General Science Solved Past Paper 9th Class 2013 Karachi Board

SECTION “A” (COMPULSORY) (M.C.Q.S)

1. Choose the correct answer for each from the given options:

(i) What are aerosols?
* Harmful
* Small material particles suspended in air
* Radioactive substance
* Water vapour

(ii) In order to reduce air pollution we should reduce:
The number of vehicles
* The number of tree
* The electrical appliances
* Hydral power plants

(iii) The unit of measurement of an electric current is called:
* Voltage
* Ampere
* Volt
* Electric energy

(iv) PCSIR was set up in.
* 1952
* 1954
* 1962
* 1964

(v) The central office of Suparco in Pakistan is situated at:
* Karachi
* Lahore
* Islamabad
* Peshawar

(vi) Iodine 131 is used in the treatment of disease of:
* Heart
* Bones
* Thyroid glands
* brain

(vii) It is the important part of bones and teeth:
* Calcium
* Sodium
* Iron
* Magnesium

(viii) Energy is defined as:
* Force
* work
* fuel
* Ability to work

(ix) The industrial resolution came in 1st century after the invention of:
* Electricity
* Electromagnet
* Steam Engine
* Microscope

(x) Science is thought to be the knowledge based on:
* Assumptions
* Predictions
* Big ideas
* Observation

(xi) The hardest substance in nature is:
* Diamond
* Graphite
* Lead
* Magnesium

(xii) The most essential element in petroleum and in other organic compounds is:
* calcium
* sulphur
* magnesium
* carbon

(xiii) How much blood an average human body contains?
* About one litre
* About five litres
* About ten litres
* About fifteen litre

(xiv) Which one of the following foods represents a balanced diet?
* fish
* apple
* eggs
* milk

(xv) Human nervous system contains:
* spinal cord, nerves, brain
* Liver
* Heart
* Brain, glands and kidneys

(xvi)Energy is produced in an animal body, when food reacts with:
* oxygen
* carbondioxide
* blood
* digestive system

(xvii) A type of psychosis:
* schizophrenia
* Anxiety
* Hysteria
* Depression

(xviii) Malaria is caused by:
* virus
* bacteria
* fungi
* protozoon

(xix) Green house effect keeps the earth’s atmosphere:
* warm
* cold
* green
* fertile

(xx) Which one is not a fossil fuel?
wood
* coal
* oil
* natural fuel gas

SECTION “B” (SHORT-ANSWER QUESTIONS)

NOTE:Answer 10 questions from this section. No answer should exceed 03 to 04 sentences.

2. Write translation of the Quranic verses about the importance of water for living things.

ANSWER:

Importance of water in Quranic Verses:
(i) AI mighty Allah has said in Holy Quran that “We have made from water every living thing.” (Sura AI-Ambiya, Ayah 30
(ii) In Sura Noor, Ayah 45 Allah says “And Allah has created every animal from water and of them there a same that crawl on their bodies and there are some that walk on two legs and some others that walk on four legs. Allah creates whatever He will. Allah is able to do all things.”

3. Write impact of science on our society.

ANSWER:

IMPACT OF SCIENCE ON SOCIETY:
Science and its development have great impact on our society. We can hardly find any aspect of life not affected by science.
(i) In agriculture high yielding varieties of seeds, insecticides and fertilizers are possible due to science and technology.
(ii) Computer and its various kinds have brought a revolution in our lives.
(iii) The internet and television and telephone entertainment have also brought communication and very close and easy.
(iv) Life saving drugs and modern methods of treatment and operations have brought a revolution in treatment of diseases.
(v) Bullet. trains, supersonic aero planes, modem buses and cars havr made transport very quick.
(vi) The things we use in our homes, washing machine, electric miners-blenders, pressure cookers etc. have all made domestic work easy.

