Which of the following is a correct statement about the circulation of blood in humans?
A. The right ventricle pumps blood to the lungs.
B. Pulmonary vein carries deoxygenated blood.
C. The left atrium receives deoxygenated blood from the body.
D. Pulmonary artery carries oxygenated blood.
Answer: Option A
Solution (By JKSSB Mock Tests)
The right ventricle pumps deoxygenated blood through the pulmonary artery to the lungs for oxygenation. The pulmonary artery is the only artery carrying deoxygenated blood. Pulmonary veins carry oxygenated blood from lungs to the left atrium. The left atrium receives oxygenated blood, not deoxygenated. The right atrium receives deoxygenated blood from the body. Thus, C is correct.
Explanation:
Angiotensin II is a powerful octapeptide hormone formed in the blood by the action of angiotensin-converting enzyme (ACE). It has multiple effects to increase blood pressure and volume. It is a potent vasoconstrictor, increasing systemic vascular resistance. Crucially, it also acts on the zona glomerulosa of the adrenal cortex to stimulate the secretion of the mineralocorticoid hormone aldosterone. Aldosterone then acts on the kidneys to increase sodium and water reabsorption, further increasing blood volume and pressure.
Explanation:
Ecological succession is the gradual and predictable process of change in the species composition of an ecological community over time. It occurs after a disturbance (secondary succession) or on a newly formed, lifeless substrate (primary succession). The final, stable community that is in near equilibrium with the environment is called the climax community. The entire sequence of communities is called a sere.
No comments yet. Be the first to start the discussion!