CBSE Class 10 Biology Mid-Term Exam 2026-27

CBSE Class 10 Biology Mid-Term Exam 2026-27 | Important Questions & Answers

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CBSE Class 10 Biology Mid-Term Exam 2026-27

CBSE Class 10 Biology Mid-Term Exam 2026-27 की तैयारी कर रहे विद्यार्थियों के लिए यह पोस्ट बहुत उपयोगी है। यहाँ आपको Class 10 Biology Important Questions with Answers दिए गए हैं, जो NCERT concepts और परीक्षा की तैयारी को ध्यान में रखकर तैयार किए गए हैं। इसमें 2 Marks, 3 Marks और 5 Marks Questions के साथ-साथ महत्वपूर्ण short-answer और long-answer questions शामिल हैं।

इस CBSE Class 10 Biology Important Questions 2026-27 के माध्यम से विद्यार्थी Life Processes, Control and Coordination, How do Organisms Reproduce?, Heredity और Our Environment जैसे महत्वपूर्ण topics की बेहतर तैयारी कर सकते हैं। प्रत्येक प्रश्न के साथ सरल और परीक्षा-उपयोगी उत्तर दिए गए हैं, ताकि revision कम समय में प्रभावी तरीके से किया जा सके।

अगर आप Class 10 Biology Mid-Term Exam 2026-27 Important Questions, chapter-wise questions, previous exam pattern और answers की तलाश कर रहे हैं, तो यह study material आपके revision के लिए एक उपयोगी resource हो सकता है। नियमित practice के साथ इन questions को तैयार करने से concepts मजबूत करने और exam में बेहतर प्रदर्शन करने में मदद मिलेगी

Biology class 10 important Question Answer

CBSE Class 10 Biology Mid-Term Exam 2026-27
Q1. What happens when an acid reacts with a metal? Write an example.

Answer:
When an acid reacts with a metal, salt and hydrogen gas are generally produced.

Example:
Zn + 2HCl → ZnCl₂ + H₂↑

Hydrogen gas can be tested by bringing a burning matchstick near it; it burns with a characteristic ‘pop’ sound.

Q2. What is a displacement reaction? Give one example.

Answer:
A displacement reaction is a reaction in which a more reactive element displaces a less reactive element from its compound.

Example:
Zn + CuSO₄ → ZnSO₄ + Cu

Here, zinc displaces copper from copper sulphate.

Q3. Explain the importance of pH in everyday life.

Answer:

  1. The pH of the stomach is acidic and helps in digestion.
  2. Tooth decay begins when the pH of the mouth falls below about 5.5.
  3. Plants require a suitable soil pH for healthy growth.
Q4. Explain any three methods of asexual reproduction. [3 Marks]

Answer:

  1. Binary fission: One organism divides into two daughter organisms. Example: Amoeba.
  2. Budding: A small outgrowth develops on the parent and separates to form a new organism. Example: Hydra.
  3. Spore formation: Spores are produced in specialised structures and can develop into new organisms. Example: Rhizopus.
Q5. Why is variation important for the survival of a species? [3 Marks]

Answer:

  1. Variations help organisms adapt to changing environmental conditions.
  2. Some variations may give an organism an advantage in survival.
  3. Useful variations can help a species survive environmental changes over generations.
Q6. Explain sex determination in human beings. [3 Marks]

Answer:

  1. Females generally have XX sex chromosomes, while males have XY.
  2. All ova carry an X chromosome, whereas sperm may carry either X or Y.
  3. If an X-carrying sperm fertilises the ovum, the combination is XX; if a Y-carrying sperm fertilises it, the combination is XY.
Q7. Explain Mendel’s monohybrid cross. [3 Marks]

Answer:
Mendel crossed a pure tall pea plant (TT) with a pure dwarf pea plant (tt).

