Please I need help with question 1 and 2. Thanks 1. Consider three yellow, round

Question

Please I need help with question 1 and 2. Thanks

1. Consider three yellow, round peas, labeled A, B, and C. Each was grown into a plant and crossed to a plant grown from a green, wrinkled pea. Exactly 100 peas derived from each cross were sorted into phenotypic classes as follows: A: 51 yellow, round 49 green, round B: 100 yellow, round C: 24 yellow, round 26 yellow, wrinkled 25 green, round 25 green, wrinkled What are the genotypes of plants A, B, and C? (Use gene symbols of your own choosing, be sure to define each one.) 2. Identical twins are produced from the same sperm and egg (which splits after the first mitotic division), whereas fraternal twins are produced from separate sperm and separate egg cells. If two parents with brown eyes (a dominant trait) produce one twin boy with blue eyes, what are the following probabilities? A. If the other twin is identical, he will have blue eyes. B. If the other twin is fraternal, he or she will have blue eyes. C. If the other twin is fraternal, he or she will transmit the blue eye allele to his or her offspring D. The parents are both heterozygotes

Explanation / Answer

Here we are crossing Yellow, round with green, wrinkled. The progeny obtained will be all yellow, round. This shows that the yellow and round are dominant phenotype.

Here one plant is green and wrinkled, so it is fully recessive, this comes under the test cross when fully recessive plant is crossed with heterozygous dominant giving rise to 1;1 ratio.

(a) Yy RR x yy rr

Progeny

50% Yy Rr(Yellow, round)

50% yy Rr(green, wrinkled)

We obtained 1:1 ratio. The same ration like 49 round:51 wrinkled was shown in option 1.

(B) Here 100 yellow, round

YYRR (Yellow round) x yyrr (green wrinkled)

YYRR x yyrr

Progeny will be all YyRr

(C)Here in this option, we obtained 24 yellow round; 26 yellow wrinkled; 25 green round; 25 green wrinkled

Yellow   round   x green wrinkled

YyRr       X       yyrr

Progeny will be 25% YrRr, 25% Yyrr, 25% yyRr and 25% yyrr. (Independent assortment of genes)

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