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Class - 10 ( Science )

NCERT Class 10 Science Chapter 7 Control and Coordination

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INTEXT QUESTIONS AND ANSWERS of NCERT Class 10 Science Chapter 7 Control and Coordination

 

PAGE – 119

 

  1. What is the difference between a reflex action and walking?

Ans : Reflex action is a spontaneous involuntary or automatic nerve mediated response to a stimulus produced at the unconscious level. But walking is a voluntary action , which requires our thinking and is within our control .

 

2. What happens at the synapse between two neurons ?

Ans : A synapse is a gap between the two neurons . At the synapse , the electrical signals are converted into chemicals that can easily cross over the gap and pass on to the next neurons where it is again converted into an electrical signal.

NCERT Class 10 Science Chapter 7 Control and Coordination

3. Which part of the brain maintains posture and equilibrium of body ?

Ans : Cerebellum .

This is the back of the brain . It co ordinates voluntary muscle movements and helps to maintain posture , balance and equilibrium .

 

4. How do we detect the smell of an agarbatti ( incense sticks ) ?

Ans : Smell of an incense stick is detected by the olfactory receptors present in the nose . The information is transmitted to olfactory lobe located in the fore brain which interprets the information .

 

5. What is the role of brain in reflex action ?

Ans : in a reflex action , the brain plays no part . The spinal cord , which reacts without thinking about how to respond to stimuli , is in charge of these automatic actions . They receive information from all parts of the body and integrate it.

NCERT Class 10 Science Chapter 7 Control and Coordination

 

PAGE – 122

 

  1. What are plant hormones ?

Ans : Plant hormones are chemical compounds present in very low concentration in plants . Plant hormones help to co – ordinate growth , development and responses to the environment .

 

2. How is the movement of leaves of sensitive plant is different from movement of a short towards light ?

Ans: The type of movement of leaves of the sensitive plant is known as a nastic movement . But the movement of shoot is diectional towards light.

This type of movement does not depend on the direction of stimuli. The movement of the shoot towards light is due to growth controlled by growth hormone .

 

3. Give an example of plant hormone that promotes growth .

Ans : Auxin.

Auxin is a plant hormone that promotes growth .

NCERT Class 10 Science Chapter 7 Control and Coordination

4. How do auxin promote growth of a tendril around a support ?

Ans : Some plants like the pea plant climb up other plants or support by means of tendrils. These tendrils are sensitive to touch . When a tendril comes in contact with a support, auxin stimulates faster growth of the cells on the opposite side that’s why the tendril forms a coil around the support . This causes the tendril to circle around the object and thus cling to it . It is due to accumulation of auxin .

NCERT Class 10 Science Chapter 7 Control and Coordination

5. Design an experiment to demonstrate hydrotropism .

Ans : Growth movements in response to the stimulus of moisture are termed as hydrotropic movements.

place some ready to germinate seeds of pea in moist sawdust in a shallow box whose bottom has been replace by a wire gauze .

Keep the apparatus undisturbed for 2-3 days. Keep the sawdust moist. After some time radicles will pass through the sieves . Then the  radicles curve upwards again to enter into the moist sawdust ,the roots are positively hydrotropic and the curvature is more than that due to entropic effect .

NCERT Class 10 Science Chapter 7 Control and Coordination
NCERT Class 10 Science Chapter 7 Control and Coordination

NCERT Class 10 Science Chapter 7 Control and Coordination

PAGE – 125

 

1. How does chemical co ordination take place in animals ?

Ans : Chemical co ordination takes place in animals with the help of chemical messengers called as hormones . They are secreted by endocrine glands. The hormones are carried by the blood to the site of action . The hormones are consumed during their action . Hormones regulate the growth , development and homeostasis of the animals .

 

2. Why is the use of iodized salt advisable ?

Ans : Iodine is essential for the thyroid  gland to produce thyroxin hormone. Thyroxin regulates carbohydrate , protein and fat metabolism in the body so as to provide the best balance for growth . Iodine is essential for the synthesis of thyroxin . In case iodine is deficient in our diet,there is a possibility that we might suffer from goitre. This deficiency disease is known as goitre . Therefore iodized salt is advised.

 

3. How does our body respond when adrenaline is secreted into the blood ?

Ans : When secreted in large amounts it speeds up the heartbeat and hence supplies more oxygen to the muscles. The breathing rate also increases due to contractions of diaphragm and rib muscles . It also increases the blood pressure. All these responses enable the body to deal with any stress or emergency .

 

4. What are some patient of diabetes treated by giving injections of insulin ?

Ans : Insulin is a hormone which is produced by the pancreas and helps in regulating blood sugar levels . If  it is not secreted in proper amounts the sugar level in the blood rises causing many harmful effects .

NCERT Class 10 Science Chapter 7 Control and Coordination

 

EXERCISES

 

  1. Which of the following is a plant hormone ?
  1. Insulin
  2. Thyroxin
  3. Oestrogen
  4. Cytokinin

 

Ans : d. Cytokinin

 

2. The gap between two neurons is called a 

  1. Dendrite
  2. Synapse
  3. Axon
  4. Impuls

Ans : b. Synapse

 

3. The brain is responsible for

  1. Thinking
  2. Regulating the heart beat
  3. balancing the body
  4. All of the above

Ans: d. All of the above

NCERT Class 10 Science Chapter 7 Control and Coordination

4.What is the function of receptors in our body ? Think of a situation where receptors do not work properly . What problems are likely to arise ?

Ans: Receptors are present in all parts of the body for example in the ski , eyes , nose, tongue, etc.

The function of receptors is to detect information from the environment.

If receptors do not detect the information there will not be any co – ordination. It may lead to accidents. Body response will not be there .

 

5. Draw a structure of a neuron and explain its function .

Ans : Structure of neuron :

 

 

 

 

 

 

 

 

NCERT Class 10 Science Chapter 7 Control and Coordination

 

Function : 

  1. Dendrites of a neuron collect information from the receptor.
  2. Axon conducts information as electrical impulse.
  3. Terminal arborization pass the information as chemical stimulus at synapse for onward transmission.

 

NCERT Class 10 Science Chapter 7 Control and Coordination

6. How does phototropism occur in plants ?

Ans : Phototropism is the directional response of a plant that allows the plant to grow towards or some cases away from the light. These directional or tropic movements can be either towards the stimulus or away from it , so, in two different kind of phototropic movement, shoots respond by bending towards light while roots respond by bending away from it.

 

7. Which signals will get disrupted in case of a spinal cord injury ?

Ans: Reflex action will be disturbed because reflex arcs are located in the spinal cord . so, the quick responses needed to safe guard the body will not take place . The delayed responses may cause harm to the body.

As both of these signals meet in a bundle in the spinal cord , so, if there is any spinal cord injury then botyh of these signals will  be disrupted.

NCERT Class 10 Science Chapter 7 Control and Coordination

8. How does chemical co ordination occur in plants ?

Ans : Chemical co ordination occurs in plants with the help of phytohormones or plant hormones secreted by plants. Auxin, cytokinin, gibberellin , abscisic acid are plant hormones. These hormones regulate the growth and development of the plants. They also regulates various metabolic activities in the plants. All growth processes are regulated by one or more phytohormones acting synergistically or antagonistically.

