Which of the following is a steroid hormone? MCQ with Answer and Explanation

Explanation:
The hypothalamus is a small, highly complex region located at the base of the brain, near the pituitary gland. It is the primary link between the nervous and endocrine systems. It controls the pituitary gland (the 'master gland') both neurally (via the posterior pituitary, where it stores and releases ADH and oxytocin) and hormonally (via the anterior pituitary, by secreting releasing and inhibiting hormones that regulate the production of anterior pituitary hormones). Through the pituitary, the hypothalamus regulates a vast array of bodily functions.

Explanation:
Lactase is a brush border enzyme in the small intestine that hydrolyzes lactose (milk sugar) into its constituent monosaccharides. Maltase acts on maltose, sucrase on sucrose, amylase on starch. Lactose intolerance results from lactase deficiency.

Explanation:
Pellagra is caused by a severe deficiency of Vitamin B3 (Niacin) or its precursor, the amino acid tryptophan. The classic symptoms are the '4 Ds': dermatitis (symmetrical, pigmented rash on sun-exposed skin), diarrhea, dementia (neurological symptoms), and eventually death if untreated. It is historically associated with diets heavily reliant on untreated corn (maize), which has low bioavailable niacin and tryptophan.