CBSE Class 10 Biology Control and Coordination Worksheet Set C

Question. In a neuron conversion of electrical signal to a chemical signal occurs at :
(a) Cell body
(b) Dendritic end
(c) Axonal terminals
(d) Axon
Answer : C 

Question. The growth of tendrils in pea plants is due to :
(a) Effect of gravity
(b) Effect of chemicals
(c) Rapid cell division in tendrillar cells that are away from the support
(d) Rapid cell division in tendrillar cells in contact with the support
Answer : C 

Question. The shape of guard cells changes due to change in the :
(a) Protein composition of cells
(b) Temperature of cells
(c) Amount of water in cells
(d) Position of nucleus in cells
Answer : C

Question. The substance that triggers the fall of mature leaves and fruits from plants is due to :
(a) Auxin
(b) Gibberellin
(c) Abscisic acid
(d) Cytokinin
Answer : C

Question. Which of the following is a plant hormone ?
(a) Insulin
(b) Thyroxin
(c) Oestrogen
(d) Cytokinin
Answer : C

Question. The movement of root away from light is :
(a) Positive phototropism
(b) Negative hydrotropism
(c) Negative phototropism
(d) Positive geotropism
Answer : C

Question. Cretinism results due to :
(a) Excess secretion of growth hormone
(b) Under secretion of thyroxin
(c) Excess secretion of adrenaline
(d) Under secretion of growth hormone
Answer : B

Question. The gap between two neurons is called a :
(a) Dendrite
(b) Synapse
(c) Axon
(d) Impulse
Answer : B

Question. The brain is responsible for :
(a) Thinking
(b) Regulating the heart beat
(c) Balancing the body
(d) All of the above
Answer : D

Question. Involuntary actions in the body are controlled by :
(a) Medulla in fore brain
(b) Medulla in mid brain
(c) Medulla in hind brain
(d) Medulla in spinal cord
Answer : C

Question. Match the following
Column I                 Column II
(a) Thyroxine          (i) Causes breasts to develop in females
(b) Adrenaline        (ii) Causes the male to start producing sperms
(c) Insulin              (iii) Prepares the body for an emergency
(d) Estrogen          (iv) Controls the metabolic rate
(e) Testosterone     (v) Regulaates the amount of sugar in blood
Answer : (a) (iv), (b) (iii), (c) (v), (d) (i), (e) (ii).

Question. Fill in the blanks
(a) A neuron which carries an impulse to the brain is called a ............................... neuron.
(b) ............................... is the hormone that causes phototropism in plants.
(c) The response of leaves to the sunlight is called............................... .
Answer :
(a) Sensory, (b) Auxin, (c) Phototropism.

Assertion and Reasoning Based Questions

Directions : In the following questions, a statement of assertion is followed by a statement of reason. Mark the correct choice as :
(a) If both assertion and reason are true and reason is the correct explanation of assertion.
(b) If both assertion and reason are true, but reason is not the correct explanation of assertion.
(c) If assertion is true, but reason is false.
(d) If assertion is false but reason is true.

Question. Assertion : In spite of not having nervous system, plants can sense things.
Reason : Plants can sense things with the help of hormones.
Answer : (a) 

Question. Assertion : Synapse is a gap through which nerve impulse pass from one neuron to the next.
Reason : Neuron is the functional unit of nervous system.
Answer : (b)

Question. Assertion : It is advised to have iodized salt in our diet.
Reason : It prevents us from goitre.
Answer : (a) 

Question. Assertion : Cerebrum controls the body posture.
Reason : Cerebrum is not connected to internal ear.
Answer : (d) 

Question. Assertion : Cytokinins promote cell division in plants.
Reason : Full form of ABA is abscisic acid.
Answer : (b)

Very Short Answers Type Questions

Question. What are parthenocarpic fruits ?
Answer : Fruits that are not produced by fertilisation process and are seedless are called parthenocarpic fruits.

