction is the failure of chromosomes to separate properly during meiosis. This can result in monosomy (one chromosome instead of a pair) and trisomy (three chromosomes instead of a pair) conditions, as well as chromosomes with missing or extra segments. See Table I for some of the genetic conditions and clinical effects caused by chromosomal mutations. Table I

Q6. What is the difference between monosomy and trisomy? Q7. How could nondisjunction result in an individual with Down syndrome? 2. Observe the abnormal human karyotype chart found in FIGURE III.

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FIGURE III – Abnormal Human Karyotype Chart

Q8. What is the sex of the individual? ______________ Q9. What is the total chromosome count? __________ Is this normal? __________ Q10. Using Table I, identify the condition present in this individual. ____________________ Part III – Internet Activity The following site has an interactive karyotype activity. Go to the site and read the introduction, then click on the patient histories. http://www.biology.arizona.edu/human_bio/activities/karyotyping/karyotyping.html Start with Patient A and complete the karyotype. Answer the questions below and repeat for Patients B and C. Q11. What notation would you use to characterize Patient A’s karyotype? ______________ Q12. What diagnosis would you give Patient A? _____________ Q13. What notation would you use to characterize Patient B’s karyotype? ______________ Q14. What diagnosis would you give Patient B? _____________ Q15. What notation would you use to characterize Patient C’s karyotype? ______________ Q16. What diagnosis would you give Patient C? ______________

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Genetics

We all know that children tend to resemble their parents. Parents and their children tend to have similar appearance

because children inherit genes from their parents and these genes influence characteristics such as skin and hair

color.

How do genes influence our characteristics?

1. A gene is a segment of a ________ molecule that gives the instructions for making a protein. Different versions of

the same gene are called alleles, and different alleles give the instructions for making different versions of a

__________________. The different versions of a protein can result in different observable characteristics (i.e.

different phenotypes).

Each cell in your body has two copies of each gene (one inherited from your mother and one inherited from your

father).

· If both copies of a gene have the same allele, the person is homozygous for that gene.

· If the two copies of a gene have different alleles, the person is heterozygous for that gene.

This chart shows an example of how genes influence our characteristics.

2. Circle the genotypes in the chart that are homozygous. Explain how these two different homozygous genotypes

result in different phenotypes. What is the molecular mechanism?

3a. In a heterozygous person, often a dominant allele determines the phenotype and the other recessive allele does

not affect the phenotype. This means that a heterozygous person has the same phenotype as a person who is

homozygous for the ___________________ allele.

(dominant/recessive)

For example, a person who is heterozygous Aa has the same phenotype as a person who is homozygous AA because

skin cells that have at least one A allele produce enough melanin to result in normal skin color.

3b. For this gene, which allele is dominant? ___ A ___ a

- Which allele is recessive? ___ A ___ a

- What evidence supports your conclusion about which allele is dominant and which is recessive?

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How does a baby inherit genes from his or her mother and father?

Each gene is a part of a DNA molecule which is contained in a chromosome. During meiosis, the gene-carrying chromosomes move from the parent’s cells to

the gametes, and during fertilization, the gene-carrying chromosomes move

from the gametes to a zygote which develops into a baby. Thus, we can

understand how a baby inherits genes from his or her mother and father by

understanding how the gene-carrying chromosomes move during meiosis and

fertilization.

Inheritance of Albinism

To learn more about how genes are inherited, we will start with a specific question:

If both parents are heterozygous (Aa), what different combinations of A and/or a alleles could be observed in

the children of these parents?

To answer this question, your group will use model chromosomes to show how meiosis and fertilization result in

inheritance. Each parent will have a pair of homologous chromosomes, one with an A allele and the other with an a

allele.

➢ One of you should use your model chromosomes

to demonstrate how meiosis produces different

types of eggs, and another group member should

demonstrate how meiosis produces different

types of sperm.

4. In this chart, record the allele in each type of egg

produced by meiosis. Record the allele in each type of

sperm.

➢ Next, use chalk to outline the rectangles shown in

this chart on your lab table and put a model

chromosome for each type of sperm and egg in

the appropriate positions. Model fertilization for

each type of sperm and egg.

