Question

I'm so confused on how to do punnet squares. help?

Answer 1

A brown heterozygous rabbit is an animal hat has two different alleles ("B" & "b" are different. One is capital (dominant), and one is lowercase (recessive). a homozygous white rabbit would be someone who has the same alleles. For example, it could have two capital B's (BB) or two lowercase b's. However since we know white fur is recessive and the rabbit is showing recessive WHITE fur, we would represent it as two little b's.

Let's set up our punnett square by drawing a square or box


Then, divide the box up into four equal squares inside the box.

Now, we are going to put our genotypes (Bb & bb) above the box and on the left side ( as shown in the picture.

You cross them kind of like cross multiplying. Remember, the capital B always comes first when needed.

THERE'S YOUR PUNNETT SQUARE! Let's solve the problems.

1.
Genotype is the genetic code. (Ex: Bb, VV, rr)
Phenotype on the other hand is the physical trait (brown fur, blue eyes, rolling your tounge)

So the genotypes of the new generation are Bb & bb

While the phenotypes are brown fur and white fur. Remember, the dominant trait always covers up the recessive. For example, Bb. The rabbit would take brown fur but could give white fur to her offspring because she has a recessive trait for white fur. However, bb would give the rabbit white fur since there is no dominant trait to cover up the recessive.

2.
50% of the rabbit are going to be brown and 50% of the rabbits are going to be white.

This is because the recessive gene isn't covered up by a dominant trait for 50% of the rabbits (bb) but the other 50% will have brown fur because the dominant trait is covering it up.

Hope that clears everything up about punnett squares. Good luck! (:

Answer 2

Look it up on the internet an it will give a good example