NCERT Exemplar Class 9 Science Solutions Chapter 15 Improvement in Food Resources

NCERT Exemplar Class 9 Science Solutions Chapter 15-MCQ

Question:1

Which one is an oil yielding plant among the following?
(a) Lentil
(b) Sunflower
(c) Cauliflower
(d) Hibiscus
Answer: B
Generally, oils are extracted from seeds or other parts of fruits and flowers.
These oils are mostly used for cooking purposes.
Coconut oil, olive oil, palm oil, sunflower oil, soyabean oil, mustard oil etc are examples of vegetable oils we get from plants. Lentils and cauliflower are not used to extract any oil.
Oil can be extracted from Hibiscus, but it is less used therefore the best option will be sunflower.
Hence, the correct option is B.

Question:2

Which one is not a source of carbohydrate?
(a) Rice
(b) Millets
(c) Sorghum
(d) Gram
Answer: D
We get many nutrients of different types from different plants. These nutrients can be protein, vitamins, minerals, fats, and carbohydrates et cetera.
Generally, cereals are good source of carbohydrates as rice millets and sorghum.
We get carbohydrates from grams, but they are also a main source of proteins.
Therefore, the correct option of this question will be option D

Question:3

Find out the wrong statement from the following
(a) White revolution is meant for increase in milk production
(b) Blue revolution is meant for increase in fish production
(c) Increasing food production without compromising with environmental quality is called as sustainable agriculture
(d) None of the above
Answer: D
Dr Verghese Kurien launched the white revolution in 1970. This is also known as flood revolution. This revolution intended to grow the milk production and dairy farming by using modern techniques.
In 1960, to increase the utilisation of water and benefit of fishermen or fisher farmers, this revolution was initiated. This is known as blue revolution.
Sustainable agriculture is defined as increasing food production without compromising with environmental quality. It can be achieved by techniques like crop rotation, cover crops, soil enrichment Permaculture et cetera.
Hence, the correct option is D.

Question:4

To solve the food problem of the country, which among the following is necessary?
(a) Increased production and storage of food grains
(b) Easy access of people to the food grain
(c) People should have money to purchase the grains
(d) All of the above
Answer: D
As the population is growing rapidly, we require more food to feed the population. Agricultural scientists are looking for different methods to increase the food production over several years. For better farming scientists thought of increasing production and storage of food grains and proper distribution of these food grains to the general people. Government supports financially and technically to former for buying food grains and using effective methods informing.
Hence, the correct option is D.

Question:5

Find out the correct sentence

1. Hybridisation means crossing between genetically dissimilar plants

2. Cross between two varieties is called as inter specific hybridisation

3. Introducing genes of desired character into a plant gives genetically modified crop

4. Cross between plants of two species is called as inter varietal hybridisation

(a) (i) and (iii)
(b) (ii) and (iv)
(c) (ii) and (iii)
(d) (iii) and (iv)

Answer: A
For having good qualities of different plants, the process of crossing between genetically dissimilar plants are used and this process is called hybridisation. There are multiple type of hybridisation and they are developed for different needs.

• If this crossing is done between different varieties, it is called Intervarietal hybridisation.

• If the crossing is done between different genes, then it is called inter- generic hybridisation.

• If crossing is done between different species of same gene it is called inter-specific hybridisation.

• In genetically modified crops we tried to introduce genes of the desired character into any plant.

Hence, the correct option is A.

Question:6

Weeds affect the crop plants by
(a) killing of plants in field before they grow
(b) dominating the plants to grow
(c) competing for various resources of crops (plants) causing low availability of nutrients
(d) all of the above
Answer: D
In the cultivated field of farms some undesired plants species grow along with desired crops. These, undesired plants are called weeds.
These weeds start use resources like space, water, light, and nutrients of the crops.
The weeds suppress the growth of crops by causing low availability of nutrients.
Enormous growth of weeds could kill the plants in the field before they grow.
Hence, the correct option is D.

Question:7

Which one of the following species of honeybee is an Italian species?
(a) Apis dorsata
(b) Apis florae
(c) Apis cerana indica
(d) Apis mellifera
Answer: D
Honeybee is a special kind of fly and its genus name is Apis. Almost 20,000 species of Honeybee are recorded.
Apis florea is a small honeybee of south east Asia.
Apis dorsata is a large honeybee of south east Asia.
Apis cerena is an Indian domestic honeybee.
Apis melifera is the most common honeybee which is domesticated. It is also known as Italian bee.
Hence, the correct option is D.

