Human heart is made up of how many chambers?
- (a)Only three
- (b)Only two
- (c)Only one
- (d)Only four
Correct — D, Only four. The human heart has four chambers: two upper chambers called atria (the right atrium and left atrium) that receive blood, and two lower chambers called ventricles (the right ventricle and left ventricle) that pump it out. The right side handles deoxygenated blood and sends it to the lungs, while the left side handles oxygenated blood and pumps it to the body. This four-chambered plan, shared by birds and mammals, keeps oxygenated and deoxygenated blood fully separated (double circulation).
- (a)Only three — A three-chambered heart (two atria and one ventricle) is found in amphibians and most reptiles, not in humans.
- (b)Only two — A two-chambered heart (one atrium and one ventricle) is characteristic of fishes, not humans.
- (c)Only one — No vertebrate, and certainly not a human, has a truly single-chambered heart.
The human heart is a four-chambered muscular pump. The two atria receive incoming blood and the two ventricles pump blood out; the left ventricle, which pushes blood to the whole body, has the thickest wall. Separating the four chambers allows oxygenated and deoxygenated blood streams to stay apart, supporting efficient double circulation.
The trap is that biology also teaches the heart types of lower vertebrates — two chambers in fish, three in amphibians — and a candidate may misfire and pick 'three' or 'two'. Humans are mammals, so the answer is firmly four.
- The human heart has 4 chambers: 2 atria (upper, receiving) and 2 ventricles (lower, pumping).
- The right side carries deoxygenated blood to the lungs; the left side carries oxygenated blood to the body.
- Four chambers keep the two blood streams separate — the basis of double circulation.
- Chamber count by group: fish 2, amphibians/most reptiles 3, birds and mammals 4.
- Applying the fish (2) or amphibian (3) heart plan to humans
- Confusing the number of chambers with the number of valves
UPPSC/UPSC ask basic human physiology as single-fact recall or as comparative anatomy across animal groups.
No directly related past PYQ was found.
- practice — not a real PYQ
A three-chambered heart (two atria and one ventricle) is characteristic of which group of animals?
- (a)Fishes
- (b)Amphibians
- (c)Birds
- (d)Mammals
Answer(b) Amphibians — they have two atria and a single ventricle.
- practice — not a real PYQ
The two upper, blood-receiving chambers of the human heart are called?
- (a)Ventricles
- (b)Atria
- (c)Valves
- (d)Septa
Answer(b) Atria — the right and left atria receive blood returning to the heart.