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ICSE Class X Board Examination

ICSE Biology (Science Paper 3) — Board Examination 2025

Board2025Subject code 523
Open source paper at oswaal360.com (opens in a new tab)
Board
ICSE Class X Board Examination
Class
Class 10
Subject
Biology
Year
2025
Total marks
Not verified
Duration
Not verified

Verification and rights

Follows the published ICSE syllabus structure and links back to the source, but has not been reconciled line by line against a Council document.

Imported board paper from Oswaal Books (reproduction of CISCE board paper) on 2026-08-29.

Questions in this paper

  1. 1((i))15] Select the correct answers to the questions from the given options. (Do not copy the questions, write the correct answer only).
    The number of live births per thousand people per year is called:
  2. 1((ii))15] Select the correct answers to the questions from the given options. (Do not copy the questions, write the correct answer only).
    The structure that lies at the junction of the choroid and the iris and is itself a part of the choroid is called:
  3. 1((iii))15] Select the correct answers to the questions from the given options. (Do not copy the questions, write the correct answer only).
    Assertion (A): Seminal vesicles pour an alkaline secretion into the semen as it passes through the ureter.
    Reason (R): The female vagina is acidic and needs to be neutralized for sperm survival.
  4. 1((iv))15] Select the correct answers to the questions from the given options. (Do not copy the questions, write the correct answer only).
    The hormone that induces vigorous contractions of the uterus in a pregnant mother is:
  5. 1((v))15] Select the correct answers to the questions from the given options. (Do not copy the questions, write the correct answer only).
    A scientist wanted to conduct a genetic experiment on mice. He cut the tails of all the mice and made
    them reproduce. What will be the phenotype of the offsprings?
  6. 1((vi))15] Select the correct answers to the questions from the given options. (Do not copy the questions, write the correct answer only).
    Assertion (A): A turgid plant cell is in a balanced state.
    Reason (R): In a turgid cell, turgor pressure and wall pressure are equal and in the same direction.
  7. 1((vii))15] Select the correct answers to the questions from the given options. (Do not copy the questions, write the correct answer only).
    The optimum temperature for photosynthesis is:
  8. 1((viii))15] Select the correct answers to the questions from the given options. (Do not copy the questions, write the correct answer only).
    Ajay and Vijay are siblings. Ajay can roll his tongue while Vijay cannot. What is the genotype of their
    parents?
  9. 1((ix))15] Select the correct answers to the questions from the given options. (Do not copy the questions, write the correct answer only).
    Assertion (A): Deficiency of antidiuretic hormone causes an increase in urination.
    Reason (R): Antidiuretic hormone acts on the kidney to reabsorb water from the kidney tubules.
  10. 1((x))15] Select the correct answers to the questions from the given options. (Do not copy the questions, write the correct answer only).
    A phase of cell division where the spindle fibres disappear is:
  11. 1((xi))15] Select the correct answers to the questions from the given options. (Do not copy the questions, write the correct answer only).
    Assertion(A): Arachnoid layer helps in speeding up the transmission of nerve impulses along the axons.
    Reason(R): Axon endings at the synapse secrete acetylene.
  12. 1((xii))15] Select the correct answers to the questions from the given options. (Do not copy the questions, write the correct answer only).
    Many nuclear power plants are constructed near water sources. They use water for cooling their
    machinery and release it back into the water stream. Identify the kind of pollution caused.
  13. 1((xiii))15] Select the correct answers to the questions from the given options. (Do not copy the questions, write the correct answer only).
    Owls are nocturnal animals. They are active at night and hunt small animals for food. Owls have large
    eyes and can see well at night. This is due to:
  14. 1((xiv))15] Select the correct answers to the questions from the given options. (Do not copy the questions, write the correct answer only).
    Sunil tried to match the tropic movements in plants with the stimulus they respond to. The tabulation is
    given below:
    Tropism Stimulus
    P Thigmotropism Touch
    Q Geotropism Water
    R Chemotropism Chemicals
    S Phototropism Gravity
    Identify the correct pair:
  15. 1((xv))15] Select the correct answers to the questions from the given options. (Do not copy the questions, write the correct answer only).
    Observe the following picture, identify the defect and the cause of the defect.
  16. 2((ii))Given below is the diagram of a human heart. Read the information below the diagram and fill in the
    blanks:
    The human heart pumps blood throughout the body. It is the size of a large fist. The heart is located between the lungs
    in the thoracic cavity. It has four chambers. The heart functions all through the lifespan of a person and is responsible
    for the survival of the person.
    The heart is enclosed by a membrane called    5 marks
  17. 2((iii))Arrange the terms in each group in the correct order. Write them in a logical sequence beginning with
    the term that is underlined.    5 marks