NCERT Class 10 Science Chapter 7 Control and Coordination

9. What is the need for a system of control and co ordination in an organism ?

Ans : An organism needs control and co ordination system for the following functions :

  1. To save the body of the organisms from the harmful changes in the environment.
  2. To control the speed of voluntary and involuntary actions .
  3. To have the capability to think and learn for responding to any stimuli.

 

10. How are involuntary actions and reflex actions different from each other ?

Ans : Reflex actions are the spontaneous responses by voluntary organs but involuntary actions are by the involuntary organs.

The difference between involuntary actions and reflex actions are :

Involuntary actions Reflex actions
i. Involuntary actions are the actions which are not controlled by our will. i. Reflex actions are the sudden action in response to something.
ii. They do not need any kind of stimulus to work. ii. They required stimulus for its action
iii. These actions are regulated by the brain.  iii. These actions are regulated by the spinal cord.
iv. They do not involve skeletal muscle. iv. They do involve skeletal muscle.
v. these actions are performed throughout one’s life. v. These actions are produced in response to an event of an emergency.
vi. This action may be quick or slow. vi. Reflex actions are always quick.
vii. For example : The beating of the heart is an involuntary action . salivating when food is put in the mouth.  vii. For example : Immediate withdrawl of hands upon touching a hot cup of tea. closing the eyes , when bright light is focused.

NCERT Class 10 Science Chapter 7 Control and Coordination

NCERT Class 10 Science Chapter 7 Control and Coordination

11. Compare and contrast the nervous and hormonal mechanism for control and co ordination in animals .

Ans: 

 

Nervous System Hormonal System
i. It consists of the central nervous system (CNS) and peripheral nervous system(PNS) i. It consists of endocrine glands.
ii. Nervous system has a network of nerves spread through out the body. ii. Hormonal system does not has such a network.
iii. Neural responses are quick and short lived.  iii. Hormonal effects are slow but are long term.

 

 

12. What is the difference between the manner in which movement takes place in a sensitive plant and the first movement in our legs ?

Ans : The movement in the sensitive plant is involuntary action , but the change in our legs is a voluntary action. 

Plants have some specialized protein for the movement in sensitive plants. But animals have some concentrated protein . This protein helps the muscles to move.

There are two types of tissues helps to transfer the information in the animal cell, but there is no cell is available in a plant cell.

Our legs are provided with nerves which have connection with muscles. To lift the leg, the brain passes information to nerves.

 

NCERT Class 10 Science Chapter 7 Control and Coordination

NCERT Class 10 Science Chapter 7 Control and Coordination

  NCERT Class 10 Science Chapter 7 Control and Coordination

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NCERT Class 10 Science Chapter 7 Control and Coordination

Class – 10 HSLC HUMAN EYE AND COLOURFUL WORLD INTEXT QUESTIONS AND ANSWERS

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Class – 10 HSLC HUMAN EYE AND COLOURFUL WORLD INTEXT QUESTIONS AND ANSWERS

INTEXT QUESTIONS AND ANSWER of Page No – 190

  1. What is meant by power of accommodation of the eye ?

Ans : The  power of accommodation of the eye is the maximum variation of its power for focusing on near and far (distant) objects . For a normal eye the power of accommodation is about 4 dioptres.

2. A person with myopic eye can not see objects beyond  1.2 m distinctly . What should be the type of the corrective lens used to restore proper vision ?

Ans: A person with a myopic eye can use concave or diverging lens to restore proper vision.

Class – 10 HSLC HUMAN EYE AND COLOURFUL WORLD INTEXT QUESTIONS AND ANSWERS

3. What is the far point and near point of the human eye with normal vision?

Ans: For a normal eye with normal vision the far point is at infinity and the near point is at 25 cm from the eye.

4. A student has difficulty reading the blackboard while sitting in the last row. What could be the defect the child is suffering from ? How can it be corrected ?

Ans : The child is suffering from myopic . He should use concave lenses of suitable focal length.

Class – 10 HSLC HUMAN EYE AND COLOURFUL WORLD INTEXT QUESTIONS AND ANSWERS

 

Class - 10 HSLC HUMAN EYE AND COLOURFUL WORLD INTEXT QUESTIONS AND ANSWERS
Class – 10 HSLC HUMAN EYE AND COLOURFUL WORLD INTEXT QUESTIONS AND ANSWERS

Class 10 Science Chapter 11 The Human Eye and the Colourful World answer 

TEXTBOOK EXERCISE

  1. The human eye can focus objects at different distances by adjusting the focal length of the eye lens . This is due to
  1. Presbyopia
  2. accommodation
  3. near- sightedness
  4. far- sightedness

Ans : b. accommodation

2. The human eye forms the image of an object at its

  1. Cornea
  2. Iris
  3. Pupil
  4. Retina

Ans: d. Retina

3. The least distance of distinct vision for a young adult with normal vision is about

  1. 25 m
  2. 2.5 m
  3. 25 cm
  4. 2.5 cm

Ans : a. 25 m

4. The change in focal length of an eye lens is caused by the action of the

  1. pupil
  2. retina
  3. ciliary muscles
  4. iris

Ans : c. ciliary muscles

Class – 10 HSLC HUMAN EYE AND COLOURFUL WORLD INTEXT QUESTIONS AND ANSWERS

5. A person needs a lens of power – 5.5 dioptres for corecting his distant vision . For correcting his near vision he needs a lens of power + 1.5 dioptre . What is the focal length of the lens required for correcting (i) distanct vision and (ii) near vision ?

Ans : (i) Power of distant viewing part of the lens, P1 = – 5.5 D

Focal length of this part , f1 = 1 / P1

= 1/ -5.5 m

= – 18.73 cm

(ii) As power of the near vision part is measured relative to the main part of the lens of power – 5.5 D , so we use

=P1  + P2 = P

=> -5.5 + P2 = +1.5

=> P2 = + 1.5 + 5.5

=> P2 = + 6.5 D

Focal length of near vision part, f2 = 1 / P2

=1/ + 6.5  m

= + 15.4 cm

Class – 10 HSLC HUMAN EYE AND COLOURFUL WORLD INTEXT QUESTIONS AND ANSWERS

6. The far point of a myopic person is 80 cm in front of the eye . What is the nature and power of the lens required to correct the problem ?

Ans : For the myopic eye

u = – a

v = – 80 cm

f = 1

1/ v – 1/ u  = 1/f

=> (1 / – 80)   – ( 1 /  – a)   = 1 / f

=> f = – 80 cm

therefore, f = – 0. 80 m

Power of the lens is P = 1 / f

=> P = 1 / – 0.80

=> P = – 1. 25 D

A concave lens , P = – 1.25 D

Class – 10 HSLC HUMAN EYE AND COLOURFUL WORLD INTEXT QUESTIONS AND ANSWERS

7. Make a diagram to show how hypermetropia is corrected . The near point of a hypermetropic eye is 1 m . What is the power of the lens required to correct this defect ?

Assume that the near point of the normal eye is 25 m.

Ans:  The object placed at 25 cm from the correcting lens must produce a virtual image at 1 m or 100 cm.

v = – 25 cm

u = – 100 cm

by lens formula ,

1 / f  =  1 / v   –   1 / u

=> 1 / f   =  1 / -100  –  1 / – 25

=> 1 / f   =  1/ – 100  + 1 / 25

=> 1 / f  =  3 / 100

=> f     =    100 / 3  cm

f  =  1  / 3  m

therefore, Power , P =  1 / f

=  1 /  (1/3)

= + 3 D

Class – 10 HSLC HUMAN EYE AND COLOURFUL WORLD INTEXT QUESTIONS AND ANSWERS

8. Why a normal eye not able to see clearly the objects placed closer than 0.5 cm ?

Ans : A normal eye is unable to clearly see the objects place closer than 25 cm because the ciliary muscles of the eye unable to contract beyond a certain limit .

