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Tag: Chapter 7 – How do Organisms Reproduce?

  • Class 10th Science Chapter 7 – How do Organisms Reproduce? – In-text Questions

    PAGE 114 – QUESTIONS & ANSWERS

    Q1. What is the importance of DNA copying in reproduction?

    Answer:

    DNA copying is important because:

    • It ensures that genetic information is passed from parents to offspring.

    • It maintains similar body design and characteristics in the next generation.

    • It also introduces variations, which help in the survival and evolution of species.

    Parent Cell DNA⟶Copied DNA⟶Daughter Cells

    Q2. Why is variation beneficial to the species but not necessarily for the individual?

    Answer:

    Variation helps a species survive changes in the environment.
    For example, if climate or temperature changes, some individuals with useful variations survive.

    But variation may not help the same individual because:

    • It might not provide immediate advantage.

    • Some variations may even be harmful.

    Example: If temperatures rise suddenly, heat-resistant bacteria survive, others die.

    PAGE 119 – QUESTIONS & ANSWERS

    Q1. How does binary fission differ from multiple fission?

    Binary Fission Multiple Fission
    One parent cell divides into two equal daughter cells

    One parent cell divides into many daughter cells
    Example: Amoeba, Leishmania Example: Plasmodium

    Q2. How will an organism be benefited if it reproduces through spores?

    Answer:

    • Spores can survive harsh conditions because they have thick protective walls.

    • They spread easily by wind or water.

    • They reproduce quickly to form new individuals.

    Example: Bread mould (Rhizopus)

    Q3. Can you think of reasons why more complex organisms cannot give rise to new individuals through regeneration?

    Answer:

    Complex organisms have:

    • Highly specialised tissues and organs arranged in a fixed pattern.

    • Cannot be divided into pieces without damaging vital organs.
      Therefore, regeneration cannot form a complete individual.

    Example: Humans cannot regrow full bodies.

    Q4. Why is vegetative propagation practised for growing some types of plants?

    Answer:

    Vegetative propagation is used because:

    • Plants grow faster and bear fruits earlier.

    • New plants are genetically identical to parents (same qualities preserved).

    • Useful for plants not producing seeds naturally.

    Q5. Why is DNA copying an essential part of the process of reproduction?

    Answer:

    Because it ensures:

    • Transfer of hereditary information to offspring.

    • Development of new individuals similar to parents.

    • Introduction of variations that support evolution.

    PAGE 126 – QUESTIONS & ANSWERS

    Q1. How is the process of pollination different from fertilisation?

    Pollination Fertilisation
    Transfer of pollen from anther to stigma Fusion of male gamete & female gamete
    Occurs by wind, water, insects

    Occurs inside ovule
    No zygote formation Zygote is formed

    Q2. What is the role of the seminal vesicles and the prostate gland?

    Answer:

    They produce fluid that mixes with sperms to form semen, which:

    • Provides nutrition

    • Helps transport the sperms easily

    Q3. What are the changes seen in girls at the time of puberty?

    Answer:

    • Development of breasts

    • Menstruation begins

    • Growth of hairs in armpits & pubic region

    • Widening of hips

    • Oily skin and pimples

    Q4. How does the embryo get nourishment inside the mother’s body?

    Answer:

    Through the placenta, which:

    • Transfers oxygen & nutrients from mother’s blood to embryo

    • Removes waste products from embryo’s blood

    Q5. If a woman is using a copper-T, will it help in protecting her from sexually transmitted diseases?

    Answer:

    No.
    Copper-T prevents pregnancy by blocking the movement of sperms,
    but it does not prevent STDs like AIDS or syphilis.

    Condoms help prevent STDs.