The pigment present in rod cells of the retina that is responsible for vision in dim light is: MCQ with Answer and Explanation

Explanation:
Vaccination introduces antigens (weakened or killed pathogens) to stimulate the body's own immune system to produce antibodies and memory cells without causing disease. This is artificial active immunity. Natural active immunity is acquired by recovering from infection. Artificial passive immunity is direct administration of antibodies (e.g., antiserum). Natural passive immunity is transfer of maternal antibodies to fetus.

Explanation:
The endocrine part of the pancreas—the islets of Langerhans—contains β-cells that secrete insulin (lowers blood glucose), α-cells secrete glucagon (raises blood glucose), and δ-cells secrete somatostatin. Exocrine pancreas secretes digestive enzymes (trypsin, lipase, amylase). Pepsin is from stomach, bile from liver, gastrin from stomach. Insulin deficiency causes diabetes mellitus.

Explanation:
Biodiversity hotspots are biogeographic regions with high levels of species richness and endemism that are under threat. The Western Ghats and Sri Lanka, along with the Himalayas, are recognized biodiversity hotspots in India. They harbor a vast array of flora and fauna, many of which are found nowhere else in the world, due to their unique geographical and climatic conditions.