Consider statements about genetics: 1. DNA replication is semi-conservative. 2. Transcription occurs in the cytoplasm. 3. Translation occurs at ribosomes. Which are correct? MCQ with Answer and Explanation

Explanation:
The beta cells of the pancreatic islets of Langerhans produce insulin, which lowers blood glucose by promoting cellular uptake and glycogen synthesis. The liver stores glucose, the spleen filters blood, the thyroid regulates metabolism.

Explanation:
Vitamin D3 (cholecalciferol) is synthesized in the epidermis of the skin when 7-dehydrocholesterol is exposed to ultraviolet B (UVB) radiation from sunlight. Vitamin B12 (cobalamin) is unique among vitamins as it contains the metal ion cobalt in its structure. Vitamin K, not Vitamin A, is essential for the synthesis of blood clotting factors. Vitamin A is crucial for vision and immunity. Thus, statements 1 and 2 are correct.

Explanation:
The Golgi apparatus receives proteins from the rough ER, modifies them (e.g., glycosylation), sorts them, and packages them into vesicles for transport to the plasma membrane, lysosomes, or secretion. Lysosomes digest, rough ER synthesizes proteins, mitochondria generate ATP.