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For the purpose of this problem assume that in humans the gene for curly hair is

ID: 18848 • Letter: F

Question

For the purpose of this problem assume that in humans the gene for curly hair is controlled by a single gene and that the allele for curly hair (C) is dominant to that for straight hair (c).

If the first child born to parents who are both heterozygous for type of hair is a boy with straight hair, what is the probability that the second child will be a curly-haired son? (PLEASE NOTE: the chance that an offspring will have a particular gender, male or female, is always ½). (please show all math/work)

Parental genotypes: ___________ x ___________
Punnett square:

Explanation / Answer

For the purpose of this problem assume that in humans the gene for curly hair is controlled by a single gene and that the allele for curly hair (C) is dominant to that for straight hair (c).

If the first child born to parents who are both heterozygous for type of hair is a boy with straight hair, what is the probability that the second child will be a curly-haired son? (PLEASE NOTE: the chance that an offspring will have a particular gender, male or female, is always ½). (please show all math/work)

Parental genotypes:    heterozygou   Cc             x    heterozygous    cC
Punnett square:

C

c

C

CC

curly hair-homozygous

Cc

curly hair-heterozygous

c

Cc

curly hair-heterozygous

Cc

straight hair-homozygous

Every isuse is new and independ event

Occurence of one event doesnot have affect on other

Probability 0f second child will be a curly-haired son= ¾= 0.75

C

c

C

CC

curly hair-homozygous

Cc

curly hair-heterozygous

c

Cc

curly hair-heterozygous

Cc

straight hair-homozygous