Class7 Chapter 03. Plants fiber and fabric
A Tick the correct options:
1. Which of the following is not a natural fibre?
(a) cotton (b) rayon √ (c) silk (d) wool
2. Lohi is the breed of
(a) cow (b) silk moth (c) sheep √ (d) buffalo
4. Sheep are sheared in season
(a) summer √ (b) spring (c) autumn Ö (d) winter
3. How many weeks are required for the eggs of silk moth to hatch? See book
(a) one (b) two √ (c) three (d) four
6. Which of the following silk is produced when raw silk is twisted?
(a) spun (b) coloured (c) thrown √ (d) mooga
5. What do we call the silky covering spun by the silkworm for its protection?
(a) moth (b) larvae (c) pupa (d) cocoon√
B. Fill in the blanks:
1. Alpaca is generally found in South America.
2. Silk and wool fibres are obtained from animals.
3. Silk is obtained from cocoons of silkworm.
4. Natural fibres are obtained from plants and animals.
6. The fewer the burrs, the better is the wool.
7. The eggs are warmed to a suitable temperature in an oven
8. During the period of spinning of its cocoon, a silkworm is transformed into Pupa.
C. State whether the following statements are True (T) or False (F).
Rewrite the false statements correctly:
1. Silk is obtained from cocoons of silkworms. (T)
2. The process of washing the fleece of sheep to remove dust, dirt, sweat and grease is
called shearing. False Scouring.
3. The rearing of silkworms for obtaining silk is called sericulture. T
4. The damaged or waste cocoons are used to produce raw silk. F Spun silk
D. Very Short Answer Questions:
1. What is the process of removing the burrs from fleece called?
2. Name any two breeds of sheep found in India.
Ans. Merino ,Lohi
3. Name the process of removing hair from the body of a sheep.
4. Name the sheep which is found in Gujarat and whose wool is used in hosiery.
6. Which country leads the world in silk production?
5. What is the process of taking out threads from the cocoon called?
Ans. reeling the silk
7. Name two wool-yielding animals.
Ans. Sheep, goat, yak and camel.
E. Short Answer Type-I Questions:
1. What is meant by rearing of sheep?
Ans. The raising and breeding of domestic sheep is called rearing of sheep.
Sheep are raised principally for their meat (lamb and mutton), milk (sheep's milk), and
2. What is throwing?
Ans. Throwing is the process of twisting and doubling the single raw silk fibres into
usable thread after reeling and cleaning.
3. Why does shearing not hurt the sheep?
Ans. Shearing doesn't usually hurt a sheep. It's just like getting a haircut.
4. What is meant by scouring?
Ans. The sheared skin with hair is thoroughly washed in tanks to remove grease, dust
and dirt. This is called scouring.
5. What is cocoon?
Ans. A cocoon is a soft covering that an insect spin with silky thread to protect itself.
F. Short Answer Type-| Questions:
1. What is meant by selective breeding? What is its purpose?
Ans. Selective breeding is a kind of artificial selection in which two different kind of
breed are crossed to develop new organisms with desirable characteristics. For example
native breeds (female) crossed with exotic breed (male).
2. What is silk? How do we get silk from cocoon?
Ans. Silk is a kind of animal which are soft and lustrous.
The cocoons are kept under the sun or boiled or exposed to steam. The silk fibres
3. (a) What are raw silk and spun silk?
(b) On burning silk, it gives out the smell of burning hair. Give reason.
Ans. (a) Silk fibre obtain from cocoon and twisted to make stronger thread is called raw
silk. Silk fibre obtain from damaged cocoon is called spun silk.
(b) On burning silk gives out the smell of burning hair as it is made up of protein
4. With the help of a flow chart only, describe the life cycle of a silkworm.
5. (a) What is sorter's disease?
Ans. People working in wool industry sometimes they get infected by a bacterium called
anthrax, which causes a fatal blood disease called sorter’s disease
(b) Name two Indian breeds of sheep and also mention the quality of wool produced.
Ans. (i) Deccani sheep breed - low grade fibres, mostly used for the manufacturing rough
(ii) Gaddi Sheep Breed - wool is fine and lustrous and it is used for manufacturing of
high quality kulu shawls and blankets.