Question:8

Find out the correct sentence about manure
(i) Manure contains large quantities of organic matter and small quantities of nutrients.
(ii) It increases the water holding capacity of sandy soil.
(iii) It helps in draining out of excess of water from clayey soil.
(iv) Its excessive use pollutes environment because it is made of animal excretory waste.
(a) (i) and (iii)
(b) (i) and (ii)
(c) (ii) and (iii)
(d) (iii) and (iv)
Answer: B
Manure is also known as fertiliser and it is used in agriculture. Animal waste, peels of vegetable and fruits are used to create manure.
Manure increases the fertility of land by giving it organic matters and nutrients to the soil. A small quantity of nutrients and large quantity of organic matter is given to the soil by manures.
Manure increases the humus level in soil which increases the water retention capacity of soil.
It is eco-friendly and saves our environment from use of chemical synthetic compounds.
Hence, the correct option is B.

Question:9

Cattle husbandry is done for the following purposes
(i) Milk Production
(ii) Agricultural work
(iii) Meat production
(iv) Egg production
(a) (i), (ii) and (iii)
(b) (ii), (iii) and (iv)
(c) (iii) and (iv)
(d) (i) and (iv)
Answer: A
The term ‘cattle’ is coined for and generally used for cows (Bos idicus), bull (Bos taurus) and buffaloes (Bos bubalis).
Animal Husbandry related to cattle is done for the below mentioned purposes:

1. Milk Production: Female cows and buffaloes (milch animals) produce milk.

2. Agricultural Work: Bull is used for ploughing the fields, transporting agricultural produce and breeding purposes.

3. Meat Production: Cattle including cow, bull and calf are commercially bred for meat production such as Beef and Veal.

Egg production is done by hen (Junglefowl) which do not fall under the category of cattle and are broadly classified under Poultry Farming.
Hence, the correct option is A.

Question:10

Which of the following are Indian cattle?
(i) Bos indicus
(ii) Bos domestica
(iii) Bos bubalis
(iv) Bos vulgaris
(a) (i) and (iii)
(b) (i) and (ii)
(c) (ii) and (iii)
(d) (iii) and (iv)
Answer: A
Bos is derived from Latin which means a cow or a bull
Bos indicus: Also termed as Zebu are domestic cattle which originates from Indian subcontinent and South Asia and are a part of Indian cattle. They are also known as humped cattle.
Bos domestica: They are the African species.
Bos bubalis: They are generally termed as wild water buffalo and are found in parts of India and Southeast Asia.
Bos vulgaris: This species is mainly found in Thailand, Nepal and Bhutan and does not belong to Indian cattle breed.
Hence, the correct option is A.

Question:11

Which of the following are exotic breeds?
(i) Brawn
(ii) Jersey
(iii) Brown Swiss
(iv) Jersey Swiss
(a) (i) and (iii)
(b) (ii) and (iii)
(c) (i) and (iv)
(d) (ii) and (iv)
Answer: B
Brawn: It is also termed as Head cheese and is basically a meat jelly made by flesh coming from the head of a pig or calf.
Jersey: This breed of cow originated from of the Channel Islands of United Kingdom called Jersey. The major usage of this breed is for dairy and draught.
Brown Swiss: This cattle breed is also termed as American Brown Swiss and it originates from United States. The major use of this breed is for dairy purposes.
Jersey Swiss: There is no breed or term as such.
Hence, the correct option is B.

Question:12

Poultry farming is undertaken to raise following
(i) Egg production
(ii) Feather production
(iii) Chicken meat
(iv) Milk production
(a) (i) and (iii)
(b) (i) and (ii)
(c) (ii) and (iii)
(d) (iii) and (iv)
Answer: A
Poultry farming is majorly used to produce eggs and Chicken meat. Although the feathers are produced by the poultry; however, they are considered to be a waste and requires proper waste management.
Poultry does not produce milk. Milk production is done by Cattle.
Hence, the correct option is A.

