📘 Life Processes – MCQs (Class 10 Science)

🔹 Part 1: Questions 1–25

Q1. Which of the following is NOT considered a life process?

A) Nutrition
B) Respiration
C) Reproduction
D) Excretion

Correct Answer: C) Reproduction

Explanation:

• A) Nutrition → Essential for energy supply.
• B) Respiration → Essential for energy release.
• ✅ C) Reproduction → Helps continuation of species, but not essential for individual survival.
• D) Excretion → Removes wastes, vital for survival.

Q2. The raw materials for photosynthesis are:

A) Glucose and Oxygen
B) Water and Carbon dioxide
C) Oxygen and Nitrogen
D) Starch and Water

Correct Answer: B) Water and Carbon dioxide

Explanation:

• A) Glucose & O₂ → Products, not raw materials.
• ✅ B) Water (H₂O) + Carbon dioxide (CO₂) → Raw materials, sunlight & chlorophyll required.
• C) O₂ & N₂ → Not involved in photosynthesis.
• D) Starch & H₂O → Starch is stored product, not raw material.

Q3. In autotrophic nutrition, organisms prepare food using:

A) Inorganic substances
B) Organic substances
C) Minerals only
D) Proteins only

Correct Answer: A) Inorganic substances

Explanation:

• ✅ A) Inorganic substances (CO₂ & H₂O) are used with sunlight.
• B) Organic substances → Already prepared food.
• C) Minerals only → Required but not food source.
• D) Proteins only → Not a food source for autotrophs.

Q4. Which pigment traps solar energy in plants?

A) Carotene
B) Chlorophyll
C) Xanthophyll
D) Anthocyanin

Correct Answer: B) Chlorophyll

Explanation:

• A) Carotene & C) Xanthophyll → Accessory pigments.
• ✅ B) Chlorophyll → Main photosynthetic pigment.
• D) Anthocyanin → Provides color, not photosynthesis.

Q5. The process of breaking down glucose in the absence of oxygen is called:

A) Aerobic respiration
B) Anaerobic respiration
C) Photosynthesis
D) Transpiration

Correct Answer: B) Anaerobic respiration

Explanation:

• A) Aerobic respiration → Requires O₂.
• ✅ B) Anaerobic → Without O₂, produces less energy.
• C) Photosynthesis → Food preparation, not breakdown.
• D) Transpiration → Loss of water, not energy release.

Q6. In human beings, the site of gaseous exchange is:

A) Trachea
B) Bronchi
C) Alveoli
D) Bronchioles

Correct Answer: C) Alveoli

Explanation:

• A) Trachea → Passage for air.
• B) Bronchi → Divides air passage.
• ✅ C) Alveoli → Thin-walled sacs, site of gas exchange.
• D) Bronchioles → Connect bronchi to alveoli.

Q7. The enzyme present in saliva that helps in digestion is:

A) Pepsin
B) Amylase
C) Lipase
D) Trypsin

Correct Answer: B) Amylase

Explanation:

• A) Pepsin → Digests proteins in stomach.
• ✅ B) Amylase (ptyalin) → Breaks starch into maltose.
• C) Lipase → Breaks fats.
• D) Trypsin → Protein digestion in small intestine.

Q8. Which organ secretes bile?

A) Pancreas
B) Stomach
C) Liver
D) Small intestine

Correct Answer: C) Liver

Explanation:

• A) Pancreas → Secretes insulin & digestive enzymes.
• B) Stomach → Secretes HCl & pepsin.
• ✅ C) Liver → Produces bile (stored in gall bladder).
• D) Small intestine → Absorbs food, secretes juices.

Q9. The main function of bile is to:

A) Digest proteins
B) Emulsify fats
C) Absorb glucose
D) Break starch

Correct Answer: B) Emulsify fats

Explanation:

• A) Proteins → Digested by pepsin/trypsin.
• ✅ B) Bile salts break fats into tiny droplets (emulsification).
• C) Glucose absorbed in intestine, not by bile.
• D) Starch broken by amylase.

Q10. The finger-like projections in the small intestine are called:

A) Microvilli
B) Villi
C) Cilia
D) Papillae

Correct Answer: B) Villi

Explanation:

• A) Microvilli → On villi surface.
• ✅ B) Villi → Increase surface area for absorption.
• C) Cilia → Hair-like structures, not for absorption.
• D) Papillae → Found on tongue.

Q11. Which part of the plant loses water during transpiration?

A) Root hairs
B) Xylem vessels
C) Stomata
D) Phloem

Correct Answer: C) Stomata

Explanation:

• A) Roots → Absorb water.
• B) Xylem → Transport water.
• ✅ C) Stomata → Pores for transpiration & gas exchange.
• D) Phloem → Transports food.

Q12. Blood from lungs to heart is carried by:

A) Pulmonary artery
B) Pulmonary vein
C) Aorta
D) Vena cava

Correct Answer: B) Pulmonary vein

Explanation:

• A) Pulmonary artery → Carries deoxygenated blood to lungs.
• ✅ B) Pulmonary vein → Brings oxygenated blood from lungs to heart.
• C) Aorta → Distributes oxygenated blood from heart to body.
• D) Vena cava → Brings deoxygenated blood to heart.

