Class 7 Basic Science Chapter 1 Question Answer Notes Towards A Hundredfold Yield

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Towards A Hundredfold Yield Class 7 Questions and Answers Notes

Class 7 Basic Science Chapter 1 Towards A Hundredfold Yield Question Answer Pdf

Basic Science Class 7 Chapter 1 Question Answer Kerala Syllabus

Let Us Assess

Question 1.
Identify the statement which does not suit organic fertilizers.
a. Can be prepared at home
b. Required in large quantities
c. Destroy soil structure
d. Can’t apply the required component alone
Answer:
c. Destroy soil structure,
d. Can’t apply the required component alone

Question 2.
Match the following
a. Apiculture – Rearing of fish
b. Cuniculture – Rearing of silkworm
c. Sericulture – Rearing of honey bees
d. Pisciculture – Rearing of rabbits
Answer:
a. Apiculture – Rearing of honey bees
b. Cuniculture – Rearing of rabbits
c. Sericulture – Rearing of silkworm
d. Pisciculture – Rearing of fish

Question 3.
You have learned about layering.

a. Identify the type of layering shown in the figure.
b. While layering in this way, at which position should we cut the plant, A, B or C?
Answer:
a. Serpentine layering
b. B

Question 4.
Look at the picture.

a. Identify stock and scion from A and B.
b. What is the advantage of attaching the stem of Malgoa to the local variety of mango tree?
c. Is there any merit in attaching the stem of a local variety of mango tree to the same variety?
Answer:
a. Scion – A, Stock – B

b. When attaching the stem of Malgoa to the local mango variety, the superior qualities of both varieties will combine and get a hybrid mango variety. The new plant will have the qualities of local mango variety like no special care needed, grows well in our soil, etc. Similarly, the qualities of malgoa, like big, sweet and good quality fruits, earlier flowering will be got to the new plant.

c. No.

Question 5.
List different methods of pest control. Give examples for each type.
Answer:
a) Biological Control

• The method of controlling the population of a pest species using another organism.
• Ladybug is an insect which eats the pests that grow on plants. Trichogramma is another friendly insect of this kind.
• Frog, Mabuya, Calotes, Bug etc. feed on pests which infest crops.
• When pesticides are applied, these friendly agents also get destroyed along with the pests.

b) Mechanical Control

• The method of controlling pests by removing them manually or using traps is called mechanical control.
• Pheromone trap is an example of this. It is available in the market.

c) Pesticides

• Pesticides are of two types: chemical pesticides and organic pesticides.
• Pesticides prepared using chemical substances are called chemical pesticides.
• Organic pesticides are comparatively less harmful than chemical pesticides.
• Tobacco decoction, neem oil emulsion, garlic-kanthari (Chilli) mixture, etc. are some organic pesticides.

Class 7 Basic Science Chapter 1 Extended Activities Answers

Question 1.
Prepare an agricultural edition on the topic ‘Agriculture: Yesterday and Today’ by including proverbs and pictures related to agriculture and information collected from farmers.
Answer:
(Hints: Some proverbs related to agriculture are given below to help you to prepare your agricultural edition.)
• “A small leak will sink a great ship.” (This proverb applies to agriculture in the sense that small problems, like neglecting fences or irrigation, can lead to big losses.)

• “The best-laid plans of mice and men often go astray.” (This proverb reminds farmers that even with careful planning, nature can be unpredictable.)

• “Early to bed and early to rise makes a man healthy, wealthy, and wise.” (This proverb emphasizes the importance of hard work in agriculture, where long hours are often necessary.)

• “Don’t count your chickens before they hatch.” (This proverb reminds farmers not to be overconfident about their harvest until it’s actually brought in.)

• “A single rotten apple spoils the whole barrel.” (This proverb can be applied to the importance of preventing pests and diseases from spreading in crops.)

Question 2.
Observe the picture. In some places, plastics are used for mulching in farms. Record its benefits in your Science Diary.

Answer:

• Soil moisture conservation.
• Minimizing soil compaction and erosion.
• Regulation of soil temperature.
• Soil fertility improvement.
• Mitigation of salt stress.
• Plant growth, development, and yield.
• Lowering the spread of diseases.
• Decline of weeds.

