IMPROVEMENT
IN FOOD RESOURCES
NCERT TEXTBOOK QUESTIONS
Q.1.
What do we get from cereals, pulses, fruits and vegetables?
Answer:
The
cereals (i.e.,
wheat,
rice, maize, millets and sorghum) provide us carbohydrates. The
pulses (i.e.,
gram,
pea, black gram, green gram, pigeon pea, lentil, etc.) give us
protein. Fruits and vegetables give us carbohydrates, proteins, fat,
vitamins, minerals, and lots of fibers.
Q.2.
How do biotic and abiotic factors affect crop production?
Answer:
Crop
production can go down due to biotic
(diseases due
to infection by viruses or fungi, insects and nematodes) and abiotic
(drought,
salinity, water logging, heat, cold and frost) stresses
under
different situations.
Q.3.
What are the desirable agronomic characteristics for crop
improvement?
Answer:
If
we develop those varieties of crops which contain desired agronomic
traits (e.g.,high
yield, dwarfness, early maturing, etc.) then it will help in setting
higher production. Thus, tallness and profuse branching are desirable
characters for fodder crops. Dwarfness is desired in cereals, so that
less nutrients are consumed by these crops. Dwarf varieties of
cereals also provide protection from lodging.
Q.4.
What are the macronutrients and why are they called macronutrients?
Answer:
The
macronutrients are nitrogen, phosphorus, potassium, calcium,
magnesium and sulphur. They are called macronutrients because they
are required by crop plants in large amounts.
Q.5.
How do plants get nutrients?
Answer:
There
are three
different
sources from where a plant gets the 16 essential nutrients: air,
water and soil. The nutrients taken from air and water are carbon,
oxygen and hydrogen and these are taken by stomata (of leaf),
lenticel (of stem) and root-hairs (of roots). Rest 13 nutrients are
obtained from soil. These 13 nutrients remain dissolved in water in
the soil and are absorbed by the plant roots.
Q.6.
Compare the use of manure and fertilizers in maintaining soil
fertility.
Answer:
Manure
contains many organic substances of biological origin which can be
easily degraded and absorbed by plants. It helps in recycling of
biological waste. Manures increase the fertility of soil for long
duration without causing any harm. However, the chemical fertilizers
(e.g.,
urea)
improve soil fertility for short duration but cause environmental
hazard. Continuous use of fertilizers in a particular area/crop field
causes destruction of soil fertility.
Q.7.
Which of the following conditions will give most benefits? Why?
(a)
Farmers use high quality seeds, do not adopt irrigation or use
fertilizers.
(b)
Farmers use ordinary seeds, adopt irrigation or use fertilizers.
(c)
Farmers use quality seeds, adopt irrigation, use fertilizers and use
crop protection measures?
Answer:
The
conditions of (c)
will give the most benefits because all these conditions are required
for good crop production. High quality seeds germinate properly and
grow to healthy plants. Irrigation helps crop plants to fight against
draught stress. Fertilizers provide desired nutrients and crop
protection measures (e.g.,
use
of pesticides, etc.) protect the crop plants from diseases, weeds and
pests.
Q.8.
Why should preventive measures and biological control methods be
preferred for protecting crops?
Answer:
Preventive
measures (such as use of resistant varieties of crops) and biological
control methods should be preferred for protection of crops because
they are ecologically safe, target specific and harmless to other
life forms.
Q.9.
What factors may be responsible for losses of grains during storage?
Answer:
There
are two
main
factors responsible for lose during storage.
A.
Biotic factors include:
1.
Insects, e.g.,
grubs
of pulse beetle; grubs and adults of rice weevil; wheat weevil;
catterpillar of grain and flour moth; larvae and adult of rust red
flour beetle; larvae of rice moth and grubs and adults of lesser
grain borer.
2.
Rodents, e.g.,
striped
squirrel, house rat, house mouse, lesser bandicoot rat, etc.
3.
Birds, e.g.,
parakeet,
sparrow, bulbul, blue rock pigeon, crow, etc.
4.
Mites; 5. Fungi; and 6. Bacteria.
B.