Question:13

Poultry fowl are susceptible to the following pathogens
(a) Viruses
(b) Bacteria
(c) Fungi
(d) All of the above
Answer: D
Poultry fowl is susceptible to variety of diseases caused by different pathogens. The different pathogens which cause these diseases are mentioned below:
Bacteria: Diseases such as Fowl Cholera, caused by Pasteurella Multocida which is a type of bacteria.
Viruses: Diseases such as Avian Influenza, caused by virus – type A Orthomyxoviruses.
Fungi: Diseases such as Aspergillosis caused by mold which is a type of fungus.
Hence, the correct answer is D.

Question:14

Which one of the following fishes is a surface feeder?
(a) Rohus
(b) Mrigals
(c) Common carps
(d) Catlas
Answer: D
Rohus: It belongs to the carp family of fish and is mostly found in South Asia. These fishes are generally large in size and are omnivores. They are column feeders, and their feeding takes place on food available in the mid column.
Mirgals: It belongs to the carp family of fish and is found in rivers of India. They come under the category of bottom feeders as the feed on vegetation(decayed) found at the bottom.
Common carps: It belongs to the carp family of fish and is mostly found in Asia and Europe. These fishes are omnivores and feed on zooplankton, insects and crustaceans found at the bottom. They are bottom feeders.
Catlas: It belongs to the carp family of fish and is found in Bangladesh, India, Pakistan and Nepal. They are surface feeders and feed on zooplankton.
Hence, the correct option is D.

Question:15

Animal husbandry is the scientific management of
(i) animal breeding
(ii) culture of animals
(iii) animal livestock
(iv) rearing of animals
(a) (i), (ii) and (iii)
(b) (ii), (iii) and (iv)
(c) (i), (ii) and (iv)
(d) (i), (iii) and (iv)

Answer:D
Animal husbandry is the scientific management of animal breeding, animal livestock and rearing of animals.
Hence, the correct answer is D.

Question:16

Which one of the following nutrients is not available in fertilizers?
(a) Nitrogen
(b) Phosphorus
(c) Iron
(d) Potassium
Answer: C
Fertilizers are the chemical substances which provide nutrients to a plant, which leads to an increase in the growth and yield of a plant or crop. They provide Potassium, Nitrogen and Phosphorus to the plant. The use of these chemical substances(fertilizers) should be kept under prescribed doses as they can lead to water pollution and soil destruction if not used properly.
Hence, the correct answer is C.

Question:17

Preventive and control measures adopted for the storage of grains include
(a) strict cleaning
(b) proper disjoining
(c) fumigation
(d) all of the above
Answer: D
The losses caused by storage of grains can turn out to be very high and cause a huge damage to the agricultural produce. When the storage spaces are not properly managed, factors such as insects, mites, fungi and bacteria can lead to weight loss of produce, declination in the quality of the produce and discolouration.
In order to prevent this the storage places should be managed by taking Preventive and control measures which include:
Strict cleaning: The produce is properly cleaned before it is moved for storage.
Proper disjoining: Different produce should be kept at separate levels from each other.
Fumigation: Chemicals are used in the storage spaces to kill the pests.
Hence, the correct answer is D.

NCERT Exemplar Class 9 Science Solutions Chapter 15-Short Answer

Question:18

Match the column A with the column B

Answer: (a)-(ii), (b)-(iii), (c)-(i), (d)-(iv)
Rohu: It belongs to the carp family of fish and is mostly found in South Asia. These fishes are generally large in size and are omnivores. They are column feeders, and their feeding takes place on food available in the mid column.
Mirgal: It belongs to the carp family of fish and is found in rivers of India. They come under the category of bottom feeders as the feed on vegetation(decayed) found at the bottom.
Catla: It belongs to the carp family of fish and is found in Bangladesh, India, Pakistan and Nepal. They are surface feeders and feed on zooplankton.
Fish farming is also termed as pisciculture which includes raising fishes for commercial purposes. A similar term for fish farming is Culture fishery where selected species of fishes are cultivated on a pond.

Question:19

Fill in the blanks
(a) Pigeon pea is a good source of______.
(b) Berseem is an important_______crop.
(c) The crops which are grown in rainy season are called_______crops.
(d) ______are rich in vitamins.
(e) ______crop grows in winter season.
Answer:

1. Pigeon pea is a good source of Protein.
Pigeon pea is a type of legume which belongs to the Fabaceae family. It is perennial in nature, so it can be grown throughout the year. It is a good source of Protein as the protein levels are high in this legume. It consists important amino acids such as lysine and methionine.
2. Berseem is an important fodder crop.
Berseem is leguminous fodder crop, which is perennial in nature, so it can be grown throughout the year. This fodder crop remains succulent and soft during all the growth stages. This fodder crop can grow in areas without irrigation and high-water table.
3. The crops which are grown in rainy season are called Kharif crops.
There are three broad classifications crop:

1. Rabi – These crops are grown in winter season and harvested in the spring season. Examples of such crop are Wheat and Barley

2. Kharif – These crops are grown in rainy season. Examples of such crop are Rice and Maize.

3. Zaid – These crops are grown in summer season. They are a filler between the Kharif, and Rabi crops Examples of such crop are Watermelon and Cucumber.