6. (a) Why do wool yielding animals have a thick coat of hair on their bodies?
Ans. wool yielding animals have a thick coat of hair on their bodies so that sheep can
withstand with cold weather.
(b) The process of removing hair from the body of sheep is called shearing. Why is
shearing done in summers?
Ans. Sheep are usually found in hilly and cold region. Shearing of sheep done in
summers because sheep can survive without their protective coat of hair.
G. Long Answer Questions:
1. Write the various steps involved in the production of silk cloth from silk moth.
Ans. a. Incubation: The silk moth eggs are warmed to a temperature suitable for
hatching. This is known as incubation.
b. Rearing: After hatching, the silkworms are fed on mulberry leaves for six weeks, and
the worms eat almost continuously and increase in size.
c. Spinning: Branches of trees or shrubs are placed in their rearing houses. The worms
climb these branches and make their cocoons out of one continuous thread.
d. Reeling: The cocoons are first boiled or treated in ovens, killing the insects by heat.
The silk fibre is then obtained from the cocoons by a delicate process known as reeling.
This fibre woven into cloth.
2. Describe the process of wool production.
Ans. The different processes involved in wool production are shearing, scouring, grading,
dyeing, and drying.
Shearing: The process of removal of the fleece from an animal is called shearing.
Scouring: The sheared hair is washed properly to remove dirt, dust, and grease. The
process of removing dirt, dust, and grease from the sheared hair is called scouring.
Grading : the wool is sorted on the basis of length, colour, texture
Dyeing: As the natural colour of fleece is white, brown, or black, the sheared wool is
dyed in different colours.
Drying : In this process, containers of wool are put through rollers to squeeze out as
much water as possible. Then the wool is weighed and packed into bales. The bales are
transported to the mills where they are processed further for making cloth
3. Discuss various varieties of natural silk.
Ans. Eri silk – it may be white or brick-red ;
Muga silk - golden-yellow silk thread which is very attractive and strong.
Mulberry silk – it contributes to around 90 percent of the world silk production.
Tasar silk - copperish colour mainly used for furnishings and interiors.
H. HOTS (Higher Order Thinking Skills) Questions:
1. How is selective breeding advantageous for us?
Ans. selective breeding increase the production by selecting best variety of animals.
2. Why are animal activists against the silk production?
Ans. Animal activists are against the present process of getting silk from the cocoon
because in this process the pupa are killed in a cruel way by boiling them in water.
A. Tick the correct options:
1. Which one is a source of fat?
(a) soya bean oil √ (b) apple
(c wheat (d) none of these
2. For protein test, we add solution along with caustic soda solution
(a) copper sulphate √ (b) magnesium sulphate
(c) calcium sulphate (d) iodine
3. Which of the following food items shows a positive starch test?
(a) butter (b) egg
(c) rice√ (d) oil
4. Obesity is due to excessive intake of
(a) proteins (b)fats√
(c) minerals (d) vitamins
5 Spongy and bleeding gums are symptoms of
(a) beriberi (b)scurvy√
(c) rickets (d) night blindness
6. Which vitamin is essential for proper vision in darkness?
(a) vitamin D (b) vitamin A √
(c) vitamin C (d) vitamin B
B. Fill in the blanks:
1. Carbohydrates and fats provide us energy.
2. Carrot is a rich source of vitamin A
3. Beriberi is caused due to deficiency of vitamin B..
4. The diet that contains all components of food in the required proportion is called
5. Deficiency of vitamin D causes a disease known as Rickets.
C. Match the following:
Column A Ans Column B
1. Fluorine (d) (a) beriberi
2. Iron (e) (b) rickets
3. Vitamin B, (a) (C) kwashiorkor
4. Protein deficiency (c) (d) dental caries
5. Vitamin D (b) (e) anaemia
D. Very Short Answer Questions
1. Name two food items that are rich in (a) phosphorus (b) calcium.
Ans. (a) Meat, Fish (b) Milk, leafy vegetable
2. Name two sources of roughage.
Ans. Wheat, bean, pea
3. Which mineral is essential for the formation of bones and teeth?
4. Which component of food plays an important role in transporting substances and
nutrients in our body?
