CBSE Class 10 Science Control and Coordination Assignment Set B

 Question. Which is/are correct correct about insulin?
(a) It controls blood sugar.
(b) It is produced by islets of Langerhans.
(c) It is produced by parathyroid gland.
(d) It is called the fight and flight hormone.
Answer : A , B

Question. Gustatoreceptors lie
(a) on the tongue
(b) in the nose
(c) in the ear
(d) in the eyes
Answer : A

Question. Gigantism results from
(a) growth hormone
(b) thyroxine
(c) adrenalin
(d) testosterone
Answer : A

Question. Synaptic terminal is the end of
(a) cyton
(b) dendrite
(c) axon
(d) none of the above
Answer : C

Question : Which Plant hormone essential for cell division ? 
a. ethylene
b. gibberellins
c. auxin
d. cytokinin
Answer : D

Question : Name the place where largest number of neurons are found in the human body. 
a. Stomach
b. Heart
c. Brain
d. Lungs.
Answer : C

Question : Auxins are 
a. Vitamins
b. Enzymes
c. Proteins
d. Hormones
Answer : D 

Question : The substance that cause fall of mature leave and fruits from plants is due to: 
a. auxin
b. gibberllin
c. cytokinin
d. ABA
Answer : D

Question : Which hormone cause uterine contraction that leads to labour pain? 
a. vasopressin
b. thyroxin
c. Estrogen
d. Progesterone
Answer :  D

Mark the statements true(T) or false(F).

Question. Ovaries produce only one hormone.
Answer : false

Question. Spinal cord arises from the medulla.
Answer : true

Question. Human brain and spinal cord are solid.
Answer : false

Fill in the blanks.

Question. Cerebellumis the centre of ...... action and cerebrum controls ...... .
Answer : involuntary, intelligence

Question. The pituitary gland lies on ...... .
Answer : diencephalon

Question. In a nerve cell, ...... receive the stimulus and ...... transmits the impulse.
Answer : dendrons, axon

Question. ...... is the master gland.
Answer : Pituitary

Match the columns.

             A                                      B
(i) Diencephalon         (a) Coordinating cerebellum and cerebrum
(ii) Spinal nerves        (b) Rapid loss of water
(iii) Algesireceptors     (c) Apical meristem
(iv) Pons                    (d) Controls hunger, thirst
(v) Auxin                    (e) Feeling of pain
(vi) Turgor change       (f) 31 pairs

Answer : (i) (d)  (ii) (f)  (iii) (e)  (iv) (a)  (v) (c)  (vi) (b)

CCT BASED QUESTIONS

While playing with her little brother in the garden, Pooja observed a very strange behavior of plants. She saw that the leaves of a creeper are getting closed with the touch. She is amused by this and tried to find out the reason behind this. Next day at the school she asked her science teacher that do plants have nervous system like us? Can they respond to the stimuli? Her teacher explained that: In the case of plants, they are completely devoid of the nervous system and other special organs. However, plants learn to respond to different stimuli by certain movements.This response may be rapid movements like nastic movement or slow process like tropism. Pooja’s teacher has given few questions to solve. Let’s help her to solve the questions.

Observe the diagram and answer the questions following it.

Question. In the figure we can see that the plant’s growth is affected by a specific stimulus. Both stem and leaves are affected by the stimulus. Below given are possible reasons of it.
A. Accumulation of auxin in parts of the stem that is away from light
B. Leaves are rearranged to capture more sunlight
C. Light doesn’t play any role in plant growth
Choose the correct reason;
a. Option A
c. Option C
b. Option B
d. both option A and B
Answer : D

Question. In the figure. We can observe few changes in the root growth. Which situation is explaining the growth perfectly?
a. The root is showing positive geotropism.
b. The root is showing positive phototropism.
c. The root growth is independent of any external stimuli
d. None of these
Answer : A

Question. Unlike us plants do not have any sense organs. They have few chemicals which produce responses. Those chemicals are called as
a) Pheromones
b) Phytohormones
c) Neurons
d) Nephrons
Answer : B

Question. Name the hormone which inhibit growth
a) auxin
b) gibberellin
c) abscisic acid
d) cytokinin
Answer : C

Very Short Answer

Question : Name the largest cell present in the human body. 

Answer :  Neuron or nerve cell.

Question. Name the hormone which is associated with the metabolism of carbohydrates, proteins, calcium and phosphorus.
Answer: Thyroxine.

Question. Why do living organisms show movement?
Answer: To use changes in the environment to their advantage.

Question. What are the functions of the Hypothalamus?
Answer: Hypothalamus regulates the secretion of hormones from pituitary gland.

Question. Why are endocrine glands called ductless glands?
Answer: Endocrine glands are called ductless glands because they do not have any external duct to discharge their secretions into the blood stream.

