A cow that is heterzygous for the black coat allele is crossed with a bull that is homozygous for the red coat allele. Which of the following Punnett squares represents this cross?
A. B B
b Bb Bb
b Bb Bb That's one punnett square
B. B b
B BB Bb
b Bb bb That's one punnett square
C. B b
b Bb bb
b Bb bb That's one punnett square
D. B b
B BB Bb
B BB Bb That's one punnett square
Is the answer c?
You don't indicate which color is dominant. If Black is dominant, then C is correct.
Hey if you could not post 3 times in a row that would be great. But I agree with PsyDAG.
To determine which Punnett square represents the cross between a heterozygous black coat cow and a homozygous red coat bull, we need to understand the principles of inheritance and how alleles are passed down.
First, let's define the alleles involved in coat color inheritance. In this case, we have two alleles: B represents the black coat allele, and b represents the red coat allele.
When a cow is heterozygous for the black coat allele (Bb), it means that it carries one copy of the black allele and one copy of the red allele. On the other hand, when a bull is homozygous for the red coat allele (bb), it means that it carries two copies of the red allele.
To create Punnett squares, we list the possible combinations of alleles from the parents across and down the grid. Each square in the grid represents a potential genotype of the offspring.
Now, let's analyze the options given:
A. B B
b Bb Bb
b Bb Bb
This Punnett square represents a cross between two homozygous black coat cows (BB) and a homozygous red coat bull (bb). It is not the correct representation for the given scenario.
B. B b
B BB Bb
b Bb bb
This Punnett square represents a cross between a heterozygous black coat cow (Bb) and a homozygous red coat bull (bb). Therefore, this is the correct representation for the given scenario.
C. B b
b Bb bb
b Bb bb
This Punnett square represents two homozygous red coat cows (bb) crossed with a heterozygous black coat bull (Bb). It is not the correct representation for the given scenario.
D. B b
B BB Bb
B BB Bb
This Punnett square represents a cross between two homozygous black coat cows (BB) and a heterozygous black coat bull (Bb). It is not the correct representation for the given scenario.
Therefore, the correct answer is option B, as it represents a cross between a heterozygous black coat cow (Bb) and a homozygous red coat bull (bb).