CBSE Class 9

NCERT Solutions for Class 9 Science Chapter 14 Natural Resources

These Solutions are part of NCERT Solutions for Class 9 Science. Here we have given NCERT Solutions for Class 9 Science Chapter 14 Natural Resources. LearnInsta.com provides you the Free PDF download of NCERT Solutions for Class 9 Science (Biology) Chapter 14 – Natural Resources solved by Expert Teachers as per NCERT (CBSE) Book guidelines. All Chapter 14 – Natural Resources Exercise Questions with Solutions to help you to revise complete Syllabus and Score More marks.

More Resources

• NCERT Solutions for Class 9 Science
• HOTS Questions for Class 9 Science
• Value Based Questions in Science for Class 9
• NCERT Exemplar Solutions for Class 9 Science
• Previous Year Question Papers for CBSE Class 9 Science

NCERT TEXT BOOK QUESTIONS

IN TEXT QUESTIONS

Question 1.
How is our atmosphere different from the atmosphere of Venus and Mars ?
Answer:

Question 2.
How does atmosphere act as a blanket ?
Answer:
Atmosphere or air is a bad conductor of heat. It, therefore, functions as a blanket.

1. It does not allow sudden increase in temperature during the daylight hours when sun shines overhead.
2. There is no sudden cooling during night. Atmosphere slows down the escape of heat to the outer space from the area of earth under darkness.
3. Atmosphere maintains the average temperature of the earth fairly steady not only during the day but throughout the year.

Question 3.
What causes winds ?
Answer:
Winds are basically caused by heating of air in certain parts. The hot air rises upwards. This creates an area of low pressure. Cooler air from adjacent higher pressure areas passes into this area. This creates wind. The factors which control movement of winds in different directions in different parts of the earth are

1. Uneven heating of land in different parts of earth
2. Differences in heating and cooling of land and water.
3. Barrier of mountains
4. Rotation of earth.

Question 4.
How are clouds formed ? (CCE 2011)
Answer:
Clouds are wet air masses that float in the direction of prevailing wind. They develop when water vapours are formed in large number. There is evaporation from the surface of water bodies and wet areas due to their heating during the daytime. Plants also give out water vapours in transpiration while animals do so in exhaled air and perspiration. Air also heats up during daytime. The hot air along with water vapour rises up. At a height, air expands and becomes cool. Cooling causes the water vapours to condense. Suspended particles of dust and other materials function as nuclei around which water vapours condense. When a large wet air mass collects, cloud is formed.

Question 5.
Answer:
List any three human activities that you think would lead to air pollution.

1. Burning of fossil fuels in industries, vehicles and thermal plants.
2. Processing industries like textiles, asbestos, flour mills.
3. Stone crushing.

Question 6.
Why do organisms need water ? (CCE 2011)
Answer:
Organisms need water due to following reasons :

1. Component of Living Matter: Water is a major component (60-90%) of living matter.
2. Solvent: Water is a general solvent for chemicals found in the living world.
3. Reaction Medium: All biochemical reactions occur in the medium of water.
4. Transport: Substances are transported in the body of a living organisms only in the dissolved state.
5. Turgidity: Cells, cell organelles, tissues and other structures maintain their shape only when they contain sufficient water to make them turgid.
6. Temperature Buffer: Water protects the body from sudden changes of temperature.
7. Wastes: It helps in separation and elimination of metabolic wastes.

Question 7.
What is the major source of fresh water in the city/town/village where you live ?
Answer:
Ground water which is pumped out by tube wells (In some it is local reservoir, canal or river.

Question 8.
Do you know of any activity which may be polluting this water source ?
Answer:
Dumping of industrial wastes from where pollutants seep into soil to reach ground water (sewage and industrial effluents in case of canal or river water).

Question 9.
How is soil formed ? What is the function of humps in soil ? (CCE 2011, 2012)
Answer:
Soil is formed through two processes of weathering and humification.
Weathering
It is pulverisation of rocks or breaking of rocks into fine particles. There are three types of weathering — physical (atmospheric changes and mechanical forces), chemical and biological. Sun, water, wind and living organisms perform them.

