Question: 2. Imagine that you cross two strains of beef cattle. The red cattle had an average body weight o…

2. Imagine that you cross two strains of beef cattle. The red
cattle had an average body weight of 800 + 60 (mean + variance)
pounds, while the brown cattle had an average body weight of 620 +
60 pounds. Imagine both these strains of cattle are homozygous for
all the gene alleles that influence body weight in cattle, and all
the genes that influence body weight in cattle exert equal and
additive effects on body weight. 2A. What do you expect the mean
and variance of body weight to be in the F1 offspring? 2B. If you
cross the F1 offspring with each other, what do you expect the mean
and variance of body weight to be in the F2 offspring? (Give me the
variance in general terms—you can’t give me a specific number from
what I have given you.) 2C. If you backcross a number of the F1
offspring to a number of the red parents, what do you expect the
mean and variance of body weight to be in the F2 offspring? (For
the variance, just compare their variance to that of the red
parents, the F1 generation, and the F2 generation.) 2D. Imagine you
cross several of the F1 offspring with each other, and get a mean +
variance = 700 + 120 for body weight in the F2 offspring. How many
genes influence body weight in your cattle? Round your calculated
number to the nearest whole number.

3. A farmer is growing corn. His present crop produces an
average of 4.7 ears per plant. If he selects a pair of plants that
between them produced an average of 8.4 ears per plant, and the
narrow-sense heritability of ears per plant is 0.78, what can he
expect for an average number of ears per plant in the next
generation?