1. ANSWER: [A] Explanation: The correct answer is [A] (ii) and (iv). During inhalation, the diaphragm flattens and the chest cavity becomes larger, allowing air to enter the lungs. Residual volume never decreases, and the diaphragm is raised only during exhalation.

    ANSWER: [A]

    Explanation: The correct answer is [A] (ii) and (iv). During inhalation, the diaphragm flattens and the chest cavity becomes larger, allowing air to enter the lungs. Residual volume never decreases, and the diaphragm is raised only during exhalation.

    See less
    • 121
  2. ANSWER: [A] Explanation: The correct answer is [A] Fore brain. The forebrain (cerebrum) is called the “thinking part” of the brain. It controls intelligence, reasoning, learning, memory, emotions, and voluntary actions. Midbrain and hindbrain mainly control reflexes, balance, and involuntary activitRead more

    ANSWER: [A]

    Explanation: The correct answer is [A] Fore brain. The forebrain (cerebrum) is called the “thinking part” of the brain. It controls intelligence, reasoning, learning, memory, emotions, and voluntary actions. Midbrain and hindbrain mainly control reflexes, balance, and involuntary activities.

    See less
    • 29
  3. ANSWER: [A] Explanation: The correct answer is [A] Oestrogen. Oestrogen, secreted by the ovaries, regulates the menstrual cycle and development of female reproductive organs. Deficiency of oestrogen often causes irregular menstrual cycles. Testosterone is male hormone, while adrenalin and thyroxin aRead more

    ANSWER: [A]

    Explanation: The correct answer is [A] Oestrogen. Oestrogen, secreted by the ovaries, regulates the menstrual cycle and development of female reproductive organs. Deficiency of oestrogen often causes irregular menstrual cycles. Testosterone is male hormone, while adrenalin and thyroxin are unrelated to menstruation.

    See less
    • 113
  4. ANSWER: [D] Explanation: The correct answer is [D] 100% tall with round seeds. Genotype of parents → TTRR × ttrr. F₁ offsprings get one dominant allele from tall-round parent and one recessive from short-wrinkled. So all F₁ = TtRr (tall and round), showing dominant traits.

    ANSWER: [D]

    Explanation: The correct answer is [D] 100% tall with round seeds.

    Genotype of parents → TTRR × ttrr. F₁ offsprings get one dominant allele from tall-round parent and one recessive from short-wrinkled.
    So all F₁ = TtRr (tall and round), showing dominant traits.

    See less
    • 64
  5. ANSWER: [C] Explanation: The correct answer is [C] It is used as a refrigerant and in fire extinguishers. Ozone is poisonous at ground level. Ozone layer protects from harmful UV rays. Ozone forms when O₂ combines with free O atom (O₃). Refrigerants/fire extinguishers use CFCs, not ozone.

    ANSWER: [C]

    Explanation: The correct answer is [C] It is used as a refrigerant and in fire extinguishers.

    Ozone is poisonous at ground level.

    Ozone layer protects from harmful UV rays.

    Ozone forms when O₂ combines with free O atom (O₃).

    Refrigerants/fire extinguishers use CFCs, not ozone.

    See less
    • 31