Blog

Study tips that actually help

Real strategies from real teachers and toppers. New post every week.

Control and Coordination Class 12 Biology Chapter 9 Questions And Answers Maharashtra Board
Class 12 | Biology Maharashtra Board Textbook Solutions
15 Apr 2026

Control and Coordination Class 12 Biology Chapter 9 Questions And Answers Maharashtra Board

Q. 1. Multiple choice questions. 1. The nervous system of mammals uses both electrical and chemical means to send signals via neurons. Which part of the neuron receives impulse?(a) Axon(b) Dendron(c) Nodes of Ranvier(d) Neurilemma Answer. (b) Dendron 2. ……………. is a neurotransmitter.(a) ADH(b) Acetyl CoA(c) Acetyl choline(d) Inositol Answer. (c) Acetyl choline 3. The supporting cells that produce myelin sheath in the PNS are ______.a. Oligodendrocytesb. Satellite cellsc. Astrocytesd. Schwann cells Answer. (d) Schwann cells 4. A collection of neuron cell bodies located outside the CNS is called …………….(a) tract(b) nucleus(c) nerve(d) ganglion Answer. (d) ganglion 5. Receptors for protein hormones are located …………….(a) in cytoplasm(b) on cell surface(c) in nucleus(d) on Golgi complex Answer. (b) on cell surface 6. If parathyroid glands of a man are removed, the specific result will be ——a. onset of agingb. disturbance of  Ca++c. onset of myxoedemad. elevation of blood pressure Answer. (b) disturbance of Ca++ 7. Hormone thyroxine, adrenaline and non¬adrenaline are formed from ……………(a) Glycine(b) Arginine(c) Ornithine(d) Tyrosine Answer. (d) Tyrosine 8. Pheromones are chemical messengers produced by animals and released outside the body. The odour of these substance affects …………….(a) skin colour(b) excretion(c) digestion(d) behaviour Answer. (d) behaviour 9. Which one of the following is a set of discrete endocrine glands?a. Salivary, thyroid, adrenal, ovaryb. Adrenal, testis, ovary, liverc. Pituitary, thyroid, adrenal, thymusd. pituitary, pancreas, adrenal, thymus Answer. (c) Pituitary, thyroid, adrenal, thymus 10. After ovulation, Graafian follicle changes intoa. Corpus luteumb. Corpus albicansc. Corpus spongiosumd. Corpus callosum Answer. (a) corpus luteum 11. Which one of the following pair correctly matches a hormone with a disease resulting from its deficiency?a. Parathyroid hormone – Diabetes insipidusb. Leutinising hormone – Diabetes mellitusc. Insulin – Hyperglycemiad. Thyroxine – Tetany Answer. (c) Insulin – Hyperglycaemia 12. ……………. is in direct contact of brain in humans.(a) Cranium(b) Dura mater(c) Arachnoid(d) Pia mater Answer. (d) Pia mater Q. 2. Very very short answer questions. 1. What is the function of red nucleus? Answer. Red nucleus plays an important role in controlling posture and muscle tone, modifying some motor activities and motor coordination. 2. What is the importance of corpora quadrigemina? Answer. Corpora quadrigemina consists of 4 solid rounded structures, viz. superior and inferior colliculi. Superior colliculi control visual reflexes while inferior colliculi control auditory reflexes. 3. What does the cerebellum of brain control? Answer. Cerebellum of brain is an important centre which maintains equilibrium of body, posture, balancing orientation, moderation of voluntary movements and maintenance of muscle tone. 4. Name the three ear ossicles. Answer. Malleus [hammer], incus [anvil] and stapes [stirrup]. 5. Name the anti abortion hormone. Answer. Progesterone. 6. Name an organ which acts as temporary endocrine gland. Answer. Placenta. Corpus luteum in ovary. 