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DNA. What makes you….you!. What type of cells are these?. What is the arrow pointing to?. Discovering - DNA. 1800’s – with discovery of microscope, scientists realized something [DNA] existed in the nucleus 1950’s – Rosalind Franklin- using X-ray discovered a stand
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DNA What makes you….you!
What type of cells are these? What is the arrow pointing to?
Discovering - DNA 1800’s – with discovery of microscope, scientists realized something [DNA] existed in the nucleus 1950’s – Rosalind Franklin- using X-ray discovered a stand of DNA consists of a “double helix” or spiral shaped ladder - Watson and Crick- “ sides of ladder” consists of sugars and phosphates and “steps of ladders” are nitrogen base pairs Video: Cracking the Code of Life | Watch NOVA Online | PBS Video
DNA phosphate DNA- [Deoxyribonucleic Acid] threads of chromatin Sugar Shape - like a spiral ladder 1. Rungs = Pairs of Nitrogen Bases A-T = Adenine - Thymine G-C = Guanine - Cytosine 2. Handrails = Alternating Phosphate and Deoxyribose Sugar * Base pairs always attached to sugar Nitrogen base
Inside the Nucleus The Human Genome Project, 3D Animation - YouTube Gene - a section of DNA coil, determines traits of organism Heredity-passing of genes from parent > offspring
Alleles - different forms a gene may have for a trait Genetics-study of how alleles affect generations of offspring
98% of genes for Humans & Chimps are alike Total Base Pairs = 3.2 billion Total Genes = 30,000 Genes between Humans only differ by 0.01% To read all 3.2 billion base pairs aloud -it would take 9.5 years The Human Genome Project, 3D Animation - YouTube
Mutations- a permanent change in genes or chromosomes (Discovery Ed) A-T-C-A-T-G-G-C-T Isoleucine Methionine Alanine A-T-G-A-T-G-G-C-T A-T-G-A-T-G-G-C-T Substitution Methionine A-T-C-A-A-T-G-G-C-T A-T-C-A-A-T-G-G-C-T Insertion A-T-C-T-G-G-C-T A-T-C-T-G-G-C-T Deletion
Mutations http://app.discoveryeducation.com/search?Ntt=mutations http://app.discoveryeducation.com/search?Ntt=mutations
Seedless Grapes? http://www.youtube.com/watch?v=RjsU_rJpTWg Grafting/Cuttings http://www.youtube.com/watch?v=-EwtyO16dFg
Alleles One comes from mom, one from Dad Dad Mom Eye color
Genetic Cross-random pairing of one gene from each parent Gregor Mendel = Father of Genetics Dominant- “what is seen” [Capital letter] Recessive-“what is hidden” [Lower case letter] Phenotype-physical trait that appears ex: Tall Genotype-genetic make-up represented by letters ex: TT
What would all the possible genotypes be for the trait of tallness in a pea plant? Homozygous [homo means same, zygous means pair] = TT, tt Heterozygous [hetero means different, zygous means pair] = Tt
Monogenic Inheritance Dominant Traits • Tongue roller • Hand clasp • Unattached earlobe • Straight Pinky • Hairy finger- 2nd section • Dimples • Cleft Chin • Straight hair line • Freckles • Hitch hiker thumb • Brown eyes • Second toe longer than big toe 13. Finger divide- 2 vs 1
Genetics in Harry Potter? • What types of inherited genetic traits are described in the Harry Potter series?
Inherited Physical Traitsin Harry Potter "All the Weasleys have red hair, freckles, and more children than they can afford." -- Draco Malfoy (Sorcerers Stone, Ch.6) He was almost twice as tall as a normal man and at least five times as wide. (Sorcerer’s Stone, Ch.1) Harry had a thin face, knobby knees, black hair, and bright green eyes.(Sorcerer’s Stone, Ch.1) A pale boy with a pointed face and white-blond hair, Draco greatly resembled his father. His mother was blonde too... (Goblet of Fire, Ch.8)
Applying Genetics to the Harry Potter Characters • What are some phenotypes (observable traits) described in the four excerpts from the Harry Potter books?
Applying Genetics to the Harry Potter Characters • What are some phenotypes (observable traits) described in the four excerpts from the Harry Potter books? • Freckles • Hair color • Eye color • Height
Applying Genetics to the Harry Potter Characters • A genetic trait can be described in two ways: • Phenotypes are observable traits resulting from how one’s genes are expressed. Ex., hair color, a talent, sickle cell disease, etc. • AGenotype consists of two letters that represent a gene’s allele pair that results in a phenotype.