  • F₁ generation: All plants were tall (Tt).
  • Self-pollination of F₁ plants produced F₂ generation.
  • The F₂ generation showed a 3:1 phenotypic ratio of tall to dwarf plants, demonstrating dominance and segregation.
Q8. What is biological magnification? Why is it harmful? [3 Marks]

Answer:

  1. Biological magnification is the increase in concentration of certain non-biodegradable harmful substances at successive trophic levels.
  2. The concentration is generally highest in organisms at the top of the food chain.
  3. It can cause harmful effects on organisms and may seriously affect human health.
Q9. Differentiate between biodegradable and non-biodegradable substances. [3 Marks]
BiodegradableNon-biodegradable
Can be broken down by microorganismsCannot be easily broken down by microorganisms
Usually do not remain in the environment for very longMay persist for a long time
Example: vegetable wasteExample: plastic
Q10. Explain the 10% law of energy transfer. [3 Marks]

Answer:

  1. Only about 10% of the energy available at one trophic level is transferred to the next trophic level.
  2. The remaining energy is used in various life processes and released as heat.
  3. Therefore, the amount of available energy decreases at successive trophic levels.

CBSE Class 10 Biology Mid-Term Exam 2026-27

Q11. Explain the role of different enzymes in human digestion. [3 Marks]

Answer:

  1. Salivary amylase breaks down starch into simpler sugars in the mouth.
  2. Pepsin in the stomach helps digest proteins.
  3. In the small intestine, enzymes from the pancreas and intestinal glands digest carbohydrates, proteins and fats into simpler substances.
Q12. Why is the small intestine well suited for absorption of digested food? [3 Marks]

Answer:

  1. The inner lining of the small intestine has numerous finger-like projections called villi.
  2. Villi provide a large surface area for absorption.
  3. They contain a rich network of blood capillaries that transport absorbed nutrients to different parts of the body.
Q13. How does gaseous exchange take place in plants? [3 Marks]

Answer:

  1. Plants exchange gases mainly through tiny pores called stomata.
  2. Carbon dioxide enters and oxygen comes out through stomata during photosynthesis.
  3. Oxygen and carbon dioxide also move through intercellular spaces by diffusion.

CBSE Class 10 Biology Mid-Term Exam 2026-27

Q14. Explain the transportation of water in plants. [3 Marks]

Answer:

  1. Water is absorbed from the soil by the roots.
  2. It is transported upward through the xylem.
  3. Transpiration pull, along with root pressure and other forces, helps in the upward movement of water.
MId-term Science Important Question Answer Chemistry Download Link
Q15. What is transpiration? State two advantages of transpiration. [3 Marks]

Answer:
Transpiration is the loss of water in the form of water vapour from the aerial parts of plants, mainly through stomata.

Its advantages are:

  1. It helps in the upward movement of water and minerals.
  2. It helps cool the plant.
Q16. Why is separation of oxygenated and deoxygenated blood necessary in humans? [3 Marks]

Answer:

  1. It prevents mixing of oxygenated and deoxygenated blood.
  2. It ensures that body tissues receive blood with sufficient oxygen.
  3. It allows humans to meet the high energy requirements needed for maintaining body temperature and performing various activities.
Q17. Explain the pathway of a reflex action. [3 Marks]

Answer:

  1. A stimulus is detected by a receptor.
  2. The sensory neuron carries the message to the spinal cord.
  3. The spinal cord sends the response through a motor neuron to the muscles, which act immediately.
Q18. What is phototropism? Explain with an example. [3 Marks]

Answer:

  1. The directional growth of a plant part in response to light is called phototropism.
  2. Shoots generally show positive phototropism and grow towards light.
  3. Auxin promotes greater cell growth on the shaded side, causing the shoot to bend towards light.
Q19. Write three differences between nervous control and hormonal control. [3 Marks]
Nervous ControlHormonal Control
Uses electrical impulses through neuronsUses chemical hormones
Usually produces rapid responsesUsually produces slower responses
Effects are generally short-livedEffects may last longer
Q20. What is coordination? Why is it important in organisms? [3 Marks]

Answer:

  1. Coordination is the process by which different organs and systems work together in a controlled manner.
  2. It helps an organism respond appropriately to changes in its surroundings.
  3. It ensures proper functioning of different body parts.
Q21. What are the advantages of sexual reproduction? [3 Marks]