4. Vegetables are rich in vitamins.
Vegetables are one of the main sources for nutrition in our diet. They can be cooked or eaten raw. They are low in calories and fat however filling. Vegetables provide a wide range of vitamins in our diet. Examples for such cases are Vitamin A, K and B6.
5. Rabi crop grows in winter season.
Rabi crops are grown in winter season and harvested in the spring season. Examples of such crop are Wheat and Barley.

Question:20

What is a GM crop? Name any one such crop which is grown in India.
Answer:
GM crop is the abbreviation for the Genetically modified crop. In such plants, their DNA is modified by genetic engineering. This is mainly done to modify the existing species of a plant in order to make them resistant towards pests and diseases, improved nutrient efficiency.
Example of such crop grown in India is Bt Cotton (Bacillus thuringiensis). It is the only approved GM crop in India. Bt cotton is the modified version of cotton which is specifically designed to fight against the bollworm.

Question:21

List out some useful traits in improved crop?
Answer:
The traits in an improved crop are mentioned below:
1.Higher yield: The improved crops provide a higher yield per acre.
2.Improved quality: The crop quality of a produce holds a significant use. Every crop based on its quality is utilised in our everyday meal. Improved crop can provide better quality of the produce. The examples of improved quality crop are wheat with high baking quality, high quality of oil in oilseeds, high quality of protein in pulses.
3.Biotic and abiotic resistance: Improved crops are more resistant towards biotic stresses such as insects, diseases and nematodes. They also hold a higher resistance towards abiotic stresses such as water logging, salinity and drought.
4.Change in maturity duration: Improved crops have a shorter duration of maturity i.e., the duration in which a particular crop is grown and harvested. In case of improved crops this duration is short which turns out to be economical for the farmers and provide them with the opportunity to grow more crops each year.
5. Wider adaptability: Improved crops are highly adaptable towards different environmental conditions such as climate, soil, ground water and surface water. It provides the farmer to grow a wide variety of crops during different seasons and conditions throughout the year.
6. Desirable agronomic characteristics: Improved crops provide appropriate desired conditions such as tallness and dwarfness of crops required for higher productivity. Examples of such desired characteristics are tallness for fodder crops like Berseem, dwarfness for cereals (so they consume less nutrients).

Question:22

Why is organic matter important for crop production?
Answer:
Organic matter consists of animals and plant remains which have gone through decomposition. This also includes the waste product produced by the animals and plants. When these remains and waste go through decomposition, they provide large amounts of nutrition to the living organisms in the soil and enriches it.
Organic matter is extremely important for crop production as it provides nutrients to the soil, binds the soil particles, and enhances the capacity of soil to hold the water. This provides a sustainable environment for crop production.
Generally, the soils consist between 2%-10% of organic matter.

Question:23

Why is excess use of fertilizers detrimental for the environment?
Answer:
Fertilizers are the chemical substances which provide nutrients to a plant, which leads to an increase in the growth and yield of a plant or crop. They provide Potassium, Nitrogen and Phosphorus to the plant. The use of these chemical substances(fertilizers) should be kept under prescribed doses as they can lead to water pollution and soil destruction if not used properly.
Excessive use of fertilizers leads to destruction of the soil fertility as the fertilizers prevent the replenishment of organic matter along with harmful effects on micro-organisms present in the soil. The excess fertilizers which are washed during irrigation gets mixed into the water streams and lead to water pollution. Hence, excessive use of fertilizers is detrimental for the environment.