5. Record the genetic makeup (the alleles) for each type of zygote produced by

fertilization.

Biologists use a similar chart to analyze inheritance However, biologists omit much of the

detail shown above and use a simplified version called a Punnett Square.

6. For this Punnett square:

-Write "gametes" and draw arrows to each symbol that represents the genetic makeup of

a gamete.

-Write "zygotes" and draw arrows to each symbol that represents the genetic makeup of a zygote.

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7. The genetic makeup of each zygote in the Punnett square represents a possible genotype of a child of this couple.

Explain why the genotype of each child is the same as the genetic makeup of the zygote that he or she developed

from.

8. For an Aa mother, what fraction of her eggs have an a allele? _____

- What fraction of an Aa father's sperm have an a allele? _____

- What fraction of this couple's children would you expect to have the aa genotype? _____

- Explain your reasoning.

10. For each of the four Punnett squares above (from #8 and #9), circle the genotype of anyone who would have

normal skin and hair color.

- In these four Punnett squares there is only one example of a child who would have a different phenotype that was

not observed in either parent. Use an * to indicate this example.

Notice that all of the children with normal skin and hair color have at least one parent who also has normal skin and

hair color. Also, almost all of the albino children have at least one albino parent. These findings fit with our general

observation that children tend to resemble their parents.

11. Explain why two albino parents will not have any children with normal skin and hair color, but two parents with

normal skin and hair color could have an albino child.

12. Albino children are rare in the general population. Based on this observation, what is the most common genotype

for parents? Explain your reasoning.

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Coin Toss Genetics

The way genes behave during meiosis and fertilization can be modeled by using two-sided coins, where heads

represent the dominant allele (A) and tails represent the recessive allele (a). This table explains how the coin toss

model of inheritance represents the biological processes of meiosis and fertilization for heterozygous (Aa) parents.

Biological Process How This Will Be Modeled in Coin Toss Genetics

Meiosis in an Aa parent produces gametes. Each

gamete has an equal probability of having an A allele

or an a allele.

You toss your coin and check for heads up vs. tails

up. This represents the 50-50 chance of getting an

A allele or an a allele.

Fertilization of an egg by a sperm produces a zygote.

Each gamete contributes one allele to the genotype of

the child that develops from the zygote.

Two students each toss a coin and the result of

this pair of coin tosses indicates the genotype of

the child that develops from the zygote.

➢ Find someone to “mate” with.

➢ Each of you will toss your coin; record the results as the genotype of the first child in the first family of four

children in the table below. Make three more pairs of coin tosses and record the genotypes for the second,

third and fourth children in this family.

➢ Repeat this procedure three times to determine the genotypes for three more families of four children each,

and record your results in the table.

➢ Complete the last three columns for these four families of coin toss children, and add your results. Give your

teacher the total numbers for the AA, Aa and aa genotypes.

➢ Use a checkmark (✔) to indicate any coin toss family of 4 children that has exactly the numbers of AA, Aa and

aa genotypes predicted by the Punnett square.

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To understand why some of the coin toss families do not have exactly the predicted number of children with each

genotype, answer these questions.

1. Does the genotype produced by the first pair of coin tosses have any effect on the genotype produced by the

second pair of coin tosses? ___ yes ___ no

2. If a coin toss family has one aa child, could the second child in this family also have the aa genotype? ___ yes

___ no Explain your reasoning.

In real families the genotype of each child depends on which specific sperm fertilized which specific egg, and this is

not influenced by what happened during the fertilizations that resulted in previous children. Therefore, the genotype

of each child is independent of the genotype of any previous children.

3. Suppose that a mother and father who are both heterozygous Aa have two children who also are heterozygous Aa. If this couple has a third child, what is the probability that this third child will also be heterozygous Aa?

- Explain your reasoning.

As a result of random variation in which particular sperm fertilizes which particular egg to form a zygote, the

proportions of each genotype and phenotype vary in different families, and the observed proportions of each

genotype and phenotype often do not match the predictions of the Punnett square.

4. Suppose that you had data for 20 families of four children each where both parents were heterozygous Aa. Would

each of these families have exactly one albino child, as predicted by the Punnett square? Explain why or why not.