1. Sun: It causes expansion of rocks by heating. Cooling causes their contraction. Different parts of rocks expand and contract at different rates. Uneven expansion and contraction produces cracks leading to fragmentation of rocks.
2. Water:
   1. Wetting and Drying: Certain rock components can pick up and lose moisture. They undergo swelling and contraction resulting in fragmentation of rocks.
   2. Frost Action: Water seeping in cracks would swell up and exert a great pressure if it freezes due to low temperature. The rock would undergo fragmentation.
   3. Abrasion: Running water carrying rock fragments would break and grind rocks occurring in the pathway. Rain and hail also cause rock breaking.
3. Wind: Dust and fine sand carried by wind cause abrasion of the rock surface when wind strikes the same.
4. Living Organisms: Lichens secrete chemicals to dissolve minerals from the rock surface. This produces crevices where dust collects. Mosses grow there. They cause deepening of crevices and development of small cracks. Roots of short lived plants widen these cracks. Roots of larger plants cause fragmentation of rocks by entering the cracks and growing in size.

Humification
Partially decomposed organic matter or humus mixes with weathered rock particles to form soil. Humus helps in formation of soil crumbs which are essential for maintaining proper hydration and aeration of soil.

Question 10.
What are the methods of preventing or reducing soil erosion ?
Answer:
Soil Erosion: It is removal of top soil by agency of wind or water. Wind and water are also the agencies which cause weathering of rocks and carrying the fine particles to other places for the formation of soil. Removal of top soil by water or wind leaves the underneath subsoil and rocky base exposed. Very little plant growth occurs there.
Factors Promoting Soil Erosion

1. It destroys herbs, grasses and seedlings. The soil is exposed. Trampling by animals causes compaction of soil which reduces its porosity and percolation.
2. Removal of litter or scraping of forest floor leaves the ground bare for action of agencies causing erosion.
3. There is decreased absorption of water as the latter does not stay for long on the slope. Run off water passing along the slope gathers speed and develops high cutting and carrying capacity.
4. Felling of Trees: Felling of trees in excess of regeneration capacity of a forest causes deforestation. It also leaves large area bare for action of wind and water. Deforestation or clearing of forest not only destroys biodiversity but also leads to large scale soil erosion.
5. Clean Tilling: Clean tilling of crop fields exposes the soil to erosion.
6. Heavy Rain and Strong Winds. Uncovered soil is eroded quickly by heavy rain and strong wind.

Question 11.
What are two different states in which water is found during the water cycle ?
Answer:
Liquid and vapour, occasionally solid (snow) as well.

Question 12.
Name two biologically important compounds that contain both oxygen and nitrogen. . (CCE 2014)
Answer:
Proteins and nucleic acids.

Question 13.
List any three human activities which would lead to an increase in the carbon dioxide content of air.
Answer:

1. Increasing combustion of fossil fuels (coal, petroleum, natural gas) in homes, industries, transportation and power projects.
2. Increasing use of wood for cooking and heating.
3. Deforestation leading to reduced utilisation of carbon dioxide in photosynthesis.

Question 14.
What is green house effect ? (CCE 2011, 2012, 2013)
Answer:
Green house effect is keeping an area warm by allowing the solar radiations to pass in but preventing long waves to escape due to presence of radiatively active gases and glass panes.

Question 15.
What are the two forms of oxygen found in the atmosphere ? (CCE 2011, 2014)
Answer:

1. Diatomic oxygen, O₂
2. Triatomic oxygen or ozone, O₃.

NCERT CHAPTER END EXERCISES

Question 1.
Why is the atmosphere essential for life ? (CCE 2012)
Answer:

1. Oxygen: Atmosphere contains oxygen which is essential for combustion and respiration of most organisms.
2. Carbon Dioxide: Atmosphere provides carbon dioxide for photosynthesis of plants.
3. Protection: Atmosphere filters out lethal cosmic rays and high energy ultraviolet rays.
4. Temperature Buffer: Atmosphere does not allow daytime temperature to rise abnormally nor does it allow night time temperature to fall down drastically. This provides favourable temperature for the living organisms.
5. Other Functions: Air currents help in dispersal of spores and other dissemules. Water cycle operates through atmosphere and produces rain to replenish fresh water over land.

