Deficiency of vitamin D in children leads to: MCQ with Answer and Explanation

Explanation:
While restriction enzymes were first observed by Linn and Arber, the first Type II restriction endonuclease (HindII), which is the type used in genetic engineering because it cuts at specific recognition sites, was isolated and characterized by Hamilton O. Smith, Kent W. Wilcox, and Thomas J. Kelly in 1970 from Haemophilus influenzae. For this discovery, Smith shared the Nobel Prize in Physiology or Medicine in 1978. Kary Mullis invented PCR.

Explanation:
Osmosis is the special case of diffusion of water across a semipermeable membrane down its concentration gradient (from high to low water potential). It does not require energy. Diffusion refers to solute movement, active transport requires energy against a gradient, and plasmolysis is the shrinking of protoplasm due to water loss.

Explanation:
The plasma membrane is selectively permeable, regulating the entry and exit of specific molecules into and out of the cell. Lysosomes are membrane-bound organelles containing powerful hydrolytic (digestive) enzymes for intracellular digestion. The nucleolus is the site of ribosomal RNA (rRNA) synthesis and ribosome assembly, not protein synthesis, which occurs at ribosomes. Thus, statements 1 and 3 are correct.