Question

I do not understand how to do this. Pls, explain.

Answer 1

The answer should be A. They could have genotype Cc or cc

Step-by-step explanation:

C c

`{c}\\{c}`
`\left[\begin{array}{ccc}Cc&cc\\Cc&cc\end{array}\right]`

I tried to make a punnet square as best as I could..

To jog your memory about the basics of punnet squares and what certain words mean.

• Dominance is shown by a capital letter, while recessive is denoted by lowercase

If a person is homozygous they carry two identical alleles (CC or cc).

• Two capitals mean a person is homozygous dominant, whilst two lowercase means a person is homozygous recessive.

If a person is heterozygous that means that they carry two different alleles, one dominant and one recessive (Cc).

• The dominant allele will always be present over the recessive.

As the statement shows, individual 5 is heterozygous, meaning their genotype is Cc.

Their partner is a shaded individual, which means they have cystic fibrosis, which is homozygous recessive. This means their genotype is cc.

When doing a punnet square, you will see the two outcomes of possible genotypes are Cc and cc. This means there is a 50% (or 2/4) chance of individual 12 being healthy (Cc), or there is a 50% (or 2/4) chance of the individual having cystic fibrosis (cc).