Question 2.
Why is water essential for life ?
Answer:

Organisms need water due to following reasons :

1. Component of Living Matter: Water is a major component (60-90%) of living matter.
2. Solvent: Water is a general solvent for chemicals found in the living world.
3. Reaction Medium: All biochemical reactions occur in the medium of water.
4. Transport: Substances are transported in the body of a living organisms only in the dissolved state.
5. Turgidity: Cells, cell organelles, tissues and other structures maintain their shape only when they contain sufficient water to make them turgid.
6. Temperature Buffer: Water protects the body from sudden changes of temperature.
7. Wastes: It helps in separation and elimination of metabolic wastes.

Question 3.
How are living organisms dependent on soil ? Are organisms that live in water totally independent of soil as a resource ? ‘
Answer:
All terrestrial organisms depend upon plants for their food and its contained energy. Plants are dependent on soil for anchorage, absorption of water and nutrients. Without them plants cannot manufacture food. So, all living terrestrial organisms depend upon soil.
Aquatic organisms are apparently not connected with soil. However, aquatic autotrophs require inorganic nutrients for manufacture of food. Nutrients reach water bodies only when rain water passes over and inside the soil. Therefore, aquatic organisms are not totally independent of soil as a resource.

Question 4.
You have seen weather reports on television and in newspapers. How do you think we are able to predict the weather ?
Answer:
Weather reports depict areas of low and high pressure, prevailing direction of wind, dryness or wetness of air masses, clouds and their progress, presence and progress of any cyclone, etc. Predictions are then made whether a particular area will or will not receive rain, have calm weather or high speed wind and dust storm.

Question 5.
We know that many human activities lead to increasing levels of pollution of air, water bodies and soil. Do you think that isolating these activities to specific and limited areas would help in reducing pollution ?
Answer:
Restricting pollution related activities to specific and limited areas will not reduce pollution in those areas. The same may rather increase. There are two benefits of such a practice

1. Joint pollution treatment plants can be installed
2. The residential and commercial areas away from such pollution generating regions will be comparatively free from pollution.

Question 6.
Write a note on how forests influence the quality of our air, soil and water resources. (CCE 2012)
Answer:
Air Resources:

1. Oxygen-Carbon Dioxide Balance. Forests maintain the optimum level of oxygen and carbon dioxide. They function as sink for excess carbon dioxide being produced due to excessive combustion. Forests also release a lot of more oxygen to compensate for excess being consumed elsewhere in respiration and combustion.
2. Control of Air Pollution. Both suspended particles and gaseous pollutants are picked up by forest plants.

Soil Resources: Roots of the forest plants hold the soil firmly. Forest cover protects the soil from direct pounding by rain drops. Forest soil is also sufficiently porous to reduce run off and increase infiltration of rain water. All the three factors prevent soil erosion.
Water Resources:

1. Rainfall. Forests help in increasing the amount and periodicity of rain fall.
2. Forest trees retain a lot of water at their bases. Percolation of water into interior of earth produces springs which form rivulets with perennial flow of water.

SELECTION TYPE QUESTIONS

Alternate Response Type Questions :
(True/False, Right/Wrong, Yes/No)

Question 1.
As 75% of earth’s surface is covered with water, the outer crust of earth is called hydrosphere.
Question 2.
Combustion consumes oxygen and liberates carbon dioxide.
Question 3.
Winds develop due to uneven heating of earth.
Question 4.
Carbon monoxide and carbon dioxide produce acid rain.
Question 5.
The amount of rainfall directly influences the abundance and diversity of like forms.
Question 6.
Soil has no role in supplying nutrients to aquatic biota
Question 7.
Pesticides and fertilizers are harmful to soil as they kill the microorganisms involved in recycling of nutrients.
Question 8.
Green house gases are the ones which allow the heat emitted by earth to pass out.

Matching Type Questions :

Question 9.
Match the articles of the column I and column II (Single Matching)

Question 10.
Match the contents of columns I, II and III (Double matching)

Question 11.
Match the pollutants with the type of pollution—air (A), water (W) and soil (S) (Key or check List matching)

Question 12.
Match Stimulus with Appropriate Response.