Class 7 Basic Science Chapter 1 Intext Questions and Answers

Question 1.
Aren’t our goals the same while cultivating fruits, vegetables, or cereals too? What things are to be taken care of to achieve this? Discuss with your friends and write in your Science Diary.
Answer:

• Fertile soil
• Favourable climate
• Quality seeds are planting materials.
• Proper manuring
• Weed control and pest control
• Nurturing

Question 2.
Observe the pictures and answer the questions given below.

a) Where are seeds formed? What about fruits?
b) What factors should be considered while selecting the best seeds?
Answer:
a) Seeds are formed as the result of reproduction that occurs in plants. The ovules inside the ovary of a flowering plant after fertilization form into a seed. Later ovary changed into fruit. So, inside the fruit, we can see the seeds.

b) Refer to topic 1.

Question 3.
Look at these plants.

Which of these plants would you choose to collect seeds from? Why?
Answer:
Plant 1. A single plant can produce many fruits. Seeds should be collected from the ripened fruits produced during the middle of the plant’s lifespan.

Question 4.
Factors to be considered while selecting seeds are given below. Put a tick mark in the appropriate box.

Answer:
Plant selected for seed collection: High-yielding, Healthy plant
Fruits selected for seed collection: Fruits formed at the middle of the plant’s life span.
Seeds selected: Have normal weight, Normal size.

Question 5.
Are new plants formed only from seeds? Observe the pictures given below. From which parts of these plants do saplings form?

Answer:
Curry leaf plant: Stem cuttings
Ginger plant: Underground stem (a swollen fleshy portion of the stem, that grows slightly below the surface of the soil).
Bryophyllum: Leaf
Pepper plant: Root

Question 6.
Find out examples of plants which reproduce through vegetative propagation and sexual reproduction. Write them in the Science Diary.

Answer:

Vegetative propagation				Sexual reproduction
Root	Stem	Leaf	Underground stem	Seed
Breadfruit	Moringa	Bryophyllum	Dioscorea	Moringa
Rose	Tapioca	Begonia	Ginger	Paddy
Dahlia	Sugarcane	Aloe	Potato	Wheat
Guava	Shoe flower	Zamia	Colocasia	Pea

Question 7.
In Moringa, young plants are produced from seeds and by planting stem cuttings. Can you find more examples of plants which can reproduce both through sexual reproduction and vegetative propagation?
Answer:

• Sheemakonna (Gliricidia)
• Mint plant
• Strawberry
• Potato
• Spider plant

Question 8.
List out the advantages and disadvantages of plants produced through layering. Record it in the Science Diary.
Answer:
Advantages of layering:

• Plants can be propagated using less space.
• Hard-to-root plants propagated using layering techniques generally form roots more quickly with greater overall success than when they are propagated from cuttings.
• Possess the qualities of the mother plant
• Small size and short lifespan
• Early flowering and fruiting

Disadvantages of layering:

• Time-consuming
• Plants have a shorter life span than plants that are propagated from seeds.
• Absence of taproot system
• Require more care.

Question 9.
The characteristics of two varieties of mango trees are given in the table. Analyze the table.

a) Which variety is better in terms of the quality of fruits?
b) Does the indigenous variety have any advantages over the Neelam variety?
c) If a sapling is produced by joining the stem of Neelam mango with the young plant of Indigenous variety, what specialties will it have?
Answer:
a) If you prioritize unique flavours and supporting local varieties, go for the Indigenous variety. Neelam might be a better choice if you prefer a reliable, sweet, and tart taste with a good shelf life.

b) Yes. Advantages of Indigenous variety:

• Indigenous varieties can have a wide range of flavours and textures depending on the specific type. Some might be known for intense sweetness.
• These varieties might be less commercially available and harder to find outside their local regions and grow well in our soil.
• Indigenous varieties may have evolved natural resistance to local diseases, reducing the need for pesticides, and doesn’t need any special care.

c) If a sapling is produced by grafting the stem (scion) of a Neelam mango tree onto the rootstock of a young indigenous mango plant, the resulting tree could have some interesting characteristics, combining traits from both varieties.

