BS Zoology Semester Exam MCQs

Insects rely on innate immune mechanisms such as phagocytic hemocytes, melanization, clotting, and antimicrobial peptides.

Hemocytes in many invertebrates participate in phagocytosis, encapsulation, clotting, and antimicrobial defense within hemolymph.

Plasma is the liquid component of blood that transports dissolved nutrients, hormones, wastes, ions, and proteins.

Blood circulation transports heat within the body. Ectotherms use behavior and circulation to manage body temperature.

Melanization is an invertebrate immune reaction that encapsulates or kills invaders. It is common in arthropod defense.

Large animals have cells far from the external environment. Circulatory systems transport gases, nutrients, wastes, hormones, and immune components efficiently.

Leukocytes or white blood cells participate in immune defense, including phagocytosis, antibody production, and cell-mediated responses.

Cardiac output is the volume of blood pumped per minute and equals heart rate times stroke volume. It is a core determinant of blood flow.

Earthworms have a closed circulatory system with major vessels that direct blood flow. This supports exchange and transport through the segmented body.

Small or flat animals may exchange materials effectively by diffusion because cells are close to the external environment. Large animals require transport systems.

Platelets are essential for normal clot formation. Low platelet count can lead to prolonged bleeding or easy bruising.

Vasodilation increases vessel diameter, reducing resistance and often increasing blood flow to a tissue.