Question

T.H. Morgan also performed the following set of breeding experiments involving another mutant strain with yellow body colors, Xy, which is linked to X chromosome. The allele for the normal brown body color is indicated with Xy+. The interpretation of the breeding outcomes ended up discovering genetic linkage.

​P: female with normal eye and body color (w+,y+/w+,y+)

​​​x

​ male with white eye and yellow body (w,y/Y)

14. In this cross, F1 flies had the following phenotypes and genotypes. Which is INCORRECT?

A. all the F1 females were normal eye and body colors.

B. all the F1 females were white eyes and yellow body colors

C. all the F1 males were normal eye and body colors.

D. all the F1 females showed w,y/w+,y+ genotype.

E. all the F1 males showed w+,y+/Y genotype.

15. T.H. Morgan crossed F1 males and females to derive the F2 progenies. Then, he counted the number of male flies based on their phenotypic category. He saw two dominant categories, making up almost 99% of the progenies. Which were these two categories?

A. w ,y /Y and w+,y /Y

B. w+,y+/Y and w ,y /Y

C. w+,y /Y and w ,y+/Y

D. w ,y+/Y and w+,y+/Y

E. w ,y+/Y and w ,y /Y

16. He also saw two minor categories, making up 1% of the progenies. Which were these two categories?

A. w ,y /Y and w+,y /Y

B. w+,y+/Y and w ,y /Y

C. w+,y /Y and w ,y+/Y

D. w ,y+/Y and w+,y+/Y

E. w ,y+/Y and w ,y /Y

17. These two minor categories are the products of __________ during the meiosis of F1 ______ flies.

A. segregation, male

B. segregation, female

C. crossing-over, male

D. crossing-over, female

E. independent assortment, female

18. Why didn't he count the number of F2 female flies?

A. all the F2 female flies were normal eye color and body color.

B. all the F2 female flies showed the exact same patterns as the male flies.

C. all the F2 females showed unexplainable outcomes.

D. all of the above.

E. none of the above

Answer 1

Answer-

14) Incorrect option is B) All the females were white eyes and yellow body colors.

Explanation for all answers is provided below:

Normal brown body color - yt mutant yellow body color - y normal eye - wt mutant eye - w gametes | - gamota female, with normal eye, body Male with normal eye, body color. 14) In FL, white Incorrect option is (B) All the females were eyes and yellow body colors. 15) Parental gametes, ie no cross est male Male are are making up almost gos 99% Dominant catagories here are making up. because no crossing over is taking place. the genotypes of male offspring will be (B) Wt, yt/Y and w.gly

It crossing over takes place, then minor categories (making up 1% of the progenies) will form. 3 crossing wer © & Ó Ö — - zameters gametes w + male with normal eye, yellow body color : minor male male with white eye ye normal brown. body color. categories - (c) wt, y/y; w, yt/Y N (17) these two minor categories are the products of crossing over during the meiosis of fi female flies. crossing over will be seen in females ar they have ax clocomosomes males are hemizygous. so, crossing over will not be seen here. 18) In fa generation All females will get one of their x chromosome from male parent, which is (with dominant. So all the females in F2 will be have normal eye and normal body color; no matter what kind of gameter (parental or recombinant) will come from mother. . Morgan did not count the number of f2. female flies because (A) Al the fa females were normal eye color and body color.