Q 5 – Identify which of the following statements about thyroxin is incorrect? (a) Thyroid gland requires iodine to synthesize thyroxin. (b) Thyroxin is also called thyroid hormone. (c) It regulates protein, carbohydrates and fat metabolism in the body. (d) Iron is essential for the synthesis of thyroxin.
(a) Thyroid gland requires iodine to synthesize thyroxin.
Q 6 – The secretion of which hormone leads to physical changes in the body when you are 10-12 years of age? (a) Oestrogen from testes and testosterone from ovar. (b) Estrogen from adrenal gland and testosterone from pituitary gland. (c) Testosterone from testes and estrogen from ovary. (d) Testosterone from thyroid gland and estrogen from pituitary gland.
(c) Testosterone from testes and estrogen from ovary.
Q 7 – Which of the following statements are true? (i) Sudden action in response to something in the environment is called reflex action (ii) Sensory neurons carry signals from spinal cord to muscles (iii) Motor neurons carry signals from receptors to spinal cord (iv) The path through which signals are transmitted from a receptor to a muscle or a gland is called reflex arc (a) (i) and (ii) (b) (i) and (iii) (c) (i) and (iv) (d) (i), (ii) and (iii)
Control and coordination are the functions of the nervous system and ……… in our body.
The nervous system uses ……… impulses to transmit messages.
Central nervous system consists of ……… and ……… .
Largest part of the brain is ………………..
Deficiency of ……… hormone in childhood leads to dwarfism in humans.
The growth of pollen tubes towards the ovules is the result of a ……… movement.
The Hindbrain consists of three centres called ………………, ………………….. and ………………
…………….. no. of pairs of nerves arise from the Spinal Cord .
A microscopic gap between a pair of Adjacent neurons over which nerve impulses pass when going from one neuron to the next is known as ………………..
The various sense organs are present in our body with special receptors. The Photoreceptors are present in ………………., Phonoreceptors are present in …………….., Olfactory receptors are present in ………………………., Olfactory receptors are present in ………………………., gustatory receptors are present in ………………………… and thermoreceptors are present in ………………………..
Following questions consist of two statements – Assertion (A) and Reason (R). Answer these questions selecting the appropriate option given below: (a) Both A and R are true and R is the correct explanation of A. (b) Both A and R are true but R is not the correct explanation of A. (c) A is true but R is false. (d) A is false but R is true.
Q 10. Assertion(A) : Insulin regulates blood sugar level. Reason (R) : Sufficient secretion of insulin will cause diabetes.
Q 11. Assertion(A) : Animals can react to stimuli in different ways. Reason (R) : All animals have a nervous system and an endocrine system involving hormones.
(a) Both A and R are true and R is the correct explanation of A.
Q 12. Assertion(A): A receptor is a specialized group of cells in a sense organ that perceive a particular type of stimulus. Reason (R) : Different sense organs have different receptors for detecting stimuli.
(b) Both A and R are true but R is not the correct explanation of A.
Q 13. Assertion(A) : The brain is also known as the central nervous system. Reason (R) : Central nervous system controls and regulates the voluntary actions.
Transmission of nerve impulses between two neurons takes place through the synapse. At the end of the axon, the electrical impulse sets off the release of some chemicals (neurotransmitters). These chemicals cross the gap or synapse and start a similar electrical impulse in the dendrite of the next neuron.
Q 19 – What are Cerebral reflexes . Explain with an example ?
The main function of progesterone is to prepare the endometrium (lining of your uterus) for a fertilized egg to implant and grow. If a pregnancy doesn’t occur, the endometrium sheds during your menstrual period. If conception occurs, progesterone increases to support the pregnancy