Question

Quiz 8: Genetics and Heredity Add relevant, accurate information for extra credit. Follow directions. Return on 4/s I) A woman has a cop y of the gene for an autosomal dominant disorder. This means: a. b. c. d. She will be a carrier of the disorder but won't have it She will have the disorder She will not have the disorder Her partner will have the disorder 2) Create a Punnett Square out of the following information about Tay-Sachs Dis e. A woman is a carrier of Tay-Sachs Her husband has Tay-Sachs Use a big"A" to represent the dominant gene (the normal, healthy allele) and a little "a" to r (the Tay-Sachs allele). Fill in their genotypes and the probable outcomes for offispring in appropriate spaces Mother ↓ Father 3) What are the chances that their children will have Tay-Sachs? a, b, c. d. 04 or 0% 1.4 or 25% 2.4 or 50% 3:4 or 75% 4) What are the chances that their children will be carriers of Tay-Sachs? a. 1:4 or 25% b, 2.4 or 50% c, 3:4 or 75% d. 44 or 100% 5) What is the best definition of pleiotrophy? a. One gene affects one trait. b. Two genes affect one trait. c. One gene affects many traits d. One gene affects pleiotrophs.

Answer 1

Answer:

1). B. She will have the disorder.

Explanation: In autosomal dominant disorder, there would be no carrier. Because, even one dominant allele is enough to express the trait.

2).

Woman (Aa) x man (aa)---Parents

	a	a
A	Aa (normal)	Aa (normal)
a	aa (Tay-Sachs)	aa (Tay-Sachs)

50% = Normal

50% = Tay-Sachs

3). B: 2:4 or 50%

4). B. 2:4 or 50%

5). One gene affects many traits

Explanation:

Pleiotropy occurs when one gene influences two or more seemingly unrelated phenotypic traits.

6).

a). Genotype (G)

b). Phenotype (P)

7). A). 0%

Explanation: Onle copy is not sufficient to express X-linked recessive disorder. She needs two copies. Hence, there is no chance of developing disease in her.

8). A). 0%

Explanation: Girls get one copy from mother and another copy of alleles from father. Then only she could able to develop disease. If the father doesn’t have the copy of alleles, it is not possible to develop the disease in the girl child.

9). A). 0%

Explanation:

Boy child will get X-chromosome from the mother only as he consists only one X-chromosome. There is no relation of the father to boy child. So this information is not explained about the disease condition in the boy child.