Who introduced the binomial nomenclature system? MCQ with Answer and Explanation

Explanation:
PCR involves repeated cycles of high-temperature denaturation (around 94°C) to separate the DNA strands. Normal DNA polymerases would be destroyed at these temperatures. Therefore, a thermostable DNA polymerase is required. Taq polymerase, isolated from the thermophilic bacterium Thermus aquaticus found in hot springs, is the most commonly used enzyme because it can withstand the high denaturation temperatures without losing its activity, eliminating the need to add fresh enzyme after each cycle.

Explanation:
Kidneys are retroperitoneal, not in the abdominal cavity proper. They produce renin, and filter ~180 L/day (GFR ~125 mL/min). So 1 is incorrect.

Explanation:
Rhizobium is a symbiotic bacterium found in legume root nodules that fixes atmospheric nitrogen into ammonia. Yeast (Saccharomyces cerevisiae) undergoes anaerobic respiration, producing CO2 that leavens bread dough. The vast majority of bacteria are harmless or beneficial (e.g., gut flora, decomposers); only a small fraction are pathogenic to humans. Thus, statements 1 and 2 are correct.