4. Write five benefits of exercise for the physical fitness of a person.

ANSWER:

(1) The muscles will become healthy and strong.
(2) The blood circulation is enhanced and reaches every part of the body providing it the necessary energy and oxygen.
(3) Taking exercise increases the efficiency of lungs which provide increased amounts of oxygen to blood which takes it to different parts of organs and cells of the body and in turn they become fresh and active and ready to perform their functions well.
(4) The weight of the body remains quite proportional to the height because the extra fat is consumed up and does not store in the body. As a result the body looks smart and slim.
(5) The person who takes exercise daily and regularly remains active, healthy and enthusiastic. His blood circulation is increased and keeps the energy at proper level. Therefore he does not feel any exertion and fatigue.

5. Write five different between Red blood cells and white blood cells.

ANSWER:

Differnce between Red Blood Cells and White Blood Cells

Differnce between Red Blood Cells and White Blood Cells

6. What is the anomalous expansion of water? Write its three examples.

ANSWER:

Anomalous Expression of Water:
When water is cooled below 4°C it expands unlike other liquids. This expansion continues up to 0°C when it changes to ice.
This unused behavior of water is called anomalous expansion of water.
Examples:
(1) If a bottle filled with water is kept in the freezer of a refrigerator it cracks when water expands on freezing below 4°C.
(2) In cold weather, the water in the radiator will freeze and crack the car radiator tubes; for this reason a chemical ‘glycol’ called antifreeze is added.
(3) Water supply pipes burst during severe winter due to the expansion of water which freezes inside these pipes.

7. Write the First Aid for a snake bite.

ANSWER:

Snake Bite:
Biting of a snake is dangerous and may cause death if immediate medical treatment is not given. Before that first aid measure are as follows:
(i) Keep the victim from moving around, and lie him down.
(ii) The bitten part must be kept at a level below the heart.
(iii) Apply construction band about 2 to 4 inches above the bite. It should neither by extremely tight never loose.
(iv) If severe symptoms develop, make a cut along the long axis with a sharp sterilized blade. Do not make cross cut incisions. Suction should be done with a suction cup if available or with mouth. The venom should be spitted out and mouth. The venom should be spitted out and mouth of first aider be rinsed.
(v) The victim should be taken to a good hospital quickly.

8. What is laser? Write its four uses.

ANSWER:

Laser is nothing but light of one colour, one wave length and is highly amplified. It does not disperse. Therefore, it goes in one direction for longer distance without any significant change in its intensity.
Uses of Laser:
(i) Lasers are used for microsurgery of the retina of human eye.
(ii) Five lasers are used to destroy the harmful tissues of body.
(iii) Lasers are used for welding metal joints or cutting through thick metal plates.
(iv) Lasers are also employed in tanks, missiles and bombers to locate the exact position of the enemy and to measure the speed and distance of enemy planes.
(v) Very powerful lasers are being used for uranium enrichment and for producing extremely high temperature to initiate fusion reactions, It can be safely said that lasers are one of the most extensively used scientific discoveries of recent times.

9. What are Minerals? Name any four minerals found in Pak. & mention their uses.

ANSWER:

Minerals are chemical compounds naturally present in earth’s crust. They are the raw materials for obtaining metals, non-metals and other useful products.
Four important minerals of Pakistan are:
(i) Chromite: It is used for polishing other metal.
(ii) Gypsum: It is used for the manufacture of glass & cement.
(iii) Mica: It is used in electrical instrument.
(iv) Gem Stones: It is used for polished on jewellery.

10. Write uses of Radio Isotopes in agriculture & medicine.

ANSWER:

Uses of Isotopes:
Isotopes are atoms of the same element but having different Atomic mass due to presence of Neutrons. Some of them are radio active, and emit different radiations.
Uses of Radio-Isotopes:
(1) In Agriculture:
(i) Radio isotopes are used to find out the optimum intake of a fertilizer.
(ii) Good varieties of seeds have been produced after mutation through radiation. These seeds give strong plants, more yields of crops.
(iii) Radiation is used to kill bacteria and preserve food stuff.
(iv) Irradiation for a calculated fixed time of seeds is done to give better vegetables and fruits.

(2) In Medicine:
(i) Phosphorus P-32 is used to locate precisely the position of tumour in brain.
(ii) Radio cohatt-60 has been widely used to treat cancerous tumours inside the body.
(iii) lodine-131 is used to study thyroid glands.
(iv) Radio strontium is useful and effective in the treatment of internal hemorrhages and wounds.