• The fruit might have a flavor that leans towards Neelam’s sweetness with a subtle hint of the indigenous variety’s unique characteristics, like grow well in our soil and does’t need any special care.
• The fruit might inherit Neelam’s good shelf life and pleasant aroma, while potentially retaining some disease resistance from the indigenous rootstock.

Question 10.
What are the advantages of producing saplings through grafting? Discuss and write them in the Science Diary.
Answer:

• Early flowering and fruiting
• It can be used to produce varieties of seedless fruits.
• It enables us to combine the most desirable characteristics of the two plants in its flowers and fruits

Question 11.
What is the reason for the early flowering and fruiting of mango saplings produced through grafting?
Answer:
The maturity of the Scion is one reason. In grafting, a piece of stem (scion) from a mature, fruiting mango tree is joined with the rootstock (young seedling). This scion already has the genetic makeup for flowering and fruiting. The rootstock, although genetically distinct from the scion, can also play a role. Some rootstock varieties are dwarfing or precocious, meaning they can influence the grafted tree to mature faster and start flowering earlier.

Question 12.
Haven’t you seen the bud growing beneath the grafted area? Will the quality of the plant be affected if this bud is not removed? Write in the Science Diary.

Answer:
Yes. If the bud is not removed, it can compete with the grafted scion for resources (water, nutrients, sunlight). This can lead to stunted growth, reduced fruit production, and potentially lower-quality fruit in the grafted variety.

Question 13.
A sapling is to be produced by using Malgoa and Gomav which is an indigenous variety of mango tree. Which should be the rootstock? Which would be the scion? Write the reason for this in the Science Diary.
Answer:
Scion: Malgoa
Rootstock: Gomav
There are a few reasons for using Gomav as the rootstock:
Answer:
a) Variety 1: Green-coloured long chilies, less in number
Variety 2: Red coloured, round-shaped or short chillies, seen as clusters.
b) Chillies with intermediate or red or green colour with either long or round in shape and produce more number of fruits.

Question 17.
Observe the illustration of pollination in a pumpkin plant.

Is it in self-pollination or cross-pollination that the qualities of both plants are combined? Why?
Answer:
In cross-pollination. It involves the transfer of pollen grains from one flower to another flower of two different plants. So from this cross, the characters of both the plants may combine.

Question 18.
Examine the stages of artificial pollination shown below.

When should these activities be performed? Put a tick mark. Discuss the reason.
Immediately after blooming.
After the flower has fully bloomed
When the flower begins to wither
Answer:
Immediately after blooming. When the flower fully bloomed, self-pollination may happen if it is a bisexual flower.

Question 19.
Can good quality seeds alone give a better yield? What other things are to be considered for a better yield? Write them in the Science Diary.
Answer:

• Fertile soil
• Pest control
• Suitable climate
• Irrigation
• Fertilizers and manures.

Question 20.
Which are the fertilizers commonly used by the farmers of your locality? List them after conducting an interview with farmers of your locality.
Answer:

• Cow dung
• Urea
• Compost
• NPK Mixture
• Chicken manure
• Kitchen waste
• Bone meal
• Factamfos
• Super phosphate

Question 20.
Classify the fertilizers into organic and chemical by examining your list and the pictures given below.


Answer:

Organic fertilizers	ChemicaI ferfflizers
Cow dung	Urea
Chicken manure	NPK Mixture
Compost	Factamfos
Bone meal	Super phosphate

Question 21.
Pest infestation in plants is a major issue faced by farmers. How can pest infestation be controlled?
Answer:
Refer to subtopic 5.2. (The major pest control measures).

Question 22.
Shouldn’t weeds also be controlled for getting a good yield? How can weeds be controlled? Write in the Science Diary.
Answer:

• Removal of weeds by pulling out with the hand.
• Removal of weeds by using the trowel.
• Removal of weeds by some agricultural techniques like ploughing, burning, etc.
• Spraying weedicides.
• Crop rotation.
• Intercropping.

Towards A Hundredfold Yield Class 7 Notes Extra Questions and Answers

Question 1.
What are seeds? How are they formed?
Answer:
Seeds are defined as small plant parts formed as a result of reproduction that occurs in plants. It stores food and has the potential to develop into a new plant under optimal conditions.