5. Your teacher will give you the class data to enter in the last line of the table on page 51. Are the percents of each

genotype in the class data similar to the predictions of the Punnett Square?

The random variation observed in small samples usually averages out in large samples. Therefore, the predictions of

the Punnett Square are usually more accurate for larger samples of children.

Genetics of Sickle Cell Anemia

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Red blood cells are full of hemoglobin, the protein that carries oxygen. One hemoglobin allele codes for normal

hemoglobin, and another allele codes for sickle cell hemoglobin. In a person is homozygous for the sickle cell allele, sickle cell hemoglobin tends to clump into long rods that cause the red blood cells to assume a sickle shape or other

abnormal shapes, instead of the normal disk shape. This causes a disease called sickle cell anemia.

1. Normal disk-shaped red blood cells can barely squeeze through the capillaries (the tiniest blood vessels). What

problems might be caused by red blood cells that are sickle-shaped or have other abnormal shapes?

2. Most children with sickle cell anemia have parents who do not have sickle cell anemia. Explain how a person can

inherit sickle cell alleles from parents who do not have sickle cell anemia. Is the sickle cell allele dominant (S) or

recessive (s)? Explain your reasoning. Include a Punnett Square in your answer.

The sickle cell allele illustrates some common complexities of genetics that we have ignored thus far. Read the

information in this box, and then answer questions 3 and 4.

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People who are homozygous for the sickle cell allele have sickle cell anemia, including pain and organ damage due to blocked circulation and anemia (low red blood cell levels) due to more rapid breakdown of red blood cells. People who are heterozygous for the sickle cell allele almost never experience these symptoms. Therefore, the allele for sickle cell hemoglobin is generally considered to be recessive and the allele for normal hemoglobin is generally considered to be dominant.

However, a heterozygous person does not have exactly the same phenotype as a person who is homozygous for the allele for normal hemoglobin. Specifically, people who are heterozygous for the allele for sickle cell hemoglobin are less likely to develop severe malaria than people who are homozygous for the allele for normal hemoglobin.

Malaria is caused by a parasite that infects red blood cells. The red blood cells of heterozygous individuals have both sickle cell and normal hemoglobin. Malaria parasites are less able to reproduce in red blood cells that have some sickle cell hemoglobin. This explains why people who are heterozygous for the allele for sickle cell hemoglobin have less severe malaria infections than people who are homozygous for the allele for normal hemoglobin.

3. Explain how the hemoglobin gene illustrates the following generalization:

A single gene often has multiple phenotypic effects.

4. Often, when geneticists investigate a pair of alleles, neither allele is completely dominant or completely recessive.

In other words, the phenotype of a person who is heterozygous for these two alleles is different from the phenotypes

of people who are homozygous for either allele. Explain how this general principle is illustrated by the sickle cell and

normal alleles for the hemoglobin gene.

Flower Color Genetics Lab

Objective

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Apply concepts of statistics and probability to explain the variation and distribution of expressed traits in a population. Background A certain species of plant produces either bright red flowers or pure white flowers. In working out the inheritance of a trait with contrasting forms such as flower color, it is important to determine which symbols will be assigned to the alternative forms (alleles) of the genes for the trait (in this case, red and white). The first letter for one of the alternative forms of the trait is generally used to represent the alleles for a trait. A capital letter is usually assigned to the dominant allele, and a lowercase letter is assigned to the recessive allele. For example, if R is used to represent red, then r would represent white. Or, if W is used to represent white, then w would represent red. The pair of genes that determines a trait is called a genotype. The genotype is represented by the pair of letters that symbolizes the alleles present. When both genes in the pair are the same, the genotype is said to be homozygous. When the genes in a pair are different, the genotype is said to be heterozygous. Purpose In this activity, you will perform simulated crosses between red-flowered plants and white-flowered plants. Based upon the preceding paragraph, identify and state the problem that needs to be solved before the inheritance of flower color in this plant can be studied further. To recall how the results of a cross are predicted, complete the following exercise. In cats, black coat color, B, is dominant to white coat color, b. To predict the possible coat colors of the kittens that would result from a cross between two heterozygous black cats (Bb x Bb), complete the following Punnett square.

