CBSE Class 10 Science Control and Coordination VBQs Set 05

This is Set 05 of value based and competency questions (VBQs) for CBSE Class 10 Science Chapter 6, Control and Coordination, with step-by-step answers and a Teacher's Note for each question. The questions place the hormones and brain parts in real life, such as iodised salt, diabetes care, safety on the road, drug abuse and health charts.

Value Based Questions

Question 1. Rahul went to the fruit market to buy fruits. He saw that the shopkeeper was spraying some powder-like substance on the unripe fruits. He asked the shopkeeper about the powder. The shopkeeper replied that it helps in ripening of fruits quickly.
(i) Can you name the substance the shopkeeper is using to quickly ripen the fruits?
(ii) Give some other functions of the substance named by you in part (i).
(iii) Give some examples of growth promoting and growth inhibiting hormones.
Answer:
(i) The plant hormone ethylene (supplied through ethylene-releasing chemicals) is used to ripen the fruits quickly.
(ii) Ethylene also helps in breaking the dormancy of seeds and buds, and in the shedding (abscission) of leaves and fruits.
(iii) Growth promoting hormones: auxins, gibberellins and cytokinins. Growth inhibiting hormone: abscisic acid.
Value: Fruits ripened naturally on the tree are the safest. A careful buyer should wash fruits well before eating and avoid fruits ripened with unknown chemicals.
In simple words: Ethylene is the ripening hormone; naturally ripened fruits are the safest choice.

Teacher's Note:
1. Ethylene is a gaseous plant hormone, so the powder only releases it.
2. Link the plant hormone with the real life habit of washing fruits.

Question 2. Ram has met with an accident after which he lost the capacity to
(i) walk in a straight line,
(ii) smell anything,
(iii) feel full after eating.
Which part of the brain is damaged in each case?
Answer:
(i) The cerebellum is damaged, because it controls and coordinates muscular activity and maintains the posture and balance of the body.
(ii) The olfactory lobe of the forebrain is damaged, as it is the centre of smell.
(iii) The hypothalamus (forebrain) is damaged, because the centres of hunger and thirst are located in it.
Value: Head injuries can damage these centres, so wearing a helmet while riding is important.
In simple words: Each lost ability points to the brain part that controls it; a helmet protects the brain.

Teacher's Note:
1. Learn the brain parts with their functions as pairs.
2. Safety rules such as helmets protect the brain and spinal cord.

Question 3. One day when Geeta was reading the newspaper she saw the picture of the shortest and the tallest person in the world. Next day when she went to school she asked her teacher about this condition.
(i) Which gland and hormone might be responsible for this condition?
(ii) What is the cause of the condition given in the above article and give scientific terms associated with the above two conditions?
(iii) Can this disease be cured?
Answer:
(i) The pituitary gland and its growth hormone.
(ii) Over-secretion of growth hormone in childhood causes gigantism (very tall), and under-secretion of growth hormone in childhood causes dwarfism (very short).
(iii) These conditions arise from too much or too little hormone. Under the guidance of a doctor, hormone treatment given early in childhood can help in many cases, so a child with unusual growth should be taken to a doctor in time.
Value: People with such conditions should be treated with respect and understanding.
In simple words: Too little growth hormone gives dwarfism and too much gives gigantism.

Teacher's Note:
1. Name the gland, the hormone and the disorder together in one line.
2. Show empathy; these conditions are not a person's fault.

Question 4. (A) While on a roller coaster ride, Aditya noticed an increase in his heartbeat and his breathing. Which hormone is responsible for the changes in Aditya's body?
(B) When some particles (like sand or dust) fall into our eyes, our eyes start to water on their own and we blink to get the particle out of our eyes. This is a type of reaction to a stimulus that the human body shows.
(i) Is the above-mentioned reaction involuntary or voluntary?
(ii) What is the specific name given to the pathway that brings about this immediate reaction to a stimulus?
(iii) What are the names given to: (1) the organ that responds to a stimulus? (2) the part of the brain that receives sensory impulses?
Answer:
(A) Adrenaline, the emergency hormone from the adrenal glands, increases the heartbeat and breathing rate.
(B)(i) It is an involuntary action (a reflex action).
(ii) The pathway is the reflex arc.
(iii) (1) The organ that responds to a stimulus is the effector (muscle or gland). (2) The sensory impulses are received by the forebrain (the sensory areas of the cerebrum).
In simple words: Fear raises adrenaline; a speck in the eye triggers a reflex arc and the eye blinks and waters.