Abiotic factors. They
include moisture, temperature and other non-living environmental
factors.
Q.10.
Which method is commonly used for improving cattle breeds and why?
Answer:
The
milk production of cattle can be increased by the technique of
selective breeding. This is done by cross breeding between a local
breed (indigenous breed, e.g.,
Red
Sindhi, Sahiwal) cow and an exotic (foreign breed, e.g.,
Brown
Swiss) bull. The local cow is selected for the character of disease
resistance. The exotic breed of bull is selected for the character of
prolonged period of lactation and high yield of milk. The breeding
may be done by natural methods or by artificial insemination (i.e.,
injecting
the semen obtained from the desired bull into reproductive tract
(vagina) of the cow during fertility period). The desired characters
are thus obtained in the next generation.
Q.11.
Discuss the implication of the following statement:
“It
is interesting to note that poultry is India’s most efficient
converter of low fiber food stuff (which is unfit for human
consumption) into highly nutritious animal protein food”.
Answer:
Poultry
birds utilise such agricultural products which are unfit for human
consumption. In return, they give us eggs and high quality meat which
serve as a cheap source of animal protein.
Q.12.
What management practice are common in dairy and poultry farming?
Answer:
In
both dairy and poultry farming, there are: (i)
Maintenance of temperature; (ii)
Proper housing facilities having hygienic conditions; (iii)
Proper feeding; and (iv)
Prevention and control of diseases and pests.
Q.13.
What are the differences between broilers and layer and in their
management?
Answer:
Broilers
are reared for meat production and layer is for egg production.
Therefore, their management, feed and shelter should be properly
planned. The layer should produce more number of large sized eggs
without growing too much and broiler should be allowed to grow well
so that they are able to yield more meat.
The
nutritional and housing requirement for broilers and layers are
different as serve different purpose.
Broilers
are fed with vitamin (especially vitamin A and K) rich supplementary
diet for better growth and feed efficiency. The breeder should take
care of broilers; they should maintain feathering and carcass quality
of broilers.
The
layers have two different phases in their life: the growing period
and laying period. During the growth period they should be given
enough space without overcrowding. Feed is given in restricted
manner. During the egg laying period they should be given enough
space and proper lighting. Feed rich in vitamins, minerals and
micronutrients help in hatching and determining the quality of eggs.
Q.14.
How are fish obtained?
Answer:
There
are two methods of obtaining fish. One method is capture
fishing in
which the fish are obtained from natural resources such as fresh
water resources (i.e.,
canals,
pools, reservoirs and rivers), brackish water resources (i.e.,
estuaries
and lagoons) and marine fishery resources (i.e.,
coastline
and deep seas). The other method is by fish
farming (or
culture
farming), which
is concerned with culturing, feeding, breeding and fish production.
Fish farming is based on aquaculture
which
pertains to production of useful aquatic plants and animals such as
fishes, prawns, crayfish, lobsters, crabs, shrimps, mussels, oysters
and seaweeds by proper utilisation of available waters in the
country. Aquaculture includes mariculture and freshwater culture
fisheries.
Q.15.
What are the advantages of composite fish culture?
Answer:
Composite
fish culture is also called polyculture
of fishes. It
is advantageous, economical and profitable from business point of
view. It yields about 8-9 times more production as compared to
monoculture.
In
composite fish culture, 5 or 6 speciess of fast growing fish are
cultured in single fish pond which do not compete with each other for
space and nutrition. They live in distinct zones inside the pond and
have distinct feeding habits. For example, a highly yielding Indian
fish pond may contain following six species of fishes: 1. Silver carp
which is a surface feeder and feeds on phytoplankton; 2. Catla which
is also a surface feeder but it feeds on zooplankton; 3. Rohu which
is column feeder and it feeds on detritus; 4. Grass carp which feeds
on aquatic plants (including weeds); 5. Mrigal which is a bottom
feeder and it feeds on detritus; and 6. Common carp which is
omnivorous bottom feeder.
Q.16.
What are the desirable characters of bee varieties suitable for honey
production?