Procedure

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In order to simulate crosses between plants with red or white flowers, you will use solutions to represent flower color. The pink solutions represent plants with red flowers. The clear solutions represent plants with white flowers. Assume that plants with a particular flower color may or may not be carrying a gene for alternate flower color. When you mix the two solutions, the color of the resulting mixture represents a flower color that could be observed among the offspring of two plants if you were to actually cross plants with flowers the same colors as the solutions. Caution: The solutions you will use in the following experiment contain chemicals that could damage your skin, eyes or clothing. Follow the suggested safety precautions. Also, be aware that contamination will have adverse effects on your data, pay attention and only mix solutions in designated containers. If you feel that contamination has occurred, let your instructor know immediately. When you have finished your experiment, all solutions may be rinsed down the sink drain. 1. Obtain 8 small test tubes from the materials table. Label them 1-8. 2. Obtain 1 mL of each of the solutions in the table below. Be careful not to contaminate solutions! 3. Record the “flower” color (red or white) of each to complete the table.

Color

Solution #1

Solution #2

Solution #4

Solution #5

Solution #7

4. Perform Cross #1: pour solution #1 and solution #2 into test tube #3; invert to mix. Record the phenotypes (colors) of the parents and resulting offspring in the boxes below.

5. Perform Cross #2: pour solution # 4 and solution #5 into test tube #6; invert to mix. Record the phenotypes (colors) of the parents and resulting offspring in the boxes below.

6. Based on the background information and the results of cross #1 and cross #2, which flower color is dominant? Which flower color is recessive? Use the Punnett squares below to determine heredity of flower color.

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Cross #1

Cross #2

7. Fill in the boxes below with the genotype of each flower based on your prediction above. If you determined red to be the dominant flower color, use R/r to represent red/white flowers. If you determined white to be the dominant flower color, use W/w to represent white/red flowers. If a genotype cannot be determined with complete certainty, write both possible genotypes.

8. Test your prediction of the dominant flower color by performing Cross #3: pour solution # 6 (test tube #6) and solution #7 into test tube #8; invert to mix. Record the phenotypes (colors) of the parents and resulting offspring in the boxes below.

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9. Fill in the boxes below with the genotype for Cross #3. If a genotype cannot be determined with complete certainty, write both possible genotypes.

Conclusion Write a paragraph explaining your initial question and hypothesis and whether or not your data supported or refuted your initial ideas. Use examples from your data and analysis as evidence for your argument of the trait type in this flowering plant. Include any revisions you made during the lab or revisions you would do if you attempted this investigation again. Finally, discuss strengths and weaknesses of using this simulation model for crossing flowering plants.

Soap Opera Genetics Genetics to Resolve Family Arguments

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I. How could our baby be an albino? Tiffany and Joe have just had a baby and are very surprised to learn that their baby is albino with very pale skin and hair color. Tiffany‘s sister has come to visit Tiffany and the new baby, so Joe goes out to talk with his sister Vicky.

Did Tiffany have an affair? Joe is very angry. He tells Vicky, "I think Tiffany had an affair with Frank! He’s the only albino we know. Obviously, Tiffany and I aren't albino, so Frank must be the father."

1. Luckily, Vicky remembers her high school biology, so she explains that heterozygous parents can carry a recessive allele for albinism. She draws a Punnett Square to show how two heterozygous parents with normal skin and hair color could have an albino baby. Draw this Punnett Square. Use A for the dominant allele that results in normal skin and hair color and a for the recessive allele that can result in very pale skin and hair color. 2. Joe is still mad and he doesn't understand Vicky's explanation. He says "You aren't even speaking English! What are heterozygous parents? What's a recessive allele? And what's the connection between alleles and skin color?" Answer his questions.

3. Once Joe understands this much, he asks for a better explanation of the Punnett square. Draw a new, more complete Punnett Square that includes the genotypes of both parents, labels to indicate which symbols represent the genetic makeup of eggs, sperm, or zygotes, thin arrows (→) to represent meiosis, and fat arrows (⇒) to represent an example of fertilization. 4. Joe says "Okay, I'm beginning to understand, but what are zygotes? What's the connection between the zygotes in the Punnett square and our baby?" Answer Joe's questions.