Question:24

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 is called as ———.
(c) Planting soyabean and maize in alternate rows in the same field is called as ———.
(d) Growing different crops on a piece of land in pre-planned succession is known as———.
(e) Xanthium and Parthenium are commonly known as———.
(f) Causal organism of any disease is called as ———.
Answer:
(a) Farming without the use of chemicals as fertilizers, herbicides and pesticides is known as organic farming.
Organic farming is a type of farming in which the use of chemicals is minimum to nil. The majority of nutrients to the crop and soil are provided by manure and farm wastes.
(b) Growing of wheat and groundnut on the same field is called as mixed cropping.
Mixed cropping is defined as cultivating two or more crops simultaneously on same land.
Examples for such cropping are wheat and gram, wheat and groundnut.
(c) Planting soyabean and maize in alternate rows in the same field is called as intercropping.
Intercropping is a type of cropping in which two or more crops are grown simultaneously on same land but in a definite pattern. Examples for such cropping are soybean and maize, bajra and lobia.
(d) Growing different crops on a piece of land in pre-planned succession is known as crop rotation.
Crop rotation is the process in which different crops are grown on a land based on a specific sequence.
(e) Xanthium and Parthenium are commonly known as weeds.
In the cultivated field of farms some undesired plants species grow along with desired crops. These, undesired plants are called weeds
(f) Causal organism of any disease is called as pathogen.
Pathogens are also known as infectious agents which causes diseases. The prominent types are virus, bacteria, fungi, single celled and multi-celled organisms.

Question:25

Match the following A and B
(A) (B)
(a) Cattle used for tilling and carting (i) Milk producing female
(b) Indian breed of chicken (ii) Broiler
(c) Sahiwal, Red Sindhi (iii) Draught animals
(d) Milch (iv) Local breed of cattle
(e) Chicken better fed for obtaining (v) Aseel
meat
Answer:
(a)- (iii):
Draught animals are also termed as working animals which include domesticated ox and bull. These types of cattle are used for laborious tasks on the farm such as tilling and carting.
(b)-(v):
Aseel chicken is the breed which originates in Indian subcontinent.
(c)-(iv):
Sahiwal is of Zebu breed and originated in Sahiwal (Region of Punjab before the division of India and Pakistan). These are majorly used for dairy purposes.
Red Sindhi is also of Zebu breed and originated in Sindh region of Pakistan. They are amongst the most popular dairy breeds across India, Bangladesh and Pakistan.
(d)-(i):
Bos indicus(cows) which are milk-producing are termed as Milch.
(e)-(ii):
Chickens which are fed with the supplement feeds rich in vitamin to increase the growth rate and feed efficiency for the purpose of obtaining meat are termed as Broilers.

Question:26

If there is low rainfall in a village throughout the year, what measures will you suggest to the farmers for better cropping?
Answer:
Low rainfall in a village throughout the year can cause drastic outcomes for farmers and can lead to crop destruction.
The measures farmers can take are:
1. Creating water catchment areas in the farms, so during the rainfall, farmers will be able to hold the water.
2. Using drought-resistant crops such as Pearl millets, chickpea and dryland cereals, so that the crop cycle does not get affected.
3. Use of manure and organic matter to increase the capacity of soil to hold the water for prolonged duration.
4. Use of improved crops with higher adaptability to the environment.

Question:27

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 :

Question:28

Define the term hybridization and photoperiod.
Answer:
Hybridization:
It is the process in which two genetically dissimilar plants are crossbreed in order to receive a resultant third variety of plant with unique traits than the two using for cross breeding. The plants belonging to same species are easier to cross breed and produce a hybrid of higher fertility. Examples of such hybridization are cross breeding two varieties of rice to produce a hybrid rice breed.
Photoperiod:
The growth of plants is dependent on sunlight. The plants use sunlight to produce their food using photosynthesis. Photoperiod is basically the duration or period of sunlight every day. The changes in photoperiod plays a significant role in a plant’s growth.

Question:29

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, mustard are————crops.
Answer :
a. Photoperiod affect the flowering process.
b. Kharif crops are cultivated from June to October.
c. Rabi crops are cultivated from November to April.
d. Paddy, maize, green gram and black gram are Kharif crops.
e. Wheat, gram, pea, mustard are Rabi crops.

Question:30

Cultivation practices and crop yield are related to environmental condition. Explain.
Answer:
Environmental conditions such as water, photoperiod (duration of sunlight), temperature and climate play a significant role in the crop production. These conditions lead to the process of choosing different cultivation practices for different conditions. For example, Rabi crops are selected for winter seasons, as Kharif crops cannot sustain or grow in the environmental conditions of winter season.
The crop yield is affected by these environmental conditions as growth of crop and duration of the cycle totally depends on these conditions.