Question. Give an example of plant hormone that promotes growth ? 
Answer : Auxin is a plant hormone that promotes growth.

Question. Why are the electrochemical signals not an efficient means of communication in plants ?
Answer : Plants do not have nervous system i.e., specialised tissues like neurons as in case of animals nor do they have endocrine system to carry electrochemical signals.
So, it is not an efficient means of communication in plants.

Question. Why Mimosa pudica leaves dropped down when touched ?
Answer : Due to changes in turgour pressure when we touch the leaves of Mimosa pudica plant leaves dropped down. The stimulus of touch leads to loss of turgour at the base of leaflets and petioles leading to drooping down of leaves.

Question. Why are some patients of diabetes treated by giving injections of insulin ?
Answer : Insulin is secreted by beta cells of Islets of Langerhans of pancreas. They convert excess glucose to glycogen stored in liver thus lowering glucose level in the blood. In diabetes patients, the sufficient amount of insulin is not secreted by pancreas so they have high sugar level in their blood. To control the sugar level they are treated by giving insulin injections.

Short Answers Type Questions

Question. Name the endocrine gland which secretes growth hormone. What will be the effect of the following on a person :
(a) Deficiency of growth hormone
(b) Excess secretion of growth hormone
Answer : Pituitary gland secretes growth hormone.
(a) Deficiency of growth hormone causes dwarfism.
(b) Excess secretion of growth hormone causes gigantism.

Question. What is the difference between the manner in which movement takes place in a sensitive plant and the movement in our legs ?
Answer :
S.No.   Movement in sensitive      plant Movement in legs
1. It occurs in response                   It occurs voluntarily
to external stimuli like                     according to our will.
touch. 
2. It occurs due to change               It is controlled by
in turgour pressure in                     cerebellum of hind brain.
the cells of plant due to
change in water content.
3. It involves hormonal                   It involves nervous control. 
control. 
4. There is no such                         This action is brought
involvement of proteins.                  about by contraction and
                                                     relaxation of muscles and
                                                     some muscles proteins
                                                     are involved.

Long Answers Type Questions

Question. What are reflex actions ? GIve examples ? Explain reflex are by an example with labelled diagram ?
Answer : Reflex action is a quick, automatic, involuntary, unconscious response in the body brough about by a stimulus. Examples of reflex action :
(a) Withdrawal of hand suddenly on touching a hot plat.
(b) Withdrawal of finger suddenly when pricked by a thorn.
(c) Shivering of the body on feeling cold.
(d) Sudden closure of the eyelids when bright light falls on the eye.

Reflex arc : It is the shortest route taken by impulse from receptor to effector.
Example : When we touch a hot plate by our finger, we instantly withdraw our hand. Here stiimulus is touching a hot plate, receptors are our fingers. The specialiser epithelial cells of our fingers respond to stimulus and convert into impulse. The impulse is carried by sensory neuron to spinal cord which generates a motor impulse. This impulse is carried by motor neuron to effector organ i.e., muscles of hand. Response is withdrawal of our hand.

ORAL QUESTIONS

Questions Based on High Order Thinking Skills (HOTS)

Question. The chemical substance P is made and secreted by the meristematic tissue at the tip of stem (or shoot) of a plant. The chemical substance P is responsible for a phenomenon Q in plants in which the stem bends towards a source of light. The same chemical substance P has an opposite effect on the root of a plant. It causes the root of a plant to bend away from the source of light in a process called R.
(a) What is the chemical substance P ?
(b) State whether P prefers to remains in the sunlit side of a stem or in shade.
(c) What is the effect of substance P on the rate of growth of (i) a root, and (ii) a stem ?
(d) What is the name of process (i) Q, and (ii) R ?
(e) What is the general name of chemical substances like P ? Name another substance which belongs to this class of chemical substances.
Answer : (a) P is auxin hormone
(b) In shade
(c) (i) Decreases the rate of growth of root (ii) Increases the rate of growth of stem
(d) (i) Positive phototropism (ii) Negative phototropism
(e) Plant hormones ; Gibberellin

