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Home Q & A Board Biology-Related Homework Help Genetics and Developmental Biology
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MikeMello MikeMello
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9 years ago
1. In the silkworm (Bombyx mori), translucent skin (Zod) is recessive to the wildtype opaque skin (Z+) and is a Z-linked phenotype.

a. What is the difference between a ZZ-ZW and XX-XY sex determination system?

Answer: The ZW system is reversal of XY. Females have 2 dif chromomomes (Z&W) and males have 2 of the same (Z&Z)

 b. Can a female silkworm inherit the Zod allele from her father or mother or both?

Answer:  Father only

 c. Can a male silkworm inherit the Zod allele from his father or mother or both?

Answer: Both


 We perform the following three crosses with silkworms:
 A. A translucent male crossed with a wildtype female.


 a.What are the parental genotypes for this cross?

Answer: Z-Z- vs Z+W

 b. list the expected phenotypic ratios.

Answer: 2:2 ratio


 B. A homozygous wildtype male crossed with a translucent female.

 a.What are the parental genotypes for this cross?

 Answer: Z+Z+ vs Z-W

 b.list the expected phenotypic ratios.

Answer: not sure???

C. A heterozygous wildtype male crossed with a translucent female

a. What are the parental genotypes for this cross?

Answer: not sure???

b. list the expected phenotypic ratios

Answer: not sure???
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wrote...
#1
9 years ago
Similar Question
In the silkworm (Bombyx mori), translucent skin (Zod) is recessive to the wildtype opaque skin (Z+) and is a Z-linked phenotype.

a.   What is the difference between a ZZ-ZW and XX-XY sex determination system?

b.   Can a female silkworm inherit the Zod allele from her father or mother or both?

c.   Can a male silkworm inherit the Zod allele from his father or mother or both?


We perform the following three crosses with silkworms:
A. A translucent male crossed with a wildtype female.

a.What are the parental genotypes for this cross?

b.Draw the Punnett square and list the expected phenotypic ratios.


B. A homozygous wildtype male crossed with a translucent female.

a.What are the parental genotypes for this cross?

b.Draw the Punnett square and list the expected phenotypic ratios.
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rsb
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#2
9 years ago
a. The ZZ-ZW sex-determination system is found in reptiles, birds, and insects. The ZW sex-determination system is reversal of XY system. In which, females have two different chromosomes (Z and W), while males have only two same kind of chromosomes (ZZ).

b. A female inherits Zod allele from her father or mother or both.

c. A male inherits Zod allele from her father or mother or both.

A. a. The parental genotypes for this cross Z-Z- vs Z+W

b. Expected phenotypic ratio is 2:2 (2 translucent, 2 wild type opaque)
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