The chemical name of vitamin B₂ is: MCQ with Answer and Explanation

Explanation:
The 'ozone hole' is a severe, seasonal thinning of the stratospheric ozone layer that occurs most prominently over the Antarctic region during the Southern Hemisphere's spring (September to November). This is due to the unique meteorological conditions in the Antarctic stratosphere, including the formation of Polar Stratospheric Clouds (PSCs) during the dark, cold winter, which provide surfaces for chemical reactions that release active chlorine from CFCs, rapidly destroying ozone when sunlight returns.

Explanation:
Aldosterone, secreted by the adrenal cortex, increases sodium reabsorption (and water follows) and potassium secretion in the distal tubule and collecting duct. ADH increases water reabsorption only. Renin is an enzyme, natriuretic peptides inhibit sodium reabsorption.

Explanation:
Crossing over is the exchange of genetic material between non-sister chromatids of homologous chromosomes during prophase I of meiosis. This leads to genetic recombination. Sister chromatid exchange does occur but crossing over specifically refers to the exchange between homologues.