Teacher's Note:
1. Adrenaline is secreted into the blood, so its effect is slower than a reflex.
2. Receptor to effector is the order of a reflex arc.

Question 5. (A) A doctor has advised Sameer to reduce sugar intake in his diet and do regular exercise after checking his blood test reports. Which disease do you think Sameer is suffering from? Name the hormone responsible for this disease and the organ producing the hormone.
(B) Which hormone is present in the areas of rapid cell division in a plant and which hormone inhibits the growth?
Answer:
(A) Sameer is suffering from diabetes mellitus. The hormone is insulin, produced by the pancreas. Its deficiency raises the blood sugar level.
(B) Cytokinin is present in the areas of rapid cell division (fruits and seeds). Abscisic acid inhibits growth.
Value: Regular exercise, controlled sugar intake and regular check-ups help to keep diabetes under control.
In simple words: Diabetes means too little insulin; diet and exercise help to manage it.

Teacher's Note:
1. Write disease, hormone and organ in that order.
2. Sugar-rich food and a lazy lifestyle increase the risk.

Question 6. Ramesh's friend was diabetic and every day before her meal in the recess she had to check her sugar level. To monitor it at times she used to take injections also. Ramesh was very fond of sweets but she never carried any sweets in her tiffin. They both shared each other's tiffin.
(a) What is the cause of diabetes?
(b) Which hormone helps the cells of the body to use the sugar of the blood?
Answer:
(a) Diabetes is caused when the pancreas does not secrete enough insulin, so the blood sugar level stays high.
(b) Insulin, secreted by the pancreas, lowers the blood sugar by helping the cells to take up glucose and the liver to store it as glycogen. This is why some patients are given insulin injections.
Value: Ramesh showed care and friendship by not carrying sweets and by supporting her friend.
In simple words: A diabetic friend needs insulin and support, and Ramesh gave both care and friendship.

Teacher's Note:
1. Do not say that insulin digests sugar; it controls the blood sugar level.
2. Support for a diabetic friend is a good value to mention.

Question 7. A group of students studied that many people suffered with a disease called Goitre. Students brought iodised salt packets and advised people to eat the same.
(a) Which hormone deficiency leads to the Goitre?
(b) Name one disease caused due to deficiency of hormone other than Goitre.
Answer:
(a) Deficiency of thyroxine, which needs iodine for its synthesis, leads to goitre (swollen neck).
(b) Diabetes mellitus is caused by the deficiency of insulin. (Dwarfism, due to deficiency of growth hormone, is another example.)
Value: The students used their knowledge to spread health awareness in the community.
In simple words: Iodised salt gives iodine for thyroxine and prevents goitre.

Teacher's Note:
1. Iodine is needed only for thyroxine, not for insulin.
2. Awareness drives are a good example of social responsibility.

Question 8. A motorcycle rider without helmet met with an accident and suffered a spinal cord injury. In this case, which signals will get disrupted and why?
Answer:
Step 1: Reflex arcs are formed in the spinal cord, so the reflex actions and the involuntary actions will be disturbed.
Step 2: Nerves from all over the body meet in the spinal cord on their way to the brain. After the injury, impulses from the body parts will not reach the brain and the messages from the brain will not reach the body parts.
Final answer: Reflex signals and the signals between the brain and the body will get disrupted.
Value: Always wear a helmet, because the cranium and vertebral column protect the brain and spinal cord only up to a limit.
In simple words: A damaged spinal cord cuts the line between the brain and the body, so wear a helmet.

Teacher's Note:
1. Reflexes work through the spinal cord, so they are lost first.
2. Mention the safety message in value based answers.

Question 9. A certain chemical in the nervous system makes you feel "high", a rewarded feeling. It binds to a certain receptor. A famous drug "Heroin" has a molecular shape which resembles dopamine. Think about the effect of the drug.
Answer:
Step 1: Because the drug has a shape like dopamine, it can bind to the same receptor and start the same feeling.
Step 2: The usual amount of the natural chemical then no longer gives the same strength of feeling, so the person needs the drug again and again.
Final answer: The drug leads to dependence and addiction, which harms the nervous system and the whole body.
Value: Say no to drugs and seek help from parents, teachers and doctors.
In simple words: A drug that copies a natural chemical can trap the brain into addiction.

