Genetics

A man with blood type A, whose mother had blood type O, marries a woman of blood type AB. The chance of this couple having a child with blood type O is

0%

Albinism (lack of skin and hair pigmentation) is caused by a recessive autosomal allele. A woman and man, both normally pigmented, have an albino child together. The couple has a second child. What is the probability this child will be a son with albinism

1/2

In the cross, AaBbCc x AaBbCc, what is the probability of producing the genotype AABBCC

1/64

A recessive allele on the x-chromosome is responsible for red-green colorblindness in humans. A woman with normal color vision whose father is colorblind marries a colorblind male. What is the probability that a son this couple already has will be color blind?

50%

Black fur in mice (B) is dominant to brown fur (b). Short tails (T) are dominant to long tails (t). What fraction of the progeny of crosses BbTt × BBtt will be expected to have black fur and long tails?

50%

Theoretically, if a carrier hemophiliac married a normal male, what percentage of their male offspring would be expected to be carriers?

50%

A couple who are both carriers of the gene for cystic fibrosis have two children who have cystic fibrosis. What is the probability that their next child will be phenotypically normal?

75%

What is the probable phenotype of Sam?

Aa

A man who carries an allele of an X-linked gene will pass it on to _____.

All of his daughters

According to the pedigree, shading is caused by

An autosomal recessive allele

A man with red-green colorblindness marries a woman who is neither colorblind nor a carrier for this trait. Which statement would best describe their future offspring?

None of their children would be color blind, but all of their daughters will be carriers

In cattle, roan coat color (mixed red and white hairs) occurs in the heterozygous (Rr) offspring of red (RR) and white (rr) homozygotes. Which of the following crosses would produce offspring in the ratio of 1 red:2 roan:1 white?

Red x White

in pea plants, tall (T) is dominant to short (t) and purple (P) flowers are dominant to white (p) flowers. In a cross of the two plants, the following phenotypic ratios were observed: 252 tall purple, 247 tall white, 251 short purple, and 250 short white. What most likely were the genotypes of the parent plants for this cross?

Ttpp x ttPp

What is the probability that the next child of Alan and Tina will have the genetic disorder?

Unable to determine based on the information given

Using the information in #7 above, what is the genotype of the albino child they have?

XaY