Animal Anatomy & Physiology Flashcards

What is the primary function of hemocytes in insect immunity?

Answer: Phagocytosis, encapsulation, and clotting of foreign invaders

Hemocytes (plasmatocytes, granulocytes, and lamellocytes) carry out cellular immune responses including phagocytosis of bacteria and encapsulation of parasites.

The Johnston's organ, located in the pedicel of insect antennae, is primarily a receptor for:

Answer: Antennal deflection caused by sound, gravity, or flight-induced airflow

Johnston's organ is a chordotonal organ that detects mechanical deflection of the antennal flagellum and is critical for sound perception in mosquitoes and Drosophila.

In insects undergoing incomplete metamorphosis (hemimetaboly), the immature stages are called:

Answer: Nymphs

Hemimetabolous immatures are called nymphs; they resemble adults and develop wing pads externally without a pupal stage.

Which structure connects the brain to the corpora cardiaca and corpora allata, forming the insect endocrine control center?

Answer: Retrocerebral complex

The retrocerebral complex (brain + corpora cardiaca + corpora allata) coordinates production and release of key developmental and metabolic hormones.

The intersegmental muscles of the insect abdomen are primarily used for:

Answer: Respiratory pumping and oviposition movements

Abdominal intersegmental muscles compress and expand the abdomen to ventilate the tracheal system and power ovipositor and stinger movements.

Which cuticular layer is most responsible for waterproofing in terrestrial insects?

Answer: Epicuticle wax layer

The epicuticular wax layer, composed of long-chain hydrocarbons, forms a lipophilic barrier that dramatically reduces transcuticular water loss.

Adipokinetic hormone (AKH) in insects is functionally analogous to which vertebrate hormone?

Answer: Glucagon

Like glucagon, AKH mobilizes stored lipids and carbohydrates from the fat body during periods of high energy demand such as flight.