11. What is air pollution? Write down two harmful effects of air pollution and two ways to control it.

ANSWER:

Addition of harmftJI gases, germs, bacteria and dust in air is called Air Pollution. These things in air cause diseases.
Harmful Effects of Air Pollution:
(i) Poisonous gases, germs affect the lungs and the whole body and causes diseases.
(ii) Air pollution reduces oxygen content in air and may cause suffocation. Weather conditions change and fogs occur more.
Ways to control Air Pollution:
(i) Gaseous pollutants from industries can be removed by bubbling them through certain solution.
(ii) A device canister decomposes pollutants when placed in the exhaust when placed in exhaust system of a motor vehicle.
(iii) Green trees should be planted to add oxygen to air.

12. Name six main products of diary farming. Describe briefly any two of them.

ANSWER:

The products obtained from dairy farms are:
(i) Milk
(ii) Cream
(iii) Yogurt or Curds
(iv) Cheese
(v) Ice Cream
(vi) Butter and ghee

(i) Milk:
It is the most important liquid food containing all the ingredients necessary for health. It is very useful for growing children.

(ii) Cream:
Cream is used in break fast and in making sweet dishes and cakes.

(iii) Butter and Ghee:
Cream contains 30 to 40 percent of butter which is removed and used. When butter is melted ghee is formed which is a pure fat for health.
(iv) Yogurt:
Milk on fermentation gives yogurt or curds. It is eaten as it is or used in cooking foods.

(v) Cheese:
Cheese is used in making different bakery products and sweet meats.

(vi) Ice Cream: Ice cream is a tasty and nourishing product used by children and almost people of all ages.

13. What is allotropy? Describe two allotropic forms of carbon.

ANSWER:

ALLOTROPY:
If the- same element occurs in nature in different physical states with different physical properties but chemically they are alike, it is called Allotropy.
Crystalline Allotropic forms of Carbon are:
(i) Diamond. (ii) Graphite.
Properties of Diamond:

(i) Its density is 3.3 gm/cm³ and is the hardest substance in nature.
(ii) It is a bad conductor of electricity but when heated very strongly, changes are to graphite.

Use: Beings the hardest substance it is used to scratch glass and cut all other substances.

Properties of Graphite:
(i) It is soft and lighter than diamond and can mark paper
(ii) It is a good conductor of electricity.

Use: It is a good lubricant. It is used in making lead pencils and electrodes in cells.

14. Write any five precautionary measures to avoid an infectious disease.

ANSWER:

Precautionary measures to avoid an infectious disease:
(1) Germs the causative organism of diseases are destroyed by sterilization. If environment is made mosquito free, malaria will not spread.
(2) Pet animals, another cause of some diseases, should be vaccinated and treated. Dogs and cats with disease called rabies should be destroyed at once.
(3) Personal hygiene should be maintained and body be kept clean so the chances of entry of germ inside the body be minimized.
(4) Municipal hygiene should be stressed upon to avoid any sort of contamination of air, water, a foods and hence chances of the spread of parasites or their carriers be reduced.
(5) Routine vaccination course be done and special vaccination drive be launched in case of epidemics.

15. What are Endocrine Glands? Write the names of three endocrine glands and the hormones they secrete.

ANSWER:

Endocrine Glands:
These are dustless glands whose secretions are dropped into the blood and are very essential for body functions and healthy growth.
Three endocrine glands are:
(i) Thyroid glands: They secrete the enzyme called Thyroxin.
(ii) Pancreas glands: This gland secretes Insulin which controls the sugar level in blood.
(iii) Adrenal glands: They secrete the enzyme called cortisone.

16. Write any 3 disadvantages of Radio-Active Rays & any 2 precautionary measures to reduce danger of radiation.

ANSWER:

Disadvantages of Radiations:
Radio-active Rays though useful, seriously affect the human body.
(i) Energetic radiations penetrate deep into the body and they can destroy the vital body cells.
(ii) If strongly irradiated, they cause Anemia which is a serious disease in which red blood corpuscles decrease rapidly.
(iii) Radio active radiations may cause cataract in eyes.
Precautionary Measures:
(i) The doctor while treating a patient with radiations should take minimum possible time for radiation exposure.
(ii) Radioactive material must be kept covered in a lead box with a lid also made of lead.
Radioactive material and apparatus should be handled very carefully.