Answer:
The
desirable characters of bee varieties suitable for honey production
are: 1. They sting less. 2. They stay for longer periods in a given
bee hive. 3. They breed well. 4. They produce comparatively more
honey and wax.
Q.17.
What is pasturage and how is it related to honey production?
Answer:
Pasturage
is the availability of flowers for nectar and pollen collection for
the honeybee. The quality and taste of the honey is determined by the
kind and quantity of pasturage.
NCERT
EXERCISE
Q.1.
Explain any one method of crop production which ensures high yields.
AnsWER:
There
are a number of methods can be used to improve crop production such
as crop rotation, intercropping, mixed cropping, improving genetic
variety and more.
Crop
rotation is one such method that can help in increasing crop
production. Crop rotation is growing of different crops on a piece of
land in a pre-planned succession. Examples: cereals are grown
alternating with legumes. By crop rotation farmers can keep their
fields under continuous production, without the need to let them lay
fallow. It reduces the need for artificial fertilisers which are
expensive. Rotating crops adds nutrients to the soil.
Q.2.
Why are manures and fertilizers used in fields?
Answer:
Manure
and fertilizers are added to the soil of crop field to increase the
fertility of soil and productivity of crop. They overcome the
deficiency of nutrients in the soil of the field.
Q.3.
What are the advantage of inter-cropping and crop-rotation?
Answer:
Advantages of intercropping are as follows:
1.
More crops and yield can be obtained per unit area than single
cropping.
2.
Helps in maintaining the soil fertility.
3.
Helps in controlling unwanted pathogens and weeds.
4.
Efficient utilization of resources is there.
Advantages
of crop rotation are as follows:
1.
It helps in increasing the crop yield.
2.
It increases and maintains soil fertility.
3.
Farmer can grow more than one crop on same field in a year.
4.
It helps in controlling pathogens.
Q.4.
What is genetic manipulation? How is it useful in agriculture
practices?
Answer:
Genetic
manipulation refers to changing or introducing desired traits in
plants with help of hybridization, polyploidy, genetic engineering,
recombinant DNA technology etc. It is useful in agricultural
practices it helps us to produce crops of desired traits.
Q.5.
How do storage grain losses occur?
Answer:
Storage losses of the grains occur due to various factors such as:
•
The
various biotic factors that cause damage of crops such as insects,
rodents, fungi, mites and bacteria.
• The
abiotic factors that contribute to spoilage of grains which include
moisture, temperature of the storage area.
Q.6.
How do good animal husbandry practices benefit farmers?
Answer:
Good animal husbandry practices benefits farmers in following ways:
•
It
helps in increasing yield of milk or other products such as meat,
eggs.
•
It
helps in improving the breed of domesticated animals.
•
It
helps in proper management of farm animals thus yielding yields and
profits for farmers.
Q.7.
What are the benefits of cattle farming?
Answer:
The benefits of cattle farming are as follows:
•
Farmers
can have added income from cattle farming
•
Production
of milk is increased
•
Better
management of agricultural waste
•
Bulls
can be used as draught animals
Q.8.
For increasing production, what is common in poultry, fisheries and
bee-keeping?
Answer:
Variety
improvement, housing, rearing, sanitation, disease control and
marketing.
Q.9.
How do you differentiate between capture fishing, mariculture and
aquaculture?
Answer:
In
following table a comparison has been made between capture fishing,
mariculture and aquaculture.
Questions
Based on NCERT Question Bank (Exemplar Problems in Science)
Q.1.
Fill in the blanks
(a)
............. are rich in vitamins.
(b)
The crops which are grown in rainy season are called .............
crops.
(c)
............. crop grows in winter season.
(d)
Pigeon pea is a good source of .............
(e)
Berseem is an important ............. crop.
Answer:
(a)
Vegetables; (b)
Kharif; (c)
Rabi; (d)
Protein; (e)
Fodder.
Q.2.
Match the items of column A with those of column B.
Answer:
a
–
ii;
b
–
iii;
c
–
iv;
d
–
i.
Q.3.
What is GM crop? Name any one crop which is grown in India.
Answer:
GM
or genetically modified crop is the one which has been developed
through introduction of some specific genes from other sources, e.g.,
insect resistant Bt cotton (being grown in India), vitamin A rich
Golden rice.