Fill In the Blanks

Question 13. The earth ……………… and energy from sun are necessary to meet basic requirements of life forms.
Question 14. Surface temperature of moon varies from …………….. to 110°C.
Question 15. …………….. makes soil porous and allows water and air to penetrate deep underground.
Question 16. Carbon occurs in elemental form in ………………. and graphite.
Question 17. CFCs are carbon compounds having both ……………. and chlorine.

Answers:

SOME TYPICAL QUESTIONS

Question 1.
Name the different physical divisions of biosphere.
Answer:
Three – atmosphere (air), hydrosphere (water) and lithosphere (land).

Question 2.
Differentiate between renewable and non-renewable resources.
Answer:

Question 3.
Name the parts of India falling under wet zone.
Answer:
Wet zone (rainfall over 200 cm/yr) comprises Western Ghats, Andaman-Nicobar and North East India.

Question 4.
Name two diseases caused by
(a) Infectious agents in polluted water,
(b) Toxic chemicals in polluted water.
Answer:
(a) Infectious Agents. Jaundice, dysentery.
(b) Toxic Agents. Minamata (mercury), itai-itai (cadmium).

Question 5.
What is ozone hole ? Where is it found ? What is its effect ? (CCE 2011)
Answer:
Ozone hole is thinning of ozone in the stratosphere where it is normally present in high concentration as ozone layer. Ozone hole is formed during spring time over antarctica and to a small extent over north pole. Thinning of ozone layer or ozone hole increases the passage of harmful ultravoilet rays to earth. This has increased incidence of skin cancers, defective eye sight, reduced immunity, increased number of mutations and reduced crop yield in southern countries of southern hemisphere.

NCERT Solutions for Class 9 Science Chapter 14 Natural Resources

Hope given NCERT Solutions for Class 9 Science Chapter 14 are helpful to complete your science homework.

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NCERT Exemplar Solutions for Class 9 Science Chapter 13 Why Do we Fall Ill

These Solutions are part of NCERT Exemplar Solutions for Class 9 Science . Here we have given NCERT Exemplar Solutions for Class 9 Science Chapter 13 Why Do we Fall Ill

Question 1.
Give two examples for each of the following :

1. Acute diseases
2. Chronic diseases
3. Infectious diseases
4. Non-infectious diseases.

Answer:

1. Acute Diseases. Typhoid, Malaria, Influenza.
2. Chronic Diseases. TB (tuberculosis), Elephantiasis.
3. Infectious Diseases. Typhoid, Chicken Pox.
4. Non-infectious Diseases. Diabetes, Goitre.

More Resources

• NCERT Exemplar Solutions for Class 9 Science
• NCERT Solutions for Class 9 Science
• Value Based Questions in Science for Class 9
• HOTS Questions for Class 9 Science
• Previous Year Question Papers for CBSE Class 9 Science

Question 2.
Name two diseases caused by protozoans. What are their causal organisms ?
Answer:

1. Sleeping Sickness, caused by Trypanosoma gambiense.
2. Kala-azar, caused by Leishmania donovani.

Question 3.
Which bacterium causes peptic ulcers ? Who discovered the pathogen for the first time ?
Answer:
Bacterium Causing Peptic Ulcers. Helicobacter pylori Discovery. Warren (1984). Marshall and Warren (1985).

Question 4.
What is antibiotic ? Give two examples. (CCE 2012)
Answer:
Antibiotic. It is a biochemical produced by a microbe which kills or blocks growth of other microbes (e.g. bacteria) by blocking their life processes without harming human cells, e.g., Penicillin, Streptomycin.

Question 5.
Fill in the blocks :

1. Pneumonia is an example of ……………… disease.
2. Many skin diseases are caused by ………….. .
3. Antibiotics commonly block biochemical pathways important for the growth of …………….. .
4. Living organisms carrying the infecting agents from one person to another are called ……………. .

Answer:

1. Communicable (infectious)
2. fungi
3. bacteria
4. vectors.

Question 6.
Name the target organs of the following diseases :

1. Hepatitis targets …………… .
2. Fit or unconsciousness targets ……………… .
3. Pneumonia targets ……………. .
4. Fungal disease targets ……………. .

