All Free Biology MCQs with Answers

• A. Creatinine
• B. Bilirubin
• C. Hypoxanthin
• D. Xanthin

Explanation: Bilirubin is the end product of haemoglobin breakdown. When haemoglobin from old red blood cells is broken down, bilirubin is formed as a…

• A. 500 ml
• B. 300 litre.
• C. 5 litre.
• D. 500 litre.

Explanation: 1kg of ammonia to be excreted in the form of Ammonia requires 500 liters of waterUrea requires 50 liters of waterUric acid requires 1…

• A. 20
• B. 30
• C. 25
• D. 50

Explanation: Since only 1 ml of water is required to eliminate 1 g of nitrogen in the form of uric acid, then 50 g of nitrogen will be eliminated by 50…

• A. Planaria.
• B. Cockroach.
• C. Hydra.
• D. Earthworm.

Explanation: Earthworms are Annelids possessing complex metanephridia.

• A. Uric acid
• B. Creatine
• C. Urea
• D. Creatinine

Explanation: Option [a] Uric acid is the chemical created when the body breaks down substances called purines, nucleic acid contains purines, adenine…

• A. Urea
• B. Ammonia
• C. Salts
• D. Uric acid

Explanation: Urea is the main nitrogenous waste product in humans, that is produced in the liver after deamination of amino acids.

• A. Thermoregulation
• B. Osmoregulation
• C. Kidney Failure
• D. Excretion

Explanation: Excretion is the process why which metabolic waste is removed from our body its includes the removal of waste through kidney,skin or…

• A. CO2
• B. Uric Acid
• C. Urea
• D. Ammonia

Explanation: The table above shows that ammonia requires the highest percentage of water for excretion, which shows that ammonia contains the highest…

• A. 3.00
• B. 4.50
• C. 2.00
• D. 6.00

Explanation: Pepsin works best at a pH of around 2.00, which is highly acidic. The low pH helps denature proteins and allows pepsin to cleave peptide…

• A. Increases many folds
• B. Decreases
• C. Remains constant
• D. Is doubled

Explanation: Since CO2 reacts with water to form carbonic acid, an increase in CO2 results in a decrease in blood pH resulting in haemoglobin proteins…

• A. Air sac
• B. Trachea
• C. Larynx
• D. Bronchioles

Explanation: Option [a] Air sacs, and alveoli are present at the end of bronchioles in lungs where lungs and blood exchange oxygen and carbon dioxide…

• A. It must be permeable
• B. It must be thick for low diffusion
• C. It should be non-vascularized
• D. It should have low ventilation mechanism

Explanation: Respiratory surfaces, such as the alveoli in the lungs, must be permeable to allow the exchange of gases (oxygen and carbon dioxide)…

• A. Photorespiration
• B. Ventilation
• C. Gaseous transport
• D. Respiration

Explanation: Ventilation is the process of moving air in and out of the respiratory system, allowing for the exchange of gases (such as oxygen and…

• A. Carbonate
• B. Bicarbonate
• C. Tricarbonate
• D. Carbonic anhydrase

Explanation: About 70 percent of CO2 is transported in the form of Bicarbonate ions.

• A. Cardiac Sphincter
• B. Esophageal Sphincter
• C. Ileocolic Sphincter
• D. Pyloric Sphincter

Explanation: Explanation:The junction between esophagus and stomach is known as cardiac sphincter.

• A. Enterokinase
• B. Chyme
• C. Lipase
• D. Erypsin

Explanation: Explanation:Like Pepsin, trypsin is also secreted as inactive trypsinogen, which is activated by enterokinase.

• A. Digestion of triglycerides
• B. Digestion of lipids
• C. Digestion of all types of food
• D. Digestion of carbohydrates

Explanation: Option [A] Gastric Lipase breaks down fats in the stomach.Option [B] Lipase breaks down Lipids into fatty acids and glycerol.Option[C]…

• A. At the junction of esophagus and stomach
• B. At the junction of stomach and small intestine
• C. At the junction of ileum and large intestine
• D. At the junction of small intestine and large intestine

Explanation: Option[A] cardiac sphincter is present at the junction of esophagus and stomach.Option[B] pyloric sphincter is present at the junction of…

• A. Obesity
• B. Anorexia nervosa
• C. Dyspepsia
• D. Bulimia nervosa

Explanation: Option[a] Obesity is defined as the accumulation of abnormal or excessive fat that may impair health.Option [b] Anorexia nervosa is an…

• A. Liver
• B. Kidney
• C. Nephron
• D. Glomerulus

Explanation: Option [a] Liver plays a central role in all metabolic processes in the body.