The functional unit of the kidney is the: MCQ with Answer and Explanation

Explanation:
Fungi are heterotrophic organisms; they cannot perform photosynthesis because they lack chlorophyll and chloroplasts. They obtain nutrients through absorption after extracellular digestion (saprophytic or parasitic). The cell wall contains chitin, and most are multicellular with a filamentous body (mycelium), though yeasts are unicellular. Thus, autotrophy is not a fungal characteristic.

Explanation:
Nitrogen fixation, the conversion of atmospheric N2 to ammonia, is performed by certain bacteria and cyanobacteria (blue-green algae). Denitrification is the process where denitrifying bacteria convert nitrates in the soil back into nitrogen gas (N2), returning it to the atmosphere. Ammonification is the decomposition of organic nitrogen into ammonia by microbes; nitrification converts ammonia to nitrate. Thus, statements 1 and 2 are correct.

Explanation:
During the light reactions of photosynthesis, photolysis of water occurs at photosystem II, splitting water into protons, electrons, and molecular oxygen. The oxygen comes from water, not CO₂. This was demonstrated by using isotopically labeled oxygen (H₂O¹⁸). Glucose is formed in the Calvin cycle. Chlorophyll absorbs light but does not provide oxygen. The overall equation: 6CO₂ + 12H₂O → C₆H₁₂O₆ + 6O₂ + 6H₂O.