Assertion (A): RNA is usually single-stranded. Reason (R): RNA contains deoxyribose sugar. MCQ with Answer and Explanation

Explanation:
Plasmodesmata are microscopic channels that traverse the cell walls of plant cells, enabling the transport of water, ions, molecules, and even some viruses between them, thus ensuring cytoplasmic continuity. Gap junctions perform a similar function in animal cells, while tight junctions and desmosomes are for sealing and adhesion, respectively.

Explanation:
The mitochondrial matrix contains all Krebs cycle enzymes (except succinate dehydrogenase). Thus, the location is due to enzyme presence. R correctly explains A.

Explanation:
Transpiration occurs mainly through stomata and is a passive process driven by vapor pressure deficit. It creates transpiration pull, aiding water and mineral transport. Guttation is liquid water loss through hydathodes, bleeding is sap oozing from wounds, exudation is a general term for fluid release.