Teacher's Note:
1. Chemicals act on receptors that fit their shape.
2. Connect the answer with the harm of drug abuse.

Question 10. The gland A is attached to the wind pipe in the human body. The gland A makes and secretes a hormone B which controls the metabolism of carbohydrates, fats and proteins in the body. The non-metal element C is necessary for the formation of hormone B. The deficiency of C in the diet can cause a deficiency of hormone B in the body leading to a disease D in which the neck of a person appears to be swollen. People are advised to use salt E in cooking food so as to avoid disease D.
(A) Name (i) gland A, and (ii) hormone B.
(B) What is the element C?
(C) Name one type of food which can provide sufficient C in the diet of a person.
(D) Name (i) disease D, and (ii) salt E.
Answer:
(A) (i) Gland A is the thyroid gland. (ii) Hormone B is thyroxine.
(B) Element C is iodine.
(C) Sea food (such as sea fish) is rich in iodine. Iodised salt and dairy products also supply it.
(D) (i) Disease D is goitre. (ii) Salt E is iodised salt.
In simple words: The thyroid in the neck needs iodine to make thyroxine, and iodised salt prevents goitre.

Teacher's Note:
1. Read the clue 'attached to the wind pipe' to identify the thyroid.
2. Iodine is a non-metal.

Question 11. Put some sugar in your mouth. How does it taste? Block your nose by pressing it between your thumb and index finger. Now eat sugar again. Is there any difference in its taste? While eating lunch, block your nose in the same way and notice if you can fully appreciate the taste of the food you are eating.
(A) Identify the correct statements: (I) Taste of sugar is sweet. (II) Gustatory receptors in our tongue are responsible for taste. (III) Olfactory receptors in our tongue are responsible for smell. (IV) Receptors communicate information to the mouth so that we are able to taste things. Options: (a) Only (I) (b) Both (I) and (II) (c) (I), (II) and (III) (d) (I), (III) and (IV)
(B) When we block our nose by pressing it between our thumb and index finger, then: (a) there is no change in taste of sugar. (b) we do not get the taste of sugar. (c) there is a change in the taste of sugar. (d) sugar tastes salty.
(C) Can you fully appreciate the taste of the food you are eating if you block your nose while eating?
(D) Loss of smell and taste is one of the early symptoms of COVID-19. Justify.
(E) Assertion (A): The taste of food changes when we have a blocked nose due to common cold. Reason (R): Gustatory receptors are responsible for taste. (a) Both (A) and (R) are true, and (R) is the correct explanation of (A). (b) Both (A) and (R) are true, and (R) is not the correct explanation of (A). (c) (A) is true but (R) is false. (d) (A) is false but (R) is true.
Answer:
(A) Option (b). Statements I and II are correct. Olfactory receptors are in the nose (not the tongue), and receptors send information to the brain (not to the mouth).
(B) Option (c): there is a change in the taste of sugar, because the sense of smell is blocked and taste depends partly on smell.
(C) No. Food does not taste fully when the nose is blocked.
(D) COVID-19 can affect the olfactory receptors in the nose and the nerves that carry smell to the brain, so smell and then taste are lost.
(E) Option (b). Both are true, but the change in taste is caused by the blocked olfactory (smell) receptors, so R does not explain A.
In simple words: Taste and smell work together, so a blocked nose makes food taste dull.

Teacher's Note:
1. Gustatory receptors are on the tongue and olfactory receptors are in the nose.
2. Check each statement of an option separately.

Case Based and Competency Questions

Teacher's Note:
1. Compare the patient's values with the chart before answering.
2. Insulin comes from the pancreas, not from the adrenal gland.

Teacher's Note:
1. Read the age row carefully in the table.
2. Adrenaline prepares the body for emergencies.