5 Name one disease from which obese people may suffer.
Ans. Heart attack
6. Name one source of iodine.
Ans. Salt, water
E. Short Answer Questions:
1. Give two cooking practices that lead to the loss of nutrients in food materials
Ans. two cooking practices that lead to the loss of nutrients in food materials are
(i) Washing fruit and vegetable after cutting and peeling
(ii) Cooking food in too much water
2. Name the disease caused by the deficiency of dietary lodine and give its symptoms.
Ans. Goitre is caused by the deficiency of dietary iodine.
Neck became swollen. Slow physical and mental growth.
3. How do we get most of the water needed by our body?
Ans. we get most of the water needed by our body by drinking 6-8 glass of water a day
and eating fruits and vegetables.
4. Differentiate between the two types of carbohydrates found in food.
Ans. Sugar and starch are two type of carbohydrates present in our body. Sugar provide
instant energy to our body whereas Starch provide energy slower than Sugar.
5. Why is roughage important for us?
Ans. (i) It prevent constipation, (ii) It reduces the risk of heart attack and bowel cancer.
F. Long Answer Questions:
1. What is marasmus? What are the symptoms of marasmus?
Ans. Marasmus is a deficiency disease caused by lack of protein, Carbohydrate and fat in
diet. Children suffering from marasmus have loose folds of skin all over body.
2. What are deficiency diseases? Name three deficiency diseases and also write their
causes and symptoms.
Ans. Diseases caused by lack of balanced diet in food are called deficiency diseases.
HOTS (Higher Order Thinking Skills) Questions:
1. Mrs Sharma suggested her maid to wash the vegetables before chopping and not after chopping .Does it make a difference? Comment
Ans. Yes, washing fruit and vegetable after chopping loose some vitamin and minerals.
2. Radhika likes to carry bread and jam every day in her lunch. Is this justified? Comment
Ans. No, bread and jam are rich source of carbohydrates. There will be lack of balanced died in food and Radhika may suffer from deficiency disease.
For more detail study visit Components of food class06
E. Short Answer Type-I Questions:
1. What is the function of saliva?
Ans: The digestive functions of saliva include moistening food, and helping to create a
food bolus, so it can be swallowed easily.
Saliva contains the enzyme amylase, also called ptyalin, which is capable of breaking
down starch into simpler sugars such as maltose and dextrin that can be further broken
down in the small intestine
2. What is ingestion?
Ans: The process of taking food inside our mouth is known as ingestion.
3. What is chyme?
Ans: Partially digested food formed by the action of gastric juice in the stomach is called
4. What happens to the undigested food in the body?
Ans: The undigested food passes to large intestine.Some water is absorbed and the semi
solid waste (feces) is egested through anus.
5. What do you understand by the term assimilation?
Ans: The process of producing energy from the absorbed food is known as assimilation
6. Where is liver located? Give its function.
Ans:liver lies in front of stomach. Liver secrate bile that is stored in gall bladder. It make
the digestion of fat faster.
Note: Bile juice contains no digestive enzymes, yet it is important for digestion. Bile juice
has bile pigments such as bilirubin and biliverdin. These break down large fat globules
into smaller globules so that the pancreatic enzymes can easily act on them. This process
is known as emulsification of fats.
F. Short Answer Type-Il Questions:
1. Why we cannot breathe and swallow at the same time?
Ans: Every time we swallow, the epiglottis closes the wind pipe .If we breathe and
swallow at the same time, food or water enters wind pipe and we chock and cough.
2. In what substances carbohydrates, proteins and fats get converted into after
Ans: in small intestine Carbohydrates get converted into sugars. Proteins get converted
into amino acids. Fats get converted into fatty acids and glycerol.
3. What are the functions performed by tongue?
Ans: tongue helps in process of chewing by pushing the food towards the teeth. It also
help to mix the food with saliva.
4. Which part of the alimentary canals involved in (a) chewing of food (b) killing of
bacteria (C) absorption of food (d) formation of faeces?
Ans: (a) chewing of food – Mouth (b) killing of bacteria – stomach (C) absorption of
food – small intestine (d) formation of faeces – large intestine
5. Different types of teeth in our jaws have different functions, but they all work together
to chew the food.
