Animal Anatomy & Physiology Flashcards

Which type of insect sensillum is specialized for detecting contact chemicals (taste)?

Answer: Basiconic sensillum

Basiconic sensilla are short, peg-like structures found on mouthparts and tarsi that house contact chemoreceptors for taste.

The corpora allata produce which hormone critical for maintaining larval characteristics in insects?

Answer: Juvenile hormone

Juvenile hormone (JH) produced by the corpora allata suppresses metamorphic changes, keeping the insect in its larval form through successive molts.

In a cockroach, the cercal system is primarily used for:

Answer: Sensing airborne vibrations and triggering escape responses

Cerci bear mechanoreceptive hairs that detect low-frequency air currents caused by approaching predators, triggering rapid escape.

Oenocytes in insects are primarily associated with:

Answer: Synthesis of cuticular hydrocarbons and lipid processing

Oenocytes, found in clusters near the epidermis, synthesize cuticular hydrocarbons critical for waterproofing and chemical communication.

The peritrophic matrix in insect midguts functions mainly to:

Answer: Protect midgut epithelium from abrasion and pathogens while allowing enzyme passage

The peritrophic matrix is a semipermeable chitin-protein membrane that shields midgut cells from damage and pathogens while permitting digestive enzymes to access food.

Which muscle type dominates insect flight in species such as bees and flies that beat their wings at very high frequencies?

Answer: Asynchronous (fibrillar) flight muscle

Asynchronous flight muscles contract in response to mechanical stretch rather than each nerve impulse, enabling wing-beat frequencies far exceeding neural firing rates.

In holometabolous insects, which stage is primarily responsible for energy storage to support metamorphosis?

Answer: Late larval instars

Late larval instars (especially the last instar) feed voraciously to accumulate lipids and proteins in the fat body that fuel pupal development.