The genetic material of a bacterium is located in the: MCQ with Answer and Explanation

Explanation:
A population consists of individuals of a single species living in a specific area, not all species. A community comprises all the interacting populations of different species living together in a defined area. An ecosystem is a functional unit of nature encompassing both the biotic (living community) and abiotic (physical environment) components, interacting as a system. Only statement 2 is strictly correct in its definition.

Explanation:
Vitamin B₁₂ contains a cobalt ion at the center of its corrin ring structure, hence the name cobalamin. It is essential for DNA synthesis and nervous system function. Iron is in heme, magnesium in chlorophyll, zinc in many enzymes. B₁₂ is unique in having a metal-carbon bond.

Explanation:
Prokaryotes lack membrane-bound organelles like mitochondria, Golgi apparatus, and endoplasmic reticulum. They have 70S ribosomes, a single circular chromosome in a nucleoid, and typically a cell wall (except Mycoplasma). Eukaryotes possess membrane-bound organelles. This fundamental difference defines the two major cell types in the living world.