7. Name the type of hormones which bind to the DNA and alter the gene expression. Answer. Steroid hormones. 8. What is the cause of abnormal elongation of long bones of arms and legs and of lower jaw. Answer. Hypersecretion of growth hormones in adults causes abnormal elongation of long bones of arms and legs and of lower jaw i.e. acromegaly. 9. Name the hormone secreted by the pineal gland. Answer. Melatonin. 10. Which endocrine gland plays important, role in improving immunity? Answer. The endocrine gland, thymus plays an important role in improving immunity. Q. 3. Match the organism with the type of nervous system found in them Column A Column B (1) Neurons (a) Earthworm (2) Ladder type (b) Hydra (3) Ganglion (c) Flatworm (4) Nerve net (d) Human Answer. olumn A Column B (1) Neurons (d) Human (2) Ladder type (c) Flatworm (3) Ganglion (a) Earthworm (4) Nerve net (b) Hydra Q. 4. Very short answer questions. 1. Describe the endocrine role of islets of Langerhans. Answer. Endocrine cells of pancreas form groups of cells called Islets of Langerhans. There are four kinds of cells in islets of Langerhans which secrete hormones. 2. Mention the function of testosterone? Answer. Testosterone is a steroid sex hormone secreted by testes and cortex of adrenal glands. It controls the secondary sexual characters in males. 3. Give symptoms of the disease caused by hyposecretion of ADH. Answer. Polydipsia, i.e. frequent thirst and polyuria, i.e. frequent urination are the symptoms of the disease caused by hyposecretion of ADH. Q. 5. Short answer questions 1. Rakesh got hurt on his head when he fell down from his motorbike. Which inner membranes must have protected his brain? What other roles do they have to play? Answer. 2. Give reason – Injury to medulla oblongata may prove fatal. Answer. 3. Distinguish between the sympathetic and parasympathetic nervous system on the basis of the effect they have on: a. Heart beat b. Urinary Bladder Answer. Sympathetic Nervous System Parasympathetic Nervous System (1) Heartbeat Increases Decreases (2) Urinary bladder Relaxes and stores urine Contracts causing micturition 4. While holding a tea cup Mr. Kothari’s hands rattle. Which disorder he may be suffering from and what is the reason for this? Answer. 5. List the properties of the nerve fibres. Answer. 6. How does the tongue detect the sensation of taste? Answer. 7. State the site of production and function of Secretin, Gastrin and Cholecystokinin. Answer. Hormone Site of production Functions 1. Secretin Duodenal mucosa Stimulates secretion of pancreatic juice and bile from pancreas and liver respectively. 2. Gastrin Gastric mucosa Stimulates gastric glands to secrete gastric juice. 3. Cholecystokinin Duodenal mucosa Stimulates pancreas and gall bladder to release pancreatic enzymes and bile respectively. 8. An adult patient suffers from low heart rate, low metabolic rate and low body temperature. He also lacks alertness, intelligence and initiative. What can be this disease? What can be its cause and care? Answer. 9. Where is the pituitary gland located? Enlist the hormones secreted by anterior pituitary. Answer. The pituitary gland is attached to hypothalamus on the ventral surface of brain. It is lodged in a bony depression called sella turcica of sphenoid bone.For names of hormones: Gonadotropins- 10. Explain how the adrenal medulla and sympathetic nervous system function as a

