The polysaccharide that serves as the main energy storage in animals is: MCQ with Answer and Explanation

Explanation:
The counter-current mechanism involves the Loop of Henle and the vasa recta (blood capillaries surrounding the loop). The flow of filtrate in the two limbs of the Loop of Henle is in opposite directions, and the flow of blood in the two limbs of vasa recta is also counter-current. This mechanism helps maintain a high osmolarity gradient in the medullary interstitium, essential for concentrating urine.

Explanation:
A food chain represents the flow of energy and nutrients. The first trophic level is always occupied by producers (autotrophs), primarily green plants and algae, which convert solar energy into chemical energy via photosynthesis. The second level is primary consumers (herbivores), the third is secondary consumers (carnivores), and so on.

Explanation:
Influenza (flu) is a respiratory illness caused by the influenza virus. Malaria is a parasitic disease caused by Plasmodium and transmitted exclusively by the bite of an infected female Anopheles mosquito. Leprosy (Hansen's disease) is a chronic infectious disease caused by the bacterium Mycobacterium leprae, not a fungus. Thus, statements 1 and 3 are correct.