Two biology Questions: 1) In tomatoes, red fruit color is dominant to yellow. Su
ID: 85193 • Letter: T
Question
Two biology Questions:
1) In tomatoes, red fruit color is dominant to yellow. Suppose a tomato plant homozygous for red is crossed with one homozygous for yellow. Determine the phenotype and genotype of
a) the F1 offspring
b) the offspring of a cross of the F1 back to the red parent
c) the offspring of the F1 back to the yellow parent
2) Lesch-Nyhan syndrome is a metabolic defect caused by the lack of the enzyme hypoxanthine-guanine phosphoribosyl transferase (HGPRT). This disease is the result of an X-linked, recessive mutation and results in mental retardation, selfmutilation and early death. A normal man marries a woman who had a brother who died of LNS. Your are the genetic counselor who will advise them on the likelihood of their having a LNS baby.
a) What are the possible genotypes for the woman? What is the man’s genotype?
b) For each of the woman’s possible genotypes, what are the possible genotypes of her offspring and the implications for survival for each of them?
Explanation / Answer
ANSWER) 1.
answer) 2 a) The possible genotype of woman will be X*X( carrier of disease) and XX because her mother was a carrier of this disease due to which here brother dies.and the man genotype will be XY.
b) if the genotype of women is XX than all the child will be normal and if the genotype will be X*X than there are chances that his boy child will have this disease or it is affected