SECTION ‘C’ (DETAILED-ANSWER QUESTIONS)

Note: Attempt 3 questions from this Section.

17. Name any four Muslim scientists and describe their achievements.

ANSWER:

Four Muslim scientist to are
(1) lbn-ul- Haitham
(2) Bu Ali Sena
(3) AI Beruni
(4) Muhammed Bin Zakria AI Razi

(1) Ibn-ul-Haitham:
(i) He was great Muslim scientist and a scholar of physics Mathematics, astronomy, and medicine.
(ii) Hewrote a famous book “Ketabul Manazir” on optics.
(iii) He gave the laws of reflection for the first time.
(iv) He made the first camera the pin hole camera.
(v) He showed that light hovels in straight line.

(2) Bu Ali Sina:
(i) His book “AI Qanoon Fil Tib ” is a masterpiece book on medical science.
(ii) He wrote more than hundred books, which deal with philosophy, science, medicine and literature.
(iii) He was very good and famous Tabib of his time.
(iv) He wrote a famous book “AI-Shifa” which is a valuable asset.

(3) AI- BAIRUNI:
(i) He wrote a famous book Qanoon- AI- Masudi on astronomy and arithmetic.
(ii) He measured the circumference of earth for the first time.
(iii) He gave method to determine longitude and latitude of a place.
(iv) He also found the densities of metals.

(4) Mohummad Bin Zakaria AI Razi:
(i) Hewas a famous surgeon
(ii) He discussed in detail small pox and measles.
(iii) Hewrote the book” AI-Masudi” on medicine.
(iv) He also wrote a book Alhavi ” about medicine.

18. What is meant by Metabolism? Name its two phases and explain them with examples

ANSWER:

Metabolism:
All the living things are carrying out a number of activities like respiration, excretion, growth, reproduction etc. All these activities involve a large number of chemical reactions going on in the body of an organism all the time. once these reactions stop the organism dies. The sum of all these chemical reactions occurring within the body of an organism is called metabolism. Metabolism has two distinct phases:
(1) One phase is called anabolism which involves synthesis of organic compound like carbohydrates, proteins and fats.
(2) The other phase called catabolism involves the breaking up of these organic compounds for the liberation of energy for the body activities.
Example: (1) Photosynthesis is an example of anabolism because it involves the synthesis of carbohydrates from inorganic compounds. Respiration on the other hand is a catabolic reaction and involves the breaking up of carbohydrates into carbon dioxide and water for the liberation of energy.
Example: (2) The foods eaten by animals cannot be utilized by their body cells. They undergo a process of digestion inside digestive tube by which their insoluble parts are made soluble. As a result, carbohydrates are changed into glucose molecules; proteins into amino acids and fats into fatty acids and glycerol. The digested food molecules are then absorbed into cells where they are either constructed into a complex compound to be the part of protoplasm or broken down to produce energy.

19. Name four important industries of Pakistan and describe anyone of them with examples.

ANSWER:

Four important industries of Pakistan:
(1) Textile Industry.
(2) Sugar Industry.
(3) Iron Industry.
(4) Medicine Industry

Textile Industry:
Textile industry is the backbone of Pakistan’s economy. There is large number of big and small textile mills in Pakistan. Fine verities of cloth are manufactured in these mills. Pakistan is self-sufficient in cotton cloth. Each year millions of foreign exchange is earned through the export of cotton cloth and yarn. Main centers of textile industry are Faisalabad, Lahore and Multan in Punjab. Karachi and Hyderabad in Sindh. In N.W.F.P,there are at Peshawar, Dera Ismail Khan, Nawshera, Bannu, Haripur and Swat. Uthal and Quetta are the two textile centers in Balochistan.
About 50% of industrial labour is employed in the textile industry of Pakistan.
Pakistan has also woolen textile industry but it is not as rich as cotton textile industry. The reason that wool in Pakistan is not high quality. The major woolen textile centers are at Karachi, Lawrencepur, Rawalpindi, Lahore, Quaidabad, Harnai, Mustung, Bannu and Nawshera. At present there are 70 woollen mills in the country.
Pakistan has also a silk textile industry. Raw silk is Imported from other countries. Karachi is the biggest center of silk textile industry. Silk textile is also manufactured at Faisalabad, Lahore, Multan, Gujranwala, Peshwar, Swat, Sukkur and Hyderabad.

