CAM plants adapt to arid conditions by: MCQ with Answer and Explanation

Explanation:
Robert Hooke, in 1665, observed dead cork tissue under a microscope and coined the term 'cell' for the box-like structures he saw. Antonie van Leeuwenhoek, using his superior single-lens microscopes in the 1670s, was the first to observe and describe living microorganisms, including bacteria and protozoa. Charles Darwin proposed the theory of evolution by natural selection; the cell theory was proposed by Matthias Schleiden and Theodor Schwann. Thus, statements 1 and 2 are correct.

Explanation:
Humulin is the trade name for the first genetically engineered human insulin, approved by the FDA in 1982. Prior to this, insulin for diabetic patients was extracted from the pancreases of pigs and cows, which could cause allergic reactions. Humulin is produced by inserting the human insulin genes into Escherichia coli bacteria, which then synthesize the exact amino acid sequence of human insulin, eliminating the risk of animal-derived immune reactions.

Explanation:
Coral reefs grow by accumulation of calcium carbonate skeletons secreted by living coral polyps, but the reef structure itself is non-living. It increases in mass externally (accretion). Mushrooms, mango trees, and bacteria exhibit intrinsic growth by cell division, characteristic of living organisms. Thus, coral reef growth is non-living accumulation.