In a cross between a pea plant that has smooth yellow seeds (SsYy) with a second plant of the same genotype, what proportion of the seeds will grow up to produce smooth green seeds? a) 0/16 b) 3/16 c) 9/16 d) 16/16



Answer :

The answer is 3/16 One dominant gene. And one recessive gene

Answer:

The correct answer would be b) 3/16

As heterozygous condition SsYy results in the expression of smooth and yellow seeds so, we can conclude that S and Y are the dominant over s and y and code for smooth shape and yellow color of the seed respectively in a plant.

s code for wrinkled seed when present in homozygous condition. Similarly, y codes for green seeds when present in homozygous condition.

Cross is made between SsYy and SsYy.

Gametes formed would be SY, Sy, sY, and sy.

The same is shown in the figure attached below.

It resulted in the formation of 16 possible combinations of offspring out which:

9 are smooth and yellow seeds (1 SSYY + 2 SSYy +2 SsYY, 4 SsYy)

3 are smooth and green seeds (1 SSyy + 2 Ssyy),

3 are wrinkled and yellow seed (1ssYY + 2 ssYy),  

1 is wrinkled and green seeds (ssyy).

Hence, only 3 out of 16 would produce smooth and green seeds.

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