All Free Biology MCQs with Answers

• A. Transport of water
• B. Uptake of sodium in loop of Henle
• C. Transport of K* ions inta kidney
• D. Reabsorption of water

Explanation: Explanation:Aldosterone is a hormone that is involved in osmoregulation and blood pressure regulation.

• A. Ultrasound
• B. Dialysis
• C. Lithotripsy
• D. X-ray

Explanation: Explanation:Lithotripsy means breaking stones. It is a non-invasive procedure.

• A. Striated muscles
• B. Smooth muscles
• C. Sphincter muscles
• D. Circular muscles

Explanation: Option[a] Striated muscles are either skeletal muscles or cardiac muscles not in the urinary bladder.Option[b] Smooth muscles are present…

• A. Proximal Tubule
• B. Distal Tubule
• C. Collecting Duct
• D. Loop of Henle

Explanation: The interstitial fluid of kidney is gradually concentrated from cortical to medullary part ,thus inner medulla is highly concentrated with…

• A. Proximal Tubule
• B. Distal Tubule
• C. Collecting Duct
• D. Loop of Henle

Explanation: Antidieuretic hormone causes vesicles, which act as aquaporins, to fuse into the membranes of the collecting duct, allowing more water to…

• A. Liver
• B. Abdomen
• C. Kidney
• D. Pancreas

Explanation: Peritoneal indicates that it involves the abdominal cavity, thus dialysis fluid is introduced into the abdomen during peritoneal cavity.

• A. Sodium
• B. Calcium
• C. Potassium
• D. Bicarbonate Ions

Explanation: [A] Aldosterone is a steroid hormone secreted by adrenal glands and its main role is to regulate salt and water levels in blood.[B]…

• A. Distal Tubule
• B. Villi
• C. Cortical Tissue
• D. Proximal Tubule

Explanation: [A] Most of the reabsorption does not occur in DCT cells[B] Villi increases the surface area for absorption in Intestine not in nephron[C]…

• A. Peritubular capillaries
• B. Proximal convoluted tubules
• C. Efferent arterioles
• D. Afferent arterioles

Explanation: Bowman's capsule, a cup-like sac surrounding the glomerulus, is part of the nephron.

• A. Glomerulus
• B. Proximal Tubule
• C. Ascending loop
• D. Descending loop

Explanation: The ascending loop is only permeable to salt ions such as Cl- and Na+. The descending loop, on the other hand, is permeable to water.

• A. Efferent arterioles
• B. Renal vein
• C. Vasa recta
• D. Afferent arterioles

Explanation: The renal artery divides to give afferent arterioles which further divide into the glomerulus network at the bowman's capsule, forming the…

• A. ADH release will be inhibited
• B. ADH will be released in large amount
• C. Aldosterone will be released
• D. Anterior pituitary will produce ADH

Explanation: The anterior pituitary gland would stop releasing ADH which would consequently make the collecting duct impermeable to water so that…

• A. Glomerulus.
• B. Influence of aldosterone.
• C. ADH influencing on collecting duct.
• D. Gradual increase in osmolarity from cortex to medullary portion.

Explanation: The major factor in producing hypertonic urine in mammals is gradually increasing osmotic concentration from the cortex to the medulla.

• A. Reabsorption
• B. Pressure filtration
• C. Secretion
• D. Differential permeability

Explanation: Pressure filtration at the renal corpuscle is the least selective since all molecules with a molecular mass below 69000 pass through the…

• A. Efferent arteriole
• B. Afferent arteriole
• C. Peritubular capillaries
• D. Collecting duct

Explanation: At the distal end of the glomerulus, the capillaries rejoin to form the afferent arteriole through which blood leaves the glomerulus.The…

• A. Prototheria
• B. Metatheria.
• C. Eutheria.
• D. All of these.

Explanation: c) Eutheria: This is the correct option. Eutheria, also known as placental mammals, are a diverse group of mammals that give birth to more…

• A. Arachnida.
• B. Insecta.
• C. Myriapoda.
• D. Crustacea.

Explanation: a) Arachnida: Arachnids are a class of arthropods that include spiders, scorpions, ticks, and mites.

• A. Sepia.
• B. Teredo.
• C. Limax.
• D. Ostrea.

Explanation: Teredo is one of the genera wood-boring bivalve shipworms.

• A. Pseudocoelomata
• B. Coelomata
• C. Acoelomata
• D. None of these

Explanation: Acoelomate is an animal that does not possess a body cavity

• A. Echinodermata
• B. Annelida
• C. Arthropoda
• D. Nematoda

Explanation: Option[A] The larvae of echinodermata [called dipleurula larva] are characterized by bilateral symmetry.