Q.4.
List out some useful traits in improved crop?
Answer:
(i)
Higher yield; (ii)
Improved quality; (iii)
Resistance to biotic and abiotic stresses; (iv)
Change in maturity; (v)
Wider adaptability; (vi)
Desirable agronomic trait.
Q.5.
Why is organic matter important for crop production?
Answer:
Organic
matter forms humus.
It
is essential for crop production because it makes the soil fertile.
Organic matter has the following advantages:
(i)
It improves soil structure by forming soil crumbs.
(ii)
It increases water holding capacity of sandy soils.
(iii)
It improves aeration of clayey soils.
(iv)
During its decomposition, it liberates minerals (inorganic molecules)
which enrich the soil.
(v)
Biochemicals present in decaying organic matter improve growth of
crop plants.
Q.6.
Why is use of excess fertilizer deterimental for environment?
Answer:
Use
of excess fertilizers tend to cause:
(i)
Mineral loading of underground water.
(ii)
Excess minerals in the crop plants.
(iii)
Salinization of soil.
(iv)
Run off from fertilizers rich soil, will cause eutrophication of
water bodies.
Q.7.
Give one word for the following:
(a)
Farming without the use of chemicals as fertilizers, herbicides and
pesticides is known as .....................
(b)
Growing of wheat and groundnut on the same field in called
................
(c)
Planting of soyabean and maize in alternate rows in the same field is
called ..............
(d)
Growing different crops on a place on a piece of land in preplanned
succession is known as.
(e)
Xanthium
and
Parthenium
are
commonly known as .................
(f)
Causal organism of any disease is called as ....................
Answer:
(a)
Organic
farming; (b)
Mixed cropping; (c)
Inter-cropping; (d)
Crop rotation; (e)
Weeds;(f)
Pathogen.
Q.8.
Match column A and column B
Answer:
a
–
i;
b
–
iv;
c
–
iii;
d
–
v;
e –
ii.
Q.9.
If there is low rainfall in a village throughout the year, what
measures will you suggest to the farmers for better cropping.
Answer:
(i)
Reduce tilling; (ii)
Enrich soil with humus which increases its water holding capacity;
(iii)
Use of drought resistant and early maturing varieties of crop.
Q.10.
Group the following and tabulate them as energy yielding, protein
yielding, oil yielding and fodder crop:
Wheat,
Rice, Berseem, Maize, Gram, Oat, Pigeon gram, Sudan grass, Lentil,
Soybean, Groundnut,
Castor and Mustard.
Answer:
(i)
Energy yielding crop: Wheat, Rice, Maize, Oat.
(ii)
Protein yielding crop: Gram, Pigeon gram, Lentil, Sudan grass.
(iii)
Oil yielding crop: Groundnut, Castor, Mustard, Soybean.
(iv)
Fodder crop: Berseem, Oat, Sudan grass.
Q.11.
Define the terms hybridization and photoperiod.
Answer:
Hybridisation. It
is crossing of two (or more) types of individuals with different
useful traits in order to bring them together in the progeny.
Photoperiod.
It
is duration of day light that influences plants and other organisms
in their growth, reproduction and maturation.
Q.12.
Fill in the blanks:
(a)
Photoperiod affect the ..................... .
(b)
Kharif crops are cultivated from ..................... to
..................... .
(c)
Rabi crops are cultivated from ..................... to
..................... .
(d)
Paddy, Maize, Green Gram and Black gram are .....................
crops.
(e)
Wheat, Gram, Pea and Mustard are ..................... crops.
Answer:
(a)
Flowering
(of plants); (b)
June, October; (c)
November, April; (d)
Kharif; (e)
Rabi.
Q.13.
Cultivation practices and crop yield are related to environmental
conditions. Explain.
Answer:
All
crops do not grow under similar conditions. Some require high
temperature, some low temperature, longer duration of sunlight,
shorter duration of sunlight, more humidity , low humidity, moderate
humidity, loam soil, sandy soil, etc. Apple cannot be grown in plains
because it requires several days of low temperature. In plains, there
are two major seasons of crop plants: kharif (rainy season) and rabi
(winter season).
