All Free Biology MCQs with Answers

• A. Nephritis
• B. Nephrosis
• C. Ptosis
• D. Anuria

Explanation: Anuria is a condition characterized by the absence or significantly reduced production of urine by the kidneys.

• A. Heart
• B. Liver
• C. Stomach
• D. Kidneys

Explanation: Vasopressin, also known as antidiuretic hormone (ADH), plays a crucial role in maintaining the body's water balance.

• A. Polyuria
• B. Glycusuria
• C. Polyphagia
• D. Polydipsia

Explanation: Polydipsia is a medical name for the feeling of extreme thirstiness. Polydipsia is an early symptom of diabetes mellitus and diabetes…

• A. 140 grams
• B. 160 grams
• C. 130 grams
• D. 150 grams

Explanation: The average weight of each human kidney is about 160 grams. This value can vary slightly based on factors such as age, gender, and overall…

• A. 70-80%
• B. 80-90%
• C. 60-70%
• D. 60-80%

Explanation: Approximately 80%-90% of all nephrons in the human kidney are cortical nephrons.

• A. Ureter
• B. Urethra
• C. Urinary bladde
• D. Pelvis

Explanation: The rare site of infection in the urinary tract is the ureter. The ureter is the tube that carries urine from the kidneys to the bladder.

• A. Proximal convulated tubule
• B. Glomerulus
• C. Loop of Henle
• D. Bowman's capsule

Explanation: Option C, the "Loop of Henle," is responsible for concentrating urine in the kidney due to its unique anatomical and functional…

• A. Sweating
• B. Kidney function
• C. Evaporation through the skin
• D. Respiratory loss

Explanation: Option b is correct. Kidneys play a central role in regulating water balance through processes like filtration, reabsorption, and…

• A. Distal tubule
• B. Urethra
• C. Urinary bladder
• D. Ureter

Explanation: The urethra is the final pathway for urine to leave the body. It is a tube that connects the urinary bladder to an external opening…

• A. Middle ear
• B. Internal ear
• C. Gills
• D. Fins

Explanation: Option A: Middle ear and external ear are not found in fishes. All tetrapods i.e.

• A. pigeon
• B. frog
• C. monkey
• D. rabbit

Explanation: Occipital condyle is a rounded knob-like structure that is present at the base of the skull which articulates with the first vertebra.

• A. Typhlosole
• B. Intestinal caeca
• C. Esophagus
• D. Pharyngos mass

Explanation: The pharynx of an earthworm, particularly the pharyngeal mass, is where various digestive enzymes are secreted.

• A. Papillae
• B. Setae
• C. Pseudopodia
• D. Cuticle

Explanation: Organs of locomotion in earth worms are setae. Setae are present on parapodia on the body wall or embedded in sacs.

• A. Leopardfish
• B. Fish
• C. Crocodile
• D. None of above

Explanation: Fishes have two chambered heart which include an auricle and an ventricle.

• A. Uromastyx
• B. Salamander
• C. Seahorse
• D. Kangaroo

Explanation: Homoeothermic animals are those animals which can maintain their body temperature irrespective of external temperature variation, i.e.

• A. Sycon
• B. Leucosolenia
• C. Spongilla
• D. Euplectella

Explanation: Spongilla is the only freshwater sponge among the options provided. It is typically found in clean lakes and slow-moving streams.

• A. Amoeba
• B. Earthworms
• C. Grasshoppers
• D. Man

Explanation: Grasshoppers have an open circulatory system with a heart. Their blood just bathes over their cells.

• A. Digitgrade
• B. Unguligrade
• C. Plantigrade

Explanation: A digitgrade is defined as those group of mammals that solely walk on their toes only and not touching the ground with their heels for…

• A. Ascaris
• B. Neresis
• C. Trichinella
• D. Guinea worm

Explanation: Nematodes are free living or parasite, and live in soil, roots, human and animal intestine and muscles.

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

Explanation: Crustaceans form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill…