Question

In a monohybrid cross, if the gene for tall (T) plants was incompletely dominant over the gene for short (t) plants, what would be the predicted result of crossing two intermediate (Tt) parent plants? (Hint: You may want to complete a Punnett square.)

1) 25 percent tall, 50 percent intermediate, 25 percent short
2)50 percent tall, 25 percent intermediate, 25 percent short
3)100 percent intermediate
4)25 percent tall, 75 percent intermediate

Answer 1

The answer is 1). Two Tt parent can produce T and t for 50% separately. So for the result, TT has the probability of 50%*50%=25%. The same for tt. And Tt is 1-0.25-0.25=50%.

Answer 2

Option 1

Step-by-step explanation:

It is given that gene for tall (T) is dominant over gene for short i.e t

Thus , if T and t are present together in an allele pair then the individual would be an intermediate species.

Genotype of both the parents - Tt

Tt * Tt

TT, Tt, tt, Tt

Thus out of four offspring one is tall. Thus probability of tall species is 25%

out of four offspring one is short. Thus probability of short species is 25%

out of four offspring two are intermediate. Thus probability of intermediate species is 50%

Hence, option 1 is correct