Why aren't more babies albino? By now, Joe has calmed down and he is getting interested. He asks Vicky "If that’s how it works, it seems as though a quarter of all babies should be albino. How come there are hardly any albino babies?"

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5. What explanation should Vicky give to answer this question?

Joe is starting to feel guilty for getting so mad. He says "Geez, I feel like a jerk. I should have known that Tiffany would never cheat on me." Vicky responds, "That's okay. You were upset. Let's just forget about it." Will Tiffany and Joe's next baby be albino? Two years later, Tiffany is pregnant again, and she and Joe are discussing whether their second baby will be albino. Tiffany thinks the baby probably will be albino, but Joe remembers Vicky's explanation, and he tells Tiffany, "No, our second baby can't be albino because only one out of every four of our children should be albino. We already have one albino child, so our next three children should not be albino."

6a. Is Joe right? Explain why or why not.

6b. What is the probability that Tiffany and Joe's second baby will be albino?

6c. How do you know?

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II. Were the babies switched? Two couples had babies on the same day in the same hospital. Denise and Earnest had a girl, Tonja. Danielle and Michael had twins, a boy, Michael, Jr., and a girl, Michelle. Danielle was convinced that there had been a mix-up and she had the wrong baby girl, since Michelle had light skin, while Michael Jr. and Tonja looked more like twins since they both had dark skin.

Danielle insisted on blood type tests for both families to check whether there had been a mix-up. To interpret the results of these tests, you will need to understand the genetics of blood types.

Genetics of Blood Types The ABO blood type system is the major blood type classification system that determines which type of blood can safely be used for a transfusion. The four blood types in the ABO system refer to different versions of carbohydrate molecules which are present on the surface of red blood cells.

These different blood types result from different alleles of a gene in the DNA that give the directions for making

different versions of a protein enzyme that puts different types of carbohydrate molecules on the surface of red blood cells.

Allele Gives the directions for making a version of the enzyme that:

A puts type A carbohydrate molecules on the surface of red blood cells

B puts type B carbohydrate molecules on the surface of red blood cells

O is inactive; doesn't put either type of carbohydrate molecule on the surface of red blood cells

1. Each person has two copies of this gene, one inherited from his/her mother and the other inherited from his/her father. Complete the following table to relate genotypes to blood types.

Genotype This person's cells make: Blood Type

AA the version of the enzyme that puts type A carbohydrate molecules on the

surface of red blood cells.

OO the inactive protein that doesn’t put either type A or type B carbohydrate

molecules on the surface of red blood cells.

AO both the version of the enzyme that puts type A carbohydrate molecules on

the surface of red blood cells and the inactive protein A

2. In a person with the AO genotype, which allele is dominant, A or O? Explain your reasoning.

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3. For the genotypes listed below, which type(s) of enzyme would this person's cells make? What blood type would the person have?

Genotype Will this person's cells make the version of the enzyme needed to put this carbohydrate on the surface of his/her red blood cells?

Blood Type

BB Type A __ yes __ no; Type B __ yes __ no

BO Type A __ yes __ no; Type B __ yes __ no

AB Type A __ yes __ no; Type B __ yes __ no AB

Codominance refers to inheritance in which two alleles of a gene each have a different observable effect on the phenotype of a heterozygous individual. Thus, in codominance, neither allele is recessive — both alleles are dominant.

4. Which of the genotypes listed above results in a blood type that provides clear evidence of codominance? Explain your reasoning. Were the babies switched? Now you are ready to evaluate whether Earnest and Denise's baby girl was switched with Michael and Danielle's baby girl.

This figure shows the blood types of the families if the hospital did not make a mistake.

This figure shows the blood types of the families if Tonja and Michelle were accidentally switched.

5. One of the families shown is genetically impossible. Draw a Punnett square for each pair of parents to show how three of these families are genetically possible and to identify which family has a child who could not possibly have inherited her blood type from parents with the blood types shown.

6. Who are Tonja's parents? How do you know? Did the hospital make a mistake?

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Why do the twins look so different? Now, Danielle wants to know how her twins could look so different, with Michelle having tan skin and Michael Jr. having dark skin. First, Danielle needs to understand that there are two types of twins. Identical twins have exactly the same genes, since identical twins originate when a developing embryo splits into two embryos.