Question. Where hypothalamus gland is located?
Answer: Hypothalamus gland is located in the brain.

Question. Give an example of a plant hormone that promotes its grow th. W’here is it synthesized? 
Answer: Auxin promotes growth. It is synthesised at the shoot tip of the plant body.

Question. Mention the part of the body where gustatory and olfactory receptors are located. 
Answer: Gustatory receptors are located in Cerebrum of fore-brain. Olfactory receptors are located in Olfactory lobe of fore-brain.

Question. Name the part of the brain which is concerned with muscular coordination in the body.
Answer: Cerebellum.

Question. Which part controls the voluntary actions?
Answer: Cerebrum of fore-brain.

Question. Why hormones are called as ‘chemical messengers’ ?
Answer: Hormones are carried in the blood streams to all parts of the body, so they are called ‘chemi¬cal messengers’.

Question. Name one plant growth hormone which retards growth during extremely dry season.
Answer: Abscisic acid

Question. What are endocrine glands?
Answer: Ductless glands which manufacture hormones and secrete them directly into the blood stream.

Question. Name the glands which secrete estrogen and progesterone.
Answer: Ovaries

Question : What do we call "movement of shoot towards the light"? 

Answer :  Positive phototropism is the movement of shoot towards light.

 

Question :  Name the other name of hormones. 

Answer :  Chemical coordinators (messengers)

 

Question : List different parts of the human nervous system. 

Answer : 

 

 

Short Answer

Question : In figure A, B and C, which appears more accurate and why? 

Answer :   This movement of plant part in response to gravity is called geotropic movement and the phenomenon involved is called geotropism. Here, Figure (A) is more accurate to show geotropism. The roots of a plant always grow downward in response to the gravity (called negative geotropism) to make sure they find soil and water. On the other hand, the stem always grows up, i.e., away from gravity pull (called positive geotropism) to make sure it will get light. Both these conditions are shown in figure A.

 

Question : “Nervous and hormonal systems together perform the function of control and coordination in human beings.” Justify the statement. 

Answer :  Control and coordination of functioning of various organ and organ system of the body is under the direct control of nervous system in close coordination with endocrine(hormonal) system. This control is achieved by a complex network of neurons which carry signals in the form of electric impulses; to and from the brain and controls the body function directly whereas, the endocrine system are the ductless glands which release chemical substances directly into the blood and reaching the target site for action.

Nervous and hormonal systems are complementary to each other. Thus, it can be said that nervous and hormonal system together perform the function of control and coordination in human beings.  

 

Question : Define neurons. Identify the parts of a neuron at which: 

a. information is all together collected.

b. impulses are converted to chemical signal for further transmission.

Answer : The structural and functional units of nervous system are called neurons. It means the units which makes up the nervous system are called neurons. These are specialized units for acceptance and transmission of impulses to and fro between the brain and other body parts.

a. End of dendrite tip of nerve cell.

b. Dendrite →cell body →axon to its ends.

 

Question : How does our body respond when adrenaline is secreted into the blood? 

Answer :  When adrenaline is secreted into the blood, it prepares our body for emergency action. It speeds up heart beat and breathing, raises blood pressure and allows more glucose to go into the blood to give us a lot of energy quickly to fight or urn away from frightening situation. The blood supply decreases form the skin and digestive system and increase to skeletal muscles. All there conditions help the individual to respond the emergency situation.

Question : On touching a hot plate. wou suddenly withdraw your hand. Which category of neurons became active first and which one next?
Answer :  On touching a hot plate. first the sensory neurons are activated, which take the information to the brain or the spinal cord. Next, the motor neurons become active and bring the impulses from the brain to the muscles. In receiving these impulses. the muscles contract. and the hand is immediately removed from the hot plate.

Question : Give one example of plant part.
a. Which is positively hulrotronic as well as positively seotronic.
b. Which is positively phototronic but negatively geotropic.
Answer :  a. roots b. stem

Question : What name is given to the microscopic can between two adiacent neurons?
Answer :  Synapse

Question : If we sten on something sharp accidently we move our foot away at once what is this tvne of response known as?
Answer :  Reflex action

Question : A part of the hind brain makes possible activities like walking. skating. riding a bicycle and picking up a pencil.name this part of the hind brain.
Answer :  Cerebellum

Question : The neck of a person annears to be swollen.
a. Name the disease this person suffering from.
b. Name the mineral whose deficiency in the diet causes this disease.
Answer :  a Goitre b. Iodine

Question : Name the plant hormone:
(a) which inhibits growth and causes wilting of leaves.
(b) which promotes cell division.
Answer :  a Abscisic acid.
b. Cytokinins.

Question : Taking the example of heart beat. justify the antagonistic action of the sympathetic and the parasympathetic nerves.
Answer :  Sympathetic system increases contraction and rhythm and parasympathetic system decreases contraction and rhythm with respect to heart beat.

