Question

ou are given two true-breeding groups of rabbits. The first group has floppy ears and white fur. The second group has straight ears and black fur. When you perform a cross of these two groups to obtain a F1 generation you see that all of your rabbits have floppy ears and gray fur. If you knew that each of these traits was determined by a single gene and underwent independent assortment, then you expect to see that 75% of your F2 generation rabbits have _____ ears and _____ of your rabbits have black fur.

Answer 1

you expect to see that 75% of your F2 generation rabbits have floppy ears and 25% of your rabbits have black fur.

Step-by-step explanation:

Available data:

• Two true-breeding groups of rabbits.

• The first group has floppy ears and white fur.

• The second group has straight ears and black fur.

• 100% of the F1 generation has floppy ears and gray fur.

• Each of these traits is determined by a single gene and undergo independent assortment.

Having this information we can infer that floppy years, expressed by F allele, might be dominant over straight ears, expressed by f allele. And that the fur color is affected by incomplete dominance, being B the allele expressing black color, b the allele expressing white color and Bb the genotype for grey color.

Incomplete dominance is a condition where neither of the alleles completely dominates over the other one. Descendents possess an intermediate phenotype between the two parental phenotypes and not the dominant one.

Cross between groups

Parental) FFbb x ffBB

F1) FfBb

Cross for the ear traits:

Parental) Ff x Ff

Gametes) F f F f

Punnet square) F f

F FF Ff

f Ff ff

F2) 75% of the progeny have floppy ears, FF and Ff

25% of the progeny have straight ears, ff

Cross for the fur color traits:

Parental) Bb x Bb

Gametes) B b B b

Punnet Square) B b

B BB Bb

b Bb bb

F2) 25% of the progeny have black fur, BB

50% of the progeny have grey fur, Bb

25% of the progeny have white fur, bb