7. How do you know that Michelle and Michael Jr. are not identical twins?

Michelle and Michael Jr. are fraternal twins, the result of two different eggs, each fertilized by a different sperm. These different eggs and sperm had different alleles of the genes for skin color. Therefore, Michelle and Michael Jr. inherited different alleles of these genes, so they have different skin colors.

To begin to understand how Michelle could have tan skin and her twin brother, Michael Jr., could have dark skin, we will consider two alleles of one of the genes for skin color. Notice that, for this gene, a heterozygous

Genotype Phenotype (skin color) BB dark brown Bb light brown bb tan

individual has an intermediate phenotype, halfway between the two homozygous individuals.

When the phenotype of a heterozygous individual is intermediate between the phenotypes of the two different types of homozygous individual, this is called incomplete dominance.

8a. Explain how incomplete dominance differs from a dominant-recessive pair of alleles. (Hint: Think about the phenotypes of heterozygous individuals.)

8b. Explain how incomplete dominance differs from co-dominance.

9. The parents, Michael and Danielle, both have light brown skin and the Bb genotype. Draw a Punnett square and explain how these parents could have two babies with different color skin – one dark brown and the other tan.

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Obviously, people have many different skin colors, not just dark brown, light brown, or tan. One reason for the many different skin colors is that skin color is influenced by multiple genes with multiple alleles. Scientists have found that:

● Different skin colors result from differences in the types and amounts of the pigment melanin in skin cells.

● Several different proteins influence the production and processing of melanin molecules in skin cells. ● Different alleles of the genes that code for these proteins result in different skin colors.

Environmental influences also affect skin color. For example, exposure to sunlight can change the activity of genes that influence skin color and increase the amount of melanin in skin cells. This flowchart summarizes the multiple genetic and environmental influences on skin color.

10. This information indicates that the chart on the previous page is oversimplified. Multiple factors influence skin color, so two people who both have the Bb genotype can have different skin colors. For example, Hernando and Leo both have the Bb genotype, but Hernando’s skin is darker than Leo’s. Explain two possible reasons why Hernando and Leo have different skin colors.

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III. I don't want to have any daughters who are color blind like me!

Awilda and Frank at Breakfast Awilda: Are you sure you want to wear that new shirt to work today? A green and red shirt like that would be

better for Christmas, not for St. Patrick's Day. Frank: Oh no! Not again! I really thought this shirt was just different shades of green. Where's the red?

At Dinner That Night Frank: We should try to find a way to make sure we only have sons, no daughters. I don't want to have any

daughters who might be color blind like me. Color blindness would be a big problem for a girl. Awilda: Remember, the doctor said that he doesn't think that any of our children will be color blind. Frank: I don't see how he can be so sure about that. I'm color blind, so some of our children should be color

blind like me. Awilda: The doctor said that, since no one in my family was color blind, I almost certainly do not have the

allele for color blindness, so none of our children will be color blind. Frank: That doesn't make any sense. Neither of my parents is color blind, but I'm color blind. I think that our

children will be more likely to be color blind since they will have a color blind father.

Answer these questions to help Awilda explain to Frank why none of their children will be color blind. 1a. What are the genotypes of Frank and Awilda? (Since the allele for color blindness is located on the X chromosome, use the symbol Xcb for an X chromosome with the recessive allele for color blindness and XN for an X chromosome with the dominant allele for normal color vision. The Y chromosome does not have this gene, so it is represented by Y.)

Frank _______ Awilda _______ 1b. Draw a Punnett square for this couple and their children. 1c. Explain why none of their children will be color blind.

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Frank: Okay, I guess I don't have to worry about any of our children being color blind, but what about our

grandchildren? Couldn't some of them be color blind, especially our granddaughters? Awilda: Well, some of our grandchildren could be color blind, but I've heard that boys are more likely than girls

to be color blind. Frank: I disagree. Girls have more X chromosomes than boys, so girls should be more likely to be color blind.

Answer the following questions to explain why Awilda and Frank’s grandsons are more likely than their granddaughters to be color blind.

2a. What are the possible genotypes for Awilda and Frank's children?

