The vitamin that functions as an antioxidant and is required for the synthesis of collagen is: MCQ with Answer and Explanation

Explanation:
Lichens represent mutualism where the fungal partner provides shelter, water, and minerals, and the algal or cyanobacterial partner provides food through photosynthesis. Both benefit. Parasitism is harmful to host; commensalism benefits one without affecting the other; predation involves one killing and eating the other. Lichens are bioindicators of air pollution, sensitive to SO₂. This association is obligate.

Explanation:
Seed dispersal spreads seeds away from the parent plant, reducing competition for light, water, nutrients, and space. It also aids in colonization of new habitats and increases species distribution. Dispersal agents include wind, water, animals, and explosive mechanisms. Overcrowding would lead to resource limitation. Genetic diversity is promoted by cross-pollination, not directly by dispersal.

Explanation:
Glucagon-like Peptide-1 (GLP-1) is a powerful incretin hormone secreted by the L cells of the distal small intestine (ileum) and colon in response to food ingestion. Its primary functions are highly beneficial for glucose homeostasis: it stimulates insulin secretion from the pancreas in a glucose-dependent manner (only when blood glucose is high), inhibits glucagon secretion, slows down gastric emptying (allowing more time for nutrient absorption), and acts on the brain to promote satiety and reduce food intake. GLP-1 analogs (like exenatide) are used as drugs to treat type 2 diabetes.