Answer:

  1. It produces genetic variations among offspring.
  2. Variations increase the ability of organisms to adapt to changing environmental conditions.
  3. It contributes to the long-term survival and evolution of species.
Q22. Explain the process of reproduction in flowering plants. [3 Marks]

Answer:

  1. Pollination transfers pollen grains from the anther to the stigma.
  2. A pollen tube grows towards the ovule and carries the male gamete.
  3. The male and female gametes fuse to form a zygote, which develops into an embryo.
Q23. What happens after fertilisation in a flower? [3 Marks]

Answer:

  1. The zygote develops into an embryo.
  2. The ovule develops into a seed.
  3. The ovary develops into a fruit.
Q24. What is vegetative propagation? Give two advantages. [3 Marks]

Answer:
Vegetative propagation is a type of asexual reproduction in plants in which new plants develop from roots, stems or leaves.

Advantages:

  1. It produces plants that are generally genetically similar to the parent.
  2. It can help in producing plants with desired characteristics and is useful for multiplying plants that do not produce viable seeds.
Q25. What are the functions of the placenta during pregnancy? [3 Marks]

Answer:

  1. It provides nutrients and oxygen from the mother’s blood to the developing embryo.
  2. It helps remove carbon dioxide and waste products from the embryo.
  3. It acts as an important exchange surface between maternal and embryonic blood supplies.
Q26. What is a dominant trait? Explain with an example. [3 Marks]

Answer:

  1. A dominant trait is expressed even when only one copy of the dominant allele is present.
  2. In pea plants, tallness (T) is dominant over dwarfness (t).
  3. Therefore, both TT and Tt plants are tall.
Q27. Why did Mendel select pea plants for his experiments? [3 Marks]

Answer:

  1. Pea plants have several clear and contrasting traits.
  2. They have a short generation time and produce many offspring.
  3. They can undergo both self-pollination and cross-pollination, making controlled experiments easier.
Q28. Differentiate between genotype and phenotype. [3 Marks]

Answer:

  1. Genotype refers to the genetic constitution of an organism.
  2. Phenotype refers to the observable characteristics of an organism.
  3. For example, Tt is a genotype, while tall is the corresponding phenotype.
Q29. How are traits controlled by genes? [3 Marks]

Answer:

  1. Genes contain information for producing specific proteins.
  2. Proteins influence the structure and functioning of cells.
  3. Therefore, genes help determine the expression of various traits or characteristics.

Q30. Explain the role of decomposers in an ecosystem. [3 Marks]

Answer:

  1. Decomposers such as bacteria and fungi break down dead plants, animals and organic waste.
  2. They convert complex organic matter into simpler substances.
  3. They return nutrients to the environment and help maintain nutrient cycles.
Q31. Why are food chains generally short? [3 Marks]

Answer:

  1. Only about 10% of energy is transferred from one trophic level to the next.
  2. A large amount of energy is used in life processes and lost as heat.
  3. Therefore, very little energy remains available at higher trophic levels, limiting the length of food chains.
Q32. What would happen if decomposers were absent from an ecosystem? [3 Marks]

Answer:

  1. Dead plants and animals would accumulate.
  2. Nutrients would not be properly recycled back into the environment.
  3. The normal functioning and balance of the ecosystem would be disturbed.
Q33. Why are non-biodegradable substances harmful to the environment? [3 Marks]

Answer:

  1. They cannot be easily broken down by microorganisms.
  2. They accumulate in the environment and can cause pollution.
  3. Some harmful chemicals can enter food chains and undergo biological magnification.
Q34. Explain the relationship between trophic levels and energy transfer. [3 Marks]

Answer:

  1. Producers form the first trophic level and capture solar energy.
  2. Energy passes from producers to consumers through feeding.
  3. Only about 10% of energy is transferred to the next trophic level, so energy decreases at higher levels
Q35. What is the role of the pancreas in digestion? [3 Marks]

Answer:

  1. The pancreas secretes pancreatic juice into the small intestine.
  2. It contains enzymes that help digest carbohydrates, proteins and fats.
  3. It also contains alkaline substances that help neutralise the acidic food coming from the stomach.
Q36. How is food transported in plants? [3 Marks]

