A Little Genetics Review

Transcription

1 A Little Genetics Review

2 1. A pink elephant is mated with a blue one and all the offspring are pink with blue spots! This is an example of A. normal inheritance B. codominance C. incomplete domiance D. a sex-linked trait

3 1. A pink elephant is mated with a blue one and all the offspring are pink with blue spots! This is an example of A. normal inheritance B. codominance C. incomplete domiance D. a sex-linked trait

4 2. A dark gray chinchilla is crossed with a light gray chinchilla and there are light gray offspring and dark gray offspring. This is because of A. normal inheritance. B. codominance. C. incomplete dominance. D. sex-linked inheritance.

5 2. A dark gray chinchilla is crossed with a light gray chinchilla and there are light gray offspring and dark grey offspring. This is because of A. normal inheritance. B. codominance. C. incomplete dominance. D. sex-linked inheritance.

6 3. A normal woman and a normal man have five children, 4 boys and one girl. The girl and one of the boys are normal, the other three boys have flippitis (the uncontrolled flipping of channels with the remote). Flippitis is caused by: A. normal inheritance. B. codominance. C. incomplete dominance. D. sex-linked inheritance.

7 3. A normal woman and a normal man have five children, 4 boys and one girl. The girl and one of the boys are normal, the other three boys have flippitis (the uncontrolled flipping of channels with the remote). Flippitis is caused by: A. normal inheritance. B. codominance. C. incomplete dominance. D. sex-linked inheritance.

8 4. Back to the chinchillas If one parent is dark gray and the other is light gray, what percentage of their offspring will be light gray? How many will be dark gray? A. 50% light gray; 50% dark gray B. 25% light gray; 75% dark gray C. 75% light gray; 25% dark gray * How do you know?

9 4. Back to the chinchillas If one parent is dark gray and the other is light gray, what percentage of their offspring will be light gray? How many will be dark gray? A. 50% light gray; 50% dark gray B. 25% light gray; 75% dark gray C. 75% light gray; 25% dark gray * How do you know?

10 Here s why DD, Dd = dark gray dd = light gray Dark gray X Light gray Dd dd D d Geno: 2 Dd : 2 dd d Dd dd d Dd dd Pheno: 2 Dark gray: 2 Light gray

11 5. A normal man and a normal woman are planning to have a family but they are concerned because the man s brother has hemophilia (a disorder whose gene is located on the X chromosome). There is no history of the disease in the woman s family. What are their chances of having any children with the disorder? A. 50% B. 25% C. 100% D. 0% How do you know?

12 5. A normal man and a normal woman are planning to have a family but they are concerned because the man s brother has hemophilia (a disorder whose gene is located on the X chromosome). There is no history of the disease in the woman s family. What are their chances of having any children with the disorder? A. 50% B. 25% C. 100% D. 0% How do you know?

13 Here s why Normal X Normal X N X N X X N Y X N XN Geno: 2 X N X N :2 X N Y X N X N X N X N X N Y X N Y X N Y Pheno: 2 normal : 2 normal

14 6. More elephants If two spotted elephants were mated what types of offspring would you expect and in what ratio? A. 100% spotted B. 25% spotted; 50% blue; 25% pink C. 50% pink; 50% blue D. 50% spotted; 25% pink; 25% blue Be able to explain your answer.

15 6. More elephants If two spotted elephants were mated what types of offspring would you expect and in what ratio? A. 100% spotted B. 25% spotted; 50% blue; 25% pink C. 50% pink; 50% blue D. 50% spotted; 25% pink; 25% blue Be able to explain your answer.

16 Here s why E P E P = pink E P E B = spotted E B E B = blue Spotted X Spotted E P E B E P E B E P E B E P E P E P E P E B Geno: 1 E B E B : 2E B E P : 1E P E P Pheno: 1 Blue: 2 Spotted: 1 Pink E B E P E B E B E B