Which part of the brain controls body temperature, hunger, and thirst? MCQ with Answer and Explanation

Explanation:
Plasmolysis occurs when a plant cell is placed in a hypertonic solution, causing water to leave the cell by exosmosis, leading to shrinkage of the protoplasm and its detachment from the cell wall. Incipient plasmolysis is when protoplast just starts to pull away. Opposite is deplasmolysis (when placed in hypotonic solution). Swelling is turgidity. Animal cells undergo crenation or lysis.

Explanation:
The Blood-Brain Barrier (BBB) is formed by tight junctions between endothelial cells in brain capillaries, making it highly selective. It allows the free diffusion of small, lipid-soluble molecules and essential gases. Therefore, oxygen, carbon dioxide, and lipid-soluble substances (like alcohol, nicotine, and some anesthetics) easily cross. Glucose, a water-soluble molecule essential for brain energy, crosses via specific carrier-mediated transport (GLUT1 transporters). Large proteins, peptides, most water-soluble drugs, and pathogens like bacteria and viruses are generally blocked from entering the brain parenchyma.

Explanation:
Cyanobacteria contain chlorophyll a (like plants) along with phycobilins (phycocyanin and phycoerythrin). Chlorophyll b is in green plants, phycocyanin is an accessory pigment.