Question

how are these three genes related?
a. genes 1 and 2 are unlinked, and genes 2 and 3 are weakly linked.
b. genes 1 and 3 are unlinked, and genes 2 and 3 are strongly linked.
c. all three genes are linked, and genes 2 and 3 are strongly linked.
d. all three genes are linked, and genes 2 and 3 are weakly linked.

Explanation:

Step1: Understand gene linkage

Genes that are close together on a chromosome are linked. The closer they are, the stronger the linkage.

Step2: Analyze the positions

Gene 3 and gene 2 are very close → strongly linked. Gene 1 is far from gene 2 and 3 → unlinked to them.

Answer:

B. Genes 1 and 3 are unlinked, and genes 2 and 3 are strongly linked.