Ans: Different types of teeth in our jaws have different functions
(i) Incisors :- They help us in biting and cutting the food.
(ii) Canines : - They help us in piercing and tearing the pieces of meat.
(iii) Premolars:- They assist the molars by holding the food with their cusps and also
(iv) Molars : - They help us in chewing and grinding the food so that it can be swallowed
(b) What do we learn from our teeth that have different functions?
Ans: If we work united we will do any impossible work .
G. Long Answer Questions:
1. Briefly describe nutrition in Amoeba with the help of diagrams.
Ans: Amoeba takes in food by forming temporary finger-like projections called
pseudopodia. The pseudopodia fuse over the food particle forming a food vacuole. The
digestive enzymes from the surrounding cytoplasm enter into the food vacuole and
breakdown the food into small, water soluble molecules by chemical reactions. The
digested food from the food vacuole spreads into the whole of Amoeba cell and gets
absorbed in the cytoplasm. A part of absorbed food is used to obtain energy through
respiration and some is used for the growth of Amoeba cell. The undigested part of the
food is moved to the surface of Amoeba cell and egested (thrown out) by the rupture of
2. Describe the process of digestion in ruminants.
Ans: The stomach of a ruminant is divided into four chambers. As soon as the ruminant
swallows the food, it enters the first chamber called rumen where it gets partially
digested (converted to cud). From here, the food enters the second chamber from where
it again reaches the mouth for rumination, which is thorough chewing. The food is again
swallowed, and now it enters the third and the fourth chamber for digestion. From here,
it enters the small intestine for the absorption of nutrients.
3. What are liver and pancreas? Write their functions in detail.
Ans: liver and pancreas are organ that help in digestion of food.
Live produce bile juice that breaks down fats and stores some vitamins and minerals.
The pancreas has two main functions: an exocrine function that helps in digestion and
an endocrine function that regulates blood sugar.
Liver is the largest gland of the body. It is a reddish-brown gland situated on the right side of the upper part of the
Functions of liver are as follows:
(i) To secrete bile juice which helps in the emulsification of fats present in the food.
(ii) Detoxification- Conversion of toxic substances into non-toxic forms like conversion
of ammonia to urea which gets excreted in the urine.
(iii) Clearing the blood from drugs and other harmful substances.
(iv) Conversion of excess glucose into glycogen for storage (glycogen can later be
converted back to glucose to energy when body is in short of nutrients)
Pancreas is a organ located in the upper abdomen and adjacent to the small
intestine. It performs two main kind of functions in the body:
(i) Exocrine function: It helps in the digestion of food. It produces various enzymes such
as amylase, lipase and trypsin which helps to digest carbohydrate, fats and proteins
(ii) Endocrine function: It produces hormonal insulin and glucagon which regulate the
level of sugar present in the blood
H. HOTS (Higher Order Thinking Skills) Questions:
1. The bacteria present on uncleaned teeth convert the sugar in food into a substance 'X'
which causes tooth decay. Name the substance 'X'. Which part of the teeth does it affect?
Ans: Substance X is lactic acid which is formed in the mouth after we eat food
containing sugar. it affect enamel.
[ Note : Lactic acid lowers the pH in the mouth making it acidic. Our tooth enamel is
made up of calcium phosphate, which is the hardest material in our body, but even it
starts getting corroded when the pH in the mouth is lower than 5.5(Acidic)]
2. How is ruminant's stomach different from humans?
Ans: The stomach of a ruminant is divided into four chambers they are rumen,
reticulum, omasum, and abomasum. Human stomach is a single organ.
