The disease caused by the deficiency of vitamin B₁ is: MCQ with Answer and Explanation

Explanation:
Carbohydrates are the body's primary and most readily available source of energy, broken down into glucose for immediate cellular use. Proteins are essential 'body-building' foods, providing amino acids necessary for the growth, repair, and maintenance of tissues, muscles, and enzymes. Fats are essential macronutrients; they provide concentrated energy, are crucial for cell membrane structure, aid in the absorption of fat-soluble vitamins, and provide essential fatty acids. Thus, statements 1 and 2 are correct.

Explanation:
Renin is secreted by juxtaglomerular cells of the kidney in response to low blood pressure or sodium. It converts angiotensinogen to angiotensin I, initiating the RAAS. Liver produces angiotensinogen, adrenal aldosterone, heart ANP.

Explanation:
After ovulation, the ruptured Graafian follicle transforms into a temporary endocrine structure called the corpus luteum. Its primary function is to secrete large amounts of progesterone (and some estrogen). Progesterone is crucial for maintaining the thickened, highly vascularized uterine endometrium (secretory phase), making it receptive for the implantation of a blastocyst. If fertilization does not occur, the corpus luteum degenerates, progesterone levels drop, and menstruation begins.