Answer:

1. Liver
2. Brain
3. Lungs
4. Skin.

Question 7.
(a) Who discovered Vaccine” for the first time.
(b) Name two diseases which can be prevented by using vaccines.
Answer:
(a) Edward Jenner
(b) Pertussis, diphtheria, tuberculosis, polio.

Question 8.
Fill in the blanks :

1. ……………… disease continues for many days and causes ………………….. on body.
2.  …………….. disease continues for a few days and causes no long term effect on body.
3. …………….. is defined as physical, mental and social well being and comfort.
4. Common cold is ……………… disease.
5. Many skin diseases are caused by …………………. .

Answer:

1. Chronic, long-term effect
2. Acute
3. Health
4. Infectious (communicable)
5. Fungi.

Question 9.
Classify the following diseases as infectious and non-infectious:

1. AIDS
2. Tuberculosis
3. Cholera
4. High blood pressure
5. Heart disease
6. Pneumonia
7. Cancer.

Answer:

1. AIDS—infectious,
2. Tuberculosis—infectious,
3. Cholera—infectious,
4. High Blood Pressure—non-infectious.
5. Heart Disease—non-infectious.
6. Pneumonia—infectious,
7. Cancer—non-infectious.

Question 10.
Name any two groups of microorganisms from which antibiotics could be extracted.
Answer:
Bacteria, Fungi.

Question 11.
Name any three diseases transmitted through vectors.
Malaria (vector Anopheles), Dengue (vector Aedes), Kala-azar (vector Sandfly).

Question 12.
Explain giving reasons :

1. Balanced diet is necessary for maintaining healthy body.
2. Health of an organism depends upon the surrounding environmental conditions.
3. Our surrounding area should be free of stagnant water. (CCE 2012)
4. Social harmony and good economic conditions are necessary for good health.

Answer:

1. Balanced diet provides all the nutrients for metabolic activities of the organism.
2. Environment contributes the immediate, second level and third level of causes.
3. Stagnant water becomes the breeding site for mosquitoes.
4. Good health is not only being disease free but also physical, mental and social well being.

Question 13.
What is disease ? How many types of diseases have you studied ? Give examples. (CCE 2011)
Answer:
Disease. It is a condition of derangement or disturbed functioning of the body or its part.
Types of Diseases :

1. On the Basis of Duration. Acute and chronic.
2. On the Basis of Period of Occurrence. Congenital and acquired.
3. On the Basis of Causal Agent. Infectious and non-infectious.

Infectious or communicable diseases can be contagious or non-contagious. Non-infectious disease may be deficiency disease, metabolic disease, degenerative disease, allergy, cancer and injury.
Examples. Influenza, tuberculosis, pneumonia (infectious), cancer (non-infectious).

Question 14.
What do you mean by disease symptoms ? Explain giving two examples.
Answer:
Symptoms: They are manifestations or evidences of the presence of diseases. Symptoms are in the form of structural and functional changes in the body or body parts. They indicate that there is something wrong in the body,
e.g., wound with pus, cough, cold, loose motions, pain in abdomen, headache, fever. Symptoms do not give any exact cause of the disease. For instance, headache is due to some dozen different diseases. There may be problem of eye sight, blood pressure, examination and other stress, meningitis, etc.

Question 15.
Why is immune system essential for our health ?
Answer:
Immune system is body defence system against various types of pathogens. It has many components—phagocytic cells, natural killer cells, T-lymphocytes and B-lymphocytes. B-lymphocytes produce antibodies against pathogens and their toxins. Immune system keeps the body healthy by killing infecting microbes.

Question 16.
What precautions would you take to justify “prevention is better than cure”. (CCE 2011, 2012)
Answer:
Prevention is always better than cure as a disease always causes some damage to the body, loss of working days, besides expenditure on medication. The important precautions for preventing diseases are

1. Hygienic environment
2. Personal hygiene
3. Proper nutrition
4. Clean food
5. Clean water
6. Regular exercise and
7. Relaxation: Every body should also be aware of diseases and their spread. A regular medical check up is also reQuired.
8. Immunisation programme should be followed.

