The process of taking in food through the mouth is called: MCQ with Answer and Explanation

Explanation:
Leptin is a peptide hormone produced primarily by adipocytes (fat cells). Its concentration in the blood is proportional to the amount of body fat. Leptin acts as a satiety signal, crossing the blood-brain barrier to act on receptors in the hypothalamus. It suppresses appetite (anorexigenic effect) and increases energy expenditure, thereby regulating long-term food intake and body weight. It is often called the 'satiety hormone' or 'fat hormone'.

Explanation:
Producers (autotrophs like green plants) form the first trophic level and the base of all food chains, converting solar energy into chemical energy. Decomposers (bacteria and fungi) break down dead organic matter and waste, releasing essential inorganic nutrients back into the soil for producers to use, thus completing the nutrient cycle. Energy flow in an ecosystem is strictly unidirectional, moving from the sun to producers and then to consumers, and is eventually lost as heat; it does not flow bidirectionally. Thus, statements 1 and 2 are correct.

Explanation:
The soma (cell body) of a neuron contains the nucleus and metabolic machinery. Dendrites receive signals from other neurons and transmit them towards the soma, while the axon carries impulses away from the soma. The myelin sheath speeds up conduction by saltatory conduction (jumping between nodes), not continuous conduction.