Here are 25 multiple-choice questions on Basic Science (Biology) tailored for competitive exams like JKSSB, focusing on 12th standard biology concepts.
Basic Science (Biology) – Multiple Choice Questions
Q1. Which of the following organelles is responsible for cellular respiration, generating ATP?
(a) Ribosome
(b) Endoplasmic Reticulum
(c) Mitochondria
(d) Golgi apparatus
Answer: (c)
Explanation: Mitochondria are known as the “powerhouses” of the cell, where cellular respiration takes place to produce ATP (adenosine triphosphate), the cell’s energy currency.
Q2. The process by which green plants convert light energy into chemical energy is called:
(a) Respiration
(b) Transpiration
(c) Photosynthesis
(d) Fermentation
Answer: (c)
Explanation: Photosynthesis is the process used by plants, algae, and cyanobacteria to convert light energy into chemical energy, stored in glucose.
Q3. What is the primary function of DNA in living organisms?
(a) Controlling cell division
(b) Transporting nutrients
(c) Storing genetic information
(d) Catalyzing biochemical reactions
Answer: (c)
Explanation: Deoxyribonucleic acid (DNA) is the hereditary material in humans and almost all other organisms, carrying genetic instructions for the development, functioning, growth, and reproduction of all known organisms.
Q4. Which of the following is an example of a prokaryotic cell?
(a) Human muscle cell
(b) Yeast cell
(c) Bacterial cell
(d) Plant root cell
Answer: (c)
Explanation: Prokaryotic cells are single-celled organisms that lack a membrane-bound nucleus and other membrane-bound organelles. Bacteria and Archaea are examples of prokaryotes.
Q5. The human heart has how many chambers?
(a) Two
(b) Three
(c) Four
(d) Five
Answer: (c)
Explanation: The human heart is a four-chambered muscular organ, consisting of two atria and two ventricles, which are responsible for pumping blood throughout the body.
Q6. Which blood group is considered a universal donor?
(a) A
(b) B
(c) AB
(d) O
Answer: (d)
Explanation: Blood group O-negative is considered the universal donor because it lacks both A and B antigens and the Rh factor, meaning it can be transfused to individuals of any blood group.
Q7. Which hormone is responsible for regulating blood sugar levels in humans?
(a) Thyroxine
(b) Adrenaline
(c) Insulin
(d) Testosterone
Answer: (c)
Explanation: Insulin, produced by the pancreas, plays a crucial role in regulating blood glucose levels by allowing cells to absorb glucose from the bloodstream.
Q8. The primary site of nutrient absorption in the human digestive system is the:
(a) Stomach
(b) Large intestine
(c) Small intestine
(d) Esophagus
Answer: (c)
Explanation: The small intestine is specially adapted for absorption due to its long length and the presence of villi and microvilli, which greatly increase its surface area.
Q9. Which of the following statements about viruses is true?
(a) They are obligate intracellular parasites.
(b) They can reproduce independently outside a host cell.
(c) They possess both DNA and RNA genetic material.
(d) They are classified as prokaryotes.
Answer: (a)
Explanation: Viruses are obligate intracellular parasites, meaning they can only replicate inside the living cells of other organisms. They typically contain either DNA or RNA, but not both.
Q10. What is the purpose of chlorophyll in plants?
(a) To absorb water
(b) To transport nutrients
(c) To absorb light energy for photosynthesis
(d) To provide structural support
Answer: (c)
Explanation: Chlorophyll is the green pigment found in chloroplasts of plant cells that absorbs sunlight for photosynthesis.
Q11. The functional unit of the kidney is the:
(a) Neuron
(b) Alveolus
(c) Nephron
(d) Osteon
Answer: (c)
Explanation: Nephrons are the microscopic structural and functional units of the kidney, responsible for filtering blood and forming urine.
Q12. What is the outermost protective layer of a plant cell called?
(a) Cell membrane
(b) Cytoplasm
(c) Cell wall
(d) Nucleus
Answer: (c)
Explanation: The cell wall is a rigid, protective layer found outside the cell membrane in plant cells, fungi, bacteria, and algae.
