Consider statements about the cell wall: 1. Plant cell walls are made of cellulose. 2. Fungal cell walls contain chitin. 3. Bacterial cell walls contain peptidoglycan. Which are correct? 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:
The liver is the primary site of glycogen storage and releases glucose into the blood between meals (glycogenolysis) to maintain blood sugar. Muscles also store glycogen but for local use. The pancreas regulates blood sugar via insulin/glucagon, spleen stores blood and recycles iron, kidneys excrete waste.

Explanation:
James Watson and Francis Crick, using Rosalind Franklin's X-ray data, proposed the double helical structure of DNA in 1953.