Q13. Which chamber of the heart pumps oxygenated blood to the body?

A) Right atrium
B) Left atrium
C) Right ventricle
D) Left ventricle

Correct Answer: D) Left ventricle

Explanation:

• A) Right atrium → Receives deoxygenated blood.
• B) Left atrium → Receives oxygenated blood.
• C) Right ventricle → Pumps blood to lungs.
• ✅ D) Left ventricle → Pumps oxygenated blood to body.

Q14. Which of the following transports food in plants?

A) Xylem
B) Phloem
C) Root hairs
D) Guard cells

Correct Answer: B) Phloem

Explanation:

• A) Xylem → Water transport.
• ✅ B) Phloem → Transports food via translocation.
• C) Root hairs → Absorb water.
• D) Guard cells → Regulate stomata.

Q15. In which form is food transported in plants?

A) Amino acids
B) Starch
C) Glucose
D) Sucrose

Correct Answer: D) Sucrose

Explanation:

• A) Amino acids → Transported but not main form.
• B) Starch → Stored form, not transported.
• C) Glucose → Converted before transport.
• ✅ D) Sucrose → Main form for translocation.

Q16. Which blood vessel carries blood under high pressure?

A) Veins
B) Arteries
C) Capillaries
D) Venules

Correct Answer: B) Arteries

Explanation:

• A) Veins → Low pressure, valves present.
• ✅ B) Arteries → Thick walls, high pressure.
• C) Capillaries → Thin walls for exchange.
• D) Venules → Small veins, low pressure.

Q17. Which part of nephron collects filtrate from Bowman’s capsule?

A) Loop of Henle
B) Collecting duct
C) Proximal convoluted tubule
D) Distal convoluted tubule

Correct Answer: C) Proximal convoluted tubule

Explanation:

• A) Loop of Henle → Concentrates urine.
• B) Collecting duct → Collects urine from nephron.
• ✅ C) PCT → Receives filtrate first.
• D) DCT → Reabsorbs salts, later stage.

Q18. Which blood vessel carries blood from kidney to heart?

A) Renal artery
B) Renal vein
C) Pulmonary vein
D) Hepatic vein

Correct Answer: B) Renal vein

Explanation:

• A) Renal artery → Brings blood into kidney.
• ✅ B) Renal vein → Takes filtered blood back to heart.
• C) Pulmonary vein → Lungs to heart.
• D) Hepatic vein → Liver to heart.

Q19. Which of the following is excreted in human urine?

A) CO₂
B) Urea
C) Oxygen
D) Glucose

Correct Answer: B) Urea

Explanation:

• A) CO₂ → Exhaled via lungs.
• ✅ B) Urea → Nitrogenous waste excreted by kidneys.
• C) Oxygen → Used in respiration.
• D) Glucose → Normally reabsorbed, not excreted.

Q20. The functional unit of kidney is:

A) Nephron
B) Neuron
C) Alveolus
D) Nephridia

Correct Answer: A) Nephron

Explanation:

• ✅ A) Nephron → Structural & functional unit of kidney.
• B) Neuron → Functional unit of nervous system.
• C) Alveolus → Unit of lungs.
• D) Nephridia → In annelids.

Q21. Which respiratory organ is found in fish?

A) Lungs
B) Skin
C) Gills
D) Spiracles

Correct Answer: C) Gills

Explanation:

• A) Lungs → Mammals, birds, reptiles.
• B) Skin → Amphibians.
• ✅ C) Gills → Extract O₂ from water.
• D) Spiracles → Insects.

Q22. The small pores on leaf surface for gaseous exchange are:

A) Lenticels
B) Guard cells
C) Stomata
D) Villi

Correct Answer: C) Stomata

Explanation:

• A) Lenticels → Woody stems.
• B) Guard cells → Control stomata, not pores themselves.
• ✅ C) Stomata → Openings for gases.
• D) Villi → Found in intestine.

Q23. Which structure prevents food from entering windpipe?

A) Glottis
B) Epiglottis
C) Pharynx
D) Larynx

Correct Answer: B) Epiglottis

Explanation:

• A) Glottis → Opening of windpipe.
• ✅ B) Epiglottis → Flap covering glottis during swallowing.
• C) Pharynx → Common passage.
• D) Larynx → Voice box, not involved.

Q24. Which process in plants requires energy?

A) Diffusion
B) Osmosis
C) Active transport
D) Transpiration

Correct Answer: C) Active transport

Explanation:

• A) Diffusion → Passive.
• B) Osmosis → Passive.
• ✅ C) Active transport → Requires ATP to move against gradient.
• D) Transpiration → Passive water loss.

Q25. Which blood component helps in clotting?

A) RBC
B) WBC
C) Platelets
D) Plasma

Correct Answer: C) Platelets

Explanation:

• A) RBC → Carry oxygen.
• B) WBC → Fight infection.
• ✅ C) Platelets → Release clotting factors, form clot.
• D) Plasma → Transports nutrients, wastes.

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