Q.14.
Fill in the blanks:
(a)
A total of ...................... nutrients are essential to plants.
(b)
..................... and ..................... are supplied by air
to plants.
(c)
..................... is supplied by water to plants.
(d)
Soil supplies ..................... nutrients to plants.
(e)
..................... nutrients are required in large quantity and
called as ..................... .
(f)
..................... nutrients are needed in small quantity for
plants and are called .............. .
Answer:
(a)
16;
(b)
carbon, oxygen; (c)
Hydrogen; (d)
13; (e)
Six, macronutrients;(f)
Seven, micronutrients.
Q.15.
Differentiate between compost and vermicompost.
Q.16.
Arrange these statements in correct sequence of preparation of green
manure:
(a)
Green plants are decomposed in soil
(b)
Green plants are cultivated for preparing manure or crop plants are
used.
(c)
plants are ploughed and mixed in soil
(d)
After decomposition, it becomes green manure.
Answer:
(b)
→ (c)
→ (a)
→ (d).
Q.17.
An Italian variety Apis mellifera has been introduced in India for
honey production. Write about its merits over other varieties.
Answer:
An
Italian bee variety, Apis
mellifera,
is commonly used for commercial honey production. Bees of this
species are known for high amount of honey collection and are
non-defensive in nature.
Q.18.
In agriculture practices, higher input gives higher yield. Discuss
how?
Answer:
In
agriculture, higher yield can be obtained only by applying higher
yielding varieties, improved farming practices, modern technology,
latest agricultural machines and implements, nutrient supply, etc.
All these require high cost and knowledge of new techniques and
improvements. Therefore, a farmer’s purchasing capacity for inputs
determines the cropping system and production exercises.
Q.19.
Discuss the role of hybridisation in crop improvement.
Answer:
Hybridisation
helps in improvement of crops as we obtain crops with desired traits
or qualities through this process. The technique of hybridisation
involves introduction of characters of two desirable species into a
single offspring by means of artificial pollination. Hybridisation
can be of intergeneric and interspecific. This technique can help in
increasing crop production by introducing desired characters like
diseases resistance, high yielding varieties etc.
Q.20.
Define (i) Vermicompost; (ii) Green Manure; (iii) Biofertilizers.
(i)
Vermicompost: It
is a manure rich pulverised organic matter and worm castings.
Vermicompost is formed by the activity of earth worms on organic
remains.
(ii)
Green Manure: Green
undecomposed plant material used as manure is called green manure. It
is obtained by growing green manure crops or by collecting green
leaves from plants grown in fields, forests or wastelands. A green
manure crop can be cut and then ploughed into the soil or left in the
ground until the tilling of fields take place. The plants used as
green manure are called green manure plants. Examples: mostly mixture
of grasses and legume plants are used as green plants. Green manuring
helps in improving the soil structure and increases water holding
capacity.
(iii)
Biofertilizers: Biofertilizers
are the organisms that are used to improve the nutrient quality of
soil. Most commonly used biofertilizers are bacteria, fungi, and
cynobacteria (blue-green algae). Many plants have symbiotic
association with microorganisms. They are mutually benefitted from
each other. Eg: Legumes have symbiotic association with bacterium
Rhizobium. This bacteria helps in nitrogen fixation and in turn
bacteria derives food and gets shelter in the root nodules.
Q.21.
Discuss various methods of weed control.
Answer:
Various methods of weed control are as follows:
(a)
Weeds can be controlled by using weedicides and herbicides
(b)
By manually pulling out the weeds
Q.22.
Differentiate between the following.
(i)
Mixed cropping and Inter cropping
(ii)
Capture fishery and Culture fishery
(iii)
Bee keeping and Poultry farming
Answer:
(i)
Difference between Mixed cropping and Inter cropping
Q.23.
Give merits and demerits of fish culture.
Answer:
Merits.
1.
Economically important desired fishes are made available.
2.
A large number of fishes are raised in a small area.
3.
Fishes are made to breed in different seasons.
4.
There is a little mortality in the younger stages of the fishes.