Question 17.
Why do some children fall ill more frequently than others living in the same locality ?
Answer:
Children fall ill more frequendy due to

1. Poor personal hygiene
2. Poor domestic hygiene
3. Playing over floor
4. Eating with unclean hands.
5. Lack of proper nutrition and balanced diet. All these make the immune system weak.

Question 18.
Why are antibiotics not effective for viral diseases ? (CCE 2011, 2012)
Answer:
Antibiotics are effective against bacteria and some other non-viral pathogens as they block some of their biosynthetic pathways without affecting human beings. However, viruses do not have their own metabolic machinery. There are very few biochemical processes that can block viral multiplication. Antibiotics are not effective against them. They can be over-powered only by specific anti-viral drugs.

Question 19.
Becoming exposed to or infected with a microbe does not necessarily mean developing noticeable disease. Explain.
Answer:
An infectious microbe is able to cause a disease only if the immune system of the person is unable to put proper defence against it. Many persons have strong immune system or have acquired immunity against the pathogen or the pathogen attack is less than the infective dose. In such cases, despite exposure to infective microbe, the person will not catch the disease.

Question 20.
Give any four factors necessary for a healthy person. (CCE 2012)
Answer:

1. Environment,
   1. A clean physical environment with the help of public health services,
   2. A congenial social environment.
2. Personal Hygiene. Personal cleanliness prevents catching up of infectious diseases.
3. Nourishment. A proper balanced diet keeps the immune system strong.
4. Vaccination. Timely vaccination against major diseases protects oneself from catching those diseases.
5. Avoiding overcrowded areas
6. Regular exercise and relaxation.

Question 21.
Why is AIDS considered to be a “syndrome” and not a disease ? (CCE 2012)
Answer:
Syndrome is a group of symptoms, signs, physical and physiological disturbances that are due to a common cause. AIDS is also a complex of diseases and symptoms which develop due to failure of the body to fight off even minor infections. HIV that causes AIDS damages immune system of the patient by destroying T4 lymphocytes. As a result, even small cold leads to development of pneumonia, a minor gut infection leads to severe diarrhoea and blood loss, while skin rashes develop into ulcers.

Hope given NCERT Exemplar Solutions for Class 9 Science Chapter 13 Why Do we Fall Ill are helpful to complete your science homework.

If you have any doubts, please comment below. Learn Insta try to provide online science tutoring for you.

Value Based Questions in Science for Class 9 Chapter 13 Why Do we Fall Ill

These Solutions are part of Value Based Questions in Science for Class 9. Here we have given Value Based Questions in Science for Class 9 Chapter 13 Why Do we Fall Ill

Question 1.
The number of dengue cases had increased in Pooja’s village in the last one year. She read in her text book that diseases like dengue spread through mosquitoes which breed in stagnant water. She immediately contacted her friends and decided to kill the mosquitoes in water bodies in the locality. They also took help of nearest municipal office. Answer the following questions based on above information.

1. Which preventive measures do you suggest for prevention of such diseases caused by mosquitoes ? Mention any two measures,
2. Which values are displayed by Pooja in taking initiative.
3. Suggest one school activity for promoting such values in school students. (Sample Paper, 2012—13, CCE 2013)

Answer:

1. Preventive Measures. Avoid collection of water in pits, ensure covering of drains, proper and regular disinfection, covering arms and legs as dengue mosquito is active during day, use of mosquito nets and repellents.
2. Values,
   1. Pooja is conscious of her social responsiblity.
   2. She is doing community service,
   3. She is aware of healthy living, as well as environment protection.
3. School Activity,
   1. Group discussion on the clean environment and preventive measures against mosquito bites.
   2. Organising debates and seminar on mosquito menace and community hygiene.
   3. Organising compaigns for creating awareness amongst masses on hygienic living and hygienic environment.

More Resources

• Value Based Questions in Science for Class 9
• HOTS Questions for Class 9 Science
• NCERT Solutions for Class 9 Science
• NCERT Exemplar Solutions for Class 9 Science
• Previous Year Question Papers for CBSE Class 9 Science

Question 2.
Anish has the habit of throwing the household garbage in the drain outside her home. Her friend Smitha takes the domestic garbage to public garbage bin outside her street.

