(a) Explain the term 'Synapse'. (b) Name the neurotransmitter that allows the transmission of impulses across the synapse.

How are the Cytons and Axons of neurons arranged in the following? (a) Cerebrum (b) Spinal cord

Bharat woke up late in the morning and missed the school bus. This situation stimulated the nerves of the sympathetic system which resulted in (a) Constriction of Coronary arteries (b) Muscle relaxation (c) Decrease in Respiration rate (d) Bronchodilation

Assertion: The sympathetic nervous system prepares the body for violent action. Reason: The sympathetic nervous system accelerates the heartbeat. (a) Both Assertion and Reason are true. (b) Assertion is true but Reason is false. (c) Assertion is false but Reason is true. (d) Both Assertion and Reason are false.

Read the explanations given below and name the structures: (a) The canal through which the testes descend down into the scrotum just before the birth of a male baby. (b) The part of the brain that regulates the peristaltic movement of the alimentary canal. (c) A structure that collects the soundwaves and conducts them through the external auditory canal. (d) The point of attachment of two chromatids of a chromosome. (e) Regulation of the opening and closing of stomata.

Match the items in Column I with those in Column II: Column I Column II Leydig cells Lack of thyroxine in children Stoma 12 pairs Ova Testosterone Cranial nerve Diffusion of respiratory gases Cretinism Haploid cells 31 pairs Diploid cells

Arrange the terms in each group in the correct order. Write them in a logical sequence beginning with the term that is underlined. (a) Palisade cells, Cuticle, Upper epidermis, Spongy cells. (b) Hepatic portal vein, Stomach, Hepatic vein, Liver. (c) Cyton, Dendrites, Synaptic cleft, Axon endings. (d) Insulin release, High blood sugar, Lowers blood sugar, Stimulates glucose uptake from blood. (e) Sperm duct, Seminiferous tubule, Epididymis, Efferent ducts.

Mohan is fond of playing basketball. His concentration is on shooting the ball into the opponent’s basket as given in the picture. (a) Which part of the brain helps Mohan to concentrate in putting the ball into the basket? (b) Name the sense organ that helps to gauge the distance between the ball and the basket. (c) Name the part of the brain that co-ordinates all the voluntary muscles of his body.

Arrange the following in a logical sequence: (a) Australopithecus, Cro-Magnon, Homo erectus, Neanderthal man. (b) Pupil, Aqueous humour, Retina, Vitreous humour. (c) Effector, Receptor, Motor neuron, Sensory neuron. (d) Loop of Henle, Distal convoluted tubule, Bowman’s Capsule, Proximal convoluted tubule. (e) Water vapour, Soil water, Leaves, Ascent of Sap.

Assertion (A): Arachnoid layer helps in speeding up the transmission of nerve impulses along the axons. Reason (R): Axon endings at the synapse secrete acetylene. (a) A is True and R is False (b) A is False and R is True (c) Both A and R are True (d) Both A and R are False

Karan was standing on a high stool and cleaning the ceiling fan. He suddenly loses balance and sustains a head injury. An examination reveals that his pupils have lost the capacity to constrict in bright light. Which structure has been damaged? (a) Suspensory ligaments (b) Medulla oblongata (c) Eye lens (d) Eye lid

Copy the diagram given below. (a) Name the structure. (b) Label Gray matter and White matter.