Answer:

  1. Food prepared in leaves is transported to different parts of the plant through phloem.
  2. This movement is called translocation.
  3. Translocation can occur in both upward and downward directions and requires energy.
Q37. What is the function of haemoglobin? [3 Marks]

Answer:

  1. Haemoglobin is a respiratory pigment present in red blood cells.
  2. It binds with oxygen in the lungs.
  3. It transports oxygen to different tissues of the body.
Q38. Why do plants need a transport system? [3 Marks]

Answer:

  1. Roots absorb water and minerals from the soil.
  2. Leaves prepare food by photosynthesis.
  3. A transport system carries water, minerals and food between different parts of the plant.
Q39. Explain how the nervous system helps in coordination. [3 Marks]

Answer:

  1. Receptors detect changes or stimuli in the surroundings.
  2. Sensory neurons carry information to the central nervous system.
  3. The brain or spinal cord processes the information and sends instructions through motor neurons to produce an appropriate response.
Q40. What is geotropism? Give an example. [3 Marks]

Answer:

  1. The directional growth of a plant part in response to gravity is called geotropism.
  2. Roots generally show positive geotropism by growing towards gravity.
  3. Shoots generally show negative geotropism by growing away from gravity.
Q41. What is the role of insulin in the human body? [3 Marks]

Answer:

  1. Insulin is a hormone secreted by the pancreas.
  2. It helps regulate the level of glucose in the blood.
  3. It promotes the uptake and storage of glucose, helping maintain normal blood glucose levels.
Q42. Why is DNA copying important during reproduction? [3 Marks]

Answer:

  1. DNA contains the genetic information of an organism.
  2. DNA copying allows genetic information to be passed from parents to offspring.
  3. Small variations during DNA copying contribute to variation among offspring.
Q43. What is the importance of DNA copying in asexual reproduction? [3 Marks]

Answer:

  1. Asexual reproduction generally involves a single parent.
  2. DNA copying transfers the parent’s genetic information to the offspring.
  3. Small errors during copying can produce variations among offspring.
Q44. Differentiate between pollination and fertilisation. [3 Marks]
PollinationFertilisation
Transfer of pollen grains from anther to stigmaFusion of male and female gametes
Occurs before fertilisationOccurs after pollination
Does not form a zygoteProduces a zygote
Q45. What are the functions of the testes in human males? [3 Marks]

Answer:

  1. Testes produce sperms.
  2. They secrete the male sex hormone testosterone.
  3. Testosterone helps regulate male reproductive development and secondary sexual characteristics.
Q46. What is menstruation? [3 Marks]

Answer:

  1. If fertilisation does not occur, the thickened lining of the uterus breaks down.
  2. This lining, along with blood and the unfertilised ovum, is discharged through the vagina.
  3. This process is called menstruation and usually occurs approximately once every month.
Q47. How does reproduction help in the continuity of species? [3 Marks]

Answer:

  1. Reproduction produces new individuals of the same species.
  2. It transfers genetic information from one generation to the next.
  3. It ensures the continuity of the species even when older individuals die.
Q48. What is a food web? Why is it important? [3 Marks]

Answer:

  1. A food web consists of interconnected food chains in an ecosystem.
  2. It shows that an organism may obtain food from more than one source.
  3. It provides alternative pathways for the flow of energy and matter through an ecosystem.
Q49. What are the harmful effects of ozone layer depletion? [3 Marks]

Answer:

  1. Ozone depletion allows more harmful UV radiation to reach Earth’s surface.
  2. Excessive UV exposure can damage living organisms.
  3. It can cause health problems such as skin damage and eye disorders and can also affect plants and aquatic organisms.
Q50. Explain why energy flow in an ecosystem is unidirectional. [3 Marks]

Answer:

  1. Energy enters the ecosystem mainly as solar energy.
  2. It passes from producers to consumers through different trophic levels.
  3. Energy is ultimately lost as heat and is not recycled back to the producers, so energy flow is unidirectional.