Consider statements about cell biology: 1. Prokaryotic cells lack a true nucleus. 2. Eukaryotic cells have membrane-bound organelles. 3. Plant cells lack a cell wall. Which are correct? MCQ with Answer and Explanation

Explanation:
The pituitary gland is termed the master gland because it secretes hormones that regulate other endocrine glands. The thyroid gland secretes thyroxine, triiodothyronine, and calcitonin, which regulates blood calcium. The adrenal cortex secretes cortisol (a glucocorticoid), while the adrenal medulla secretes adrenaline and noradrenaline. Thus, statements 1 and 2 are correct.

Explanation:
The hepatic portal vein is a unique blood vessel in the circulatory system that carries nutrient-rich, but potentially toxin-laden, blood from the gastrointestinal tract (stomach, intestines), spleen, and pancreas directly to the liver, rather than to the heart. This allows the liver to process absorbed nutrients, store glycogen, detoxify harmful substances, and regulate blood composition before the blood enters the systemic circulation via the hepatic veins to the inferior vena cava.

Explanation:
GIP (glucose-dependent insulinotropic peptide) is released from the small intestine in response to fat and glucose, inhibiting gastric secretion and motility. Gastrin stimulates acid secretion, secretin stimulates bicarbonate, CCK stimulates gallbladder contraction.