AP BIOLOGY

Detailed explanation-1: -His work confirmed that genes are stored in chromosomes inside cell nuclei. He came to understand that genes are organized in a long row inside chromosomes and how traits related to each other correspond to genes that lie close to one another on the chromosomes.

Detailed explanation-2: -Using fruit flies as a model organism, Thomas Hunt Morgan and his group at Columbia University showed that genes, strung on chromosomes, are the units of heredity. Morgan and his students made many important contributions to genetics.

Detailed explanation-3: -How did Morgan explain his finding? Linked genes were inherited together because they were close to each other on the same chromosome. How did Alfred Sturtevant use gene linkage to create gene maps? He reasoned that alleles that frequently cross over must be further apart than those that hardly ever cross.

Detailed explanation-4: -Morgan’s Test Crosses In his initial test cross aimed at exploring the precise relationship between eye color and sex, Morgan bred white-eyed males (X wY) with wild-type red-eyed females (X +X +). This cross yielded only red-eyed offspring, as summarized in Table 3.