CBSE Class 10 Biology Half Yearly Exam 2025 Most Important Questions

Most schools will conduct the CBSE Class 10 Half Yearly Exam 2025 around September or October, so this is the right time to begin proper revision through the CBSE Class 10 Biology Half Yearly Exam 2025 Most Important Questions. The half-yearly paper is set as per the latest CBSE Class 10 Science Syllabus and follows the standard exam pattern of 80 marks for theory and 20 marks for internal assessment. The theory paper is divided into different sections, such as multiple choice questions (1 mark), short answer questions (2 and 3 marks), long answer type (5 marks), and case study or source-based questions (4 marks).

The most important chapters for CBSE Class 10 Biology half yearly 2025 are Life Processes, Control and Coordination, How Do Organisms Reproduce, Heredity and Evolution, and Ecology. These units carry good weightage and are frequently asked in the Class 10 half yearly question papers for Biology. These topics are very important as the “World of Living” unit, which covers Biology, usually carries around 25 marks out of 80, as seen in previous CBSE Class 10 Science papers.

In this article, we will talk about the CBSE Class 10 Biology Half Yearly Exam 2025 Most Important Questions that students should focus on to prepare smartly and score better in their exam.

CBSE Class 10 Biology Half Yearly Exam 2025 Most Important Questions

Given below is a list of all important questions for CBSE Class 10 Biology half-yearly exam 2025:

Q1: Why is respiratory pigment needed in large multicellular organisms?

Q2: Why are rings of cartilage present in the throat?

Q3: What is residual volume in the lungs, and why is it important?

Q4: Explain the action of the diaphragm and rib movement during breathing.

Q5: What is double circulation, and why is the separation of the heart's sides useful?

Q6: Trace the movement path of oxygenated blood in the body.

Q7: Structural difference between ventricles.

Q8: Composition difference between arteries and veins.

Q9: Define photosynthesis, raw materials, chemical equation, and its steps.

Q10: Explain the opening and closing of stomata.

Q11: Difference in breathing rates between aquatic and terrestrial organisms.

Q12: Function and purpose of finger-like projections in the small intestine.

Q13: Role of adrenal gland hormone adrenaline.

Q14: Role of iodine in thyroid gland function.

Q15: Functions of the pancreas in digestion and blood sugar regulation.

Q16: Define reflex action and explain with a flowchart.

Q17: Why is chemical communication better than electrical for multicellular organisms?

Q18: Hormone responsible for phototropism and its site of secretion.

Q19: Which diseases are sexually transmitted, and how to prevent them?

Q20: Difference between asexual and sexual reproduction.

Q21: Describe the path of urine formation and substances reabsorbed in the nephron.

Q22: Functions of parts of the reproductive system and changes in the uterus after fertilisation.

Q23: Methods of contraception and population control measures.

Q24: What is chemical coordination in animals? Explain with reference to hormones secreted by the thyroid gland, adrenal gland, pancreas, and pituitary gland.

Q25: What are plant hormones? Name the functions of auxin, gibberellins, cytokinin, and abscisic acid.

Q26: Which part of the brain controls posture and balance in the body?

Q27: What is the structural and functional unit of the nervous system?

Q28: Explain double circulation in humans with the help of a diagram.

Q29: Describe urine formation with three steps using a nephron diagram.

Q30: What is biological magnification?

Q31: What is ozone depletion? What are its effects?

Q32: A grassland ecosystem has 10,000 kJ of energy from the sun. Calculate the energy received by the grasshopper, frog, and snake.

Q33: Define photosynthesis. Explain its steps and write the balanced chemical equation.

Q34: Differentiate between aerobic and anaerobic respiration. Include glucose breakdown pathways.

Q35: What is the function of bile? Where is it produced and stored?

Q36: Explain the function of the cerebellum in maintaining posture.

Q37: Describe the structure and function of a neuron with a labelled diagram.

Q38: What is phototropism? Explain positive and negative phototropism with respect tothe  stem and roots.

Q39: Write the food chain and explain the unidirectional flow of energy.

Q40: What is the function of digestive enzymes like HCl, lipase, and salivary amylase?

Q41: Write two secondary sexual characters each in males and females.

Q42: Differentiate between arteries and veins, mentioning their features.

Q43: What is the function of the thyroid gland, and what happens if there is a deficiency?

Q44: Neha consumed boiled sweet potatoes and boiled eggs for breakfast. Answer:
(a) Which food is rich in protein? Where does its digestion start? Name the enzymes, conditions, and glands involved.
(b) Which food contains fats? How is it digested?
(c) Which food is rich in starch? How does its digestion start?
(d) Why does absorption of digested food mainly occur in the small intestine?

Q45: Why is the human heart separated into four chambers? How does this help birds and mammals?

Q46: Name two nitrogenous waste products removed from human blood.

Q47: Draw pollen germination on the stigma and label the pollen grain, pollen tube, stigma, and female germ cell.

Q48: What is the significance of the pollen tube?

Q49: What are the parts of a flower that develop into a seed and fruit after fertilisation?

Q50: Describe regeneration and vegetative propagation with examples.

Q51: What is the function of the brain?

Q52: What is vegetative propagation and its advantages?

Q53: What is the nature of the image formed by a convex mirror when the object distance is less than the focal length?

Q54: What is the section of DNA providing information for one protein called?

Q55: Define chemical reactions and give examples (relevant to the Biology context).

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