The hormone which increases the fertility in males is called
(a) oestrogen
(b) testosterone
(c) insulin
(d) growth hormone
(b) testosterone
Control and Coordination
A doctor advised a person to take an injection of insulin because
(a) his blood pressure was low
(b) his heart was beating slowly
(c) he was suffering from goitre
(d) his sugar level in blood was high
(d) his sugar level in blood was high. A person with diabetes will have high blood sugar because their body does not produce sufficient or no insulin hormones at all. To control blood sugar in these patients, insulin injections are given.
Dramatic changes in body features associated with puberty are mainly because of the secretion of
(a) oestrogen from the testes and testosterone from the ovary
(b) estrogen from the adrenal gland and testosterone from the pituitary gland
(c) testosterone from the testes and estrogen from the ovary
(d) testosterone from the thyroid gland and estrogen from the pituitary gland
(c) testosterone from the testes and estrogen from the ovary These are the sex hormones that begin to show up after puberty and cause the secondary character. Females release oestrogen, whereas males secrete testosterone.
Dwarfism results due to
(a) Excess secretion of thyroxin
(b) Less secretion of growth hormone
(c) Less secretion of adrenaline
(d) Excess secretion of growth hormone
(b) Less secretion of growth hormone An organism’s overall growth is controlled by growth hormones. Dwarfism results from the lack of growth hormone secretion.
Which statement is not true about thyroxin?
(a) Iron is essential for the synthesis of thyroxin
(b) It regulates carbohydrates, protein and fat metabolism in the body
(c) The thyroid gland requires iodine to synthesise thyroxin
(d) Thyroxin is also called thyroid hormone
(a) Iron is essential for the synthesis of thyroxin Iron is not essential for the synthesis of thyroxin; hence, statement a) is wrong.
What is the correct direction of flow of electrical impulses?
Answer :- C An electrical impulse is received to a neuron’s dendrites by the axonal end of another neuron. The electrical impulse then passes through the cell body and axon and arrives at the axonal end.
When a person is suffering from a severe cold, he or she cannot (a) differentiate the taste of an apple from that of an ice cream (b) differentiate the smell of a perfume from that of an agarbatti (c) differentiate red light from green light (d) differentiate a hot object from a cold object
(b) differentiate the smell of a perfume from that of an agarbatti Olfactory receptors get blocked in the cold, making it difficult to distinguish smell.
Involuntary actions in the body are controlled by
(a) medulla in fore brain
(b) medulla in mid brain
(c) medulla in hind brain
(d) medulla in spinal cord
(c) medulla in hind brain (c) medulla in hind brain Medulla is present only in hind brain
Which of the following statements about transmission of nerve impulse is incorrect? (a) Nerve impulse travels from dendritic end towards axonal end (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 (c) 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 (d) A neuron transmits electrical impulses not only to another neuron but also to muscle and gland cells
(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 Axonal ends, not dendritic ends, are where chemicals or neurotransmitters are released. Therefore, statement b) is false.