The chemical reaction that links amino acids together is a: MCQ with Answer and Explanation

Explanation:
Bacteria are unicellular prokaryotic organisms, characterized by the absence of a true nucleus and membrane-bound organelles. Fungi are eukaryotic organisms, possessing a true nucleus and membrane-bound organelles, and can be unicellular (yeasts) or multicellular (molds, mushrooms). Viruses are acellular, non-cellular entities; they consist of genetic material (DNA or RNA) enclosed in a protein coat (capsid) and lack any cellular structure or metabolic machinery. Thus, statements 1 and 2 are correct.

Explanation:
Thigmonasty (seismonasty) is a non-directional, rapid response to touch or vibration, exemplified by the drooping of Mimosa pudica leaves. Thigmotropism is directional growth towards/away from touch (e.g., tendrils). Phototropism is light-directed growth, geotropism gravity-directed.

Explanation:
Restriction endonucleases act as molecular scissors, cleaving DNA at specific palindromic recognition sequences. Polymerase Chain Reaction (PCR) is a technique used to amplify specific DNA segments exponentially. Gel electrophoresis is primarily used to separate DNA or RNA fragments based on size, though it can separate proteins (SDS-PAGE), the statement implies it's exclusively or primarily for proteins in general biotech context, but 1 and 2 are definitively core facts. Let's refine: Gel electrophoresis separates charged molecules; for DNA it's by size. Statements 1 and 2 are universally correct core principles.