Q13. Which part of the brain is primarily responsible for balance and coordination?
(a) Cerebrum
(b) Cerebellum
(c) Medulla oblongata
(d) Thalamus
Answer: (b)
Explanation: The cerebellum is located at the back of the brain and plays a vital role in motor control, including coordination, precision, and accurate timing.
Q14. The process of exchange of gases (oxygen and carbon dioxide) between the blood and the atmosphere is known as:
(a) Digestion
(b) Respiration
(c) Circulation
(d) Excretion
Answer: (b)
Explanation: Respiration, in the context of gas exchange, refers to the physiological process by which organisms obtain oxygen and release carbon dioxide.
Q15. Which vitamin is essential for blood clotting?
(a) Vitamin A
(b) Vitamin C
(c) Vitamin D
(d) Vitamin K
Answer: (d)
Explanation: Vitamin K plays a crucial role in blood coagulation by helping the body produce proteins that are necessary for blood clotting.
Q16. The phenomenon where traits are passed from parents to offspring is called:
(a) Evolution
(b) Adaptation
(c) Heredity
(d) Mutation
Answer: (c)
Explanation: Heredity (or inheritance) is the passing on of traits from parents to their offspring, either through asexual reproduction or sexual reproduction.
Q17. Which of the following is a vestigial organ in humans?
(a) Lungs
(b) Appendix
(c) Heart
(d) Brain
Answer: (b)
Explanation: A vestigial organ is an organ that has lost all or most of its original function through evolution. The appendix in humans is considered a vestigial organ.
Q18. Pollination in plants is the transfer of:
(a) Ovules to carpels
(b) Pollen grains to the stigma
(c) Seeds to the fruit
(d) Water to the roots
Answer: (b)
Explanation: Pollination is the process by which pollen grains are transferred from the anther (male part) to the stigma (female part) of a flower, enabling fertilization.
Q19. Which disease is caused by a deficiency of iodine in the diet?
(a) Scurvy
(b) Rickets
(c) Goiter
(d) Anemia
Answer: (c)
Explanation: Goiter is an enlargement of the thyroid gland, often caused by iodine deficiency, as iodine is essential for the production of thyroid hormones.
Q20. The outermost layer of the human skin is called the:
(a) Dermis
(b) Hypodermis
(c) Epidermis
(d) Subcutis
Answer: (c)
Explanation: The epidermis is the outermost layer of the skin, forming the protective barrier of the body against the environment.
Q21. Which organism is known as the “father of genetics”?
(a) Charles Darwin
(b) Gregor Mendel
(c) Louis Pasteur
(d) Robert Hooke
Answer: (b)
Explanation: Gregor Mendel, through his work on pea plants, proposed the basic principles of heredity, earning him the title “father of genetics.”
Q22. The term “symbiosis” describes a close and long-term biological interaction between:
(a) Only plant species
(b) Only animal species
(c) Two different biological organisms
(d) Organisms of the same species
Answer: (c)
Explanation: Symbiosis refers to any type of close and long-term biological interaction between two different biological organisms, which can be mutualistic, commensalistic, or parasitic.
Q23. Which of the following is a renewable source of energy?
(a) Coal
(b) Petroleum
(c) Natural gas
(d) Solar energy
Answer: (d)
Explanation: Renewable energy sources are replenished naturally on a human timescale, such as sunlight, wind, rain, tides, waves, and geothermal heat.
Q24. The function of white blood cells (leukocytes) in the human body is:
(a) Transporting oxygen
(b) Producing antibodies and fighting infection
(c) Clotting blood
(d) Transporting nutrients
Answer: (b)
Explanation: White blood cells are a crucial part of the immune system, responsible for fighting off infections and foreign invaders by producing antibodies and other defensive mechanisms.
Q25. Where does fertilization typically occur in the human female reproductive system?
(a) Uterus
(b) Ovary
(c) Vagina
(d) Fallopian tube
Answer: (d)
Explanation: Fertilization, the fusion of sperm and egg, normally takes place in the fallopian tube (or oviduct).
