Free Homeostasis MCQs with Answers

• A. Protonephridium
• B. Metanephridium
• C. Malpighian tubules
• D. Nephrons

Explanation: Malpighian tubules are insect excretory organs connected to the gut, where they release nitrogenous waste and help regulate salts and…

• A. Ammonia
• B. Urea
• C. Uric acid
• D. Trimethylamine oxide

Explanation: Earthworms are mainly ureotelic, so their principal nitrogenous waste is urea, although some ammonia may also be excreted depending on…

• A. Nephrostome
• B. Nephridiopore
• C. Flame cell
• D. Anus

Explanation: A nephridiopore is the external opening through which an earthworm's nephridium discharges excretory fluid.

• A. 1 ml
• B. 50 ml
• C. 100 ml
• D. 150 ml

Explanation: Urea requires about 50 mL of water for the excretion of 1 g of nitrogen, so the value is 50 mL per gram of nitrogen.

• A. Stored excretory products in vacuoles, at a concentration that leads to crystal formation.
• B. Accumulate waste in leaves, which fall in autumn.
• C. Production of black wood in the center.
• D. Excrete some of the waste materials directly into soil, occasionally using them as a chemical weapon against other competing plants.

Explanation: Conifers can release certain chemical wastes into the soil through their roots, and some of these substances may inhibit competing plants…

• A. CO2
• B. H2O
• C. O2
• D. Both A and B

Explanation: During autotrophic nutrition, plants carry out photosynthesis and release oxygen as a by-product when water is split during the light…

• A. Hagfish
• B. Jelly Fish
• C. Star Fish
• D. Bony fishes

Explanation: Bony fishes are generally considered to have evolved from freshwater ancestors, although many lineages later adapted to marine…

• A. Osmoconformers
• B. Osmoregulators
• C. Both depend upon the concentration of sea water
• D. None of these

Explanation: Most marine invertebrates are osmoconformers, meaning their internal osmotic concentration changes in close relation to that of seawater.

• A. Increases transpiration by increasing the surface area of the leave.
• B. Small and thick leaves to decrease the surface area proportional to the volume of the leave.
• C. Stomata closing in sufficient supply, and opening in restricted supply of water.
• D. None of these

Explanation: Hydrophytes commonly have broad leaves with a large surface area, supporting rapid transpiration and gaseous exchange in their water-rich…

• A. Protection against micro organisms
• B. Temperature regulation
• C. Excretion
• D. All of these

Explanation: Sebum forms an oily coating that reduces water loss and contains substances that inhibit the growth of microorganisms on the skin, so its…

• A. Urine
• B. Blood
• C. Glomerular filterate
• D. Coelomic fluid

Explanation: Haemodialysis passes a patient's blood through a dialysis machine, where wastes and excess salts diffuse across a partially permeable…

• A. Medicine
• B. Surgery
• C. Lithotripsy
• D. Dialysis

Explanation: Small kidney stones may pass with medicines and larger or persistent stones may be removed surgically or broken by lithotripsy using shock…

• A. Urethra
• B. Uretar
• C. Inferno Verna Cava
• D. Suprapubic Tube

Explanation: The ureter is a muscular tube that carries urine from each kidney to the urinary bladder.

• A. 1 cm
• B. 2 cm
• C. 5 cm
• D. 9 cm

Explanation: The membranous urethra is the shortest part of the male urethra and is about 1 cm long.

• A. Liver
• B. Kidney
• C. Lungs
• D. Heart

Explanation: The kidneys filter blood through millions of nephrons, removing nitrogenous wastes and excess water to form urine while retaining useful…

• A. 80.50%
• B. 90.50%
• C. 95.50%
• D. 99.50%

Explanation: The kidneys normally reabsorb about 99% of glomerular filtrate, and under restricted water supply reabsorption can exceed 99.5%, leaving…

• A. Glomerular filtrate
• B. Filtrate passing through ascending limb
• C. Filtrate passing through distal conveluted tubule
• D. Filtrate passing through collecting tubules

Explanation: Glomerular filtrate contains water, salts, glucose and amino acids because these small molecules pass through the filtration barrier from…

• A. Kidney surgery
• B. Burring a hole and removing the stone manually (nephrolithotomy)
• C. Extracorporeal Shock wave lithotripsy
• D. None of these

Explanation: A 0.4 cm stone equals 4 mm, and a stone of this size causing mild to moderate obstruction is commonly treated by extracorporeal shock-wave…

• A. Afferent and efferent arterioles
• B. Peritubualr capillaries
• C. Vasa nervosa
• D. Vasa recta

Explanation: Vasa recta are straight capillaries that run alongside the loops of Henle in juxtamedullary nephrons and help maintain the medullary…

• A. Hagfish
• B. Fresh water fishes
• C. Bony fishes
• D. None of these

Explanation: Marine bony fishes drink seawater because they lose water by osmosis, and their kidneys produce concentrated urine to remove excess salts…