All Free Biology MCQs with Answers

1411. The type of learning in which there is loss or decrease in response to repeated stimuli?

• A. Imprinting
• B. Habituation
• C. Latent learning
• D. Insight learning

Explanation: Habituation is a non-associative form of learning in which an organism's response decreases after repeated exposure to a harmless stimulus. The likely mistake is imprinting, which is rapid learning during a sensitive period rather than a gradual reduction in response.

1412. Highest form of learning is__________________?

• A. Latent learning
• B. Insight learning
• C. Operant conditioning
• D. Instinct

Explanation: Insight learning occurs when an animal suddenly reorganises its understanding of a problem and reaches a solution, rather than relying only on repeated trial and error. It is therefore considered a higher form of learning than simple conditioning or instinctive behaviour. Operant conditioning is a likely distractor because it can produce complex learned behaviour, but it depends on reinforcement rather than sudden problem-solving insight.

1413. _____________ is a nervous disorder characterized by involuntary tremors, diminished motor power and rigidity?

• A. Epilepsy
• B. Meningitis
• C. Alzheimer's disease
• D. Parkinson's disease

Explanation: Parkinson's disease results mainly from degeneration of dopamine-producing neurons involved in motor control, causing resting tremors, rigidity and reduced movement. Epilepsy is the most likely alternative because it is also a nervous disorder, but it is characterized mainly by recurrent seizures rather than progressive motor rigidity.

1414. Which is an organic compound found in most cells ?

• A. Water
• B. Glucose
• C. Oxygen
• D. Sodium chloride

Explanation: Glucose is an organic carbohydrate because it contains carbon and hydrogen bonded in a carbon-based molecular structure and serves as a major cellular fuel. Water, oxygen and sodium chloride are inorganic substances, so water is the likely distractor when students interpret “found in cells” rather than “organic compound.”

1415. ___________ are needed as a source of energy for the vital activities of the body?

• A. Calcium
• B. Iron
• C. Water
• D. Carbohydrates

Explanation: Carbohydrates are broken down into glucose and other simple sugars, which cells use in cellular respiration to release energy for vital activities. Water is essential for reactions and transport but does not serve as an energy-yielding nutrient, so option c is the likely misconception.

1416. Molish test is used for ___________?

• A. Protein
• B. carbohydrates
• C. Flavoprotein
• D. lipid

Explanation: Molisch's test is a general test for carbohydrates because carbohydrate dehydration products react with alpha-naphthol to produce a violet ring. Students may choose protein because proteins are also commonly identified by colour tests, but the Molisch reaction specifically detects carbohydrates.

1417. What is the nickname of glucose?

• A. Dextrose
• B. Sugar
• C. Glycogen
• D. Starch

Explanation: Glucose is also called dextrose, especially because naturally occurring glucose rotates plane-polarized light to the right. Glycogen and starch are storage polysaccharides made from glucose, so students may choose them by confusing a glucose name with glucose storage forms.

1418. Who is the father of carbohydrate ?

• A. Claude Silbert Hudson
• B. Anselme Payen
• C. Jons jacob Berzeliis
• D. Justus von Liebig

Explanation: Claude Silbert Hudson is commonly described in older textbooks as a father of carbohydrate chemistry because of his work on sugar stereochemistry and structural relationships. Anselme Payen is linked with the discovery of cellulose and diastase, so students may choose him by confusing important carbohydrate discoveries with the title in the question.

1419. The form of carbohydrate which is synthesised in a plants is_________?

• A. Starch
• B. Glucose
• C. Fructose
• D. Cellulose

Explanation: Plants synthesize glucose during photosynthesis from carbon dioxide and water using light energy, and glucose is then used to form other carbohydrates. Students may choose starch because it is the main storage carbohydrate in plants, but starch is produced from glucose rather than being the initial photosynthetic product.

1420. In onion food is stored in_______________?

• A. Aerial stem
• B. Root
• C. Scale leaves
• D. Bud

Explanation: An onion bulb is a modified underground stem whose fleshy scale leaves store carbohydrates and water. Students may choose a bud because the bulb contains a central growing bud, but the stored food is mainly held in the thickened scale leaves surrounding it.