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Question of the DAY DEC 6. Which cells are responsible for the passing on of genetic information from parent to offspring? A. Somatic cells B. Diploid cells C. Gametes D. Cancer cells. DO NOW DEC 6. Work in groups of 3 to complete the DO NOW
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Question of the DAY DEC 6 • Which cells are responsible for the passing on of genetic information from parent to offspring? • A. Somatic cells • B. Diploid cells • C. Gametes • D. Cancer cells
DO NOW DEC 6 • Work in groups of 3 to complete the DO NOW • Create a list of physical characteristics you have in common with your group. • Consider things like eye and hair color, style/texture of hair, shape of nose/ears, and so on. • Why do we all look different from each other?
DO NOW ANSWERED • We all have different parents. • Our parents have their own physical characteristics that are expressed. • These characteristics have been inherited from their parents as you have inherited characteristics from your parents.
AGENDA DEC 6 • Big Question: What is heredity? • 1. Question of the Day • 2. DO NOW • 3. Begin Chapter 11: Genetics • 4. Gregor Mendel and his Contributions • 5. Review and Homework • Section 11-1 and 11-2 Quiz on Wednesday • Mendel’s Crosses and Punnett Squares
11-1: The Work of Gregor Mendel • heredity: set of characteristics an organism receives from its parents • genetics: study of heredity
Gregor Mendel • born in 1822 • studied pea plants and how they reproduced
Reproduction in Pea Plants • pollen is the male sex cell • eggs are the female sex cell • reproduce by self pollination: process in whichpollen fertilizes an egg from the same plant • reproduces by cross pollination: process in which pollen from one plant fertilizes an egg from another plant
Mendel’s First Experiment • prevented flowers from self pollinating • controlled cross pollination • cut off male parts of flowers and dusted flowers with pollen from another flower • was able to cross plants with different characteristics • used purebreds: an organism that only produces offspring with only one form of a trait • A specific characteristic such as seed color or plant height
QUESTION of the Day Dec 9 • Which of the following are not examples of heredity? • A. the stripes of a zebra • B. the rows of teeth in the mouth of a Great White Shark • C. speaking a foreign language • D. a tiger hunting prey
DO NOW DEC 9 • If you crossed a Tall pea plant with a short pea plant, how would you predict the offspring produced?
AGENDA DEC 9 • BIG Question: How can characteristics of offspring be determined? • 1. Question of the day and DO NOW • 2. Mendel’s Crosses • P, F1, and F2 Generations • 3. Punnett Squares • 4. Review and Homework
DO NOW ANSWERED • You would need to know which trait, Tall or short, was the dominant one. • It is also necessary to identify the alleles from each parent that may be passed down to an offspring. • This dominant trait will most likely be expressed.
True-Breeding • True-breeding plants are plants that only carry one allele for a trait. • If these plants are allowed to self-pollinate, they will produce offspring identical to themselves. • TALL plants produce TALL plants • Green seeded plants produce Green seeded plants
Pea Plant Traits • studied only seven traits with only two options • decided to cross pea plants with different characteristics for the same trait • tall with short, green seeds with yellow seeds, round seeds with wrinkled seeds, and so on • alleles: different forms of a gene
Mendel’s Results • offspring were hybrids: organisms produced by crossing parents with differing characteristics • all hybrids had the characteristics of only one parent
Mendel’s Conclusions • 1. individual factors, called genes, control each trait • 2. principle of dominance: some factors or alleles are dominant whereas others are recessive
Mendel’s Second Experiment • allowed hybrid plants to reproduce among themselves • kept groups in order • P generation: purebred group • F1 generation: hybrid group • F2 generation: offspring of hybrids • in F2 plants, the recessive traits reappeared
Mendel’s Results • in his F2 generations, the recessive trait showed up in ¼ of the offspring • phenotype: physical characteristics • genotype: genetic makeup • homozygous: two identical alleles for a particular trait • TT, homozygous dominant • tt, homozygous recessive • heterozygous: having two different alleles for the same trait • Tt
Question of the Day DEC 11 • An organism with a genotype of bb is called • A. Heterozygous recessive • B. Homozygous dominant • C. Heterozygous dominant • D. Homozygous recessive
DO NOW DEC 11 • Determine the possible genotypes of a pea plant that is Tall and has white flowers. • Tall is dominant over short • Purple is dominant over white flowers
DO NOW ANSWERED • Possible Genotypes • TT pp where T = TallP = Purple t = short p = white • Tt pp
AGENDA DEC 11 • BIG Question: What did Gregor Mendel conclude about the inheritance of traits in pea plants? • 1. Question of the Day and DO NOW • 2. Mendel’s Crosses • P, F1, and F2 Generations • 3. Solving Monohybrid Crosses • Identifying Genotypes and Phenotypes 4. Review of Mendel’s Results and Homework QUIZ on Thursday Sections 11-1 and 11-2
genes: unit that determines traits alleles: different forms of a gene have two alleles for each trait one from each parent sex cells contain one allele when sex cells combine, create cells with two sets of genes Genes and Alleles
11-2: Probability and Punnett Squares • probability applies to genetics because the formation of gametes depends on random events
Probability and Punnett Squares • probability: the likelihood that a particular event will occur • probability = the number of times a particular event occurs ÷ the number of opportunities for the event to occur • Punnett squares analyze the results of an experimental cross • determines the probability of getting certain genotypes and phenotypes
Predicting Averages • Consider our class and the test we have recently taken. • If the test average was a 70, explain how this average is possible having only 2 test scores. • With 3 Test Scores? • These results will depend on the individual students and courses.