Question. A potted plant is growing in a transparent glass jar. In this plant, X and Y are the two growing parts having a lot of meristematic tissue. It is observed that the part X of this plant exhibits positive geotropism but negative phototropism. On the other hand, part Y of this plant exhibits negative geotropism but positive phototropism.
(a) Name the part X of plant.
(b) Name the part Y of plant.
(c) Which part of the plant, X or Y, will exhibit positive hydrotropism ?
(d) Which part of the plant, X or Y, can have tendrils on it ?
(e) Which phytohormone causes the part X to exhibit negative phototropism ?
Answer : (a) Root
(b) Stem (or Shoot)
(c) X (d) Y
(e) Auxin

Question. There are three plants A, B and C. The flowers of plant A open their petals in bright light during the day but close them when it gets dark at night. On the other hand, the flowers of plant B open their petals at night but close them during the day when there is bright light. The leaves of plant C fold up and droop when touched with fingers or any other solid object.
(a) Name the phenomenon shown by the flowers of (i) plant A, and (ii) plant B.
(b) Name one flower each which behaves like the flower of (i) plant A, and (ii) plant B.
(c) Name the phenomenon exhibited by the leaves of plant C.
(d) Name a plant whose leaves behave like those of plant C.
(e) Which plant/plants exhibit the phenomenon based on growth movements ?
Answer : (a) (i) Photonasty (ii) Photonasty
(b) (i) Dandelion flower (ii) Moonflower
(c) Thigmonasty
(d) Sensitive plant (Mimosa pudica)
(e) A and B

Question. While conducting experiments to study the effect of various stimuli on the plants, it was observed that the roots of a plant X grow and bend towards two stimuli A and B but bend away from a third stimulus C. The stem of the plant X, however, bends away from stimuli A and B but bends towards the stimulus C. The stimulus B is known to act on the roots due to too much weight of the earth. Keeping these points in mind, answer the following questions :
(a) What could stimulus A be ?
(b) Name the stimulus B.
(c) What could stimulus C be ?
(d) The branches of a fallen tree in a forest grow straight up in response to two stimuli. What could be these two stimuli out of A, B and C ? Also name these two stimuli.
Answer : (a) Water (b) Gravity (c) Light (d) B and C ; Gravity and Light (or Sunlight)

Question. P and Q are two types of plants having weak stems which cannot stand upright on their own. The plants P and Q have organs R and S respectively which can grow towards any support which they happen to touch and wind around that support. It is observed that organ R originates from the leaves of the plant whereas organ S originates directly from the stem of the plant.
(a) What is (i) R, and (ii) S ?
(b) What is the name of growth movement exhibited by the organs R and S ?
(c) Name the stimulus involved in this case.
(d) State whether the behaviour of organs R and S is a tropic movement or a nastic movement.
(e) Name one plant like P and another plant like Q.
Answer : (a) (i) Leaf tendril (ii) Stem tendril
(b) Thigmotropism
(c) Touch (of support)
(d) Tropic movement
(e) Organs like P (leaf tendrils) : Pea plant ; Organs like Q (stem tendrils) : Bitter gourd plant

Question. The top part A of the flask-shaped reproductive organ X in the flower of a plant secretes a surgery substance into its lower part B which goes towards the bottom part C of the flask-shaped organ. When a tiny grain D coming from the top part E of another reproductive organ Y in the flower falls on part A, it grows a long tube F through the organ X in response to the sugary substance and reaches the bottom part C of flaskshaped organ to carry out fertilisation.
(a) What is (i) organ X, and (ii) organ Y, inside the flower ?
(b) Name parts (i) A (ii) B, and (iii) C, of flask-shaped organ.
(c) Name (i) grain D, and (ii) part E of organ Y.
(d) Name the tube F.
(e) What is the phenomenon of growing a long tube in response to a sugary substance in the process of fertilisation in a flower known as ?
Answer : (a) (i) Carpel (ii) Stamen (b) (i) Stigma (ii) Style (iii) Ovary (c) (i) Pollen grain (ii) Anther (d) Pollen tube (e) Chemotropism

