The organelle that contains oxidative enzymes and is involved in photorespiration is: MCQ with Answer and Explanation

Explanation:
The heart is a muscular pump that circulates blood through the cardiovascular system, delivering oxygen and nutrients to tissues and removing waste. The lungs are the primary organs of the respiratory system, where gas exchange occurs: oxygen diffuses from the alveoli into the blood, and carbon dioxide diffuses from the blood into the alveoli to be exhaled. The kidneys are the primary excretory organs, filtering blood to remove metabolic waste, excess water, and ions, producing urine. All statements are correct.

Explanation:
Oxytocin, produced in the hypothalamus and released from the posterior pituitary, triggers the milk let-down reflex by causing myoepithelial cells around alveoli to contract upon suckling. Prolactin stimulates milk synthesis. Estrogen and progesterone are involved in breast development during pregnancy but not the immediate ejection reflex.

Explanation:
The Loop of Henle is a U-shaped tube extending into the renal medulla. Its primary function is to concentrate the urine by creating a hyperosmotic gradient in the medullary interstitium through the counter-current multiplier mechanism. The descending limb is permeable to water but not salts, while the ascending limb is impermeable to water but actively transports salts out. This gradient allows the collecting duct to reabsorb water under the influence of ADH.