Question : Why is abscisic acid known as stress hormone in plants?
Answer :  Abscisic acid in a plant hormone which inhibits growth. Its effects include wilting of leaves.

Question : Name the part of neuron
(a) where information is acquired.
(b) through which information travels as an electrical impulse.
Answer :  a. Dendrite b. Axon

Question : How does the plant shoot beads, when the plant is placed in a room having only one onen window?
Answer :  When the plant is placed in such a room that has only one open window. the shoot of the plant bends towards the direction of light. Plant hormone auxin is formed that diffuses towards the shady side of the shoot and stimulates the cells to live longer on the side of the shoot which is away from light. In this way the shoot bends towards the light.

Question : Who transmits nerve impulse across the synanse?
Answer :  Neurotransmitters.

Question : Give a reason to explain why
(a) adrenaline helps in dealing emergency situations?
(b) secretions of growth hormone should be specific in the human body?
Answer :  a. Adrenaline increases the heart beat and breathing rate which results in the suddly of more oxygen to muscles. It reduces the blood to the digestive system and skin. as a result the blood is further diverted to skeletal muscles. All these responses together prepare the body to deal with the emergency situations. b. If growth hormones is secreted in excess during childhood then it leads to gigantism while the less secretion of this hormone during childhood causes dwarfism.

Question : Why do leaves dron off seasonally?
Answer :  The leaves drop off seasonally as they stop producing auxins. which normally Drevents the formation of abscission zone that cuts off nutrients and water supply to leaves.

Question : Give reason why endocrine glands release their secretions into the blood?
Answer :  Endocrine glands are ductless glands and their products have to act at a distant site. Therefore. they release their secretions into the blood.

 

Long Answer

Question : What are the major parts of the brain? Mention the functions of different parts. 

Answer :   The brain is covered by a three layered system of membranes; called meninges. Cerebrospinal fluid is filled between the meninges. The CSF provides a cushion to the brain against mechanical shocks. The brain is located inside the skull for maximum protection. The human brain can be divided into three regions, viz. forebrain, midbrain and hindbrain.

 

 

Forebrain: It is divided into three regions:

1. Olfactory Lobes - These lobes receives impulses from olfactory receptors of nose region.

2. Cerebrum - It is the largest part of the brain and helps in speech, intellectuality, mapping, hearing, sight, taste, smell, etc.

3. Diencephalon - It has Hypothalamus which has control centre for hunger, thirst, sweating, emotions, etc.

Midbrain: It controls the reflex movements of head, neck and trunk in response to visual and auditory stimuli, changes in pupil size, etc.

Hindbrain: It consists of three parts:

1. Cerebellum - It maintains posture, equilibrium and Muscle tone.

2. Pon Varolii - It controls some aspects of respiration.

3. Medulla Oblongata - It controls heart rate, breathing movements, coughing, sneezing, vomiting, etc. 

 

 

Question : With the help of labelled diagram explain the general scheme to illustrate how nervous impulses travel in the body? 

Answer :

The information from the environment is detected by receptors and passed on to the dendrite of the sensory neuron, from where the electrical signals are passed on to the cyton then to axon and finally to the presynaptic knob which releases neurotransmitters which goes to the synaptic cleft and generates an electric response on to the dendrite of the next neuron and ultimately to brain (or spinal cord). The response from brain (or spinal cord) is similarly passed on to the effector, that ndergoes the desired response.

 

Question. One of the following acts as an endocrine gland as well as an exocrine gland. This one is :
(a) salivary gland
(b) pancreas
(c) pituitary
(d) parathyroid

Answer : B

Question. Which of the following helps in maintaining posture and balance of the human body ?
(a) cerebellum
(b) cerebrum
(c) medulla
(d) pons

Answer : A

Question. Which of the following is not an involuntary action ?
(a) vomiting
(b) chewing
(c) heart beat
(d) salivation

Answer : B

Question. Which of the following hormone prepares our body for action in emergency situations ?
(a) testosterone
(b) growth hormone
(c) adrenaline
(d) insulin

Answer : C

Question. One of the following controls the peristaltic movements of alimentary canal. This one is :
(a) cerebrum
(b) cerebellum
(c) pons
(d) medulla

Answer : D

Question. The hormone which is associated with male puberty is called :
(a) oestrogen
(b) adrenaline
(c) testosterone
(d) progesterone

Answer : C

Question. The number of pairs of nerves which arises from the spinal cord is :
(a) 21
(b) 31
(c) 41
(d) 51

Answer : B

Question. Cerbellum, medulla and pons are the parts of :
(a) mid-brain
(b) hind-brain
(c) forebrain
(d) spinal cord