If the object is placed at the distance less than 25 cm from the eye than the object appears blured and produces strain in the eyes .

9. What happens to the image distance in the eye when we increase the distance of an object from the eye ?

Ans : The image distance remain same equal to the distance of the retina from the eye lens . They change in object distance is compensated by the change in the focal length of the eye lens due to the action of ciliary muscles so that a clear image is formed on the same retina .

Class – 10 HSLC HUMAN EYE AND COLOURFUL WORLD INTEXT QUESTIONS AND ANSWERS

10 . Why do stars twinkle ?

Ans : Twinkling of stars : The apparent position of star is slightly different from the actual position due to refraction of star light by the atmosphere . Further , this apparent position is not stationery but keeps on changing due to the change in atmospheric conditions like density , temperature etc. The path of the rays of light coming from the star goes on varying slightly . The amount of light entering our eyes from a particular star increases or decreases randomly with time . Sometimes , the star appears bright and other times , it appears fainter . This gives rise to the twinkling effect of the star.

Class – 10 HSLC HUMAN EYE AND COLOURFUL WORLD INTEXT QUESTIONS AND ANSWERS

11. Explain Why the planet do not twinkle ?

Ans: Planets do not twinkle because they appear larger in size than the stars as they are relatively closer to earth . Planets can be considered as a collection of a larger number of  point – size sources of light . The different parts of these planets produce either brighter or dimmer effect is zero . Hence , the twinkling effect of the planets are nullified and they do not twinkle .

12. Why does the sun appear reddish early in the morning ?

Ans : During sunrise , the light rays coming from the sun have to travel a greater distance in the earth’s atmosphere before reaching our eyes . In this journey, the shorter wave length of lights are scattered out and only longer wave length are able to reach our eyes. Since blue colour has a shorter wave length and red colour has a longer wave length. The red colour is able to reach our eyes after the atmospheric scattering of light. Therefore , the sun appears reddish early in the morning .

Class – 10 HSLC HUMAN EYE AND COLOURFUL WORLD INTEXT QUESTIONS AND ANSWERS

13. Why does the sky appear dark instead of blue to an astronaut ?

Ans : The sky appears dark instead of blue to an astronaut because there is no atomsphere in the outerspace that can scatter the sunlight . As the sunlight is not scattered light reach the eyes of the astronaut and the sky appears black to them .

Class – 10 HSLC HUMAN EYE AND COLOURFUL WORLD INTEXT QUESTIONS AND ANSWERS

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Class – 10 HSLC HUMAN EYE AND COLOURFUL WORLD INTEXT QUESTIONS AND ANSWERS

Class – 10 HUMAN EYE AND COLOURFUL WORLD Additional Questions and Answers mcq

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Class – 10 Human Eye and Colourful World Additional Questions and Answers mcq

Class 10 Science has a fascinating syllabus that introduces new concepts of human physiology to the students. Chapter 11 of this syllabus explains the basic and advanced concepts of the human eye. It is about how the human eye performs to provide a colourful world to the beholder. To understand these concepts, study this chapter well and solve the Class 10 Human Eye MCQ framed by the experts.

HSLC SEBA Class 10 Science MCQs Chapter 11 The Human Eye and the Colourful World with Additional Question Answers

CBSE Class 10 Science MCQs Chapter 11 The Human Eye and the Colourful World help students learn important concepts efficiently. Students preparing for Class 10 Science Board exams must not forget to practise the multiple-choice questions. Here, we have provided the MCQs of Chapter 11, The Human Eye and the Colourful World, so that students can memorise the fundamental concepts with ease. The Human Eye and the Colourful World MCQs will help students to fetch marks from this chapter easily. These multiple choice questions on Human Eye and the Colourful World are based on the latest Class 10 Science Syllabus and are designed by our subject experts.

MCQ Questions on Human Eye and Colourful World PDF

Class – 10 HUMAN EYE AND COLOURFUL WORLD Additional Questions and Answers mcq

Class – 10 HUMAN EYE AND COLOURFUL WORLD Additional Questions and Answers mcq

 

  1. What is pupil ? What is the function of pupil human eye ?

Ans : Pupil is a narrow hole through which light enters in the eye and falls on eye lens.

The pupil regulates and controls the amount of light entering the eye .

 

2. Name the light sensitive cell present in the retina of an eye .

Ans: Rods and cones.

 

3. What do you mean by the term accommodation ?

Ans : The power of accommodation of the eye is the maximum variation of its power for focusing on near and for objects .

 

4. What is blind spot ?

Ans : At the junction of the optic nerve and the retina there are no sensory cells. so , no vision is possible at the spot. This is called the blind spot.

 

5. What is night blindness ?

Ans: Night blindness is a disease caused due to deficiency of vitamin A when patient can not see clearly in dimlight .

Class – 10 HUMAN EYE AND COLOURFUL WORLD Additional Questions and Answers mcq

6. what is color blindness ?

Ans : If some cone cells are absent from retina the person is not able to distinguish the colour of object . It is called colour blindness.

 

7. Define the part of the eye that has real , inverted image of the object formed on it .

Ans : Retina.

 

8. What is the function of ciliary muscle ?

Ans : Ciliary muscles can increase or decrease the focal length of eye lens to focus the images at retina .

 

9. Mention the common defects of vision of the human eye .

Ans: Defects of vision : A normal eye can see objects clearly at any distance between 25 cm and infinity from the eye. Sometimes , a human eye gradually loses its power of accommodation . Then we can not see the object clearly our vision becomes defective. There are mainly four common defects of vision which can be corrected by the suitable use of eye glasses.These defects are :

 

  1. Myopia or near sightedness
  2. Hypermetropia or for sightedness
  3. Presbyopia
  4. Astigmatism .

Class – 10 HUMAN EYE AND COLOURFUL WORLD Additional Questions and Answers mcq

Human Eye and Colourful World Additional Questions and Answers mcq
Class – 10 HUMAN EYE AND COLOURFUL WORLD Additional Questions and Answers mcq

10. What is myopia ? Suggest how this defect can be corrected ?

Ans : Myopia is also known as near sightedness . A person with myopia can use nearby objects but can not see distant objects distinctly .

Myopia can be corrected by using a concave lens of suitable power .

Class – 10 HUMAN EYE AND COLOURFUL WORLD Additional Questions and Answers mcq

11. What is hypermetropia ? Suggest how this defect can be corrected .

Ans : Hypermetropia is also known as far sightedness . A person with hypermetropia can see distant objects clearly but can not see near by objects distinctly.

Hypermetropia can be corrected by using a convex lens of suitable power.

 

12. Write two reasons of myopia .

Ans : Causes of myopia :

i. Excessive curvature of the eye lens .

ii. Elongation of the eye ball.

 

13. What are the causes of hypermetropia ?

Ans: Causes of hypermetropia :

i. The focal length of the eye lens is too long .

ii. The eye ball has become to small .

