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)

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.

 

 

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.