BS Zoology Semester Exam MCQs

Pheromones are chemical messages released by one individual and detected by another. They can guide mating, alarm behavior, trail following, or aggregation.

Juvenile hormone influences developmental outcome. High levels tend to maintain juvenile characteristics, while low levels permit adult differentiation during metamorphosis.

Holometabolous insects often reduce intraspecific competition because larvae and adults differ in form, food, and habitat. This helps explain their evolutionary success.

Chemoreceptors respond to chemical molecules. Insects use them to locate food, recognize mates, avoid toxins, and select egg-laying sites.

Insect feeding structures vary widely because diets differ. Chewing, piercing-sucking, siphoning, and sponging mouthparts are examples of structure matching diet.

Apolysis occurs before ecdysis. The epidermis separates from the old cuticle, creating a space where molting fluid can act and new cuticle can be produced.

The main reproductive organs are ovaries in females and testes in males. They produce gametes that unite during fertilization.

Chemoreceptors respond to chemical molecules. Insects use them to locate food, recognize mates, avoid toxins, and select egg-laying sites.

Insect feeding structures vary widely because diets differ. Chewing, piercing-sucking, siphoning, and sponging mouthparts are examples of structure matching diet.

Apolysis occurs before ecdysis. The epidermis separates from the old cuticle, creating a space where molting fluid can act and new cuticle can be produced.

Chemoreceptors respond to chemical molecules. Insects use them to locate food, recognize mates, avoid toxins, and select egg-laying sites.

Insect feeding structures vary widely because diets differ. Chewing, piercing-sucking, siphoning, and sponging mouthparts are examples of structure matching diet.