Question

suppose d were dominant and d were recessive, and you could label the d allele in the p generation with a fluorescent substance that could be inherited over several generations. you create hybrids by mating your fluorescent dd individuals to dd individuals. next, you cross two f₁ individuals (with the dd genotype). among the 1,000 f₂ offspring, how many do you predict would fluoresce? 250 500 750 1,000

Explanation:

Step1: Determine the cross

Crossing two \(Dd\) individuals (\(Dd\times Dd\)).

Step2: Use Punnett square

The Punnett square for \(Dd\times Dd\) gives genotypes \(DD:Dd:dd = 1:2:1\).

Step3: Calculate the proportion of \(D\) - containing genotypes

Genotypes \(DD\) and \(Dd\) contain the \(D\) allele. The proportion of \(DD + Dd=\frac{1 + 2}{4}=\frac{3}{4}\).

Step4: Calculate the number of fluorescent individuals

If there are \(n = 1000\) \(F_2\) offspring, the number of fluorescent individuals is \(N=1000\times\frac{3}{4}=750\).

Answer:

750