Question:31

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 supply———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:
Soil, water and air supply nutrients to plants. A total of sixteen nutrients are essential to plants out which Oxygen and Carbon are supplied through air, water supplies hydrogen, and the rest thirteen are supplied by soil. The nutrients supplied by soil are categorised into Macronutrients and Micronutrients based on the quantity requirements of these nutrients by plants. A total of six nutrients are required in large quantities (Macronutrients) which are nitrogen, phosphorous, potassium, calcium, magnesium and sulphur. The rest(seven) are micronutrients required in small quantities. They are iron, magnesium, boron, zinc, copper, molybdenum and chlorine
a) A total of sixteen nutrients are essential to plants.
b) Carbon and Oxygen are supplied by air to plants.
c) Hydrogen is supplied by water to plants.
d) Soil supply thirteen nutrients to plants.
e) Six nutrients are required in large quantity and called as Macronutrients.
f) Seven nutrients are needed in small quantity for plants and are called Micronutrients.

Question:32

Differentiate between compost and vermicompost?
Answer:
Compost:
It is made from the waste materials of animal excreta like cow dung, animal refuse, vegetable waste, weeds and domestic waste by the process of composting. Composting is the process in which the aforementioned waste material is decomposed by microbes in a pit. The resultant of this process is rich in nutrients and organic matter which provides the soil with necessary nourishment. This process
Vermicompost:
Vermicompost also known as vermicast is the process of decomposition in which various species of earthworms and worms are used to decompose the waste materials such as vegetable waste. The vermicompost has more nutrients in comparison to the compost. Also, this process is faster than composting.

Question:33

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 plant parts are used.
(c) Plants are ploughed and mixed into the soil.
(d) After decomposition it becomes green manure.
Answer:
(b) Green plants are cultivated for preparing manure or crop plant parts are used.
(c) Plants are ploughed and mixed into the soil.
(a) Green plants are decomposed in soil.
(d) After decomposition it becomes green manure.

Question:34

An Italian bee variety A. mellifera has been introduced in India for honey production. Write about its merits over other varieties.
Answer:
Apis melifera is the most common honeybee which is domesticated. It is also known as Italian bee. As a part of experimentation these European bees were introduced in several parts of India around 1880’s. Huge consignments arrived in India between 1920 and 1930.
The merits of A. mellifera over other varieties are:

1. High honey collection capacity.

2. These bees sting less in comparison to other bees.

3. These bees have a tendency to stay in single beehive for long durations.

4. They breed extremely well in comparison to other bees used for commercial purposes.

Question:35

In agricultural practices, higher input gives higher yield. Discuss how?
Answer:
In agricultural practices, higher input is required for a higher yield. The farmer needs to input the best quality resources such as seeds, fertilizers, manure, organic matter to the crop in order to receive higher yield per acre. This also includes the advanced machineries and technologies along with the latest farming practices. The farmer is required to input a substantial amount of finances to acquire the aforementioned products and technology which in turn leads to a higher yield of the produce.

NCERT Exemplar Class 9 Science Solutions Chapter 15-Long Answer

Question:36

Discuss the role of hybridisation in crop improvement.
Answer:
Hybridisation is the process in which two genetically dissimilar plants are cross-breed in order to receive a resultant third variety of plant with unique traits than the two used for crossbreeding. The plants belonging to the same species are easier to cross-breed and produce a hybrid of higher fertility. Examples of such hybridization are cross-breeding two varieties of rice to produce a hybrid rice breed.
There are multiple types of hybridisation and they are developed for different needs. If this crossing is done between different varieties, it is called Intervarietal hybridisation. If the crossing is done between different genes, then it is called inter- generic hybridisation. If the crossing is done between different species of the same gene it is called inter-specific hybridisation.
The useful traits of hybridisation in crop improvement are mentioned below:

1. Disease resistance: The hybrid plants are less susceptible to the diseases caused by pathogens

2. Selective breeding provides hybrid plants to grow at a faster rate leading to quick reaping periods for farmers and provide a higher yield.

3. Hybridisation can provide with less susceptible breed to certain difficult growing conditions.
4. The hybrid plant will have a better product quality leading to crop improvement.
5. Hybridisation will enhance the responses of the hybrid plant towards the fertilizers leading to crop improvement.

