Cells and HeredityCells and HeredityChapter 4 Modern Chapter 4 Modern

GeneticsGenetics

Section 1 Human Section 1 Human InheritanceInheritance

Section 1 Human Inheritance: Section 1 Human Inheritance: ObjectivesObjectives

To explain what multiple alleles are.To explain what multiple alleles are. To explain why some human traits show To explain why some human traits show

a large variety of phenotypes.a large variety of phenotypes. To explain how environmental factors can alter To explain how environmental factors can alter

the effects of a gene.the effects of a gene. To explain what determines sex and why some To explain what determines sex and why some

sex linked traits are more common in males than sex linked traits are more common in males than in females.in females.

To describe how geneticists use pedigrees.To describe how geneticists use pedigrees.

Section 1 Human Genetics Section 1 Human Genetics VocabVocab

1. multiple alleles1. multiple alleles

Three or more forms of a gene that Three or more forms of a gene that code for a single trait. code for a single trait.

2. sex-linked gene2. sex-linked gene

A gene that is carried on the X or Y A gene that is carried on the X or Y chromosomechromosome

3. carrier3. carrier

A person who has one recessive A person who has one recessive allele for a trait and one dominant allele for a trait and one dominant allele, but does not have the trait. allele, but does not have the trait.

4. pedigree4. pedigree

A chart or “family tree” that tracks A chart or “family tree” that tracks which members of a family have a which members of a family have a particular trait.particular trait.

NotesNotes

1. ____________ exists in pairs.1. ____________ exists in pairs.Chromosomes

2. Two traits controlled by many 2. Two traits controlled by many genes are:genes are:

– A.A.

– B.B.

height

skin color

3. Three environmental factors that 3. Three environmental factors that can effect height are:can effect height are:

– AA

– BB

– CC

Lack of protein

Lack of minerals

Lack of vitamins

4. There are __________ chromosomes 4. There are __________ chromosomes in each body cell.in each body cell.

23 pairs of

5. Males have the ______ combination 5. Males have the ______ combination of chromosomes, while females have of chromosomes, while females have the _______ combinationthe _______ combination

XY

XX

6. The _________ determines the 6. The _________ determines the gender of the offspring.gender of the offspring.

sperm

7. ________ are more likely to have a 7. ________ are more likely to have a sex-linked trait that is controlled by a sex-linked trait that is controlled by a ______________ allele.______________ allele.

Males

recessive

Cells and HeredityCells and HeredityChapter 4 Modern Chapter 4 Modern

GeneticsGenetics

Section 2 Human Genetic Section 2 Human Genetic DisordersDisorders

Section 2 Human Genetic Section 2 Human Genetic Disorders: ObjectivesDisorders: Objectives

To describe the causes and To describe the causes and symptoms of four human genetic symptoms of four human genetic disordersdisorders

To explain how genetic disorders are To explain how genetic disorders are diagnosed.diagnosed.

VocabVocab

5. genetic disorder5. genetic disorder

An abnormal condition that a person An abnormal condition that a person inherits through genes or inherits through genes or chromosomes.chromosomes.

6. amniocentesis6. amniocentesis

A technique by which a small amount A technique by which a small amount of the fluid that surrounds a of the fluid that surrounds a developing baby is removed; the developing baby is removed; the fluid is analyzed to determine fluid is analyzed to determine whether the baby will have a genetic whether the baby will have a genetic disorder. disorder.

7. 7. karyotypekaryotype

A picture of all the chromosomes in a A picture of all the chromosomes in a cell arranged in pairs.cell arranged in pairs.

NotesNotes

1. ______________________ are caused 1. ______________________ are caused by _____________________, or changes by _____________________, or changes in a person’s ______________.in a person’s ______________.

Genetic Disorders

mutations

DNA

2. Describe each order and its cause2. Describe each order and its cause

A. A. Cystic FibrosisCystic Fibrosis

– Affect- Affect-

– Cause-Cause-

Causes think mucus to build up in a person’s lungs and intestines

A mutation that is carried on a recessive allele.