For more books and full solution visit 7th Science
C. Fill in the blanks:
1. Microorganisms may be unicellular or Multicellular.
2. Lactobacillus bacteria help to make curd from milk.
3. Disease causing microorganisms are called pathogen.
4. Ammonium salt in the soil is converted first into nitrites by -- Nitrifying ----- bacteria.
5. Casein coagulation takes place only when milk is hot .
6. Salting draws out water from food.
7. Nitrate in the soil are converted by ammonifying bacteria into nitrogen gas.
8. The process of preventing food spoilage by chemical or physical methods is called food
D. Very Short Answer Questions:
1. Name any two antibiotics.
Ans. Penicillins, streptomycin, tetracycline
2. Give the names of any two communicable diseases.
Ans. Malaria , Typhoid
3. What are the two common food preservatives used at our homes:
4. Name two microbial diseases which spread through air,
Ans. Common cold,flu,tuberculosis, influenza, small pox
5. Name any one unicellular algae.
6. Name any disease caused by virus in humans
E. Short Answer Type I Questions:
1. What is pasteurization?
Ans. The process of heating milk at 70 degree for about 15 min and then cooling it for
quickly is called pasteurization. This kill the most of the bacteria without affecting flavor.
2. How do leguminous plants increase the soil fertility:
Ans. leguminous plants provide shelter to Rhizobium bacteria that help in converting
atmospheric nitrogen present in soil into useable form that is taken by plants to make
3. What is meant by nitrifying bacteria?
Ans. Bacteria which help to convert ammonia present in soil into nitrates is called
4. How does female Anopheles mosquito spread malaria?
Ans. Female Anopheles mosquito carries the malaria germ. When it bites a healthy
person, he/she can get infected with malaria.
5. How do antibiotics work?
Ans. Antibiotics kill or stop the growth of disease causing microbes
F. Short Answer Type-II Questions:
1. (a) How do viruses differ from other microorganisms? (b) What is meant by
Ans. (a) A virus is a microorganism which exhibits characteristics of living as well as
(b) The conversion of sugar into alcohol in absence of oxygen using yeast is called
2. Explain the formation of curd from milk.
Ans. Milk contains a sugar called lactose, when milk is heated to a temperature of 30-40
°C and a small amount of sour curd added to it, the lactobacillus starts to grow and
convert the lactose into lactic acid and thus milk coverted into curd.
3. What is vaccine? How does it work?
Ans. Vaccines are substance used to produce immunity to diseases in the living body.
Vaccine consist of dead or weaken microbes .When these swallowed or injected into body
of patient, the body produce antibodies to fight them. Antibodies remain in bodies and
protect it from any future attack disease causing microorganism
4. Microorganisms decompose dead organic waste of plants and animals and help in
keeping the environment clean.
(a) What would happen, if microorganisms do not perform this function?
(b) Being a student, how can you contribute in keeping the environment clean! Give two
Ans.(a) air , water and soil get polluted if microorganisms do not decompose dead
organic waste of plants and animals
(b) (ii)Always follow 3R – Reduce ,reuse and recycle (b) Avoid wastage of natural
resources and use them wisely and carefully.
G. Long Answer Questions:
1. Explain two methods of food preservation. Also, discuss the advantages of food
Ans. Food can be preserved in the following ways:
(i) Heating: Heating food to a high temperature kills microorganism e.g water and milk.
(ii) Salting: Salt prevents food spoilage by checking the growth of bacteria. Salt forces
microorganisms to lose wafer by a process called osmosis.
The advantages of food preservation are
(i) Food last for longer period (ii) Food preservation prevents the food from being
spoiled by the action of enzymes and microorganisms. (iii) It increases the availability of
out of season foodstuffs.
2. Draw a neat diagram to show nitrogen cycle and explain the process of nitrification
Ans. Nitrification is the process of conversion of ammonia into nitrates .It is carried out
by nitrifying bacteria.
Denitrification is the process of conversion of nitrates into free nitrogen gas. It is carried
out by denitrifying bacteria.
3. Describe the principle on which the following methods of food preservation are based:
(a) boiling (b) canning (c) freezing (d) dehydration
Ans. (a) boiling: Heating to food at high temperature kill bacteria.
(b) Canning: canning stop the supply of oxygen to bacteria and stop its growth.
(c) freezing: it lower the temperature that reduce the growth of bacteria
(d) Dehydration: it force bacteria to loose water by osmosis and stop growing further.
H. HOTS (Higher Order Thinking skills) Questions:
1. Why do we say that if a person suffers from chickenpox once, he/she is not likely to be attacked by the same disease in future?
Ans. when one suffers from chickenpox the body makes the antibodies that remain in
body and prevent any future attack.
