Consider statements about human nutrition: 1. Carbohydrates are the main source of energy. 2. Proteins are needed for growth and repair. 3. Fats are not needed for any bodily function. Which are correct? MCQ with Answer and Explanation

Explanation:
Parathyroid Hormone (PTH) is a peptide hormone secreted by the chief cells of the four parathyroid glands in response to low blood calcium levels (hypocalcemia). Its primary function is to increase blood calcium levels (hypercalcemic effect). It achieves this by: 1) Stimulating osteoclasts to break down bone, releasing calcium. 2) Increasing calcium reabsorption and stimulating the activation of Vitamin D in the kidneys. 3) Indirectly increasing calcium absorption in the gut via active Vitamin D. It has the opposite effect of calcitonin.

Explanation:
Guttation is the exudation of water droplets containing dissolved salts from hydathodes at leaf margins, occurring under high humidity and low transpiration, due to root pressure. Transpiration is loss of water vapor through stomata. Bleeding is oozing of sap from cut plant parts. Translocation is transport of organic solutes. Guttation is visible as morning dew drops.

Explanation:
Spectrin is a cytoskeletal protein that lines the inner surface of the RBC membrane, maintaining its biconcave shape and providing elasticity to squeeze through capillaries. Hemoglobin carries oxygen, myosin is a motor protein, keratin is structural in skin/hair. Defects in spectrin cause spherocytosis.