In the context of the history of genetics, what is the term for the ancestor who stands at the top of a common genealogy?

• A. Descendant
• B. Homozygote
• C. Allele
• D. Progenitor

Answer: (D)

Verified step by step guidance

1. Understand the question is asking for the term used to describe the ancestor at the top of a common genealogy, which means the earliest individual from whom others descend.
2. Recall that a 'descendant' refers to individuals who come after or are derived from an ancestor, so this term describes those below in the genealogy, not the ancestor itself.
3. Recognize that 'homozygote' is a genetic term describing an organism with two identical alleles for a particular gene, which is unrelated to genealogy or ancestry.
4. Know that an 'allele' is a variant form of a gene and does not refer to an individual or ancestor in a genealogy.
5. Identify that the correct term for the ancestor at the top of a genealogy is 'progenitor,' which means the original ancestor or forebear from whom others descend.