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What is Genetics? What are terms associated with Genetics?
Genetics is the study of heredity, or the branch of biology that deals with heredity and genetic variations.
Genotype: What is genetically expressed in an organisPhenotype:What is physically expressed in an organism
Homozygous: Identical pairs of genes for any given characteristic
Heterozygous: Different pairs of genes for any given characteristic
Dominant: The trait that is physically expressedRecessive: The trait that is present but not shown
Mitosis & Meiosis• Mitosis has 4 phases:
• Prophase
• PREPARE
• Chromosomes are visible
• Lose nucleus
• Metaphase
• MIDDLE
• Chromosomes line up in the middle
• Anaphase
• AWAY
• Chromosomes move towards the poles
• Telophase
• TWO NUCLEUS
• Nucleus split and reappears
• They are identical cells
• Body cells
• Diploid cells
• Meiosis goes through 2 processes:
• Prophase l
• Crossing over
• Protiens of chromatids break off and attach to the adjacent chromosomes on the homologous chromosomes
• Metaphase l
• Anaphase l
• Homologous chromosomes seperate
• Telophase l
• Prophase ll
• Mertaphase ll
• Anaphase ll
• Sister chromatids seperate
• Telophase ll
• 4 haploid cells result
• They are similar cells
• Sex cells
• Haploid cells
Stages of Meiosis l and ll
http://thumb7.shutterstock.com/display_pic_with_logo/848740/116607409/stock-vector-vector-diagram-of-the-meiosis-phases-116607409.jpg
STages of Mitosis•http://www.google.com/search?q=mitosis&safe=active&source=lnms&tbm=isch&sa=X&ei=XgubU9GfEJGOyAS2_IKYDA&sqi=2&ved=0CAYQ_AUoAQ&biw=1301&bih=620#facrc=_&imgdii=_&imgrc=nhZ-bmMsNUC3FM%253A%3BUhqCAF-wnFwS9M%3Bhttp%253A%252F%252Fdiffervs.com%252Fwp-content%252Fuploads%252F2013%252F08%252Fmitosis-vs-meiosis.jpeg%3Bhttp%253A%252F%252Fdiffervs.com%252Fdiscover-difference-mitosis-meiosis%252F%3B495%3B420\
Mitosis Video
• http://video.mit.edu/watch/lego-animation-of-mitosis-with-descriptive-titles-3077/
DNAStands for Deoxyribonucleic Acid
• Primary Function: to store and transmit the genetic information that tells cells whcih protiens to make and when to make them
• DNA is an organic compound made up or repeating subunits called nucleotides.
• Nucleotides have 3 parts:
• Sugar molecule
• Deoxyribose
• Phosphate Group
• Phosphorus
• Oxygen
• Nitrogen Bases
• Adenine (A)
• Cytosine (C)
• Guanine (G)
• Thymine(T)
VIdeo: https://answersingenesis.org/genetics//
• 2 types of Nitrogen Bases
• Purines
• Have 2 rings
• Adenine(A)
• Guanine(G)
• Pyrimdines
• Have 1 ring
• Cytosine(C)
• Thymine(T)
DNA Cont.• Base Pairings:
• Cytosine bonds with Guaning (C-G)
• Adenine bonds with Thymine (A-T)
• James Watson and Francis Crick built the 3D model or the double helix
• 2 nucleotide strands wrap around eachother to form a double spiral
• Enzymes involved in DNA replication:
• DNA Helicase
• Unwind and unzip the DNA
• Binding Proteins
• Hold open the replication fork
• DNA Primase
• Lay down the start and stop primers for the new strand
• DNA Polymerase
• Lays down one new nucleotide at a time
• DNA Ligase
• The glue that holds the new DNA strand together
• The Enzymes involved in DNA replictation
en.wikipedia.org
RNA• Stands for Ribonucleic Acid
• Responsible forthe movement of genetic information from the DNA in the nucleus to the site of protien synthesis in the cytosol
• A single sranded nucleic acid made up of repeating units
• Sugar molecule is ribose
• Thymine(T) relaced with URACIL(U)
A strand of RNAhttp://chemistry.tutorvista.com/biochemistry/nucleic-acids.html
RNA cont.
• 3 Forms of RNA
• Messenger RNA (mRNA)
• Function:
• Carries genetic info from the nucleus to the ribosome
• Transfer RNA (tRNA)
• Function:
• Binds to specific amino acids and helps form polypeptide chains (proteins)
• Ribosomal RNA (rRNA)
• Function:
• Makes up the ribosomes where proteins are made
Protein synthesis
• Protein Synthesis- The production of proteins
• The amount and kind of proteins produced in a cell determines the structure and function of the cell
• 2 Steps in Protein Synthesis
• Transcription:
• Makes mRNA from DNA
• Transcribe- to copy
• Translation:
• mRNA leaves the nucleus through pores in the nuclear membrane
• mRNA then migrates to a ribosome in the cytosol, the site of protein synthesishttp://
sciencevogel.wikispaces.com/file/view/Protein%20Synthesis
%20diagram.png/493016480/390x301/Protein
%20Synthesis%20diagram.png
Mutations/Disorders• Genetic Disorders:
• Genetic Traits and Disorders-
• Genes that control human traits can be mutated and then inherited by offspring
• Mutations-
• Definition- A change in DNA sequence that affects genetic info
• The result of some mutations are gentic disorders
• Inheritance- There are 4 main ways genetic disorders are passed....
• Single Gene Disorder
• The problem traits controlled by a single gene and are passed in a dominant/recessive manner
• Multifactoral Disorders
• These disorders result from mutations in multiple genes
• These disorders are difficult to study and treat
• EX. Alzheimer's Disease, Hypothyroidism
Karyotype showing the genetic disorder of Down Syndrome
http://learn.genetics.utah.edu/content/disorders/
chromosomal/down/images/trisomy21_karyotype.jpg
Mutations/Disorders continued
• Inheritance cont.
• Chromosomal Abnormality
• Entire chromosomes or large segments of chromosomes are missing, duplicated, or otherwise altered
• Nondisjunction-
• Failure of a chromosome to seperate from its homologue during meiosis
• One gamete receives an extra copy of a chromosome and the other gamete lacks the chromosome entirely
• Scientisits can use karyotypes to identify disorders caused by chromosomal abnormalities
• X-Linked Disorders
• Disorders in which the mutations or errors are in genes found on the X chromosomes
• Ex.- Hemophilia, Muscular Dystrophy
Review Questions
• What is the full name for DNA? Deoxyribonucleic Acid
• What two organelles can DNA be found in? Nucleus, Mitochandria
• What is the shape of DNA? Double Helix
• What is a Gene? A sequence of DNA passed on to offspring
• What are the two purines found in DNA? Adenine, Guanine
• What are the two phases of protein synthesis? Transcription, Translation
• What are the four types of chromosomal mutations?
• What is the gene that is expressed called?
• What is a mutation?
Answers
• What is the full name for DNA? Deoxyribonucleic Acid
• What two organelles can DNA be found in? Nucleus, Mitochandria
• What is the shape of DNA? Double Helix
• What is a Gene? A sequence of DNA passed on to offspring
• What are the two purines found in DNA? Adenine, Guanine
• What are the two phases of protein synthesis? Transcription, Translation
• What are the four types of chromosomal mutations? Deletions, Duplication, Insertion, Translocation
• What is the gene that is expressed called? Dominant
• What is a mutation? A change in the DNA sequence that effects genetic info