Class – 10 HUMAN EYE AND COLOURFUL WORLD Additional Questions and Answers mcq

14. What is presbyopia ? How is presbyopia rectified ?

Ans : The power of accommodation of the eye usually decreases with aging . For most of the people , the near point gradually reduces away . They find it difficult to see nearby objects comfortably and distinctly without corrective eye glasses .

The defect is presbyopia can be rectified by using bi focal lenses of suitable power .

 

15. What is astigmatism ? How it is corrected ?

Ans : Astigmatism : It is a defect of vision in which a person can not simultaneously see both the horizontal and vertical views of an object with the some clearily .

Causes of astigmatism : This defect occurs when the cornea of the eye is not perfectly spherical . This results in objects in one direction using well focused while those in perpendicular direction are not well focused .

Correction of astigmatism : Astigmatism can be corrected by using cylindrical lenses . They have different curvatures in horizontal and vertical directions and so they can be oriented suitably  to compensate for irregularities in the cornea .

Class – 10 HUMAN EYE AND COLOURFUL WORLD Additional Questions and Answers mcq

16. What is cataract ?

Ans : Due to development of membrane over the eye lens the eye become ineffective or the image becomes hazy . This problem is called cataract .

 

17. What do you mean by dispersion of light ? What is its cause ?

Ans : When a white light pass through a glass prism it splits into its seven constituent colour . This phenomenon is called dispersion of light .

Causes of dispersion of white  light  : Light rays of different colour travel  with some speed in vaccum . But in refracting medium like glass , water etc. Light or different different colours travel with different speeds . The speed of violet colour is least , while the speed of red colour is the largest in glass . As a result , the refractive index of glass is larger for violet colour and least for red colour . The violet colour is deviated most while the red colour is deviated least on passing through the prism . Other colours are deviated by immediate angles . so , different component colours of white light get dispersion on passing through a glass prism .

Class – 10 HUMAN EYE AND COLOURFUL WORLD Additional Questions and Answers mcq

18. Explain the formation of rainbow in the sky ?

Ans : A rainbow appears in the sky after as hover in the direction opposite to the sun . It is a natural spectrum of the sunlight . The water droplets in the atmosphere act as small prism . The sun light suffers a refraction and dispersion in them . They are then the internally reflected in the drop and finally refracted out . When such rays reach a observer he sees a rainbow .

 

Explain the formation of rainbow in the sky ?
Explain the formation of rainbow in the sky ?

 

 

Class – 10 HUMAN EYE AND COLOURFUL WORLD Additional Questions and Answers mcq

19. What do you mean by atmospheric refraction ?

Ans : Light coming from the celestial objects like the sun or the stars suffer refraction in the air . This is called atmospheric refraction . Several interesting phenomenon such as the twinkling of stars and early sunrise and delayed sunsets are results of atmospheric refraction .

 

20. What is tyndall effect ?

Ans : The Earth’s atmosphere contains smoke , tiny water droplets and dust grains . It resembles a colloidal solution on which small particles remain suspended when a beam of light gets scattered from such particles. The path of the beam becomes visible . The effect is called tyndall effect . This effect is usually caused by suspended particles of relatively clag size .

We can observe the tyndall effect when light enters a dusty or smoke filled enclosure through a small hole .

Class – 10 HUMAN EYE AND COLOURFUL WORLD Additional Questions and Answers mcq

21. Why is the colour  of the clear sky blue ?

Ans : When  the sunlight passes through the atmosphere it suffers on the molecules of air and suspended fine particles . The molecules of the air such as N2 and O2    and other fine particles of the atmosphere which are smaller than the wave length of light of any colour scatter the shorter wavelength more effectively. Thus the blue colour of light is scattered the most while the red is scattered the least in the atmosphere. The blue colour of the sky is due to the scattering of sunlight by molecule of the atmosphere . When we look at the sky the scattered light enters our eyes and thus light contains blue light in a large proportion . That is why the sky appears blue .

Class – 10 HUMAN EYE AND COLOURFUL WORLD Additional Questions and Answers mcq

22. Why does sun appear reddish at sunrise and sunset ?

Ans : During the sunrise and sunset the sun remain near the horizon . The light rays have to pass through a larger thickness of the atmosphere when the sum is overhead at non consequently , the lower wavelengths in the blue region are almost completely scattered away by air molecules . The higher wavelengths of the red region are least scattered and reach our eyes. Hence the sun appears almost reddish at sunrise and sunset .

 

23. The sun is visible to us about 2 minutes before the actual sunrise and about 2 minutes after actual sunset. Give reason . 

Ans : The sun is visible to us about 2 minutes before the actual sunrise and about 2 minutes about actual sunset because of atmospheric refraction . By actual sunrise by the sun . The time difference between the actual sunset and the appearance sunset is about 2 minutes .

 

24. Why are the traffic light signals ear danger signals of red colour ?

Ans : In the visible spectrum the colour has the largest wave length the red colour is least scattered by fog or dust particles . So, we can also observed red colour easily even in foggy and dusty condition .

Class – 10 HUMAN EYE AND COLOURFUL WORLD Additional Questions and Answers mcq

25. Which is the cause of blue colour of the ocean ?

Ans : The water molecules of the ocean scatter blue light more strong that light of other colours . So, ocean appears bluish .

Class – 10 HUMAN EYE AND COLOURFUL WORLD Additional Questions and Answers mcq

Human eye and Colourful World Class 10 Important Questions 
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Class – 10 HUMAN EYE AND COLOURFUL WORLD Additional Questions and Answers mcq

HSLC Class 10 Science Chapter 2 Acids-Bases and Salts Solutions

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INTEXT QUESTIONS AND ANSWERS || HSLC Class 10 Science Chapter 2 Acids-Bases and Salts Solutions 

 

Page No – 18

 

  1. You have been provided with three test tubes , one of them contains distilled water and the other two contain  an acidic solution and a basic solution,  respectively . If you are given only red litmus paper , how will you identify the contents of each test tube ?

Ans: If red litmus paper to all three test tubes , the test tube in which red litmus changes into blue contains basic solutions . Use this blue litmus paper to test the solutions in other two test tubes. The test tube in which there is no change will contain water.

 

HSLC Class 10 Science Chapter 2 Acids-Bases and Salts Solutions

 

Page No – 22

 

  1. Why should curd and sour substances not be kept in brass and copper vessels ?

Ans : Curd and sour substances are acidic and acids react with copper vessels and brass to form toxic compounds . So, curd and sour substances are not kept in brass and copper vessels . HSLC Class 10 Science Chapter 2 Acids-Bases and Salts Solutions 

 

 

2. Which gas is usually liberated when an acid reacts with a metal ? Illustrate with an example . How will you test for the presence of this gas ?

Ans: i. H 2 gas is liberated when an acid reacts with a metal.

ii. Illustrations : Set up an apparatus as shown . take some zinc granules in the test tubes. Add about 5 m L dilute hydrochloric acid slowly. soon the reaction between zinc and hydrochloric acid starts and hydrogen gas is involved.

iii. Test for H2 gas : H2 gas is not soluble in water , when passed through soap solution , if gets trapped into bubbles which burn with explosion .

 

 

3.  Metal compound a reacts with dilute hydrochloric acid to produce effervescence. The gas evolved extinguishes a burning candle . Write a balanced chemical equation for the reaction if one of the compounds formed a calcium chloride.

