Identify the correct statement about plant water relations: MCQ with Answer and Explanation

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.

Explanation:
Transpiration is the loss of water vapor primarily through the stomata on the leaf surface. Guttation is the exudation of liquid water from the margins of leaves through specialized structures called hydathodes, usually at night when root pressure is high. Phloem is responsible for the translocation of organic food (bidirectional), while xylem transports water and minerals upwards. Thus, statements 1 and 2 are correct.

Explanation:
Diatomaceous earth is a siliceous, sedimentary rock formed from the fossilized remains of diatoms. Diatoms have unique, highly resistant cell walls called frustules, made of hydrated silicon dioxide (silica). Over millions of years, these frustules accumulate on ocean and lake floors, forming diatomaceous earth, which has numerous industrial applications due to its abrasive and porous nature.