MCAT Question A Day - 2/26/14 - Answer!
In certain insects, juvenile hormone suppresses metamorphosis from larva to adult. Instead, this hormone allows the young organism to grow in size while remaining in the immature larval stage. Eventually, the juvenile hormone decreases, causing metamorphosis to take place. If the corpora allata, the site of juvenile hormone production and release, is surgically removed at an early larval stage, what is expected to happen?
A. A tiny adult will form.
B. The larva will continue to grow, and metamorphosis will occur at the normal age.
C. The larva will no longer grow or undergo metamorphosis.
D. The larva will continue to grow until it looks like a giant, adult-sized larva.
The correct answer is (A). No previous knowledge about insects, hormones, or metamorphosis is necessary. The ability to logically apply the given information is required. If juvenile hormone inhibits metamorphosis, removal of the hormone (and its source) should cause metamorphosis to occur.
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The correct answer is (A). No previous knowledge about insects, hormones, or metamorphosis is necessary. The ability to logically apply the given information is required. If juvenile hormone inhibits metamorphosis, removal of the hormone (and its source) should cause metamorphosis to occur.