20. What is fuse? Describe switch and fuse in detail.

ANSWER:

FUSE: A fuse is a safety device which breaks the flow of current when large amount of current (above than normal value) flows in the circuit.
Fuse is a thin wire of low melting point. It is in the metre when greater than normal current flows, it heats the fuse wire it melts and breaks the circuit.
Thus costly electrical appliances T.V., Refrigerator, fan, computer etc are saved from damage. When fuse goes off mistake for short circuit is rectified and a new fuse wire is put in its Socket.
Fuse is always attached in the line wire and not in the neutral wire.
SWITCH:
Switch is a sort of button for opening and closing of a circuit For example, a switch is used to turn a lamp or fan etc ON and OFF.
TYPES OF SWITCHES:
There are two types of switches.
(i) Single pole single throw (SPST)toggle switch.
(ii) Single Pole Double throw (SPOT)switch.
(i) SPST Switch is the common switch for turning a lamp etc ON an OFF.
(ii) SPDT Switch is installed to control current going to two different lamps, when one lamp is to be kept ON and other lamp is OFF and vice versa.

21. Write two causes, four symptoms and four preventive measures against anyone of the following diseases:

(a) Tuberculosis:
ANSWER:

CAUSES:
It is caused by a bacterium called Myco bacterium tubers Loges.
(i) The diseases is contagious and spread by close contacts with a patient of T.B. by using his things.
(ii) The spit of a T.B. patient carries the bacterium and this bacterium get mixed in air from the spit and causes the disease.
(iii) From the milk of T.B. affected cows and not properly boiled milk is also its cause.

SYMPTOMS:
(i) Persistent cough and lungs get affected.
(ii) Constant fever and tiredness.
(iii) Pain in legs and back, joint, night sweat.
(iv) The person feels very exhausted and tired by small amount of work.

PREVENTIVE MEASURE AGAINST T.B.
(i) B.C.G. vaccination of school children should be done.
(ii) A.T.B. patient must be isolated and his utensils and towel must be .separated. Close contact with a T.B. patient should be avoided

(b) Measles:

ANSWER:

CAUSES:
(i) It is a viral disease and is spread by respiratory route.
(ii) The virus enters the body through air also through contacts with a person suffering from measles.

SYMPTOMS:
(i) The person feels cold and headache.
(ii) Common cold and sore throat also felt.
(iii) The prominent symptom is appearance of red rashes on the body starting from face and extending on trunk and limbs.
(iv) Middle ear infection in complicated cases is also seen. Pneumonias may also by caused by virus itself or by secondary bacterial infection.

PREVENTIVE MEASURE:
(i) A vaccine called MMR is administered to children of 15 months.
(ii) Avoid contacts with a suffering persons.
(iii) Hygienic food should be taken.
(iv) Utensils and towel etc of an already Measles patient should not be used.

(c) Tetanus:

ANSWER:

CAUSES:
(i) A disease caused by bacteria found in spores in soil contaminated with horse and other animal faces.
(ii) Falling on roads by accidents, on the road contaminated with animal faucal wastes.
(iii) Deep wounds by rusty nails also cause this disease.

SYMPTOMS:
(i) Painful and violent contraction of body muscles.
(ii) Muscles of the Jaw are affected and mouth cannot be opened.
(iii) Later other skeletal muscles become affected.
(iv) Respiratory muscles are also affected in serious cases. It may result in death.

PREVENTIVE MEASURE:
(i) OPTvaccine in early months of life.
(ii) Wounds should not be left open.
(iii) Falling on contaminated soil and ground should be avoided.
(iv) Playing and fighting in places where animal faces is found, should be avoided.

Posted on December 16, 2015 in 2013 Karachi Board Past Papers

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