Class 10 Science

Control & Coordination NCERT Exemplar Problems

MCQs Part 3

Question 20: The substance that triggers the fall of mature leaves and fruits from plants is due to

  1. auxin
  2. gibberellin
  3. abscisic acid
  4. cytokinin

Answer: (c) Abscissic Acid

Question 21: Which of the following statements about transmission of nerve impulse is incorrect?

  1. Nerve impulse travels from dendritic end towards axonal end
  2. At the dendritic end electrical impulses bring about the release of some chemicals which generate an electrical impulse at the axonal end of another neuron
  3. The chemicals released from the axonal end of one neuron cross the synapse and generate a similar electrical impulse in a dendrite of another neuron
  4. A neuron transmits electrical impulses not only to another neuron but also to muscle and gland cells
    Answer: (b) At the dendritic end electrical impulses bring about the release of some chemicals which generate an electrical impulse at the axonal end of another neuron

Question 22: Involuntary actions in the body are controlled by

  1. Medulla in forebrain
  2. Medulla in midbrain
  3. Medulla in hindbrain
  4. Medulla in spinal cord
    Answer: (c) Medulla in the hindbrain

Question 23: Which of the following is not an involuntary action?

  1. Vomiting
  2. Salivation
  3. Heart beat
  4. Chewing
    Answer: (d) Chewing

Question 24: When a person is suffering from severe cold, he or she cannot

  1. Differentiate the taste of an apple from that of an ice cream
  2. Differentiate the smell of a perfume from that of an agarbatti
  3. Differentiate red light from green light
  4. Differentiate a hot object from a cold object
    Answer: (b) Differentiate the smell of a perfume from that of an agarbatti

Question 25: What is the correct direction of flow of electrical impulses?

exemplar question options

Question 26: Which statement is not true about thyroxin?

  1. Iron is essential for the synthesis of thyroxin
  2. It regulates carbohydrates, protein and fat metabolism in the body
  3. Thyroid gland requires iodine to synthesise thyroxin
  4. Thyroxin is also called thyroid hormone
    Answer: (a) Iron is essential for the synthesis of thyroxine

Question 27: Dwarfism results due to

  1. Excess secretion of thyroxin
  2. Less secretion of growth hormone
  3. Less secretion of adrenaline
  4. Excess secretion of growth hormone
    Answer: (b) Less secretion of growth hormone

Question 28: Dramatic changes of body features associated with puberty are mainly because of secretion of

  1. Oestrogen from testes and testosterone from ovary
  2. Oestrogen from adrenal gland and testosterone from pituitary gland
  3. Testosterone from testes and Oestrogen from ovary
  4. Testosterone from thyroid gland and Oestrogen from pituitary gland
    Answer: Testosterone from testes and Oestrogen from ovary

Question 29: A doctor advised a person to take an injection of insulin because

  1. His blood pressure was low
  2. His heart was beating slowly
  3. He was suffering from goiter
  4. His sugar level in blood was high
    Answer: (d) His sugar level in blood was high

Question 30: The hormone which increases the fertility in males is called

  1. Oestrogen
  2. Testosterone
  3. Insulin
  4. Growth hormone
    Answer: (b) Testosterone

Question 31: Which of the following endocrine glands is unpaired?

  1. Adrenal
  2. Testes
  3. Pituitary
  4. Ovary
    Answer: (c) Pituitary

Question 32: Junction between two neurons is called

  1. Cell junction
  2. Neuro muscular junction
  3. Neural joint
  4. Synapse
    Answer: (d) Synapse

Question 33: In humans, the life processes are controlled and regulated by

  1. Reproductive and endocrine systems
  2. Respiratory and nervous systems
  3. Endocrine and digestive systems
  4. Nervous and endocrine systems
    Answer: (d) Nervous and endocrine systems