Individual A in the family pedigree below is homozygous dominant and individual B is homozygous recessive for a particular feature. What is the percentage probability that individual F is homozygous recessive if:

Answer:

1) C

Firstly, we must find out what D is.

                 R                                    R

r               Rr                                   Rr

r               Rr                                   Rr

There is 100% chance that D is heterozygous.

Now if E is homozygous recessive, this would be the case:

                 R                                    r

r               Rr                                   rr

r               Rr                                   r

There is a 50% chance that F would be homozygous recessive

If E was heterozygous, this would be the case:

                 R                                    r

R              RR                                 Rr

r               Rr                                   rr

There would be a 25% chance that F would be homozygous recessive.

Hence, this corresponds to option C in the given table.