Robert Hooke is credited with the discovery of: MCQ with Answer and Explanation

Explanation:
Mitosis is an equational division resulting in two genetically identical diploid daughter cells, not four. Meiosis is a reductional division involving two successive stages, meiosis I and meiosis II, producing four haploid cells. Crossing over, the exchange of genetic material, occurs exclusively during the pachytene stage of prophase I in meiosis, not in mitosis. Only statement 2 is correct.

Explanation:
Vitamin C, chemically ascorbic acid, is a water-soluble vitamin essential for collagen synthesis, wound healing, iron absorption, and antioxidant function. Its deficiency causes scurvy (bleeding gums, weakness). Vitamin A is retinol, B₁ is thiamine, D is calciferol. Vitamin C is abundant in citrus fruits, guava, amla. It is heat-labile and easily destroyed by cooking.

Explanation:
The cell cycle consists of interphase (G1, S, G2) and M phase. DNA synthesis or replication occurs during the S (synthesis) phase, resulting in each chromosome having two sister chromatids. G1 is for cell growth and RNA/protein synthesis; G2 is for preparation for mitosis. M phase includes mitosis and cytokinesis. Accurate DNA replication in S phase is crucial for genetic continuity.