In chickens, the allele for a pea comb (A) is dominant to the allele for a single comb (a).
A mother with the genotype Aa and a father with the genotype Aa produce an offspring.

What is the percent chance that the offspring will have a single comb?

A. 0%
B. 25%
C. 50%
D. 75%
E. 100%

The correct answer is option B. "25%".

Explanation:

According to Mendel's laws of Inheritance, the genotype of the offspring  from a cross between chickens where the mother has the genotype Aa and the father has the genotype Aa will be 25% AA, 50% Aa and 25% aa. Since the allele for a single comb is recessive, only chickens with a aa genotype will develop a single comb. Therefore, the percent chance that the offspring will have a single comb is equal to 25%.

all answers true and false

explanation:

the level of progesterone is low at the pre-ovulatory phase of the cycle but it gradually increases and the levels are high at the luteal phase. if pregnancy occurs, the level of progesterone will be high throughout the pregnancy.

if egg is fertilized and the mother gets pregnant, progesterone starts preparing the uterus for the implantation. it starts building up the lining of uterus and make it hostile of the period of pregnancy.