Pioneer s Revision Pack

Transcription

1 1. What are phytohormones? Pioneer s Revision Pack Control and Coordination Certain chemical substances synthesised in plants that control and coordinate various growth and developmental activities of plants are called plant hormones phytohormones 2. Name the part of hindbrain which takes part in regulation of respiration. Pons take part in the regulation of respiration 3. We suddenly pull our hand when a pin pricks. Name the type of response involved in this action. Reflex action, an involuntary response is involved in it. 4. What is autonomic nervous system? Name the sub systems in which it is divided. Sol Autonomic nervous system is the part of peripheral nervous system that acts as a control system which controls visceral functions including heart rate, digestion, respiratory rate, salivation, breathing, perspiration, urination and swallowing. Autonomic nervous system in human have two major divisions, i.e., sympathetic nervous system and parasympathetic nervous system. 5. Taking the example of auxins and cytokinin together, explain. (a) A synergistic action in plants. or (b) An antagonistic action in plants. (a) A synergistic action in plants can be seen in tissue cultures of parenchyma mitosis or cell division is stimulated by both auxins and cytokinins. where (b) Example of an antagonistic action in plants is the growth of apical bud. It is accelerated by auxins and that of lateral buds is suppressed by auxins (apical dominance) whereas, S.C.O , Sector 40 D, CHD. Phone: ,

2 cytokinin accelerates the growth of the lateral buds and reduces apical dominance (action of both auxin and cytokinin are opposite to each other). 6. What are hormones? Write any two functions of hormones. Hormones are chemical substances, which coordinate the activities of living organism and also their growth. Functions (i) They help in coordinating the activities of our body, (ii) Hormones regulate several functions in the human body like growth, metabolic activities and reproduction 7. Define 'nerve impulse'. Which structure in a neuron helps to conduct a nerve impulse? (a)towards the cell body. (b) Away from the cell body. The information passing through the neurons in the form of chemical and electrical signals is called nerve impulse. (a) Dendrites conduct nerve impulse towards the cell body. (b) Axons conduct nerve impulse away from the cell body or to another neuron/tissue. 8. (a) State the main function of pituitary gland'. (b)write the effects of (i) Excessive and (ii) Sluggish activity of this gland on the growth of a child. (a) The main function of pituitary gland is the secretion of growth hormone. (b) Its excessive secretion (hypersecretion) results in gigantism. The sluggish activity, (hyposecretion) of this gland causes dwarfism. S.C.O , Sector 40 D, CHD. Phone: ,

3 Control and Co-ordination {Chapter Test} M:M: 30 M: Time: 40Mins 1. What is the stimulus in geotropism? [1] The stimulus in geotropism is gravity. 2. Name three glands associated with digestion of food. State their secretions. [3] Three glands with their secretions are as follows (a) Salivary glands (b)liver (c) Pancreas Secretes Saliva Secretes Bile juice Secretes Pancreatic juice 3. How is the movement of leaves of the sensitive plant different from the movement of a shoot towards light? The movement of leaves of the sensitive plant is not dependent upon the growth of the plant. while the movement of a shoot of a plant towards light is growth dependent movement. The movement of leaves of sensitive plants is not directional while the movement of shoot is directional. The movement of leaves of sensitive plant is neither away nor towards the stimulus (like touch) whereas movement of a shoot is towards the stimulus. 4. Name one hormone released by each of the following glands and write then-functions, (a) Pituitary (b)testis (c) Ovary [3] Gland Hormone Function (a) Pituitary Growth hormone Growth regulation. (b)testis Testosterone Brings changes inmales during puberty. [3] S.C.O , Sector 40 D, CHD. Phone: ,

4 (c) Ovary Oestrogen Brings changes in females during puberty. 5. A young green plant receives sunlight from one direction only. What will happen to its shoots and roots? [2] The shoots of the plant bend towards the light whereas roots bend away from light. 6. What is reflex action? State its mechanism and advantages. [5] The automatic and involuntary response of effector organs to a stimulus is called reflex action. Mechanism Steps involved in reflex action are (i) Receiving of stimulus by effector organ, (ii) Activation of sensory nerve impulse, (iii) Sensory impulse carried to spinal cord, (iv) Transmission of impulse to motor neurons. (v) Impulse conducted by motor neurons to effector organ. The advantages of reflex action are (i) It helps our body to give quick response to the stimuli. (ii) It protects the body from harmful stimuli. 7. What are receptors in our body? Name the four types of receptors and state their functions. [4] A group of cells, which detect a stimulus and initiate impulse in the sensory nerves are called receptors. Types of receptors and their functions are as follows (i) Photoreceptors for sight (eyes)(i) (ii) Phonoreceptors for sound (ears) S.C.O , Sector 40 D, CHD. Phone: ,

5 (iii) Gustatory receptors to get taste (tongue) (iv) Olfactory receptors to get smell (nose) 8. In a neuron, [3] (a) where is information received? (b) how does information travel? (c) where does impulse get converted into chemical signal? (a) In a neuron, information is received in dendrites. (b) Information travels through axons in a neuron. (c) Impulse gets converted into chemical signal at axon endings (synapse). 9. Write the technical terms for following events. [2] (a) The movement of plant in the direction of light, (b) The movement of plant parts in response to water. (c) The movement of plant parts towards chemical substance. (d) The downward movement of roots in response to gravitational force. (a) The term used is phototropism it is because the movement of plant in the direction of light is called phototropism. (b) The term used is hydrotropism it is because the movement of plant parts in response to water is called hydrotropism. (c) The term used is chemotropism it is because the movement of plant parts towards chemical substance is called chemotropism. (d) The term used is geotropism the downward movement of roots in response to gravitational force is called geotropism. 10. In the figure given below [4] S.C.O , Sector 40 D, CHD. Phone: ,

6 (a) Which type of movement is shown by the plant in above activity? (b) The information below shows the function of the responses of plants To gain mineral salts in the soil and to get support. Name the response related with the functions above. (a) Photo tropic movement is shown by the plant because its shoot bends in the direction of light. (b) At the above functions like, to gain mineral salts in the soil and to get support are done by roots. These roots grow towards the gravity. Therefore, the response related to the above function is due to gravity i.e., positive geotropism. S.C.O , Sector 40 D, CHD. Phone: ,