In maize, a dominant allele (A) is responsible for seed color, while a recessive
ID: 168287 • Letter: I
Question
In maize, a dominant allele (A) is responsible for seed color, while a recessive allele (a) is responsible for colorless seeds. Another gene has a recessive allele (w) that results in waxy starch, while the dominant allele (W) results in normal starch. The two genes segregate independently. An AaWw plant is self crossed. What are the phenotypes and relative frequencies of the offspring? In cattle, the hornless condition (H) is dominant over the horned (h) phenotype. A particular hornless bull is bred to three cows. Cow A, which is horned, produces a horned calf; hornless cow B produces a horned calf; and horned cow C produces a hornless calf. What are the genotypes of the bull and the 3 cows, and what phenotypic ratios do you expect in the offspring of each of the 3 matings? In jimsonweed, purple flower (P) is dominant to white (p) and spiny pods (S) are dominant to smooth (s). A true-breeding plant with white flowers and spiny pods is crossed to a true-breeding plant with purple flowers and smooth pods. Determine the phenotype of a. the F_1 generation: b the F_2 generation (produced by interbreeding the F_1): c. the progeny produced by a cross of an F_1 individual with the white, spiny parent (assume the parent is true-breeding): d. the progeny produced by a cross of an F_1 individual with the purple, smooth parent(assume the parent is true-breeding): If a man and a woman are heterozygous for a gene, and if they have 3 children, what is the chance that all three will also be heterozygous? Cystic fibrosis is inherited as an autosomal recessive disorder. Two parents without cystic fibrosis have 2 children with cystic fibrosis and three children without. The parents come to you for genetic counseling. a. What is the probability that their next child will have cystic fibrosis? b. If the parents have 2 more children, what is the probability that both children will have the same phenotype (i.e. both have cf or both don't have cf)?Explanation / Answer
In maize a dominat allele (A) is responsible for seed color
dominant allele ------A -------------seed color
recessive allele--------- colorless ----------a
dominant allele ------W -------------normal starch
recessive allele-----w---- waxy starch
Aa Ww x Aa Ww
A W
A w
a W
a w
A W
A W A W seed color normal starch
A w A W seed color normal starch
a W A W seed color
normal starch
a w A W seed color
normal starch
A w
A W A w seed color
normal starch
A w A w seed color
waxy starch
a W A w seed color normal starch
a w A w seed color
waxy starch
a W
A W a W seed color normal starch
A w a W normal starch seed color
a W a W normal starch seed color
a w a W normal starch seed color
a w
A W a w seed color normal starch
A w a w waxy starch seed color
a W a w normal starch seed color
a w a w colorless ,waxy starch
phenotype
frequency
seed color ,normal starch
9/16
seed color ,waxy starch
3/16
colorless ,normal starch
3/16
colorless ,waxy starch
1/16
Phenotypic ratio= 9:3:3:1
A W
A w
a W
a w
A W
A W A W seed color normal starch
A w A W seed color normal starch
a W A W seed color
normal starch
a w A W seed color
normal starch
A w
A W A w seed color
normal starch
A w A w seed color
waxy starch
a W A w seed color normal starch
a w A w seed color
waxy starch
a W
A W a W seed color normal starch
A w a W normal starch seed color
a W a W normal starch seed color
a w a W normal starch seed color
a w
A W a w seed color normal starch
A w a w waxy starch seed color
a W a w normal starch seed color
a w a w colorless ,waxy starch
Related Questions
drjack9650@gmail.com
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.