Free Homeostasis MCQs with Answers
698 Homeostasis MCQs from Biology, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
Homeostasis maintains a stable internal environment through the kidney and urinary system, thermoregulation and excretion. The kidney topics include filtration, selective reabsorption, urine formation and water balance, while thermoregulation involves sweating, vasodilation, vasoconstriction and hormonal control; excretion is different from egestion, which removes undigested food.
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Read the Homeostasis notesFree MDCAT chapter notes with key terms698 questions · page 4 of 35
- A. Vasodilation & sweating
- B. Vasoconstriction
- C. Shivering
- D. Renin secretion
Explanation: Cooling in hot conditions depends on dilating the skin arterioles so more warm blood reaches the surface and on evaporating sweat, which…
Correct answer: Vasodilation & sweating- A. Freshwater Fish
- B. Amphibians
- C. Birds
- D. Mammals
Explanation: Uric acid is almost insoluble, so it can be excreted as a paste with very little water, which suits birds both for flight and for…
Correct answer: Birds- A. Skin
- B. Liver
- C. Lungs
- D. GIT
Explanation: Sweat is produced by sweat glands and sebum by sebaceous glands, both located in the skin.
Correct answer: Skin- A. hepatology
- B. hematology
- C. mycology
- D. None of These
Explanation: Hepatology is the branch of medicine concerned with the liver and its diseases.
Correct answer: hepatology- A. Excretion
- B. Circulation
- C. Reproduction
- D. Pollution
Explanation: Excretion removes metabolic wastes such as urea and also eliminates excess water and salts from the body, mainly through the kidneys.
Correct answer: Excretion- A. Kidney
- B. Liver
- C. Lungs
- D. Heart
Explanation: The liver is a major metabolic organ, carrying out carbohydrate, lipid, and protein metabolism as well as detoxification and synthesis of…
Correct answer: Liver- A. External space
- B. Internal Body cavity
- C. In gut
- D. In Bladder
Explanation: In an earthworm, the nephrostome is the ciliated funnel that opens internally into the coelom and receives coelomic fluid.
Correct answer: Internal Body cavity- A. Nephrostome
- B. Nephridiopore
- C. Flame cell
- D. Anus
Explanation: The nephrostome is the funnel-shaped opening through which an earthworm's nephridium receives fluid from the coelom.
Correct answer: Nephrostome- A. Blood
- B. Lymph
- C. Gut
- D. Hemolymph
Explanation: In insects, Malpighian tubules remove nitrogenous wastes and salts from the haemolymph, the insect equivalent of blood.
Correct answer: Hemolymph- A. Nephrostome
- B. Nephridiopore
- C. Both of these
- D. None of these
Explanation: The nephrostome of an earthworm has cilia that create a current and draw coelomic fluid into the nephridium.
Correct answer: Nephrostome- A. Hydra
- B. Planaria.
- C. Humans
- D. Birds.
Explanation: Birds excrete nitrogen mainly as uric acid, which requires little water and forms a semi-solid paste, an adaptation useful for flight and…
Correct answer: Birds.- A. Ammonia
- B. Urea
- C. Uric acid
- D. Trimethylamine oxide
Explanation: Ammonia is the most toxic of these nitrogenous wastes because it interferes rapidly with cellular metabolism and must be diluted with…
Correct answer: Ammonia- A. Round worms
- B. Flateworm
- C. Tape worms
- D. Segmented worms
Explanation: Protonephridia are flame-cell excretory systems found in flatworms, including planarians and tapeworms.
Correct answer: Flateworm- A. Ammonia
- B. Urea
- C. Uric acid
- D. Trimethylamine oxide
Explanation: Aquatic animals commonly excrete ammonia because it is highly toxic but can be rapidly diluted and removed in abundant water.
Correct answer: Ammonia- A. Excessive urea which will increase their internal solute concentration and prevent body shrinkage in hypertonic environment
- B. Trimethyl alanine
- C. Ammonia
- D. Trimethylamine oxide
Explanation: Trimethylamine oxide, commonly called TMAO, acts as an important osmolyte in marine animals and helps maintain internal solute balance in…
Correct answer: Trimethylamine oxide- A. Bony Marine fishes
- B. Fresh water fishes
- C. Both depending upon the surrounding water
- D. None of these
Explanation: Freshwater fishes gain water by osmosis because their body fluids are more concentrated than the surrounding water, so they excrete a…
Correct answer: Fresh water fishes- A. Osmoconformation
- B. Osmoregulaton
- C. Anhydrobiosis
- D. Anhydrosis
Explanation: Anhydrobiosis is a state in which an organism tolerates extreme dehydration by greatly reducing metabolic activity until water returns.
Correct answer: Anhydrobiosis- A. Stem
- B. Leaves
- C. Flowers
- D. Roots
Explanation: Leaves are called excretophores because plants commonly remove or store wastes in leaves that later fall, carrying those wastes away.
Correct answer: Leaves- A. It does not produce waste material
- B. Due to absence of mesoderm
- C. The whole body cells are in contact with water
- D. It has pseudocoelom.
Explanation: Hydra has no specialised excretory organs because its simple body is surrounded by water and its cells can lose soluble wastes directly by…
Correct answer: The whole body cells are in contact with water- A. Creatinine
- B. Trimethyamine oxide
- C. Pyrimidine
- D. Ammonia
Explanation: Ammonia is the simplest nitrogenous waste and is formed when amino acids are deaminated; many aquatic animals excrete it directly because…
Correct answer: Ammonia