Animal Anatomy & Physiology Flashcards

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

Answer: Tracheal system

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

The insect hemolymph differs from vertebrate blood primarily because it:

Answer: Lacks red blood cells and does not primarily transport oxygen

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

In insects, the proventriculus functions primarily to:

Answer: Grind and filter food before it enters the midgut

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

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

Answer: Protocerebrum

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

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

Answer: Discontinuous gas exchange cycles with valve-like closures

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

The fat body in insects serves a function most analogous to which vertebrate organs combined?

Answer: Liver and adipose tissue

The fat body stores lipids and glycogen, detoxifies compounds, and synthesizes proteins—roles divided between the liver and fat tissue in vertebrates.

During insect metamorphosis, larval tissues are broken down and reorganized by which cell type in the pupa?

Answer: Imaginal discs and histoblasts

Imaginal discs (in holometabolous insects) and histoblasts are clusters of undifferentiated cells that form adult structures from larval tissue breakdown.