ACE Animal Anatomy & Physiology 2

Question 1

Which insect organ system is primarily responsible for gas exchange, delivering oxygen directly to tissues?

Accepted Answer

Tracheal system

Answer

Insects use a tracheal system of tubes that deliver oxygen directly to cells, bypassing the circulatory system for gas transport.

Question 2

The insect hemolymph differs from vertebrate blood primarily because it:

Accepted Answer

Lacks red blood cells and does not primarily transport oxygen

Answer

Insect hemolymph transports nutrients, hormones, and waste but relies on the tracheal system—not hemolymph—for oxygen delivery.

Question 3

In insects, the proventriculus functions primarily to:

Accepted Answer

Grind and filter food before it enters the midgut

Answer

The proventriculus acts as a gizzard-like valve that grinds food and controls passage of material into the midgut.

Question 4

Which structure in the insect nervous system acts as the primary processing center analogous to a vertebrate brain?

Accepted Answer

Protocerebrum

Answer

The protocerebrum is the largest region of the insect brain and processes visual information and higher-order functions.

Question 5

Spiracles in insects are regulated by which mechanism to prevent desiccation?

Accepted Answer

Discontinuous gas exchange cycles with valve-like closures

Answer

Discontinuous gas exchange cycles allow spiracles to remain closed most of the time, conserving water while still enabling CO₂ release.

(ACE) Associate Certified Entomologist Practice Test