Question

Hox genes are regulatory genes in multicellular animals that code for transcription factors that determine the basic body plan in a developing embryo. They act as switches that turn other genes on and off.
Scientists have found that a mutation in a fruit fly hox gene produces flies with legs instead of antennae sticking out of their heads. Another hox gene mutation results in fruit flies with two pairs of wings instead of one pair. Hox genes affect body plans by controlling the expression of many other genes.
Many multicellular animals have the same hox genes. Which statement is evidence for this claim?
(1 point)
• The body plans of complex animals typically have a large number of mutations.
• The body plans of complex animals are very similar to one another.
• There is a wide variety of body plans in complex animals.
• The body plans of complex animals change over generations.

Answer 1

The body plans of complex animals are very similar to one another.

Explanation: If many multicellular animals share similar body plans, that suggests common underlying regulatory genes (like Hox genes) control those plans across species.