BS Zoology Semester Exam MCQs

Tympanal organs detect airborne sound vibrations. They occur in different body regions depending on the insect group and are important in communication and predator detection.

Insect endocrine glands release hormones that coordinate growth, molting, metamorphosis, reproduction, and other physiological processes.

Complete metamorphosis includes egg, larva, pupa, and adult. Larvae and adults often use different foods and habitats, reducing competition within the species.

Hovering requires strong flight muscles and fine control of wing movement. Many flies and some bees can maintain position in air while feeding or surveying the environment.

The insect foregut receives food and may include structures such as crop and gizzard. It is lined with cuticle and helps store or mechanically process food.

Most insects use a tracheal system for gas exchange. Oxygen travels through spiracles and tracheae directly to tissues, reducing dependence on blood for oxygen transport.

The dorsal vessel functions as the insect heart and aorta. It moves hemolymph forward through the body cavity.

Insect muscles work in coordinated opposing groups. One muscle contracts to move a body part while another can return it, allowing controlled locomotion.

The midgut is the main digestive and absorptive region. Enzymes act on food here, and nutrients pass into the hemolymph.

Spiracles connect the tracheal system to the outside. Their opening and closing help balance oxygen uptake with water conservation.

Hemolymph is the circulating fluid of insects. It supports transport and immunity, but oxygen transport is usually handled mainly by the tracheal system.

Insect muscles work in coordinated opposing groups. One muscle contracts to move a body part while another can return it, allowing controlled locomotion.