Test 2, Deck 5 Flashcards
In humans, red-green eye color blindness is caused by sex-linkage recessive allele. A normal man marries a normal woman whose father was color-blind. Whats is the probability that they will have a color-blind son? list the genotypes and phenotypes of all children
1/4 blind son
1/4 normal male
1/2 normal woman
In humans, red-green eye color blindness is caused by sex-linkage recessive allele. If a normal man mates with a color-blind women what is the chance that they will have a color blind son?
100%
In humans, red-green eye color blindness is caused by sex-linkage recessive allele. If a normal male mates with a color-blind woman, what is the chance that they will have a color-blind daughter ?
zero chances
The black and yellow pigment on cat coats are determined by X-linked pair of alleles. Males are black (Cb) or yellow (Cy). Females are black, calico or yellow. A female produces 2 calico females, 2 black females, 1 black male, 1 yellow male, what is the genotypes of the parents ?
Parents: Male (black) X(Cb)Y
Female (calico X(cb)X(Cy)
The black and yellow pigment on cat coats are determined by X-linked pair of alleles. Males are black (Cb) or yellow (Cy). Females are black, calico or yellow. if a black female and a yellow male are crossed, what is the probability of getting a calico female ?
1/2
In Drosophila, white eyes is sex-linked factor recessive to red eyes. Vestigial (small) wings are recessive to normal wings, but these are autosomal chr. Two flies produce 300 red, normal males; 300 white, normal males; 100 red vestigial males and 100 white vestigial males. Similar phenotypes for females, how many females would you expect to be white, vestigial? What are the genotypes of parents?
100 white vestigial females
Parents: VvX(R)X(r) VvX(r)Y
In guinea pigs, color pattern and ear shape is controlled by two X-linked pairs of alleles. Colors: black, gray (heterozygote) and white. Ear shape: pointed, semi (heterozygote) and round. Two guinea pigs cross and produce: white pointed males, gray round females, white semi female. What are the genotypes and phenotypes of the parents? What is the inheritance?
Sex-linked and incomplete dominance
Parents: X( b,a)Y X(B,A)X(b,a)
A man has the X-linked trait for male baldness, but spouse does not. What proportion of sons are expected to inherit this trait?
Zero
If a female carries an X-linked recessive lethal gene causing the abortion of the embryo at an early stage when it is expressed, what proportion in offspring would be male?
1/3
If a female carries an X-linked recessive lethal gene causing the abortion of the embryo at an early stage when it is expressed, what proportion of the female offspring would be homozygous recessive?
Zero
If a female carries an X-linked recessive lethal gene causing the abortion of the embryo at an early stage when it is expressed, what proportion of the female offspring would be carriers ?
1/2
When true-breeding brown dogs are mated with true-breeding white dogs, all F1 are white. When F1xF1, the F2 are 12/16 white, 3/16 black and 1/16 brown. Which could be the genotype of the black puppies?
A-bb (A for creating a pigment, bb )
Brachydactyly (short fingers) is rare autosomal dominant phenotype. The ability to taste the chemical phenylthiocarbamide (PTC) is also autosomal dominant. A man is brac. and his wife is not. both can taste PTC, but their mothers cannot. Which options could be the genotype of the man?
BbTt
Crosses of long fur and short fur rabbits produce medium fur rabbit. This is consistent of which inheritance pattern?
Incomplete dominance
Two cream-colored guinea pigs are crossed and produce yellow cream or white. This is consistent with which of the following inheritance patterns?
Incomplete dominance
