ACE Nutrition & Dietary Needs 2 — Questions and Answers
Question 1: Which nutrient class provides the primary energy source for most insects during flight?
- Carbohydrates
- Proteins
- Lipids (Correct answer)
- Nucleic acids
Correct answer: Lipids
Lipids (particularly stored fat) serve as the primary fuel for sustained insect flight due to their high energy density.
Question 2: What is the term for insects that feed exclusively on plant sap from the phloem?
- Xylophages
- Phytophages
- Phloem feeders (Correct answer)
- Stenophagous
Correct answer: Phloem feeders
Phloem feeders, such as aphids and whiteflies, use piercing-sucking mouthparts to access nutrient-rich phloem sap.
Question 3: Symbiotic microorganisms in the gut of wood-boring beetles primarily help the host by:
- Producing defensive chemicals
- Synthesizing essential amino acids (Correct answer)
- Regulating molting hormones
- Generating digestive heat
Correct answer: Synthesizing essential amino acids
Endosymbiotic bacteria in wood-borers supplement the nitrogen-poor wood diet by synthesizing essential amino acids the host cannot produce.
Question 4: Which of the following is an example of a stenophagous insect?
- American cockroach
- Monarch butterfly larva (Correct answer)
- German cockroach
- House fly larva
Correct answer: Monarch butterfly larva
Monarch butterfly larvae are stenophagous, feeding almost exclusively on milkweed (Asclepias spp.).
Question 5: The primary role of sterols in insect nutrition is to:
- Provide quick energy for bursts of activity
- Serve as precursors for molting hormones (Correct answer)
- Act as osmotic regulators in hemolymph
- Function as antioxidants
Correct answer: Serve as precursors for molting hormones
Insects cannot synthesize sterols de novo and must obtain them from the diet; sterols are essential precursors for ecdysteroids (molting hormones).
Question 6: Which feeding guild describes insects that consume decaying organic matter and contribute to nutrient cycling?
- Predators
- Detritivores (Correct answer)
- Parasitoids
- Nectarivores
Correct answer: Detritivores
Detritivores, such as dung beetles and certain fly larvae, feed on decomposing organic matter and play a critical role in nutrient cycling.
Question 7: Blood-feeding insects such as mosquitoes primarily use blood proteins for:
- Egg development (vitellogenesis) (Correct answer)
- Powering sustained flight
- Building exoskeletal chitin
- Synthesizing defensive secretions
Correct answer: Egg development (vitellogenesis)
Female mosquitoes require a blood meal rich in proteins to fuel vitellogenesis — the production of yolk proteins necessary for egg maturation.
ACE Nutrition & Dietary Needs 2
Which nutrient class provides the primary energy source for most insects during flight?