Ans: Metal compound A is Ca CO 3

Gas evolved is CO 2

Balanced equation

Ca CO 3 (s) + 2 H Cl (aq) ———> Ca Cl 2 (aq) + CO 2 (g) + H 2 O (l)

 

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Page No – 25 || HSLC Class 10 Science Chapter 2 Acids-Bases and Salts Solutions 

  1. Why do H Cl , H NO 3 etc , show acidic characters in aqueous solution while solutions of compounds like alcohol and glucose do not show acidic character ?

Ans : H+ ions in aqueous solution are responsible for acidic character . H Cl , H NO 3 etc. generate H+ ions in water while C2 H5 OH and glucose do not do so and hence do not show acidic character.

 

 

2. Why does an aqueous solution of an acid conduct electricity ?

Ans: Acid when forms a solution in water , gets ionised , due to the presence of these ions electricity is conducted through it.

 

 

3. Why does dry HCl gas not change the colour of the dry litmus paper ?

Ans: Dry HCl    gas does not generate H+ ions and hence does not change the colour of dry litmus paper.

 

HSLC Class 10 Science Chapter 2 Acids-Bases and Salts Solutions

4. While diluting an acid , why is it recommended that the acid should be added to water and not water to the acid ?

Ans: When acid and water mix ,the reaction is highly exothermic , the acid may splash , cause burns and even the container can break . To avoid this and allow the heat evolved to be absorbed by  water . Slowly acid is added to water for diluting it. HSLC Class 10 Science Chapter 2 Acids-Bases and Salts Solutions 

5. How is the concentration of hydronium ions (H 3 O + ) affected when a solution of an acid is diluted ?

Ans: When a given amount of an acid is added to water there area fixed number of hydronium ions per unit volume of the solution . On dilution the number of hydronium per unit volume decreases and concentration of hydronium ion decreases.

 

 

6. How is the concentration of hydroxide ions (OH–) affected when excess base is dissolved in a solution of sodium hydroxide ?

Ans: When base is mixed with water there is decrease in the concentration of OH– ions per unit volume.

 

HSLC Class 10 Science Chapter 2 Acids-Bases and Salts Solutions
HSLC Class 10 Science Chapter 2 Acids-Bases and Salts Solutions

 

Page No – 28 || HSLC Class 10 Science Chapter 2 Acids-Bases and Salts Solutions 

  1. You have two solutions , A and B . The pH of solution A is 6 and pH of solution B is 8 . Which solution has more hydrogen ion concentration ? Which of this acidic and which one is basic ?

Ans : Solution A has more hydrogen ion concentration . Solution A is slightly acidic and solution B slightly basic.

 

 

2. What effect does the concentration of H+ (aq) ions have on the nature of the solution ?

Ans: If a solution has highly concentration of H+ ions it is more acidic in nature.

 

 

3. Do basic solutions also have H+ (aq) ions ? If yes , then why  are these basic ?

Ans: Yes , basic solution also have H+ ions but they are basic in nature due to more number of OH– ions.

 

 

4. Under what soil condition do you think a farmer would treat the soil of his fields with quick lime ( calcium oxide) or slaked lime (calcium hydroxide ) or chalk ( calcium carbonate ) ?

Ans: Plants work well in the pH range 6 – 8 . So when the soil becomes acidic, farmers treat the soil fields with bases like quick lime or slaked lime or chalk.

 

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Page No – 33 || HSLC Class 10 Science Chapter 2 Acids-Bases and Salts Solutions 

  1. What is the common name of the compound CaOCl2 ?

Ans : The common name of CaOCl2 is bleaching powder and chemical name calcium oxychloride.

 

 

2. Name the substance which on treatment with chlorine yields bleaching powder .

Ans : Calcium hydroxide [Ca(OH)2] when treated with chlorine yields bleaching powder.

Ca(OH)2 + Cl2 ———–> CaOCl2 + H2O

 

HSLC Class 10 Science Chapter 2 Acids-Bases and Salts Solutions

3. Name the sodium compound which is used for softening hard water .

Ans: Sodium Carbonate.

 

 

4. What will happen if a solution of sodium hydrocarbonate is heated ? Give the equation of the reaction involved .

ans: When sodium hydrocarbonate is heated , sodium carbonate , water and carbon dioxide gas is obtained .

2 NaHCO3 —–(heat)—–> Na2CO3 + H2O + CO2

 

 

5. Write an equation to show the reaction between plaster of Paris and water.

Ans : 2 CaSO4 . 1/2 H2O + H2O ————> 2 CaSO4 . 2 H2O

 

 

 

TEXT BOOK EXERCISES || HSLC Class 10 Science Chapter 2 Acids-Bases and Salts Solutions 

 

  1. A solution turns red litmus blue , its pH is likely to be
  1. 1
  2. 4
  3. 5
  4. 10

Ans: d. 10

 

 

2. A solution reacts with crushed egg – shells to give a gas that turns lime water milky . The solution contains

  1. NaCl
  2. HCl
  3. LiCl
  4. KCl

Ans: b. HCl

 

 

3. 10 mL of a solution of  NaOH is found to be completely neutralised by 8 mL of a given solution of HCl . If we take 20 mL of the same solution of NaOH , the amount HCl solution required to neutralise it will be

  1. 4 mL
  2.  8 mL
  3. 12 mL
  4. 16 mL

Ans : d. 16 mL

 

 

4. Which one of the following types of medicines is used for treating indigestion ?

  1. Antibiotic
  2. Analgesic
  3. Antacid
  4. Antiseptic

Ans : c. Antacid

 

 

5. Write word equations and then balanced equations for the reaction taking place when –

  1. dilute sulphuric acid reacts with zinc granules.
  2. dilute hydrochloric acid reacts with magnesium ribbon.
  3. dilute sulphuric acid reacts with aluminium powder.
  4. dilute hydrochloric acid reacts with iron filings.

Ans:

a.  step I  Zinc granule + dilute hydrochloric acid ———-> Zinc chloride + hydrogen gas

step II  Zn (s) + dil HCl (aq) ———–> ZnCl2 (aq) + H2(g)

step III  Zn (s) + 2 HCl (aq) ———–> ZnCl2 (aq) + H2(g)

 

b.   step I  Magnesium + dilute Hydrochloric acid  ——–> magnesium chloride + hydrogen gas

step II  Mg (s) + dil HCl (aq) ———> MgCl2 (aq) + H2 (g)

step III  Mg (s) + 2 HCl (aq) ———-> MgCl2 (aq) + H2 (g)

 

c.  step I  Aluminium + dilute sulphuric acid ——–> Aluminium sulphate + Hydrogen gas

step II  Al (s) + dil H2SO4 ———-> Al2 (SO4)3 + H2 (g)

step III   2Al (s) + 3H2SO4(aq) ———-> Al2(SO4)3(aq) +H2 (g)

 

d. step I  Iron + dilute hydrochloric acid ——-> Iron chloride + Hydrogen

step II  Fe (s) + dil HCl (aq) ———> FeCl2 (aq) + H2 (g)

step III Fe(s) + 2HCl (aq) ——-> FeCl2 (aq) + H2 (g)

 

6. Compounds such as alcohol and glucose also contain hydrogen but are not categorised as acids. Describe an activity to prove it.

Ans : Take a beaker and keep and cork in it with two nails fixed on it. Connect the nails to the battery , bulb and key as shown in the figure. Now add ethanol in it and record your observation repeat the same set up for glucose and record your observations .