Predicting Averages • Probabilities predict the average outcome of a large number of events. • Cannot predict the precise outcome of an single event. • Also true for genetics. • Larger numbers of offspring will produce results closer to the expected values/ratios. • In the F1 Gen of Mendel’s pea plants, only 3 or 4 offspring may not the predicted offspring. • However, hundreds or thousands of these offspring will produce ratios very close to expectations of Mendel’s results.
Question of the Day Dec 12 • Which ratio did Mendel find in his F2 Generation of pea plants? • A. 3:1 • B. 1:3:1 • C. 1:9 • D. 4:3
DO NOW DEC 12 • Solve the following problem… • Cross a Heterozygous Long-clawed panther with a short-clawed panther. • List all of the possible genotypes and their phenotypes. • What ratio of panther cubs with short claws?
DO NOW ANSWERED Dec 12 • L = LONG CLAW DOMINANT • l = short claw
AGENDA DEC 12 • BIG Question: How do geneticts use the principle of probability? • 1. Question of the Day and DO NOW • 2. Section 11-1/11-2 QUIZ TOMORROW • 3. Principles of Segregation and Independent Assortment • 4. Inheriting Traits Lab Investigation • 5. Review and Homework
Segregation • the separation of alleles during gamete formation • when gametes, or sex cells, come together, new combinations occur • gene combinations can be represented in a chart using Punnett squares • monohybrid cross: crossing one trait
Segregation • F1 plants each have one dominant and one recessive allele. • When the F1 plants are crossed with each other, the recessive allele reappears in the offspring (F2 Gen)
AGENDA DEC 13 • BIG QUESTION: What is a dihybrid cross? • 1. CHAPTER 11-1 and 11-2 QUIZ • 2. Dihybrid Crosses • 3. Inheriting Traits LAB • 4. Homework and Review • Finish Lab Packet and Drawing • Dihybrid Crosses Practice Problems
Independent Assortment • process by which genes segregate independently • ifa plant has a round seed, it does not mean it will always have a yellow seed • can cross two traits, called a dihybrid cross, and have independent assortment • get all sort of genotypes
A Summary of Mendel’s Work • genes control heredity • genes are inherited from each parent • some forms of the gene may be dominant and others may be recessive • segregation occurs during the formation of reproductive cells • genes for different traits may sort independently of one another
Dihybrid Crosses • Solving for two different traits. • Parents --- RrYy and RrYy • R = Wrinkled seed Y = Yellow seed • Capital Letters = DOMINANT TRAITS • Use the FOIL method to determine all of the possible genotypes of the parents. • F=first O=outer I=inner L=last
Dihybrid Crosses • Parent Genotypes – RrYy • Use FOIL Method to find possible allele combinations. • F – RY O – Ry I – rY L – ry • Allele Combinations – RY RyrYry
Question of the Day DEC 16 • All hybrids have which of the following genotypes? • A. Homozygous dominant • B. Heterozygous • C. Homozygous recessive • D. Both A and C
DO NOW DEC 16 • Cross a homozygous Tall, heterozygous yellow seeded pea plant with a short, green seeded pea plant. • What percentage of the offspring will be tall and green seeded?
AGENDA DEC 16 • BIG Question: How do alleles separate independently from one another? • 1. Question of the Day and DO NOW • 2. Sections 11-1 and 11-2 Quiz Tomorrow • 3. Dihybrid Crosses Practice • 4. Homework and Review
many genes have more than one allele or have alleles that are neither dominant nor recessive incomplete dominance: neither allele is completely dominant or recessive The phenotype for a heterozygous offspring is somewhere in the middle. 11-3: A Closer Look At Heredity
Incomplete Dominance • Cross a Red Flowered plant with a White Flowered plant. • What are the genotypes and phenotypes of the offspring? • Will offspring have White Flowers?
Codominance • codominance: both alleles are expressed and contribute to the phenotype • Example: Roan horse • CWCW White Coat • CRCR Red Coat • CRCW Roan Coat • Cross a Roan Horse with a Red coated Horse.
a trait that has more than two alleles eye color blood type traits that are controlled by more than one gene facial appearance Multiple Alleles Polygenic Traits
Multiple Alleles Polygenic Traits • Blood types in humans. • A • B • AB • O • ALLELES: A, B, O • Coat color in rabbits • Four different alleles • Skin color in humans • Eye color is various organisms • Fruit flies