1. TEST ON TUESDAY, FEBRUARY 12 GENETICS REVIEW ANSWERS

2. QUESTION #1 Who is the “father” of genetics? Gregor Mendel

3. QUESTION #2 What are Mendel’s 3 principles? What do they each say? 1.Principle of Dominance – some alleles are dominant, others are recessive 2.Principle of Segregation – during Meiosis, the alleles separate so that each gamete gets one 3.Principle of Independent Assortment – during Meiosis, the alleles separate independently from each other

4. QUESTION #3 Match the following. Homozygous dominant – two of the same alleles (dominant) for a trait Homozygous recessive – two of the same alleles (recessive) for a trait Heterozygous – Two different alleles for a trait

5. QUESTION #4 How many alleles are used to determine blood type? 3 alleles (I A, I B, and i) How many blood types are there? 4 blood types (A, B, AB, and O)

6. QUESTION #5 Match the following. Incomplete dominance – red flower x white flower = pink flower Codominance – black chicken x white chicken = black & white chicken Multiple alleles – blood type Polygenic traits – height, skin color

7. QUESTION #6 In a pedigree, what does it mean if the circle or square is shaded? The person has the trait

8. QUESTION #7 Define each of the following: P generation – the parents of a genetic cross F 1 generation – the offspring of the P generation F 2 generation – the offspring of the F 1 generation

9. QUESTION #8 Why is colorblindness more common in males than in females? Because it is carried on the X chromosome and males only have one X

10. QUESTION #9 What does dominant mean? The trait that is expressed What does recessive mean? The trait that is hidden Which one is symbolized with a capital letter? dominant

11. QUESTION #10 What disease is caused by a dominant allele? Achondroplasia Huntington’s disease

12. QUESTION #11 When you flip 1 coin, what is the chance of getting heads? ½ If you flip 2 coins, what is the chance of getting tails/tails? ¼

13. QUESTION #12 Which chromosome are most sex- linked genes found on? X

14. QUESTION #13 What are the sex chromosomes of a female? XX What are the sex chromosomes of a male? XY

15. QUESTION #14 Match the following. Phenotype – round seed Genotype – Rr Allele – R

16. QUESTION #15 What are the possible genotypes for the following blood types? A = I A I A or I A i B = I B I B or I B i AB = I A I B O = ii

17. QUESTION #16 How many chromosomes does a normal human cell have? 46

18. QUESTION #17 What are autosomes? All of the other chromosomes (not the sex chromosomes)

19. QUESTION #18 What is heredity? The passing of traits from parents to offspring

20. QUESTION #19 In a pedigree what does a circle represent? female What does a square represent? male

21. QUESTION #20 Answer the following questions about this family… What color are the father’s eyes? Brown. What is his genotype? Bb What color are the mother’s eyes? Blue. What is her genotype? bb They have a daughter who has brown eyes. What is her genotype? Bb They have a son who has blue eyes. What is his genotype? bb

22. QUESTION #21 A blue-eyed man mates with a woman who is heterozygous for brown eyes. Complete a Punnett square to show their possible offspring. BbBb b Bb bb

23. QUESTION #21 CONT. What are the genotypes of the parents? Mom – Bb and Dad – bb. What are the genotypes and phenotypes of the offspring? Genotypes – Bb 50%, bb 50% Phenotypes – brown eyes 50%, blue eyes 50%

24. QUESTION #22 When a white, flat squash (WWFF) is crossed with a yellow, round squash (wwff), all the osspring are white and flat (WwFf). Suppose two of these offspring are crossed (WwFf x WwFf). Make a Punnett square of the cross of the two offspring. Give the phenotypes and genotypes of the offspring.

25. QUESTION #22 CONT. WWFFWWFfWwFFWwFf WWFfWWffWwFfWwff WwFFWwFfwwFFwwFf WwFfWwffwwFfwwff WFWf wF wf WF Wf wF wf

26. QUESTION #22 CONT. Genotypes: WWFF 1/16, WWFf 2/16, WwFF 2/16, WwFf 4/16, WWff 1/16, Wwff 2/16, wwFF 1/16, wwFf 2/16, wwff 1/16 Phenotypes: White, flat 9/16, white, round 3/16, yellow, flat 3/16, yellow, round 1/16