Example: Freckles • Two possible phenotypes for freckles are: • Has Freckles (observable) • No freckles (observable) • A genotype for freckles is indicated by two alleles in the freckle gene. The possible alleles using the first letter of the trait “f” are: • F (dominant) = Has Freckles • f (recessive) = No freckles
Freckles: Genotypes & Phenotypes Question: Using F and f, what are possible genotypes of the allele pair for freckles? GenotypePhenotype (alleles inherited from parents) (physical appearance) F F ====== has freckles F f ====== has freckles f f ====== no freckles One dominant allele (F) is sufficient for its trait (has freckles) to be observable, but both alleles have to be recessive (f) for the recessive trait (no freckles) to be observable.
Punnett Squares-visual tool used to display the possibilities of a genetic cross The parents’ homozygous genotypes are: Mom = F F Dad = f f Mom’s Traits F F D a d’ s T r a i t s f f
Punnett Squares F F f f F F F f
Example: Red Hair • Red hair color is recessive to brown color. One way to describe the hair color alleles are: • Red hair = r (notes recessive red color) • Brown hair = R(notes dominant brown color) Question: Using r (red hair) and R (brown hair) alleles,what possible genotypes of the allele pair are there? Genotype(allele pair) Phenotype (appearance) RR ====== brown hair Rr ====== brown hair rr ====== red hair
Punnet Square: Weasley Family All Weasley children have freckles and red hair. Use the Punnett Square to predict the most likely genotypes of Molly and Arthur Weasley for the two traits. Use the following allele possibilities that we identified previously: • r (notes recessive red color) = Red hair • R(notes dominant brown color) = Brown hair • F (dominant) = Has Freckles • f (recessive) = No freckles
Punnett Square: Weasley Family All Weasley children have freckles and red hair—100% probability. Possible genotypes for their red hair (recessive trait) and freckles (dominant trait) are: rr only for red hair and Ffor FF for freckles. Create Punnett squares to find out more about their parents Molly and Arthur: rr rr Ff/FF Ff/FF Ff/FF Ff/FF rr rr Both parents have rr. At least one parent has FF.
Punnet Square: The Potters Question 1: Harry has dark/brown hair like his father, but his mom had red hair. Using the genotypes of rr, Rr, and RR, what possible genotypes does each of the Potters have? The phenotypes of the Potters are: James Potter (dad)—dark/brown hair Lily Potter (mom)—red hair Harry Potter—dark/brown hair
Punnet Square: The Potters Using the genotypes of rr, Rr, and RR, what are possible genotypes for Harry’s parents? • Mom-Lily (red hair) = rr • Dad-James (dark hair) = Rr or RR The parents’ genotypes lead to 2 Punnett Squares. r r R r r r R R
Punnet Square: The Potters Given Harry’s parents’ possible genotypes, the two Punnett Squares can be completed as follows: The only possible genotype for Harry’s dark hair is Rr. r r R RrRr r rrrr r r R RrRr R RrRr
Punnet Square: The Potters Questions : Harry marries Ginny who has red hair. What are possible genotypes of their children’s hair colors?
Punnet Square: Harry & Ginny Harry marries Ginny who has red hair. What are possible genotypes of their children’s hair colors? First, what are the genotypes for Harry and Ginny’s hair colors? Harry’s genotype = Rr Ginny’s genotype = rr
Punnet Square: Harry & Ginny Harry marries Ginny who has red hair. What are possible genotypes of their children’s hair colors? Given Harry and Ginny’s genotypes, Rrand rr, we can fill in thePunnett Square for their children’s genotypes. Their children have a 50%chance of having red ordark hair colors.
DNA Unit Review • What are the steps of the DNA ladder made of? Nitrogen Base Pairs : A-T, G-C 2. What are the sides of the ladder made of? Phosphates and sugars 3. What are base pairs always attached to? Sugar 4. Where are genes located? On chromosomes 5. Different forms of the same genes are called? Alleles
6. Physical appearance of a trait is called? Phenotype 7. Genetic make up of an organism? Genotype 8. What does the term heterozygous mean? Homozygous? Different gene combinations, dominant and recessive Same gene pairs • What is a mutation? Are they always harmful? Permanent change to an organism No create variety
10. What is the purpose of using a Punnett square? • Determine probability of traits that can be inherited • 11. What is the process that involves one cell dividing two times to • create four new cells with half the number of chromosomes? • Meiosis • 12. What type of cells undergo meiosis? • Sperm and Egg • How many chromosomes are in a human • egg cell? • 23 ----- Why not 46?
What is it called when many genes create ONE trait? • polygenic inheritance • What is the term for more than two possibilities of a trait? • multiple alleles • 16. When both genes are expressed equally for a trait it is called? • incomplete dominance
Creation of Proteins Base pairs form amino acids which link together to form proteins