Observation : The bulb will not glow because charge is not flowing through it .

Conclusion : The experiment shows that glucose and ethanol do not ionise , H+ ions are not released , therefore they do not conduct elctricity. HSLC Class 10 Science Chapter 2 Acids-Bases and Salts Solutions 

 

Picture

Compounds such as alcohol and glucose also contain hydrogen but are not categorised as acids. Describe an activity to prove it.
Compounds such as alcohol and glucose also contain hydrogen but are not categorised as acids. Describe an activity to prove it.

 

 

HSLC Class 10 Science Chapter 2 Acids-Bases and Salts Solutions

 

7. Why does distilled  water not conduct electricity, whereas rain water does ?

Ans : Rain water contains ions of acids and so it conducts electricity whereas there are no ions in distilled water.

 

 

8. Why do acids not show acidic behaviour in the absence of water ?

Ans: Acids in water give hydronium ions which are responsible for their acidic behaviour . But in the absence of water acids do not generate hydronium ions and thus do not show acidic behaviour.

 

 

9. Five solutions A,B,C,D and E when tested with universal indicator showed pH as 4, 1, 11, 7 and 9 respectively . which solution is

  1. neutral
  2. strongly alkaline
  3. strongly acidic
  4. weakly acidic
  5. weakly alkaline

Arrange the pH in increasing order of hydrogen – ion concentration.

Ans : a. D     b. C     c. B     d. A      e. E

pH values in increasing order of hydrogen – ion concentration :

11< 9 < 7< 4< 1 .

 

 

10. Equal lengths of magnesium ribbons are taken in test tubes A and B . Hydrochloric acid (HCl) is added to test tube A , while acetic acid ( CH3COOH) is added to test tube B . Amount and concentration taken for both the acids are same . In which test tube will the fizzing occur more vigorously and why ?

Ans : In test tube A  hydrochloric acid is present  which is a strong acid as compared  to acetic acid  in test tube B. The fizzing occurs more vigorously in test tube A as HCl is strong and dissociates completely into H+ and Cl– ions for the reactions.

 

 

11. Fresh milk has a pH of 6 . How do you think the pH will change as it turns into curd ? Explain your answer .

Ans : pH of milk falls below 6 as it turns into curd due to the formation of lactic acid during this process.

 

 

12. A milkman adds a very small amount of baking soda to fresh milk .

a. Why does he shift the pH of the fresh milk from 6 to slightly alkaline ?

b. Why does this milk take a long time to set as curd ?

Ans : a. pH is shifted to alkaline so that milk does not spoil by becoming curd and does not release lactic acid . The formation of lactic acid is prevented by adding baking soda which is alkaline in nature.

b. Milk will take long time to set as curd because milk is made alkaline by addind baking soda and the lactic acid released , if any will get neutralised by the alkali and slowly it will become acidic .

HSLC Class 10 Science Chapter 2 Acids-Bases and Salts Solutions

 

13. Plaster of Paris should be stored in a moisture – proof container. Explain why ?

Ans: Plaster of Paris is Calcium sulphate hemihydrate ( CaSO4 . 1/2 H2O). On exaposure to moisture it absorbs moisture and becomes gypsum (CaSO4 . 2H2O) which does not have the required setting property.

 

HSLC Class 10 Science Chapter 2 Acids-Bases and Salts Solutions 

14. What is a neutralisation reaction ? Give two examples .

Ans : The reaction in which acid reacts with base ( loses their property ) to form salt and water is called neutralisation reaction. e.g ;

i. HCl (aq) [acid] + NaOH (aq) [base]——–> NaCl [salt] + H2O [water]

ii. HCl (aq) + KOH (aq) ————> KCl + + H2O

 

HSLC Class 10 Science Chapter 2 Acids-Bases and Salts Solutions

15. Give two important uses of washing soda and baking soda.

Ans : Uses of washing soda :

i. It is used in glass , soap and paper industries.

ii. It is used to remove permanent hardness of water.

Uses of baking soda :

i. It is used as an antacid .

ii. It is used in soda , acid , fire extinguisher.

 

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HSLC Class 10 Science Chapter 2 Acids-Bases and Salts Solutions

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LIFE PROCESS Class 10 Science Chapter 6 All Question and Answers

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LIFE PROCESS Class 10 Science Chapter 6 All Question and Answers

Page No- 95

INTEXT QUESTIONS of LIFE PROCESS Class 10 Science Chapter 6 

  1. Why is diffusion insufficient to meet the oxygen requirement of multicellular organisms like humans?

Ans: In multicellular organisms, all the cells may not be in direct contact with the surrounding environment . Thus simple diffusion will not be the requirements of all the cells.

 

2. What criteria  do we use to decide whether something is alive?

Ans: Some movements either visible like locomotion from one place to another and growth related movements or invisible movement such as movement of molecules are the criteria whether something is alive.

 

3. What are outside raw materials used for by an organism?

Ans: An organism uses outside raw materials mostly in the form of food (since life on earth depends on carbon based molecules,most of these food sources are also carbon based ) and oxygen . The raw materials required by an organism can be quite varied depending on the complexity of the organism and its environment.

LIFE PROCESS Class 10 Science Chapter 6 All Question and Answers

4. What processes would you consider essential for maintaining life?

Ans:   Life processes such as nutrition , respiration, transportation, excretion etc. are essential for maintaining life.

 

LIFE PROCESS Class 10 Science Chapter 6 All Question and Answers

Page No. 101 of LIFE PROCESS Class 10 Science Chapter 6 

  1. What are differences between autotrophic nutration and heterotrophic nutration ? 

Ans:

Autotrophic  Nutrition Heterotrophic Nutration
(i) Food is synthesized from simple inorganic raw materials such as CO 2 and water. (i) Food is obtained directly or indirectly from autotrophs. This food is broken down with the help of enzymes.
(ii) Presence of green Pigment (chlorophyll) and sunlight  is necessary. (ii) No pigment is required in this type of nutrition.
(iii) Food is made from inorganic component. (iii) Food is made from organic component.
(iv) Food is generally prepared during day time. (iv) Food can be prepared at all times.
(v) All green plants and some bacteria have this type of nutrition.  (v) All animals and fungi have this type of nutrition.

LIFE PROCESS Class 10 Science Chapter 6 All Question and Answers

 

2. What do plants get each of the raw materials required for photo synthesis? 

Ans: Plants need the following things :

(i) Carbon dioxide : which plants get from the atmosphere through stomata.

(ii) Water : which plants absorb from the soil through roots and transport to leaves.

(iii) Sunlight: which plants get from the sun.

(iv) Chlorophyll is present in chloroplast found in green leaves and green parts of plants.

 

 

3. What is the role of the acid in our stomach?

Ans: The acid in our stomach mainly hydrochloric acid (H Cl) plays several important roles:

  1. Digestion of food : It helps break down food, especially proteins , by creating an acidic environment for the enzyme pepsin to function.
  2. Killing harmful microbes : The acid kills many bacteria and pathogens that enter the body through food.
  3. Activating enzymes : It activates pepsinogen into pepsin , the enzyme that digests proteins.

 

4. What is the function of digestive enzymes ? 

Ans: Digestive enzymes help in the break down of complex food substances into simple , soluble forms that can be easily absorbed by the body.