2. Why should we always wash our hands before handling food items?
Ans: We should always wash our hands before eating to prevent the germs in our hands
from entering the food so that we are prevented from getting diseases.
Fore more book solution visit: 8th science Ch_02
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Class7 Chapter 01 Nutrition in plants and Animals Cordova Science
A (Tick) the correct options:
1. Rhizobium bacteria live in the root nodules of plant
(a) wheat (b) rice (c) barley (d) peaÖ
2. Plants store food as
(a) cellulose (b) sugar (c) glucose (d) starchÖ
3. Which of the following is an insectivorous plant?
(a) Cucuta (b) DroseraÖ (c) mistletoe (d) lichen
4. The mode of nutrition shown by Cuscuta is
(a) parasiticÖ (b) symbiotic (c) saprophyte (d) autotrophic
5. On adding iodine solution, starch
(a) turns blue blackÖ (b) turns green (C) remains colourless (d) turns red
6. We keep healthy potted plant in a dark room for some days to the leaves
(a) decolourise (b) defragment (c) destarchÖ (d) deprotein
7. The portion of leaf that is not exposed to sunlight, will not make
(a) fats (b) protein (c) glucose Ö (d) starch
B.Fill in the blanks:
1. Rhizobium bacteria provide --nitrogen---- to the leguminous plants.
2. Green plants make their food by the process of photosynthesis.
3. Stomata are surrounded by guard cells.
4. Cuscuta is a -Total--- parasite.
5. The roots of saprophytes contain organisms called ….symbionts
C. Very Short Answer Questions:
1. Name any two heterotrophs.
2. Name any two insectivorous plants.
Ans: Venus flytrap, pitcher plants, butterworts, sundews
3. Name the pores through which leaves exchange gases.
4. Name one plant in which photosynthesis occurs in plant part other than leaves. Name
the plant part.
Ans: cactus in it's stem
5. What are the two main modes of nutrition in plants?
Ans: Autotropic and heterotrophic
6. Name the green pigment present in the leaves.
D. Short Answer Type-l Questions:
1. What are autotrophs?
Ans: Organism prepare own food like green plants
2. Why is Cuscuta called parasite?
Ans: Cuscuta is called parasite as it draw nutrition from host.
3. In which form, do plants need nitrogen?
Ans: Plants absorb nitrogen from the soil in the form of nitrate (NO3−) and ammonium
4. Why are leaves of a plant green in colour?
Ans: leaves of a plant are green in colour due to presence of chlorophyll.
5. Why do some plants feed on insects?
Ans: some plants feed on insects to get nitrogenous compound from which they make
6. Define photosynthesis.
Ans: Photosynthesis is the food making process of green plant using CO2 and water in
the presence of sunlight
E. Short Answer Type-ll Questions:
1. How can we decolorized a leaf? What will you conclude when white patches do not
turn blue black adding iodine solution?
Ans: Leaf of green plant heated in a test tube containing alcohol in water bath to
decolorize. if white patches do not turn blue black adding iodine solution showing
absence of starch
2. What is saprotrophic mode of nutrition? Give one example.
Ans: The mode of nutrition in which organism derive nutrients from dead and decaying
organic matter. Eg. Mushroom.
Saprophytes breakdown organic matter by secreting digestive juice into it. Then they
absorb what they need from the digested matter.
3. How does the pitcher plant catch its food?
Ans : Pitcher plants have leaves that look like pitchers. The lid of the pitcher closes when
an insect lands on the pitcher. The trapped insect slides down the wall of the pitcher and
is digested inside it.
4. Algae and fungi live together in lichens.
(a) What is this association called? (b) What value can we learn from this association in
Ans: The fungus provides minerals and water to the alga. The alga supplies the fungus
with food that it manufactures.
(a) Symbiotic relationship (b) We live with other in mutual benefit take help and give
5. Discuss the importance of photosynthesis.
Ans: Photosynthesis helps green plant to prepare glucose. Photosynthesis use CO2 and
release O2 and thus balance the oxygen and carbon dioxide level in atmosphere. Water
vapor released during photosynthesis also help in formation of cloud and bring rain.
