Q1. Which of the following is known as the powerhouse of the cell?
a) Ribosome
b) Mitochondria
c) Endoplasmic Reticulum
d) Golgi Apparatus
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Correct Answer: b) Mitochondria
Explanation: Mitochondria are often referred to as the powerhouse of the cell because they generate most of the cell’s supply of adenosine triphosphate (ATP), used as a source of chemical energy.
Q2. Which of the following is responsible for carrying oxygen in the blood?
a) Hemoglobin
b) Insulin
c) Glucose
d) Platelets
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Correct Answer: a) Hemoglobin
Explanation: Hemoglobin is a protein found in red blood cells that carries oxygen from the lungs to the body’s tissues and returns carbon dioxide from the tissues back to the lungs.
Q3. What is the basic unit of heredity?
a) Protein
b) Gene
c) Enzyme
d) Chromosome
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Correct Answer: b) Gene
Explanation: A gene is a sequence of DNA that contains the instructions for building one or more proteins, which determine an organism’s traits and characteristics.
Q4. Which process is responsible for the conversion of sunlight into chemical energy in plants?
a) Respiration
b) Photosynthesis
c) Fermentation
d) Transpiration
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Correct Answer: b) Photosynthesis
Explanation: Photosynthesis is the process by which green plants and some other organisms use sunlight to synthesize foods with the help of chlorophyll, converting carbon dioxide and water into glucose and oxygen.
Q5. What is the powerhouse of photosynthesis in plant cells?
a) Chloroplasts
b) Vacuole
c) Nucleus
d) Cytoplasm
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Correct Answer: a) Chloroplasts
Explanation: Chloroplasts are organelles found in plant cells that contain chlorophyll and are responsible for carrying out photosynthesis.
Q6. Which enzyme is responsible for breaking down carbohydrates in the digestive system?
a) Amylase
b) Lipase
c) Protease
d) Maltase
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Correct Answer: a) Amylase
Explanation: Amylase is an enzyme produced by the pancreas and salivary glands that breaks down starches and carbohydrates into sugars such as glucose and maltose.
Q7. Which of the following is known as the “master gland” of the endocrine system?
a) Thyroid
b) Adrenal gland
c) Pituitary gland
d) Pancreas
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Correct Answer: c) Pituitary gland
Explanation: The pituitary gland is often referred to as the master gland because it produces and controls the release of hormones that regulate various bodily functions and control the activities of other endocrine glands.
Q8. Which type of blood vessels carry blood away from the heart?
a) Veins
b) Arteries
c) Capillaries
d) Venules
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Correct Answer: b) Arteries
Explanation: Arteries are blood vessels that carry oxygen-rich blood away from the heart to the rest of the body’s tissues and organs.
Q9. Which part of the brain is responsible for regulating balance and coordination?
a) Cerebrum
b) Cerebellum
c) Medulla oblongata
d) Hypothalamus
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Correct Answer: b) Cerebellum
Explanation: The cerebellum is a region of the brain located at the back of the skull that plays a key role in controlling balance, coordination, and voluntary movements.
Q10. Which of the following is responsible for protecting the body against pathogens?
a) Antibodies
b) Hormones
c) Enzymes
d) Antigens
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Correct Answer: a) Antibodies
Explanation: Antibodies are proteins produced by the immune system in response to the presence of foreign substances called antigens, and they help the body recognize and neutralize pathogens such as bacteria and viruses.