Question:37

Define
(i) Vermicompost
(ii) Green manure
(iii) Bio fertilizer
Answer:
1. Vermicompost:
Vermicompost also known as vermicast is the process of decomposition in which various species of earthworms and worms are used to decompose the waste materials such as vegetable waste. The vermicompost has more nutrients in comparison to the compost. Also, this process is faster than composting.
2. Green manure:
Green plants are grown on a farm and then mulched into the soil by ploughing which eventually turns into the green manure. The plants used for this purpose are also termed as Cover crops. Examples – Guar and sun hemp. The green manure helps in the enrichment of soil with phosphorus and nitrogen.
3. Biofertilizer:
The substances which consist of living micro-organisms such as blue green algae, Azotobacter, Rhizobium and Azospirilium in order to supply nutrients to the crop/plant are termed as Biofertilizers.

Question:38

Discuss various methods for weed control.
Answer:
In the cultivated field of farms some undesired plants species grow along with desired crops. These, undesired plants are called weeds. These weeds use resources like space, water, light and nutrients of the crops. The weeds suppress the growth of crops by causing low availability of nutrients. Enormous growth of weeds could kill the plants in the field before they grow.
Various methods which can be used for weed control are:

1. One of the effective ways to control weed is having a crop competition. A fast-growing crop will be extremely competitive and dominate the weed on the farm.

2. Crop rotation can provide the farmer with a balanced organic system leading to the break in cycles of weed.

3. The farmers can use high quality clean seeds to avoid the introduction of weeds on the farmland.

4. Removing the weed mechanically.

5. Proper tillage of farm leads to a better seed bed and helps in eliminating potential weed.

Question:39

Differentiate between the following
(i) Capture fishery and Culture fishery
(ii) Mixed cropping and Inter cropping
(iii) Bee keeping and Poultry farming
Answer :
(i)

(ii)

(iii)

Question:40

Give the merits and demerits of fish culture?
Answer:
Fish culture is a manmade process of raising fish in a controlled environment. The desired species of fish are raised inside man-made ponds or fish tanks. It is also termed as pisciculture.
Merits of fish culture:

1. The desired species of fish can be raised.

2. The fish yield is controllable and can be increased by implementing certain techniques and modified fish feed.

3. Provides with the fish meat at low prices. Fish meat is a good source of protein.

Demerits of fish culture:

1. It requires a significant amount of investment.

2. The fishes suffering from disease can lead to mortality of all the fishes in the tank.

3. Controlled raising of fishes can act as a threat to biodiversity.

Question:41

What do you understand by composite fish culture?
Answer:
Composite fish culture is the farming of fish in a system where a blend of 5 or 6 fish species are raised in a single pond. The selection process of these species is done on the basis of competitive attributes and feeding patterns. This selection is done to prevent any competition amongst the selected species which leads to availability of food for all the fishes.
Example: Surface feeders such as Catlas are mixed with column feeders such as Rohus, Mrigals, Grass Carp which are bottom feeders. This combination leads to an efficient utilisation of food present in the pond and enhances the yield of fish from pond.
The major problem with composite fish culture is the unavailability of quality seed. This has been resolved by the use of hormonal stimulation of fishes in the pond itself leading to a pure seed of each species in desired quantities.

Question:42

Why bee keeping should be done in good pasturage?
Answer:
The pasturage is the piece of land where the flowers are grown in order to provide bees with nectar for production of honey. The quality or value of the honey produced is dependent on the flowers in pasturage. If good variety flowers are provided to bees for nectar and pollen collection the quality of honey produced will be of higher grade. The variation in types of flowers varies the taste and quality of honey. In order to have a quality yield with varied taste of honey, farmers are required to have different flowers at the pasturage.

Question:43

Write the modes by which insects affect the crop yield.
Answer:
Crops are affected by insects in three ways:
1. Insect pests cut the parts of the plants such as root, leaf and stem affecting the plants processes such as photosynthesis leading to a decreased production of food for plant and decreased growth.
2. Insect pests attack the cell sap of a plant at various parts and feed on the nutrients of the plant resulting in poor yield of the crop.
3. Insect pests bore into fruits and stems of a plant. This leads to a decreased yield of the crop.