F. Long Answer Questions:
1. Write an experiment to show that sunlight is necessary for photosynthesis.
Ans: cover a part of a leaf of a potted plant with black paper. Use paper clips to fix the
paper on both sides of the leaf
Make sure the plant get enough sunlight Pluck the leaf and take off the paper after two
Heat the leaf in alcohol, as in the previous activity, and test for starch. Only the part of
the leaf which was exposed to sunlight will turn blue-black. This shows that sunlight is
necessary for photosynthesis.
2. How do Rhizobium bacteria and leguminous plants help each other in survival?
Ans: Plant provide shelter to Rhizobium bacteria and Rhizobium bacteria provide nitrogenous compound that plants required to make plants protein.
G. HOTS (Higher Order Thinking Skills) Questions:
1. What will happen if plant leaves are devoid of stomata?
Ans: if plant leaves are devoid of stomata there is no exchange of gases like O2 and CO2
. Plants cannot perform photosynthesis
2. What will happen if all the plants disappear from the earth?
Ans: Food chain unbalance and no life exist.
For more chapter visit 7th science
E. Short Answer Type-I Questions:
1. What is meant by agricultural implements?
Ans: Agricultural implements are any kind of machinery or tools used on a farm to help
with farming. The best-known example of this kind is the tractor.
2. How do legurninous plants help in maintaining the soil fertility?
Ans: Rhizobium bacteria present in the root of legurninous plants convert the
atmospheric nitrogen into ammonia into soil, which is used by plants.
3. What is pisciculture?
Ans: Rearing of fish is called pisciculture.
4. Why is it important to sow seeds at a correct distance from each other?
Ans: Seeds should be shown at a correct distance from each other so that seed get
sufficient sunlight, nutrients and water from the soil.
5. Give two precautions that must be taken while sowing seeds.
Ans: seeds should be shown with right spacing and at right depth
6. How does winnowing help in separation of grains from husk?
Ans: When mixture of grain and chaff dropped on the ground from a height, The heavier
seeds fall on the ground where as the lighter chaff gets blown away by the wind and fall
at a distance.
7. Why is the spraying of pesticides harmful to us?
Ans: The spraying of pesticides cause irritation to skin and respiratory problems. They
get mixed with soil and water and absorbed by plants. These then enter our bodies
through fruits and vegetables which we eat and cause us harm..
F. Short Answer Type-II Questions:
1. (a) Why is irrigation necessary? (b) Why is the drip system of irrigation a water-
Ans: Rain varies and doesnot always supply the right amount of water at right time.
Therefore it is important to supply water regularly to the crops.
2. Define fertilisers. Name any four fertilisers.
Ans: Chemical substance that contain one or more nutrients essential for plants eg
Urea., Calcium Nitrate, Ammonium Sulfate, Super Phosphate
3. The farmers of a village are celebrating the harvest festival of Baisakhi along with their
families. They are dancing and singing traditional songs.
(a) What is harvesting? Why do farmers celebrate Baisakhi? (b) What do we learn from
Ans: (a) Cutting and gathering of mature crops is called harvesting.
(b) Farmers celebrate Baisakhi to express gratitude to the Almighty for the bountiful
harvest and pray for prosperity and good times in future
G. Long Answer Questions:
1. (a) What are weedicides? (b) Name one weedicide. (c) What are the harmful effects of
weeds in the crop field?
Ans: Weedicides are chemicals that kill weeds (b) 2, 4-D and MCPA or Butachlor
(c) Weeds compete with the crop for water mineral and sunlight and therefore reduce
2.(a) Differentiate between manure and fertilizers. (b) What are the advantages of using
Ans: (a) Difference between manure and fertilizers.
(b) Organic manure is considered to be better than fertilisers. It is because of the
following reasons to be
(a) It enhances the water holding capacity of the soil.
(b) It makes the soil porous, thus making the exchange of gases easy.
(c) It also improves the texture of the soil. (d) It increases the number of friendly
1. Why do farmers level the field before sowing?
Ans: For the uniform distribution of water and manure in a field, a farmer practices
2. During ploughing why is the land pressed lightly and not tightly?
Ans: This is because loose soil allow root to breathe easily and allow root to penetrate
deeper .Loose soil also help in the growth of earthworm and microbes that provide
nutrients to soil.