Read article
Life Processes in Living Organisms Class 9 Science Chapter 15 Questions And Answers Maharashtra Board
Maharashtra Board
25 Feb 2026

Life Processes in Living Organisms Class 9 Science Chapter 15 Questions And Answers Maharashtra Board

1. Match the pairs and explain. Answer. (1 – b),(2 – c),(3 – a),(4 – e) 2. Complete the paragraph. The milk was on the stove. Rasika was engrossed watching television. She smelled something burning. She ran towards the kitchen. The milk was boiling over. She held the vessel with her bare hands but, screaming, she let it go at once. This activity was controlled by ……………….. cells. Special ends of ……………….. in these cells collected the information, from where it was transferred to the ……………….. and then towards the terminal end of the ……………….. The chemicals produced at the terminal end passed through the minute space i.e. ………………. . In this way, ……………….. were conducted in the body and the process of ……………….. was completed by conducting the impulses from ……………….. to ……………… (Nerve, muscle cell, impulse, dendrite, synapse, axon, reflex action, cell body) Answer. Nerve, dendrite, cell body, axon, synapse, impulses, reflex action, nerve, muscle cell. 3. Write notes on Root pressure, Transpiration, Nerve cell, Human brain, Reflex action Answer. 1. Root pressure (1) The pressure created in the root cells is called a root pressure. Root cells are in contact with water and minerals in the soil. But the concentration inside the cells and the concentration in the surrounding soil is different from each other and thus there is concentration gradient created. (2) Due to concentration gradient, the water and minerals from the surrounding areas enter in the root cells. (3) Due to this, the root cells become turgid and exert pressure on the adjacent cells. (4) Due to root pressure, the water and minerals enter the xylem present in the roots. To reduce this difference in concentration they are continuously pushed forward. This continuous movement creates a water column that is continuously pushed ahead. (5) The pressure exerted by the root cells thus is sufficient to lift the water up in small shrubs and small trees. 2. Transpiration (1) There are stomata on the leaves of the plants. Through these opening the excess of water is thrown out in the form of water vapours. This process is called transpiration. (2) There are two guard cells around the opening of stomata. They have an external membrane. They control the opening and closing of the stomata. (3) Also some amount of water is lost due to evaporation from the leaves. (4) As a result, water level in the epidermal layer of the leaf decreases. (5) To compensate this loss, more water is brought to the leaves through the xylem. (6) Transpiration thus helps in absorption of water and minerals and their distribution to all parts of the plant. (7) Root pressure pushes the water up during the night time. 3. Nerve cell (1) Neurons or nerve cells are structural and functional units of the nervous system that carry impulses from one place to other. (2) Neuron has the ability to generate and conduct electrochemical impulses. (3) Every neuron has three main parts, viz. cyton or cell body, axon and dendrites. Dendrites pick up the electrochemical signals produced. (4) These signals are transferred to cyton and from cyton they are sent to axons. From axon of one neuron, the impulse is then given to dendrites of next neuron. 4. Human brain (1) Human brain is highly evolved organ. It is the main controlling centre of nervous system. It is the part of the central nervous system. It is very well protected inside the cranium or cranial cavity. (2) The brain is enclosed by meninges which are protective coverings. There are hollow ventricles inside the brain which are filled up with cerebrospinal fluid. This fluid is protective and nourishing in function. The average weight of adult human brain is about 1300 – 1400 grams and there are approximately 100 billion neurons in the brain. (3) There are three main parts of the brain, viz. Cerebrum, cerebellum and medulla oblongata. 5. Reflex action (1) Reflex action is an immediate and involuntary response given to a stimulus from the environment. (2) The reflex action is so spontaneous that it does not require thinking or control by our brain. (3) Reflex actions are not controlled by brain. But the control and coordination is maintained by the reflex actions by which the load on the brain isreduced. They are of survival value as a person is saved from a dangerous situations due to reflex actions. (4) The path of reflex action is as follows : This is also known as reflex arc. Sense organs Sensory neurons -> Towards the spinal cord -> Coordination neuron -> Motor neuron-> Muscle or gland. 4. Name the hormones of the following endocrine glands and the function of each. Pituitary, Thyroid, Adrenal, Thymus, Testis, Ovary. Answer. Hormone Function (i) Growth hormone Stimulates growth of bones. (ii) Adrenocorticotropic hormone Stimulates adrenal gland. (iii) Thyroid-stimulating hormone Stimulates thyroid gland. (iv) Prolactin Stimulates milk production. (v) Follicle-stimulating hormone Controls growth of gonads. (vi) Luteinizing hormone Controls menstrual cycle and ovulation. (vii) Oxytocin Contracts uterus during parturition. (viii) Antidiuretic hormone Regulates water-level in the body. 2. Thyroid Hormone Function (i) Thyroxine Controls growth of body and metabolic activities. (ii) Calcitonin Controls calcium metabolism and calcium level in blood. 3. Adrenal Hormone Function (i) Adrenalin and nor-adrenalin Controls behaviour during crisis and emotional situation. (ii) Corticosteroid Maintains balance of Na+ and K+ and stimulates metabolism. 4. Thymus Hormone Function Thymosin Control the cells which give rise to immunity. 5. Testis Hormone Function Testosterone Stimulates growth of secondary sexual characteristics like beard, mustache, hoarse voice etc. in men. 6. Ovary Hormone Function (i) Oestrogen Stimulates growth of the endometrium. Stimulates growth of secondary sexual characteristics in women. (ii) Progesterone Prepares the endometrium for conception and maintains pregnancy. 5. Draw and label the diagrams. Human endocrine glands, Human brain, Nephron, Nerve cell, Human excretory system. Answer. 1. Human endocrine glands 2. Human brain 3. Nephron 4. Nerve cell 5. Human excretory system 6. Answer the following. a. Explain chemical co-ordination in humans and give the names and

Read article