The disease caused by deficiency of vitamin D in children is: MCQ with Answer and Explanation

Explanation:
Binary fission is the primary and most common method of asexual reproduction in bacteria. In this process, the bacterial cell replicates its DNA and then divides into two identical daughter cells. Under optimal conditions, some bacteria can divide every 20 minutes. Bacteria can also exchange genetic material through processes like conjugation, transformation, and transduction.

Explanation:
Cross-pollination between different plants promotes genetic diversity. Self-pollination does not need external agents; entomophily is by insects, hydrophily by water, anemophily by wind.

Explanation:
Xylem vessels and tracheids are dead, hollow cells at functional maturity, providing a continuous tube for water transport. Phloem sieve tube elements are living cells at maturity, though they lack a nucleus, and are responsible for transporting organic nutrients. Cambium (vascular and cork) is a lateral meristem responsible for secondary growth (increase in girth), while apical meristems are responsible for primary growth (increase in length). Thus, statements 1 and 2 are correct.