Fossils are most commonly found in which type of rock? MCQ with Answer and Explanation

Explanation:
The ozone layer, which absorbs harmful UV radiation, is located in the stratosphere. Chlorofluorocarbons (CFCs) release chlorine atoms in the stratosphere that catalytically destroy ozone molecules. Global warming is primarily driven by the greenhouse effect due to excess carbon dioxide and other greenhouse gases, not oxygen. Thus, statements 1 and 2 are correct.

Explanation:
Lysosomes contain about 40 types of hydrolytic enzymes (hydrolases) like proteases, lipases, nucleases, glycosidases, which digest macromolecules. They function in acidic pH (5.0). Oxidoreductases catalyze oxidation-reduction, transferases transfer groups, isomerases catalyze isomerization. Lysosomes are involved in autophagy, phagocytosis, and programmed cell death. Their rupture leads to autolysis, hence called 'suicide bags'.

Explanation:
Resistin is a cysteine-rich peptide hormone secreted primarily by adipose tissue in humans (though in rodents, it is mainly secreted by macrophages). Its name is derived from its proposed role in 'resistance' to insulin. Its primary function is to antagonize the action of insulin, thereby promoting insulin resistance. It does this by increasing hepatic glucose production (gluconeogenesis) and impairing glucose uptake by muscle and adipose tissue. Elevated levels of resistin are associated with obesity and type 2 diabetes, linking adiposity to insulin resistance.