Awilda and Frank's sons _______ Awilda and Frank's daughters _______

2b. Draw a Punnett square for each couple in the chart below. In each Punnett Square, circle each boy and use arrows to indicate any color blind offspring.

Punnett square if one of Awilda and Frank's daughters marries a man who is color blind

Punnett square if one of Awilda and Frank's daughters marries a man who is not color blind

2c. Explain why Awilda and Frank's grandsons are more likely than their granddaughters to be color blind.

3. Explain why having two X chromosomes decreases a woman’s risk of color blindness, instead of increasing her risk.

4. Remember that Frank is colorblind, but neither of his parents are colorblind. Which Punnett square shows how two parents who are not colorblind could have a color blind son?

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Genetic Engineering and Transgenic Organisms

Answer all questions in complete sentences!!!!! Before you begin: 1. In your own words, define the term herbicide: 2. In your own words, define the term resistant: http://www.pbs.org/wgbh/harvest/engineer/transgen.html 3. What will you be producing in this animation? 4. Where will the new gene come from? 5. What is Bt? 6. What does this gene code for? 7. What will be special about this new crop?

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Follow the steps and answer the questions as you go. Step One: 8. What is a vector? 9. How many genes were added? Step Two: 10. In your own words, what is the purpose of Agrobacterium? Step Three: 11. What is the purpose of growth medium? Step Four: 12. What is the purpose of this step? Step Five: 13. What is the purpose of this step? Step Six: 14. What is the purpose of this step? Step Seven: 15. How will scientists know if the new gene is working in the mature plant?

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Go to: http://www.pbs.org/wgbh/harvest/coming/coming.html 16. Click on any 5 different materials found at the table in any order. Write the name of the item you chose and then explain how and why it is being genetically modified. a.___________________________ Why? b.___________________________ Why? c.___________________________ Why? d.___________________________ Why? e.___________________________ Why? Go to: http://www.treehugger.com/corporate-responsibility/first-drug-made-from-genetically-engineered-animals-approved-by-fda.html 17. What was the first medicine produced by a GMO? 18. What organism was modified? 19. Where was the recombinant DNA placed? 20. Where was the new medicine produced? 21. What does the medicine do?

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Go to: http://news.bbc.co.uk/2/hi/science/nature/889951.stm 22. Explain how and why scientists have genetically modified these goats. Go to: http://abcnews.go.com/Health/story?id=117204&page=1 23. Name three ways that scientists could genetically modify organisms to use as weapons. a.___________________________________________________________________________ b.___________________________________________________________________________ c.___________________________________________________________________________ Go to: http://www.mnn.com/green-tech/research-innovations/photos/12-bizarre-examples-of-genetic-engineering/enviropig 24. Use the arrows to go through the gallery. Read the explanations on the side and classify the organisms in the chart below. You will have 10 filled in when you are finished.

Important for the Environment Important for Humans

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Go to: http://www.pbs.org/wgbh/harvest/exist/ Scroll to the bottom and click on “View all 12 arguments” 25. Read through the arguments for and against GM foods. Give 5 positives and 5 negatives of GMO’s in a t-chart below. Be thorough.

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Units 3 & 4 Reflection

A. How does each lab/activity exemplify the learning targets for the unit? Be specific about each learning

target and use the dos and don’ts suggestions!

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B. What were you able to learn by completing the labs/activities? Again, be specific about each learning

target and use the dos and don’ts suggestions!

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C. How did the labs/activities compare and contrast to each other? Again, be specific about each learning

target and use the dos and don’ts suggestions!

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D. In which labs did you experience trouble? Again, be specific and use the dos and don’ts suggestions!

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E. How does this unit of work relate to real life situations? Again, be specific and use the dos and don’ts

suggestions!

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Article Rationale & Summary

Article Title: ____________________________________________________________________________

Author(s): _____________________________________________________________________________

Source: ________________________________________________________________________________

Summary: Summarize the main points of the article in 4-6 sentences.

Rationale for inclusion in this unit: How does the material in the article relate to what was learned/studied in

this unit? Include a detailed description of at least 3 different specific examples. Again, be specific about each

connection and use the dos and don’ts suggestions!

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(Copy of Article)

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Personal Choice

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Rationale for Personal Choice

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