1. Which act of garbage disposal, Anish’s or Smitha’s is correct ?
2. What problems would the wrong habit create for the society ?
3. How can the wrong habit be corrected ?

Answer:

1. Anish’s habit of throwing garbage in the drain is wrong while that of Smitha is correct.
2. Anish’s habit of passing garbage in the drain not only blocks the drain causing overflow of drain water, spread of filth resulting in spread of flies, mosquitoes and other creatures but also produces stink all around.
3. The best method to correct Anish’s habit is that Smitha should talk to her and convince her that throwing garbage in the drain is not only harmful to her neighbours but also for her and her family.
   If she does not mend her ways, Smitha should approach Anish’s mother. Other members of the community can also join her in convincing Anish.

Question 3.
Anne came to classroom early, dragged her table and chair to a side of the room and sat there away from the rest of her classmates. In between she was putting handkerchief over her nose. Her friend Nancy asked her to lend a pen which she refused.

1. What is the reason of her putting handkerchief over the nose ?
2. Why did she sit separately away from her classmates ?
3. Why did she refuse to given pen to Nancy ?

Answer:

1. Anne must be suffering from common cold. By putting handkerchief over the nose, she was preventing the spread of cold virus through nasal droplets, wiping off the same in the process.
2. Anne sat separately so that she does not transfer the cold virus to her classmates.
3. Refusal to give her pen to Nancy is also due to her anxiety that articles contaminated by her do not transfer the disease to others. She is conscious of her social responsibility.

Question 4.

1. Why are polio drops being administered to children below five years twice every year ?
2. When was the last wild polio case reported in India ?
3. Was there any other polio case ?

Answer:

1. Polio drops are being given free to children below five years of age so that the virus of polio does not multiply in human beings and it is ultimately eradicated, as small pox has been from the world. The compaign will continue for some time more till there is no fresh case for a couple of years.
2. The last wild type polio case was reported in India during January 2011.
3. A vaccine derived polio case has been reported from Bengal during 2012.

Hope given Value Based Questions in Science for Class 9 Chapter 13 Why Do we Fall Ill are helpful to complete your science homework.

If you have any doubts, please comment below. Learn Insta try to provide online science tutoring for you.

HOTS Questions for Class 9 Science Chapter 13 Why Do we Fall Ill

These Solutions are part of HOTS Questions for Class 9 Science. Here we have given HOTS Questions for Class 9 Science Chapter 13 Why Do we Fall Ill

Question 1.
(a) Identify the figure.

(b) What do A and B depict.
Answer:
(a) Viral particles (as of SARS) coming out of host cells.
(b) A — host cell.
B — Virus.

More Resources

• HOTS Questions for Class 9 Science
• NCERT Solutions for Class 9 Science
• Value Based Questions in Science for Class 9
• NCERT Exemplar Solutions for Class 9 Science
• Previous Year Question Papers for CBSE Class 9 Science

Question 2.
Name a disease in which
(a) Antiboitic has no role.
(b) Kissing does not spread the disease while sexual contact transfers the same.
(c) Mass scale immunisation is going on.
(d) Virus, bacterium and protozoan can be causal agent.
Answer:
(a) Malaria
(b) AIDS
(c) Polio
(d) Diarrhoea.

Question 3.
What is correct ? Give reason.
(a) A person strolling in the lawn of his house is relaxing or doing exercise.
(b) Wearing socks and full sleeves at night will prevent the attack from dengue.
(c) Regular use of ORS cures diarrhoea.
Answer:
(a) Strolling is no exercise as a person moves slowly. It is a way of relaxation where stress and strain can be relieved.
(b) No. Dengue is caused by bite of Aedes mosquito which is active during day time only.
(c) Yes, ORS prevents dehydration. Diarrhoea is generally cured automatically after 1-2 days because it is mostly viral infection.

Hope given HOTS Questions for Class 9 Science Chapter 13 Why Do we Fall Ill are helpful to complete your science homework.

If you have any doubts, please comment below. Learn Insta try to provide online science tutoring for you.