Question

This pedigree chart tracks the inheritance of a recessive trait that is not sex-linked. Based on the information in the chart, which of the following statements is true about individuals 3 and 4? This pedigree chart shows three generations. The individuals are numbered from left to right, starting at the top left of the chart. Squares represent males and circles represent females. If the symbol is gray, that individual exhibits the recessive trait. If the symbol is white, the individual exhibits the dominant trait. On the first row there are two couples mated together. The first couple is made up of individuals #1 (recessive) and #2 (dominant). They have four offspring on the second row that all exhibit dominant traits: #5 (dominant), #6 (dominant), #7 (dominant), and #8 (dominant). The second couple in Generation #1 is made up of individual #3 (dominant) and individual #4 (dominant). They have three offspring in Generation 2: #9 (dominant), #10 (recessive), and #11 (dominant). Individual #8 from the first family and individual #9 from the second family mated together and produced three offspring in Generation 3. These offspring are #12 (recessive), #13 (dominant), and #14 (recessive). At least one is heterozygous for the trait. They are both homozygous dominant for the trait. They are both heterozygous for the trait. At least one is homozygous for the trait.

Answer 1

I believe the answer would be either Individual #2 must be heterozygous dominant for the trait. or Individual #11 must be homozygous for the recessive trait.

Step-by-step explanation:

I take FLVS and this is one of the questions

Answer 2

The correct answer is the third one: They are both heterozygous for the trait

If dominant allele: A
If recessive allele: a

A heterozygotic person has this genotype: Aa
A homozygotic dominant person has this genotype: AA
A homozygotic recessive person has this genotype: aa

They need to be both heterozygotic (Aa x Aa) for them to have a daughter who is recessive, while NOT having the trait themselves. By crossing their genotypes, there is 25% chance for them to have someone recessive for the trait (which they do, it's the daughter 10).