The enzyme that catalyzes the conversion of pyruvate to acetyl-CoA is: MCQ with Answer and Explanation

Explanation:
Essential amino acids are those that the human body cannot synthesize in sufficient quantities and must be obtained through the diet. There are nine essential amino acids: histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine. Glycine, alanine, and serine are non-essential amino acids that the body can produce.

Explanation:
Herbivores feed directly on producers, occupying the second trophic level. Carnivores that eat herbivores are secondary consumers.

Explanation:
Abscisic acid (ABA) is called the stress hormone because it accumulates under adverse conditions (drought, cold) and triggers adaptive responses like stomatal closure. It also promotes seed dormancy and inhibits germination. Gibberellins break seed dormancy, cytokinins promote cell division, ethylene promotes fruit ripening. ABA is antagonistic to gibberellins.