Question:44

Discuss why pesticides are used in very accurate concentration and in very appropriate manner?
Answer:
To counter the effect of insect pests and fungi on crop production, chemical substances known as Pesticides are used generally. The common types of pesticides include insecticides, fungicides and herbicides. They are sprayed across the crop for treating soil and seed. An accurate and prescribed concentration of these pesticides should be used on the crop and soil as excessive usage of this chemical can lead to poisoning of plants and animal in the zone. Excessive usage of pesticides leads to reduction of the organic matter. As these chemicals are poisonous, they can cause an intense environmental pollution if used in excess.

Question:45

Name two types of animal feed and write their functions.
Answer:
Dairy animals have certain food requirements which are categorised into two types:
1. Maintenance requirement: The food which is required by an animal for nutrients and balanced diet for a healthy life.
2. Milk producing requirement: The food required specifically for lactation period.
This feed includes:

1. Roughage:

They are also known as the Dietary fibre. Roughages are indigestible and coarse ingredients which provide bulky feeds in the diet of an animal. They promote regular bowel functions. The common examples of roughages in animal feed are silage, grass and hay.

2. Concentrates:

They are the mixture of protein and other nutrients concentrated at a very high level. Concentrates are low in fibre however are a significant part of the balanced diet of an animal. The common examples of concentrates in animal feed are maize, rice bran and gram husk.

Question:46

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 method will be employed?
Answer:
In case of large size poultry birds with no summer adaptation, the egg production will decline significantly and the cost to keep the poultry farm will go up. As no summer adaptation will lead extra cost of maintaining the farm temperature and creating a controlled environment. Large size of the birds will require a huge quantity of diet in order to get the necessary nutrients and fibre.
Crossbreeding of birds is done to achieve a breed which is smaller in size and adaptable towards summer.

Question:47

Suggest some preventive measures for the diseases of poultry birds.
Answer:
Poultry birds are highly susceptible towards diseases caused by virus, fungi, bacteria and parasites along with nutritional deficiencies. In order to prevent these diseases, farmers can take the below mentioned measures:

1. Proper cleaning: The poultry farm and the poultry should be cleaned properly along with keeping checks on the hygiene of poultry and the spaces.

2. Sanitation: The waste management of poultry excretes, and feathers should be done in a proper and timely manner.

3. Spraying of disinfectants: The disinfectants should be applied after a proper cleaning and drying of the whole farm spaces. These disinfectants can be applied using aerosols, sprays or fumigation. The examples of such disinfectants are phenolic compounds.

4. Appropriate Vaccination: Poultry has a defined vaccination schedule which should be strictly followed in order to avoid diseases in the birds.

Question:48

Figure15.1 shows the 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 show 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:
1.Plot B shows a sudden increase in the yield percentage of crop because when chemical fertilizers are used on the crop, they boost the yield suddenly; however, this increase in yield is temporary as the chemical fertilizers reduces the organic matters present in the soil and it also ends up killing the required micro-organisms.
2. Plot A shows a delayed peak because when the plot is treated by manures, the small amount of nutrients is released into the soil at a very slow rate. The manure being rich source of organic matter leads to an increase the fertility of the soil.
3. The different pattern of the two graphs is observed because of the two separate methods used to increase the yield of crop in the plots. Manure being the organic way carried out the transfer of nutrients into the soil at a slow rate, enriching the soil. Whereas the chemical fertilizers enhanced the soil fertility for a temporary period of time. The continuous use of chemical fertilizers on Plot B led to killing of micro-organisms required for soil. This affected the soil fertility and reduced the yield percentage.

Question:49

Complete the crossword puzzle (Fig.15.2)

Across
1. Oil yielding plant (9)
3. Crop grown in winter season (4)
5. Fixed by Rhizobium (8)
9. Common honey bee (4)
Downward
2. Animal feed (6)
4. A micronutrient (5)
6. Unwanted plant in crop fields (4)
7. An exotic breed of chicken(7)
8. Bottom feeders in fish pond(7)
10. A marine fish (4)
Answer:
Across
1. Oil yielding plant (9) - Sunflower
3. Crop grown in winter season (4) - Rabi
5. Fixed by Rhizobium (8) - Nitrogen
9. Common honey bee (4) - Apis
Downward
2. Animal feed (6) - Fodder
4. A micronutrient (5) - Boron
6. Unwanted plant in crop fields (4) - Weed
7. An exotic breed of chicken (7) - Leghorn
8. Bottom feeders in fish pond (7) - Mrigals
10. A marine fish (4) - Tuna