B. B. Sickle-CellSickle-Cell

– Affect-Affect-

– Cause-Cause- A mutation that affects the production of hemoglobin, a protein in red blood cells that carries oxygen

Sickle shaped red blood cells that can not carry as much oxygen as normal blood cells

C. C. HemophiliaHemophilia

– Affect-Affect-

– Cause-Cause-

A disorder in which a person’s blood clots very slowly or not at all

People with the disorder do not produce one of the proteins needed for normal blood clotting

D. D. Down SyndromeDown Syndrome

– Affect-Affect-

– Cause-Cause-

A distinctive physical appearance, some degree of mental retardation, heart defects. Many people with down syndrome lead full lives.

A person’s cells have an extra copy of chromosome 21.

Cells and HeredityCells and HeredityChapter 4 Modern Chapter 4 Modern

GeneticsGenetics

Section 3 Advances in Section 3 Advances in GeneticsGenetics

Section 3 Advances in Section 3 Advances in Genetics: ObjectivesGenetics: Objectives

To describe three ways in which To describe three ways in which people have developed organisms people have developed organisms with desired traits.with desired traits.

To explain how DNA fingerprinting is To explain how DNA fingerprinting is usedused

To state the goal of the Human To state the goal of the Human Genome Project.Genome Project.

VocabVocab

8. Selective breeding8. Selective breeding

The process of selecting a few The process of selecting a few organisms with desired traits to organisms with desired traits to serve as parents of the next serve as parents of the next generation.generation.

9. 9. InbreedingInbreeding

A selective breeding method in which A selective breeding method in which two individuals with identical or two individuals with identical or similar sets of alleles are crossed.similar sets of alleles are crossed.

10. 10. HybridizationHybridization

A selective breeding method in which A selective breeding method in which two genetically different individuals two genetically different individuals are crossed. are crossed.

11. 11. CloneClone

An organism that is genetically An organism that is genetically identical to the organism from which identical to the organism from which it was produced.it was produced.

12. 12. Genetic engineeringGenetic engineering

The transfer of a gene from the DNA The transfer of a gene from the DNA of one organism into another of one organism into another organism, in order to produce an organism, in order to produce an organism with desired traits. organism with desired traits.

13. 13. Gene therapyGene therapy

The insertion of working copies of a The insertion of working copies of a gene into the cells of a person with a gene into the cells of a person with a genetic disorder in an attempt to genetic disorder in an attempt to correct the disorder.correct the disorder.

14. 14. GenomeGenome

All of the DNA in one cell of an All of the DNA in one cell of an organism. organism.

NotesNotes

1. Two examples of selective 1. Two examples of selective breedingbreeding

– A.A.

– B.B.

Dairy cows are bred to produce larger quantities of milk

Varieties of fruits and vegetables that are bred to resist diseases

2. Two examples of inbreeding2. Two examples of inbreeding

– AA

– BB

Some purebred horses

Purebred dogs, such as Labrador retrievers and German sheperds

3. One problem with inbreeding is:3. One problem with inbreeding is:

Increases the chances of inheriting allelesthat lead to genetic disorders.

4. Two examples of hybridization 4. Two examples of hybridization

– A.A.

– B. B.

Crossing corn that produces many kernelsWith corn that is resistant to diseases

A mule coming from the cross of a mare and a donkey. The mule has the courage, stamina,and surefootedness of the donkey with the strength of a horse

5. A common example of cloning is 5. A common example of cloning is

*To make a “cutting” from a plant. The cutting can grow into a new plant

6. DNA samples from _______, ______, 6. DNA samples from _______, ______, and _____ can be used to identify a and _____ can be used to identify a person.person.

hair

skin blood

7. No two people, except 7. No two people, except _______________ have the same DNA._______________ have the same DNA.Identical twins