Which of the following is a vascular cryptogam? MCQ with Answer and Explanation

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:
Edward Jenner developed the first successful smallpox vaccine (1796). Pasteur invented pasteurization and rabies vaccine, not penicillin. Fleming discovered penicillin. Hooke coined the term 'cell' but did not discover bacteria; Leeuwenhoek observed bacteria. Thus, the correct match is Jenner - smallpox vaccine.

Explanation:
The Blood-Brain Barrier (BBB) is a highly selective semipermeable border that protects the brain from many substances in the blood. It is primarily formed by the tight junctions between the endothelial cells of the brain's capillaries. These endothelial cells are closely associated with the foot processes of astrocytes (a type of glial cell), which induce and maintain the tight junctions, restricting the passage of large molecules, toxins, and pathogens into the brain tissue.