For More solved question visit Crop production class8
Ponder over it: In our India to increase in food grain production Dr M. S. Swaminathan started green revolution In 1963. In agriculture high-yielding wheat seeds were introduced in India. Also, modern farming methods began to be used at large scale in India. So He is known as the 'Father of the Green Revolution in India.
Choose the correct option
2. The ________is an edible part of potato plant
(a) leaf (b) root (c) sternÖ (d) fruit
3 We can sprout seeds in __________
(a) rocks (b) waterÖ (c) oil (d) none of these
4. The sprouted seeds contain more
(a) carbohydrates (b) fats (c) vitamins Ö (d) water
5. The edible part of the apple plant is ___
(a) leaf (b) root (c)Stem (d) fruit Ö
6. we eat root of _______
(a) mustard (b) rajma (c) chili (d) radishÖ
7. The colour of the structures grown out from the sprouted seeds is
(a) black (b) whiteÖ (c) red (d) green
Fill in the blanks:
1. We get sugar from _Sugarcane________
2. We get milk from __Cow ____ and ___buffalo______.
3. Honeybees store honey in their ___ honey stomach _________.
4. _Rice __ and ___water___are two ingredients of boiled rice.
5. Animals that eat both plant products and flesh of other animals are called
6. Bacteria and fungi are called ____ decompose ____.
7. We should not ___waste_ food in any way.
8. Honeybees are kept in __ beehive ___ for rearing.
Very Short Answer Questions:
1. What are the animals that eat only plants and plant products called?
2. Name four food items we get from animals.
Ans: Egg, Meat, milk, Ghee
3. Name two edible stems.
Ans: Potato , sugarcane
4. What are the materials needed to prepare food items called?
5. What is the rearing of honeybees on a large scale called?
6. Name two plants whose flowers are eaten as vegetable.
Ans: Cauliflower, Braccoli
Short Answer Questions:
1. Why do we need food?
Ans: We need food
(i) to get energy
(ii) grow and replace worn out cell
(iii) protect body from diseases
2. What are edible parts? Give name of one.
Ans: Part of plants that are eaten by humans is called edible parts. Wheat, pea and rice
are plant whose edible part is seed
3. Honeybees work hard to collect nectar from flowers.
(a) Where is this nectar stored? (b) What value do you learn from honeybees?
Ans (a) bee hive (bee stomach) (b) Hard work is key of success.
4. How can food problem be solved? Give two ways.
Ans: Food problems be solved by (i) Avoid wastage of food (ii) Using modern technology
and best practices in agriculture
5. How are scavengers and decomposers useful to us ?
Ans: scavengers and decomposers feed on dead plants and animal. In this way they
decompose waste and keep our environment clean and enrich nutrients in soil.
6. What Is food chain? Give one example.
Ans: One who eats what in the environment is called food chain. Eg. Grass -> Zebra-
F. Long Answer questions:
1. How will you sprout seeds?
Ans: At first wash the seeds in water, drain the water. Keep seeds in bowl and cover it
with a wet cloth and leave them for another day. The next day, you will see the seeds have sprouted.
2. Distinguish between (a) herbivores and carnivores (b) scavengers and decomposers
Ans: (a) Animals which eat only plants or plant products are called herbivores eg cow,
goat. Animals which eat flesh of other animals are called carnivores eg lion, Tiger.
(b) An animal that feeds on dead organisms or by hunting live prey is called scavengers.
Eg. Vultures, hyenas, and wolves . They help break down or reduce organic material into
smaller pieces. These smaller pieces are then eaten by other organism called
decomposers eg, earthworm, fungi, bacteria.
HOTS (Higher Order Thinking Skills) questions:
1.Your mother makes food In the kitchen. Is she a 'producer'? Why/Why not?
Ans: No. My mother is not a producer as she uses ingredients obtain from plants
Solve the following crossword puzzle:
1. animals that eat both plants and flesh of other animals
2. Rearing of honeybees on a large scale is called
3. the materials needed to prepare food items
4. a tasty and nutritious food item we get from honeybees
5. the parts of the plant which can be eaten are called parts
Ans: edible part
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