5.
Through selective hybridisation, yield and quality of fishes are
improved.
Demerits.
1.
Only some selected high yielding and economically important breeds
are reared.
2.
Fish culture is a threat to biodiversity, since other forms of
aquatic organisms are being ignored. Even natural waters are being
seeded with economically important fishes; this too is affecting the
natural biodiversity of the water bodies.
Q.24.
What do you understand by composite fish culture?
Answer:
In
this technique more than one type of compatible fishes are cultured
simultaneous. This technique enables to get maximum fish production
from a pond or a tank through utilization of available fish food
organisms in all the natural habitat along with the artificial
feeding system.
Q.25.
Why bee keeping should be done in good pasturage?
Answer:
Bee
keeping should be done in good pasturage because as the quality and
the quantity of the honey depends on the flora of the pasturage
available for nectar and pollen collection. The pasturage should be
available.
Q.26.
Write the modes by which insects affect the crop yield.
Answer:
Insects
can cause damage to crops in a number of ways. Some insects might eat
the fruit of the crops, some insect suck sap from the stem while some
insects damage the plant parts inhibiting the growth.
Q.27.
Discuss why the pesticides are used in very accurate concentration
and at very appropriate time.
Answer:
Pesticides
are very toxic substances, they should not be used indiscriminately.
Only very accurate dose should be applied at appropriate time. Even
slight excess of the pesticides is extremely harmful.
(i)
Pesticides are harmful to soil biota. Therefore, they reduce soil
fertility.
(ii)
They pass into ground water and make it toxic.
(iii)
They enter the crop plants and make their products (leaves, stem,
flowers, fruits and seeds) toxic.
(iv)
Pesticides pass into surface water through run off form sprayed
fields and harm the aquatic biota.
Q.28.
Name two types of animal feed and write their functions.
Answer:
Two
types of animal feeds are:
Roughage:
This diet is rich in fibre. It mainly consist of silage, green
fodder, hay and legumes.
Concentrate:
The concentrate used in diet of animals are the feeds which contain
less than 18 percent crude fibre and more than 60 percent total
digestible nutrients. They are less bulky and have higher
digestibility. They have high nutritive value.
Q.29.
What would happen if poultry birds are larger in size and have no
summer adaptation capacity? In order to get small sized poultry birds
having summer adaptability, what methods will be employed?
Answer:
Larger
sized birds require more feed. Summer adaptation is connected with
egg laying. Little summer adaptation reduces egg laying. In order to
get small sized poultry birds having summer adaptability, it is
desirable to (i)
Either introduce the required exotic birds from outside and (ii)
Cross breed the local birds with exotic birds from outside. Small
sized poultry birds are preferred for (a)
Lower requirement of feed; (b)
Higher egg laying capacity; (c)
Lower requirement for space.
Q.30.
Suggest some preventive measures of the diseases of poultry birds.
Answer:
Some preventive measure of diseases of poultry birds are:
(a)
The birds should be kept in ample space.
(b)
The cages should be kept clean.
(c)
Different types of birds should not be kept together.
(d)
The young and old birds should be kept separately.
Q.31.
The figure shows two crop fields (plots A and B) have been treated by
manures and chemical fertilizers, respectively, keeping other
environmental factors same. Observe the graph and answer the
following questions:
(i)
Why does plot B shows sudden increase and then gradual decrease in
yield?
(ii)
Why is the highest peak in plot A graph slightly delayed?
(iii)
What is the reason for the different pattern of the two graphs.
Answer:
(i)
Sudden
increase. Chemical
fertilizer supplies the minerals immediately in good quantity.
Gradual
decrease. It
is due to depletion of nutrients caused by absorption by plants,
leaching to lower layer of the soil and killing of decomposer
microorganisms.
(ii)
Manures decompose slowly so that release of minerals is also delayed.
Manures take time to mix up with the soil and form crumbs, that
increase water holding and aeration of the soil.
(iii)
The difference in the two graphs indicates that manuring the soil of
crop fields is more beneficial than the use of chemical fertilizers.
Rather, use of chemical fertilizers is harmful in the longer run.
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