Answer : B

Question. Which of the following are cerebral reflexes ?
(i) a person pulls away his hand on touching a hot object
(ii) a person spits out immediately when a fly enters his mouth while talking
(iii) A person walking bare foot lifts his foot at once on stepping on to a nail
(iv) A person’s pupil contracts at once in the presence of bright light
(a) (i) and (ii)
(b) (ii) and (iii)
(c) (iii) and (iv)
(d) (ii) and (iv)

Answer : D

Question. Iodine is necessary for the synthesis of which of the following hormone ?
(a) adrenaline
(b) auxin
(c) thyroxine
(d) insulin

Answer : C

Question. Which of the following is a mis-matched pair ?
(a) adrenaline : pituitary gland
(b) estrogen : ovary
(c) pancreas : insulin
(d) progesterone : ovary

Answer : A

Question. A cell (or group of cells) in a sense organ which is sensitive to a particular type of stimulus is called :
(a) interceptor
(b) effector
(c) receptor
(d) acceptor

Answer : C

Question. Which of the following cannot be considered a receptor ?
(a) ear
(b) nose
(c) muscle
(d) eye

Answer : C

Question. One of the following is an incorrect statement about insulin. This is :
(a) it is produced in pancreas
(b) it regulates growth and development of the body
(c) it regulates blood glucose level in the blood
(d) its deficiency in the body will cause diabetes

Answer : B

Question. The spinal cord orginates from :
(a) cerebrum
(b) cerebellum
(c) medulla
(d) pons

Answer : C

Question. The involuntary actions in the body are controlled by :
(a) medulla in forebrain
(b) medulla in hindbrain
(c) medulla in spinal cord
(d) medulla in midbrain

Answer : B

Question. The underactive endocrine gland which causes goitre is :
(a) pancreas
(b) thyroid
(c) adrenal
(d) pituitary

Answer : B 

Question. Which of the following endocrine gland does not occur as a pair in the human body ?
(a) adrenal
(b) pituitary
(c) testis
(d) ovary

Answer : B

Question. The junction between two adjacent neurons is called :
(a) nerve junction
(b) sensory junction
(c) synapse
(d) neuro-muscular joint

Answer : C

Question. The life processes in humans are controlled and regulated by :
(a) reproductive and endocrine systems
(b) respiratory and nervous systems
(c) endocrine and digestive systems
(d) nervous and endocrine systems

Answer : D

Question : How does the plant shoot bends, when the plant is placed in a room having only one open window? 

Answer : When the plant is placed in such a room that has only one open window, the shoot of the plant bends towards the direction of light. Plant hormone auxin is synthesized at the shoot tips,helps the cells to grow longer. When light is coming from one side of the plant, auxin diffuses towards the shady side of the shoot. This concentration of auxin stimulates the cells to grow longer on the side of the shoot which is away from light.

Thus, the plant appears to bend towards light while growing phototropism.

 

 

 

Question : Explain how the movement of leaves of a sensitive plant different from movements of shoots towards light? 

Answer :  Movements in Mimosa pudica (touch sensitive plant) occur in response to touch.

In such movements, plant cells change shape by changing the amount of water in them resulting in folding up and drooping of leaves. This phenomenon is called thigmonasty and this movement is independent of direction of stimuli.

Plants respond to a light by growing in or away from the direction of light, this is known as phototropism. Movement of shoots towards light indicates positive phototropism. 

Question :  A person suffered a head injury, due to which he faces breathing problem. No problem was detected with his respiratory system. What could be the cause of this problem? 
Answer :  As the problem is caused due to head injury, it could be related to “Pons” a part of Hind brain responsible for regulation of respiration.

Question :  A man becomes unconscious due to head injury. A pin is pricked on his foot, he withdraws his foot. Why? Explain. 
Answer :  It is reflex action. Stimulus is perceived by receptor (skin). Sensory nerve sends the sensation from receptor to the spinal cord. Then spinal cord sends the message through motor nerves to the effectors. Effectors i.e. muscles help in withdrawing his foot.

Question :  In a family of normal sized members, there are two exceptions, one member is dwarf and one is tall like “Khali”. What could be the cause of it?  
Answer :  In case of dwarfs, there is a deficiency of growth hormone from Pituitary gland and in case of giants excess of growth hormone is produced during childhood.

Question :  Why do you blink your eyes as bright light is focused on you? 
Answer :  We blink in order to protect the eye from bright light which otherwise would damage the retina.

Question :  There is a potted plant in your drawing room, after few days you note that plant has bent to one side. What could be the reason? How has this movement been cocoordinated?
Answer :  The plant has bent to one side due to phototropic movement of the stem. This movement is due to unequal growth of the stem on both sides. This growth is initiated by the hormone auxin.

Question :  A leaf shaped gland is present above the intestine. The secretion of this gland regulates the metabolism of sugar in blood. Name the secretion and gland.
Answer : The name of the gland is pancreas. The secretion is Insulin from special cells in it.