ACE Insect Biology & Identification 3 — Questions and Answers
Question 1: The fat body in insects serves a function most analogous to which organ in vertebrates?
- Heart
- Kidney
- Liver and adipose tissue (Correct answer)
- Spleen
Correct answer: Liver and adipose tissue
The insect fat body stores energy reserves and performs metabolic functions including detoxification, much like the combined role of the liver and fat tissue in vertebrates.
Question 2: Which order includes insects known as 'true bugs,' characterized by hemelytra (partially thickened forewings)?
- Hemiptera (Correct answer)
- Homoptera
- Thysanoptera
- Neuroptera
Correct answer: Hemiptera
Hemiptera (true bugs) have distinctive hemelytra — forewings that are thickened at the base and membranous at the tip — and piercing-sucking mouthparts.
Question 3: In ants and bees, the petiole refers to:
- The stinging apparatus
- The narrow waist segment connecting thorax and abdomen (Correct answer)
- The queen's ovipositor
- A gland producing alarm pheromones
Correct answer: The narrow waist segment connecting thorax and abdomen
The petiole is the constricted node or nodes between the thorax (mesosoma) and gaster (abdomen) in Hymenoptera, giving them their characteristic narrow waist.
Question 4: Which of the following is a defining characteristic of insects compared to other arthropods?
- Having an exoskeleton
- Possessing three pairs of legs and three body regions (Correct answer)
- Breathing through book lungs
- Having compound eyes
Correct answer: Possessing three pairs of legs and three body regions
Insects (Class Insecta) are uniquely defined among arthropods by having exactly three pairs of jointed legs and three body tagmata: head, thorax, and abdomen.
Question 5: Tympanic organs in insects are used primarily for:
- Taste detection
- Sound reception (hearing) (Correct answer)
- Balance and orientation
- Chemical communication
Correct answer: Sound reception (hearing)
Tympanic organs are specialized hearing structures found in several insect orders including Orthoptera, Lepidoptera, and some Hemiptera.
Question 6: Hypermetamorphosis, as seen in blister beetles (Meloidae), differs from typical holometabolism because:
- There is no larval stage
- The larva passes through distinctly different larval forms (instars with different morphologies) (Correct answer)
- Adults emerge directly from eggs
- The pupal stage is replaced by a nymphal stage
Correct answer: The larva passes through distinctly different larval forms (instars with different morphologies)
In hypermetamorphosis, the insect goes through multiple larval forms that are morphologically distinct from one another, such as the active triungulin first instar giving way to grub-like later instars.
Question 7: The Malpighian tubules in insects function similarly to which human organ?
- Lungs
- Stomach
- Kidneys (Correct answer)
- Pancreas
Correct answer: Kidneys
Malpighian tubules filter metabolic waste from the hemolymph and pass it to the hindgut for excretion, performing the excretory function analogous to mammalian kidneys.
ACE Insect Biology & Identification 3
The fat body in insects serves a function most analogous to which organ in vertebrates?