  1. Break down food : Enzymes convert carbohydrates , proteins, and fats into simple sugars ,amino acids and fatty acids.

Examples :

Amylase : Breaks down complex carbohydrates into simpler sugar.

Lipase : Breaks down fats(lipid) into fatty acid.

Proteases (like pepsin, trypsin, chymotrypsin): Break down proteins into amino acids.

  ii. Speed Up Digestion : They act as biological catalysts, speeding up the chemical reactions during digestion.

iii. Help in Absorption : By breaking food into small molecules , they make it easier for the body to absorb nutrients in the small intestine.

 

LIFE PROCESS Class 10 Science Chapter 6 All Question and Answers

5. How is the small intestine designed to absorb the digested food ? 

Ans : The small intestine has millions of tiny finger like projections called villi . These villi increase the surface area for food absorption . Within these villi , many blood vessels are present that absorb the digested food and carry it to the blood stream. From the blood stream , the absorbed food is delivered to each and every cell of the body. 

 

 

Page No: 105 of LIFE PROCESS Class 10 Science Chapter 6 

  1. What advantage over on aquatic organism does a terrestrial organism have with regard to obtaining oxygen for respiration ?

Ans: The organisms that live in water use oxygen dissolved in surrounding water.Since air dissolved in water has fairly low concentration of oxygen, the aquatic organism have much faster rate of breathing.

Terrestrial organisms take oxygen from the oxygen rich atmosphere , through respiratory organs. So, they have much breathing rate than aquatic organisms.

 

 

2. What are the different ways in which glucose in oxidized to provide energy in various organisms?

Ans: Break down of glucose by various pathways for different organisms are:

 

LIFE PROCESS Class 10 Science Chapter 6 All Question and Answers ; Break down of glucose by various pathways for different organisms
LIFE PROCESS Class 10 Science Chapter 6 All Question and Answers ; Break down of glucose by various pathways for different organisms

 

LIFE PROCESS Class 10 Science Chapter 6 All Question and Answers

 

3. How is oxygen and carbon dioxide transported in human beings?

Ans: Transport of oxygen(O 2):

Oxygen enters the lungs when we inhale. It passes from the alveoli (air sacs) into the blood in capillaries. Haemoglobin , a protein in red blood cells (RBCs) binds with oxygen to form oxyhaemoglobin. This oxyhaemoglobin is transported through the blood to different parts of the body. In the tissues , oxygen is released and used for cellular respiration.

Transported of carbon dioxide(CO 2)

Carbon dioxide is a waste gas produced during respiration in the cells. It is carried back to the lungs in three ways

: 70% as bicarbonate ions in the plasma .

20-23% binds to haemoglobin 

A small amount ( about 7% ) is dissolved directly in the plasma.

In the lungs, carbon dioxide diffuses from the blood into the alveoli and is exhaled.

 

 

4. How are lungs designed in human beings to maximise the area for exchange of gases?

Ans: The lungs contain alveoli which provide a surface where the exchange of gases can take place. The walls of the alveoli contain an extensive network of blood vessels . These alveoli increase surface area for exchange of gases . There are 750 million alveoli in the lungs of man . If the alveolar surface is spread out it would cover about 80 m2 . Thus it makes efficient exchange of gases.

 

 

LIFE PROCESS Class 10 Science Chapter 6 All Question and Answers

Page No – 110 of LIFE PROCESS Class 10 Science Chapter 6 

 

  1. What are the component of transport system in human tan beings ? What are function of these components ?

Ans: The components of the transport system in human beings are the heart , blood and blood vessels.

Functions of the components :

(i) Heart : Heart is a pumping organ to push blood around the body. It receives deoxygenated blood from the body parts and pump it to lungs for enriching with oxygen. It receives purified blood from lungs and pumps it around the body.

(ii) Blood : Blood is fluid connective tissue . It consists of plasma in which the cells are suspended such as WBC and RBC . Plasma transports food , carbon dioxide and nitrogenous wastes in dissolved form. RBC transports oxygen. Blood also transport many other substances like hormones, salt etc. Platelets present in the blood stop bleed from injuries by forming blood clots.

(iii) Blood vessels : The blood vessels which carry oxygenated blood are called arteries . They divide to form capillaries of finer dimensions . Exchange of materials takes place across the capillaries . It is possible because the wall of capillaries are extremely thin. The blood from the tissues is returned by veins.

 

 

2. Why it is necessary to separate the oxygenated and deoxygenated blood in mammals and birds ?

Ans: Separation of oxygenated and deoxygenated blood allows a highly efficient supply of oxygen to the body. Such separation allows a highly efficient supply of oxygen to the body . This is useful in animals that have high energy needs , such as birds and mammals, which constantly use energy to maintain their body temperature.

 

LIFE PROCESS Class 10 Science Chapter 6 All Question and Answers

3. What are the components of the transport system in highly organised plants ?

Ans : The component of the transport system in highly organised plants are :

Xylem and Phloem.

 

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4. How are water and minerals transported in plants ?

Ans : Water and Minerals are transported in plants by the Xylem :

 

  1. The roots of a plant have hair called root hairs.
  2. These root  hairs absorb water and minerals from soil since these are directly in contact with the film of water in between the soil particles.
  3. Water gets into the root hair by the process of diffusion.
  4. These minerals and water absorbed by root hair pass from cell to cell by osmosis through the epidermis , root cortex , endodermis and reach the reach the root xylem.
  5. The pressure at the top of the xylem vessels is lowered whereas the pressure at the bottom of the xylem vessels remains high.
  6. Due to this , the water flows up the xylem vessels into the leaves , where it leaves by transpiration.

 

 

5. How is food transported in plants ?

Ans: Phloem transports food materials from the leaves to different parts of the plants . The transportation of food in phloem is achieved by utilizing energy from ATP which helps in creating osmotic pressure that transports food from the area of high concentration to low concentration. This movement of food materials is carried out in phloem by sieve tubes with the help of companion cells.

 

LIFE PROCESS Class 10 Science Chapter 6 All Question and Answers

Page No – 112 of LIFE PROCESS Class 10 Science Chapter 6 

 

  1. Describe the structure and functioning of nephron.

Ans: Structure of nephron :

A nephron is made up of a  globular double walled. Bowman’s capsule around a clump of capillaries of glomerulus and a tubule surrounded by blood capillaries. The tabule consists  of a proximal convoluted portion, the loop of Henle , with descending and ascending limbs and a distal convoluted part.

 

Structure of nephron ; LIFE PROCESS Class 10 Science Chapter 6 All Question and Answers
Structure of nephron; LIFE PROCESS Class 10 Science Chapter 6 All Question and Answers

 

 

Function of Nephron :

  1.  Filtration : (i) Filtration of blood takes place in Bowman’s capsule from the capillaries of glomerulus.

(ii) Blood is filtered under pressure and waste products , water , salts and glucose pass into the nephron tubules.

 

b. Reabsorption : Useful substances like glucose , amino acids and some water and salts are reabsorbed into the blood from the nephron tubule.

c. Secretion : Some extra ions and wastes are secreted into the nephron from the blood , helping to maintain balance in the body.

d. Formation of Urine : After filtration and reabsorbtion , the remaining waste forms urine, which moves to the collecting duct and then to the bladder for excretion.

