Presentation on theme: "Probability and Genetics pg"— Presentation transcript:
1Probability and Genetics pg. 656-666 Objectives:Describe the principles of probability and how Mendel applied them to inheritanceState how geneticists use Punnett squares
2Vocabulary probability Punnett square phenotype genotype homozygous heterozygouscodominance
3How are punnet squares useful to geneticists? QuestionsHow are punnet squares useful to geneticists?What is the difference between a genotype and a phenotype?A white cow is crossed with a red bull. The calf is neither white nor red, but roan. Explain how this happens!
4What was the chance of Pettygrove winnng the coin toss? Probability-the liklihood that a particular event will occur.
6Math terms Probability that coin will land heads up is 1 in 2 Probability that coin will land tails up is in 21/2 or 50 %
7Laws of probability is what is ‘likely’ to occur. Toss a coin 20 timesLikely or Expect: heads up / 10 tails upWill occur: heads / 9 tails or8 heads / 12 tailsLaws of probability is what is ‘likely’ to occur.
8? Is it more likely to land tails ? When you toss a coin more than once the results of one toss do not affect the results of the next toss.?Is it morelikely toland tails ?
9-Still have a 1 in 2 or 50% chance of landing heads.
10Is ‘Probability’ related to ‘Genetics’ ? Yes!It can help predict the results of ‘Genetic Crosses’Remember Mendel ? (the guy in a dress)T x T = T T T Tt x t = t t t tT x t = T T T t /4 will be short , /4 will be Tall
11Possible combination of alleles that parents can pass on Cool Tool Punnett Square-shows all the possible combinations of alleles that can result from a genetic cross.Possible combination of alleles that parents can pass onPossible combinations of alleles that offspring can inheritAll by chance4 possible combinationsTtTT T25%T t25%tT t25%t t25%
14Other Genetic Terms to use Phenotype-physical appearance, visible traits ex: traits you can seeGenotype-genetic make-up ex: traits you can’t seeHomozygous-identical alleles ex: T T or t t, Not purebredHeterozygous-two different alleles ex: Tt or hybridPhenotypeGenotypeTallT TT tShortt t
15EXCEPTION Remember Mendel only found Dominant and recessive genes Codominance-alleles are neither dominant or recessiveno masking takes placeSooooo……..Red Reindeer + white Reindeer =
17Probability Quiz1. An organisms’ genetic makeup , or allele combinations.2. An organism’s physical appearance, or visible traits.3. The likelihood that a particular event will occur.4. Having two identical alleles for a trait.5. A chart that shows all the possible combinations of alleles that can result from a genetic cross.6. Having two different alleles for a trait.7. A condition in which neither of two alleles of a gene is dominant or recessive.
188. How are punnet squares useful to geneticists? Questions:8. How are punnet squares useful to geneticists?9. What is the difference between a genotype and a phenotype?10. A white cow is crossed with a red bull. The calf is neither white nor red, but roan. Explain how this happens?
19Answers to Probability Quiz 1. genotype2. phenotype3. probability4. homozygous5. punnett square6. heterozygous7. codominance
20Answers:8. Shows possible genetic outcomes of offspring and the probability of each outcome.9. Phenotype is the physical appearance, Genotype is the genetic makeup.10. Co dominance.____/10