Question 14. The biology teacher while discussing 'control and coordination in animals' taught the students that animals have two systems, namely the nervous system and the endocrine system, which help to regulate all body functions. Saransh immediately asked how control and coordination take place in plants. Vidhut asked his teacher about the endocrine system. After a lot of discussion, the teacher asked the students some questions related to the topic.
(A) The endocrine system is involved in chemical coordination. How does the chemical coordination take place in animals?
(B) Some plants like the pea plant climb up other plants or fences by means of tendrils. What is the cause of the growth of tendril in pea plants?
(C) "Nervous and hormonal systems together perform the functions of control and coordination in human beings." Justify the above statement.
Answer:
(A) Endocrine glands secrete hormones directly into the blood. The blood carries them to the target organs, where they trigger a particular response.
(B) Tendrils are sensitive to touch. The hormone auxin collects on the side of the tendril away from the support, so that side grows faster and the tendril coils round the support.
(C) Nerves cannot reach every part of the body and their effect is quick but short lived. Hormones travel in the blood to all parts and their effect is slower but longer lasting. In an emergency, for example, the nervous system carries the information while adrenaline from the adrenal gland prepares the body, so the two systems work together.
In simple words: Nerves give fast, local messages and hormones give slower, wider messages, so the body uses both.

Teacher's Note:
1. Give one example such as adrenaline when you justify.
2. Auxin collects on the side away from the support.

Question 15. A student was interested in knowing about various endocrine glands in the human body, the hormones secreted by them and their functions.
(A) Which hormone is produced from the pancreas that helps in regulating blood sugar levels?
(B) Which endocrine gland is known as the master gland in human beings?
(C) Which gland secretes the growth hormone?
Answer:
(A) Insulin, which lowers the blood sugar level.
(B) The pituitary gland is called the master gland, since its hormones control other endocrine glands such as the thyroid, adrenal glands, ovaries and testes.
(C) The pituitary gland secretes the growth hormone. Its deficiency in childhood leads to dwarfism.
In simple words: The pancreas gives insulin, and the pituitary is the master gland that gives growth hormone.

Teacher's Note:
1. Make a table of gland, hormone and function for revision.
2. The pituitary hangs from the base of the brain.

Question 16. Metamorphosis is a biological process by which an animal physically develops after birth or hatching, involving a conspicuous and relatively abrupt change in the animal's body structure through cell growth and differentiation. Some insects, fish, amphibians, molluscs, crustaceans and other groups undergo metamorphosis, which is often accompanied by a change of nutrition source or behaviour. The stages of metamorphosis in butterflies are egg, larva (caterpillar), pupa (chrysalis) and adult.
(A) What are the chemicals that control such developmental changes in the butterfly's body structure called?
(B) Name ONE developmental change (other than external changes in body structure) in a human female during puberty brought about by the action of the type of chemicals mentioned in (A).
Answer:
(A) The chemicals are hormones, which are secreted by endocrine glands and control growth and development.
(B) In a human female, the hormone oestrogen brings about the onset of the menstrual cycle at puberty.
In simple words: Hormones control body changes in both insects and humans.

Teacher's Note:
1. Hormones control growth and development at every stage of life.
2. Oestrogen is released by the ovary.

Question 17. Answer the following on the basis of your understanding of the following information and related studied concepts. Thyroid gland is a bilobed structure situated in our neck region. It secretes a hormone called thyroxine. Iodine is necessary for the thyroid gland to make thyroxine. Thyroxine regulates carbohydrates, protein and fat metabolism in the body. It promotes growth of body tissues also. When there is an excess of thyroxine in the body, a person suffers from hyperthyroidism and if this gland is underactive it results in hypothyroidism. Hypothyroidism is caused due to the deficiency of iodine in our diet resulting in a disease called goitre. Iodised salt can be included in our diet to control it.
(i) Where is the thyroid gland situated?
(ii) State the function of thyroxine in the human body.
(iii) What is hyperthyroidism?
(iv) How can we control hypothyroidism?
Answer:
(i) The thyroid gland is situated in the neck region.
(ii) Thyroxine regulates the carbohydrate, protein and fat metabolism of the body and promotes the growth of body tissues.
(iii) Hyperthyroidism is the condition that occurs when there is an excess of thyroxine in the body.
(iv) Hypothyroidism caused by iodine deficiency can be controlled by including iodised salt in the diet.
In simple words: The thyroid in the neck needs iodine to make thyroxine, so iodised salt prevents hypothyroidism.

Teacher's Note:
1. Hyper means too much and hypo means too little.
2. Take all the facts for the answers from the passage.

Teacher's Note:
1. Read the table to see whether the value is low, normal or high.
2. Medical advice is needed in pregnancy, so do not suggest self-medication.