  18. 2((iv))Read the explanations given below and name the structures:
    Example: The tubules which produce sperms.
    Answer: Seminiferous tubules    5 marks
  19. 2((v))Given below is an outline of the human body showing the important endocrine glands. Match the
    glands marked (a) to (e) with their correct functions:
    Example: (f) - 6. Secretes Testosterone.
    Endocrine glands Functions
    1. Prepares the body to face stress.
    2. Secretes tropic hormones
    (a)
    3. Secretes oestrogens
    (b) 4. Maintains blood sugar level
    5. Regulates basal metabolism
    6. Secretes testosterone.
    (c)
    (d)
    (e)
    (f)
    SECTION – B (40 Marks)
    (Attempt any four questions from this Section.)    5 marks
  20. 3((i))Write the overall chemical equation for photosynthesis.1 mark
  21. 3((ii))Ramesh is a farmer who has a vineyard and cultivates grapes. To improve the shape of the grapes and
    make them elongated he sprays a particular phytohormone at the time of fruiting.
    (a) Name the phytohormone that Ramesh sprays on the plant at the time of fruiting.
    (b) These grapes are said to be seedless. What is the technical term for the formation of such fruits?    2 marks
  22. 3((iii))Mention the two pairs of nitrogenous bases that are present in a DNA strand and pair with each other
    by hydrogen bonds.    2 marks
  23. 3((iv))State any two disadvantages of living close to an airport.2 marks
  24. 3((v))Draw a neat, labelled diagram of an animal cell showing metaphase with four chromosomes.3 marks
  25. 4((i))What is the structure of DNA as proposed by Watson and Crick?1 mark
  26. 4((ii))Name the white blood cells that:
    (a) show phagocytosis
    (b) produce antibodies    2 marks
  27. 4((iii))Complete the food chain by mentioning the names of the organisms in (c) and (d):
    (d)
    (a) (b) (c)    2 marks
  28. 4((iv))State any two harmful effects of acid rain.2 marks
  29. 4((v))Given below is a picture of a tree. Mention the scientific phenomena occurring in the parts labelled (a),
    (b) and (c).
    (c)
    (b)
    (a)    3 marks
  30. 5((ii))What are biomedical wastes? Give an example.2 marks
  31. 5((iii))Differentiate between the functions of Urethra and Uterus.2 marks
  32. 5((iv))Rachna is an expert gymnast on the balance beam. She has been vigorously practising for the Olympic
    Games. Lately, she has been experiencing dizziness and losing her balance during the practise sessions.
    (a) Which part of the membranous labyrinth is responsible for maintaining the body balance on the
    beam?
    (b) Which type of balance is maintained by the structure mentioned in (a)?    2 marks
  33. 5((v))Draw a neat, labelled diagram to show that oxygen is released during photosynthesis.3 marks
  34. 6((ii))What are Vestigial organs? Give one example of a vestigial structure in the human mouth.2 marks
  35. 6((iii))Ahmed had a severe throat infection. After a few days he developed an earache too. What could be the
    reason for the pain in his ears? Explain.    2 marks
  36. 6((iv))Mr. Sharma is a 76-year-old man. His vision was gradually becoming blurred. He consulted an eye doctor
    and it was diagnosed as cataract.
    Health Eye Catarace Eye
    (a) Which part of the eye does cataract affect?
    (b) Why does the vision become blurred?    2 marks
  37. 6((v))Given below is the diagram of a plasmolysed cortical cell of a root.
    Copy the diagram and label the following parts in the diagram:
    (a) Cytoplasm
    (b) Hypertonic solution
    (c) Plasma membrane    3 marks
  38. 7((ii))In the last century, the human population has increased tremendously. Death rate has reduced and
    life expectancy has increased. This rapid growth has placed significant pressure on resources. Global
    cooperation is needed for environmental preservation.
    Overpopulation
    (a) Mention any one reason for reduction in the death rate.
    (b) Name any one resource that is under pressure due to population explosion.    2 marks
  39. 7((iii))Mention any two functions of amniotic fluid.2 marks
  40. 7((iv))Expand the following abbreviations:
    (a) CFC
    (b) CNG    2 marks
  41. 7((v))Vineet’s day begins with a cup of piping hot coffee. Caffeine is a stimulant present in coffee which
    increases the circulation of Adrenaline in the body. Vineet feels refreshed, alert and focussed.
    Coffee
    (a) Name the organ that is stimulated by caffeine which makes Vineet alert and focussed.
    (b) Give the collective term for the protective membranes of the organ mentioned in (a).
    (c) Which part of the autonomic nervous system increases the secretion of Adrenaline?    3 marks
  42. 8((ii))State the difference between Nephron and Neuron.2 marks
  43. 8((iii))Mention any two objectives of Swachh Bharat Abhiyan.2 marks
  44. 8((iv))Give any two characteristic features of a Cro-Magnon man.2 marks
  45. 8((v))A farmer cultivates a unique species of tomato plants. The two traits selected for breeding were: Colour
    of the fruits and height of the plants. The farmer initially crosses a homozygous tall plant bearing red
    fruits (TTRR) with a dwarf plant bearing yellow fruits (ttrr) and the genotype of all the offsprings of the
    F1 generation was TtRr. Next, he crosses two F1 generation plants (TtRr).
    Tall plant with red fruit Dwarf plant with yellow fruits
    (a) Explain the phenotype of the offsprings of the F1 generation obtained from the initial cross.
    (b) Mention the phenotypic ratio of the F2 generation offsprings.
    (c) State Mendel’s Law of Independent Assortment.    3 marks