The primary reason for the depletion of the ozone layer is the emission of: MCQ with Answer and Explanation

Explanation:
Pinocytosis ('cell drinking') is a form of endocytosis where the cell membrane invaginates to take in a small droplet of extracellular fluid and dissolved solutes. Phagocytosis is 'cell eating' of large particles, exocytosis is secretion, osmosis is water movement across a semipermeable membrane.

Explanation:
The Casparian strip is a band of cell wall material that runs radially and transversely through the cell walls of the endodermal cells in plant roots, but is absent from the tangential walls. It is primarily composed of suberin (a waxy, waterproof substance) and lignin (a complex polymer). This strip acts as a physical and chemical barrier, blocking the passive, apoplastic flow of water and dissolved minerals between the cells. It forces these substances to cross the selectively permeable plasma membrane and enter the symplastic pathway, allowing the plant to control what enters the vascular cylinder.

Explanation:
Mature human RBCs have a lifespan of approximately 120 days, after which they are phagocytosed by macrophages in the spleen and liver. They lack nuclei and organelles, thus cannot repair themselves. New RBCs are produced in the bone marrow at a rate of about 2 million per second. Erythropoietin stimulates RBC production.