A network of interconnected food chains is called a: MCQ with Answer and Explanation

Explanation:
Pepsin is the primary proteolytic enzyme in the stomach, breaking down proteins into peptones. Trypsin is a pancreatic enzyme secreted by the pancreas, not the liver, which continues protein digestion in the small intestine. Bile, produced by the liver, emulsifies fats, but lipase (pancreatic lipase) actually digests (hydrolyzes) them into fatty acids and glycerol. Only statement 1 is correct.

Explanation:
Molecular oxygen (O₂) accepts electrons at the end of the electron transport chain, combining with protons to form water (metabolic water). Without oxygen, the chain backs up, stopping ATP production. This is why oxygen is vital for aerobic respiration. NAD⁺ and FAD are electron carriers, cytochrome c a component.

Explanation:
The pineal gland secretes melatonin in a daily rhythm, peaking at night, thus regulating the sleep-wake cycle and seasonal biological rhythms. The pituitary controls other glands, thyroid metabolism, adrenals stress response. Light signals from the retina influence pineal activity.