Question. P, Q, R and S are four major types of phytohormones. P is a phytohormone which functions mainl y as a growth inhibitor. It promotes the wilting and falling of leaves. Q, R and S are phytohormones which allpromote growth of plants in various ways. Q is responsible for the phenomenon of phototropism in plants.
R is involved mainly in shoot extensions. The phytohormone S helps in breaking the dormancy of seeds and buds. What are P, Q, R and S ? Give one reason each for your choice.
Answer : P is abscisic acid ; Q is auxin ; R is gibberellin ; S is cytokinin

Question. A potted plant having straight parts A and B was placed horizontally on its side as shown in Figure (i). After a few days it was observed that the parts A and B of the plant acquire new positions as shown in Figure (ii).
(a) Name the phenomenon exhibited by the position of plant parts A and B in Figure (ii)
(b) Name the stimulus (other than sunlight) which causes plant part A to grow and bend upwards, and plant part B to bend downwards.
Answer : (a) Geotropism (b) Gravity

Question. When the leaves of a sensitive plant are touched with a finger, they fold up and when light fades at dusk, the petals of a dandelion flower close.
(a) State one way in which the above two processes are similar.
(b) State two ways in which the above two processes differ.
Answer : (a) Both are nasties (or nastic movements)
(b) In the folding of leaves of sensitive plant, stimulus is touch but in the folding of petals of dandelion flower, stimulus is light ; Folding of leaves of a sensitive plant is not a growth movement but the closing of petals of a dandelion flower is a growth movement.

Question. Name, the two main organs of our central nervous system. Which one of them plays a major role in sending command to muscles to act without involving thinking process? Name the phenomenon involved.
Answer : The two main organs of CNS are brain and spinal cord.
Spinal cord plays a major role in sending command to muscles to act without involving thinking process. This phenomenon is called reflex action.

Question. How does a touch – me – not plant respond on touching? What is this movement called?
Answer : Touch – me – not plant folds its leaflets on touching. This type of movement is called Growth independent movement (nastic movement)

Question. Write the name and functions of any two parts of the human hind-brain.
Answer : Two parts of human hind-brain with their functions are as follows:
(i) Cerebellum: Controls & coordinates muscular movements, maintaining body posture and equilibrium.
(ii) Medulla oblongata: which regulates the centre of swallowing, coughing, sneezing, salivation and vomiting 

Question. (a) Distinguish between voluntary and involuntary actions of our body.
(b) Choose involuntary actions, amongst the following :
Reading, Beating of heart, Salivation in the mouth on viewing tasty food, Talking.
Answer : Voluntary Actions
1. The voluntary actions are under control of Cerebrum (Forebrain).
2 These actions are slow when compared to involuntary actions
3. Activities. They are connected with the functioning of external organs.
4. Playing game, reading are examples of voluntary action.
Involuntary Actions
1. The involuntary actions are under control of Hind brain, Spinal cord
2. These actions are rapid
3. They are connected with the functioning of internal organs.
4. Breathing is an example of the Involuntary action.
(b) Beating of heart, salivation in the mouth on viewing of tasty food.

Question. Why is it advised to use iodised salt in our diet?
Answer : Iodine stimulates the thyroid gland to produce thyroxin hormone. Deficiency of this hormone results in the enlargement of the thyroid gland. This can lead to goitre.

Question. Why are some patients of diabetes treated by giving injections of insulin?
Answer : Insulin is a hormone which is secreted by pancreas regulates the levels of sugar in the blood. In diabetic patients if it is not secreted in required amount the blood sugar level rises and causes various harmful effects. So, to prevent these effects some patients of diabetes are treated by giving injections of insulin.