 

 

LIFE PROCESS Class 10 Science Chapter 6 All Question and Answers

2. What are the methods used by plants to get rid of excretory products ?

Ans: Plants can get rid of excess water by transpiration . For other wastes , plants use the fact that many of their tissues consist of dead cells and that they can even lose parts such as leaves . Many plant waste waste products are stored in cellular vacuoles. Waste products may be stored in leaves that fall off. Other waste products are stored as resins and gums, especially in old xylem. Plants also excrete some waste substances into the soil around them. 

 

 

3. How is the amount of urine produced regulated ?

Ans: 

  1. Amount of urine formed depends upon how much excess water there is in the body.
  2. When there is more quantity of dissolved wastes in the body , more quantity of water is required to excrete them. So, the amount of urine produced increases.
  3. The amount of urine produced is also regulated by certain hormones which control the movement of water and Na ions out of the nephrons.

 

Page No – 133 of LIFE PROCESS Class 10 Science Chapter 6 

Select the correct option:

  1. The kidneys in human being are a part of the system for :

 

  1. Nutrition
  2. Respiration
  3. Excretion
  4. Transportation

Ans:  c. Excretion

 

 

2. The xylem in plants are responsible for : 

  1. Transport of water
  2. Transport of food
  3. Transport of amino acid
  4. Transport of oxygen

Ans: a. Transport of water

 

 

3. The autotrophic mode of nutrition requires :

  1. Carbon dioxide (CO 2) and water
  2.  Chlorophyll
  3. sunlight
  4. All of above

Ans: d. All of above

 

 

4. The break down of pyruvate to give CO2 , water and energy takes place in :

  1. Cytoplasm
  2. Mitochondria
  3. Chloroplast
  4. Nucleus

Ans: b. Mitochondria

 

 

5. How are fats digested in our bodies ? where does the process take place ?

Ans: Fats are present in the form of large globules in the small intestine . The small intestine receives the secretions from the liver and the pancreas. The pancreas secretes pancreatic juice which contains enzymes like trypsin for digesting proteins and lipase for breaking down emulsified fats.

The walls of the small intestine contain glands which secrete intestinal juice . The enzymes present in it finally convert the fats into fatty acids and glycerol. Digestion of fat takes place in the small intestine.

 

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6. What is the role of saliva in the digestion of food ?

Ans: Role of saliva in digestion of food :

  1. The saliva contains salivary amylase enzyme that breaks down starch to sugars like maltose. 
  2. The saliva moisten the food that help in chewing and breaking down the big pieces of food into smaller ones so that salivary amylase can digest the starch efficiently.

 

 

7. What are the necessary conditions for autotrophic nutrition and what are its by products ?

Ans: The necessary conditions for autotrophic nutrition :

  1. Presence of chlorophyll in the living cells.
  2. CO 2 is necessary.
  3.  Sunlight is necessary
  4. Water is required

By products : Molecular oxygen is liberated as a by product.

LIFE PROCESS Class 10 Science Chapter 6 All Question and Answers

Extra Questions for Class -10 Science Chapter – 6 Life Processes

LIFE PROCESS Class 10 Science Chapter 6 All Question and Answers
LIFE PROCESS Class 10 Science Chapter 6 HSLC All Question and Answers

 

8. What are the differences between aerobic and anaerobic respiration ? Name some organisms that use the anaerobic mode of respiration.

Ans :

Aerobic Respiration Anaerobic Respiration
(i)It takes place in the presence of oxygen. (i) It  takes place in the absence of oxygen. 
(ii) Complete oxidation of glucose takes place. (ii) Glucose molecule is incompletely broken down.
(iii) Large amount of energy is released. (iii) Small amount of energy is released.

 

Anaerobic respiration takes place in bacteria , yeast and muscle cells.

 

 

9. How are the alveoli designed to maximize the exchange of gases ?

Ans: i. Alveoli are pouch – like air sac that is made up of simple squamous epithelium. It has a thin cell wall to facilitate gaseous exchange.

ii.The presence of millions of alveoli in the lungs provides ample surface area to facilitate gaseous exchange between the air in alveoli and blood in surrounding capillaries.

iii. Oxygen diffuses across the alveolar and capillary wall into the bloodstream while carbon dioxide diffuses from blood across the mentioned walls into the alveoli.

 

LIFE PROCESS Class 10 Science Chapter 6 All Question and Answers

10. What would be consequences of a deficiency of haemoglobin in our bodies ?

Ans: Consequences of a deficiency of haemoglobin :

  1. Haemoglobin is a pigment that is helpful in supplying oxygen in all the parts of the body through blood.
  2. It is present in the Red Blood Cells and acts as a carrier of oxygen.
  3. The deficiency of haemoglobin makes an individual anemic which means fewer red blood cells.
  4. The deficiency of haemoglobin will decrease the oxygen carrying capacity of the blood.
  5. A decrease in haemoglobin in blood will lead to slow functioning of body parts and weakness due to the less supply of oxygen.

 

 

11. Describe double circulation in human beings. Why is it necessary ?

Ans: Double circulation : In human beings the blood goes through the heart twice during each. i.e. the blood passes through the human heart two times to supply once to the whole body . So, it is called the double circulation of blood .

The double circulation of blood includes : 

(i) Systemic circulation and 

(ii) Pulmonary circulation.

i. Systemic circulation : It supplies oxygenated blood from left auricle to left ventricle there by pumped to various body parts . The deoxygenated blood is collected from various body organs by the veins to pour into vena cava and finally into right atrium. Right atrium transfers the blood into the right ventricle .

ii. Pulmonary circulation:  The deoxygenated blood is pushed by the right ventricle into the lungs for oxygenation. The oxygenated blood is brought back to left atrium of the human heart. From left atrium the oxygenated blood is pushed into the left ventricle. The left ventricle pumps oxygenated blood  into aorta for systematic circulation.

 

Necessity of double circulation : The right side and the left side of the human heart is useful to keep deoxygenated and oxygenated blood from mining. This type of separation of oxygenated and deoxygenated blood ensures a highly efficient supply of oxygen to the body . This is useful in case of humans constantly require energy to maintain their body temperature.

 

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12. What are the differences between the transport of materials in xylem and phloem ?

Ans: 

Xylem Phloem
i. Water is absorbed by the roots and is transported to the aerial parts of the plant like the stem and leaves. i. Food is formed in the leaves from where it is transported to the storage organs and the growing parts of the plants.
ii.In xylem , upward movement of water and dissolved minerals transferred into phloem tissue is mainly achieved by transpiration pull. It is caused due to suction ,created by evaporation of water molecules from the cells of leaves. ii. In translocation , material is transferred in the phloem tissue emerge from ATP . This increase the osmotic pressure that moves the materials in the phloem to tissue which have less pressure 

 

 

LIFE PROCESS Class 10 Science Chapter 6 All Question and Answers

13. Compare the functioning of alveoli in the lungs and nephron in the kidneys with respect to their structure and functioning.

Ans : The comparison of alveoli in the lungs and nephrons in the kidneys are as follow:

Alveoli Nephron
i. It is the structural and functional unit of lungs.  i. It is the structural and functional unit of kidneys.
ii.Alveoli only provide surface for enchange of gasses in the lungs. ii. Tubular part of nephron also carries the urine to collecting duct.
iii. Alveoli are very small and a large number of them are present in each lung  iii. A large number of nephron , basic filtration unit one present in each kidney.
iv. It removes carbon dioxide from the blood. iv. It removes nitrogenous wastes from the blood.

 

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