Apoptosis is best described as: MCQ with Answer and Explanation

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:
Gregor Mendel, an Austrian monk, is known as the 'father of genetics' for his pioneering experiments on inheritance in the garden pea plant (Pisum sativum) between 1856 and 1863. He studied seven pairs of contrasting traits and formulated the fundamental laws of inheritance: the Law of Segregation and the Law of Independent Assortment, which form the basis of classical genetics.

Explanation:
Beriberi is due to thiamine (B₁) deficiency. It presents as two forms: wet beriberi (cardiovascular) and dry beriberi (neurological). Thiamine is a coenzyme (TPP) in decarboxylation reactions. Common in populations consuming polished rice. Riboflavin deficiency causes cheilosis, pyridoxine deficiency causes peripheral neuropathy and anemia, B₁₂ deficiency causes pernicious anemia.