Question. What is synapse ? In a neuron cell how is an electrical impulse created and what is the role of synapse in this context ?
Answer : A synapse is the gap between the two neurons. Here the axon terminal of one neuron is in close proximity to the dendrite of the second neuron. When a nerve impulse reaches the knob like nerve ending of an axon, a tiny amount of a chemical substance is released in the synapse. At synapse the electrical signals converted into chemicals, that can easily cross over the gap and pass on to the next neurons where it again converted into electrical signals 

Question. (a) Which plant hormone is present in greater concentration in the areas of rapid cell division?
(b) Give one example of a plant growth promoter and a plant growth inhibitor.
Answer : (a) Cytokinin is present in greater concentration in the areas of rapid cell division.
(b) An example of a plant growth promoter is gibberellins and example of a plant growth inhibitor is abscisic acid.

Question. Which organ secretes a hormone when blood sugar rises in our body? Name the hormone and name one enzyme released by this organ.
Answer : Pancreas secretes a hormone when blood sugar rises in our body. Insulin is the hormone released by this organ and the name of the enzyme is trypsin present in pancreatic juice.

Question. Explain the cause of shoots of the plant bending towards light ?
Answer : Stems are positively phototropic and bend towards the direction of light. The movement is due to occurrence of more auxin on the darker side and lesser auxin on the illuminated side. As a result, there is more growth on the darker side which causes the stem to bend towards light 

 

1. What is the basic unit of nervous system?

2. How do neuron conduct message from brain to other parts?

3. What do you mean by CNS?

4. What are its main parts?

5. Which part controls reflex action?

6. What are endocrine glands?

7. What is the secretion of endocrine gland called?

8. Name a gland of human body which secretes both enzymes and hormone.

9. Which plant hormone helps in cell division?

10. Which hormones help on stem elongation?

QUIZ

1. Which system of our body is made of organised network for conducting information in the body?

2. Which part of the neuron receives information?

3. What is the name of the neuron which remains between the sensory neuron and the motor neuron? Where is it located?

4. Which part of the brain helps us to do activities like riding a cycle and walking in a straight line?

5. What are two major types of muscles we have?

6. →hat causes change in leave of ‗touch me not‘ plant?

7. Which hormone helps us to prepare to combat adverse condition?

8. Name a female sex organ which produces gametes as well as female hormone.

Clues

ACROSS

1. Composed of the brain and spinal cord (3 words).

8. Contains photoreceptors; on the inner posterior portion of eye.

9. "Inside the mouth"

11. Electrical brain activity recorded with scalp or brain electrodes (abbreviation).

13. Necessary for hearin

17. Neurotransmitter in brain, spinal cord and peripheral nervous system (abbreviation).

18. Outermost layer of meninges.

19. Neurotransmitter lacking in patients with Parkinson's disease.

21. Supportive cells of the nervous system; "glue".

22. Nerve cell.

23. Photoreceptor that is not used for color vision.

24. Photoreceptor that is used for color vision.

26. The sense of hearing.

29. Opposite of "Yes"

30. Junction between two neurons.

DOWN

1. In the brain, it is the outermost layer of the gray matter.

2. The fifth cranial nerve.

3. The middle layer of the meninges.

4. The part of the cell containing chromosomes.

5. Period of sleep when dreams occur (abbreviation).

6. The second cranial nerve.

7. Fat-like substance that surrounds some axons.

10. The first cranial nerve.

12. Fluid that fills the ventricles (abbreviation).

14. Part of neuron that takes information TO the cell body.

16. Short for "mother".

18. Electrical brain activity between 2 and 4 Hz.

20. Part of neuron that takes information AWAY from the cell body.

22. A short written letter.

24. Abbreviation for 1 across.

25. Organ for vision.

27. Opposite of "off".

28. Opposite of "yes".

ACTIVITIES / PROJECT

Make a project on various endocrine glands, their functions and related disorders.

SEMINAR

Diabetes – a silent killer.

Causes and prevention of this life style disease.