Question 2.
What are the criteria for selecting a planting material?
Answer:
Refer to topic 1.

Question 3.
List the plants whose seeds are directly planted.
Answer:
Bitter gourd, Okra (Lady’s finger), Pea, Snake gourd, Pumpkin, Cucumber, Ash gourd, Bottle gourd, etc.

Question 4
………. stage is suitable for collecting seeds.
Answer:
Middle stage

Question 5.
What are the methods that should be adopted by the farmers to ensure a good yield?
Answer:

• Care should be taken for selecting seeds or planting materials.
• Using high yielding seed varities.
• Ensure proper irrigation.

Question 6.
The technique of vegetative propagation in which branches are joined together to produce a new plant is called?
Answer:
Grafting

Question 7.
What is vegetative propagation? List the methods of vegetative propagation.
Answer:
Refer to topic 2.

Question 8.
New varieties of crops with required attributes are developed artificially by the process called……………
Answer:
Hybridization.

Question 9.
Define the following terms.
a) Budding
b) Layering
Answer:
Refer to subtopics 2.1., and 2.3.

Question 10.
What do you mean by hybridization in plants?
Answer:
Refer to subtopic 2.4.

Question 11.
What do you mean by artificial pollination? List the steps of artificial pollination.
Answer:
Refer to topic 3.

Question 12.
Mention the hybrid seeds of the lady’s finger and pea.
Answer:
Hybrid seeds of lady’s finger: Salkeerthi, Kiran
Hybrid seeds of pea: Jyothika, Bhagyalakshmi.

Question 13.
Where do high-yielding varieties of rubber plants suited for different geographical areas develop?
Answer:
Rubber Research Institute of India (RRII), Kottayam.

Question 14.
What is a microbial fertilizer? Give some examples.
Answer:
In the method of application of fertilizer, microbes are used as fertilizers. Then they are called as microbial fertilizers. Pseudomonas and Azospirillum are examples of microbial fertilizers.

Question 15.
List the major pest control measures used in agricultural fields.
Answer:

• Biological Control
• Mechanical control
• By using Pesticides

Question 16.
Differentiate between Mechanical control and biological control of pest infestation.
Answer:
Biological control:

• The method of controlling the population of a pest species using another organism.
• Ladybug is an insect which eats the pests that grow on plants. Trichogramma is another friendly insect of this kind.
• Frogs, Mabuya, Calotes, Bug, etc. feed on pests that infest crops.
• When pesticides are applied, these friendly agents also get destroyed along with the pests. Mechanical control:
• The method of controlling pests by removing them manually or using traps is called mechanical control.
• Pheromone trap is an example of this. It is available in the market.

Question 17.
Explain the following terns.
a) Cuniculture
b) Sericulture
Answer:
a) Cuniculture: It is the rearing of rabbits for their meat, fur, and wool.
b) Sericulture: It is the Rearing of silkworms for the production of raw silk.

Question 18.
The seeds received by Sonu and Meenu from their school is given below.

Tomato, Lady’s finger, Pumpkin, Spinach, Bitter gourd, Chilly, Pea, Brinjal

A. They wrote the method of planting these seeds in their science diary. Complete the table.

B. Meenu got better yield than Sonu. Write any two factors that might have helped Meenu in getting better yield?
Answer:
A.

Seeds that are planted directly	Seeds that are not planted directly
Pea	Spinach
Pumpkin	Brinjal
Lady’s finger	Chilly
Bitter gourd	Tomato

B. Climate, Irrigation, Fertile soil, Quality seeds and planting materials.

Question 19.
A. Different methods of producing quality seeds/planting materials are given below. Complete the table.

B. Write two merits and demerits of plants produced through layering.
Answer:
A.(i) Layering
(ii) Hybridization
(iii) It enables us to combine the most desirable characteristics of the two plants in their flowers and fruits
B. Merits of layering:

• Possess the qualities of the mother plant
• Small size and short lifespan
• Early flowering and fruiting

Demerits of layering:

• Time-consuming
• Plants have a shorter life span than plants that are propagated from seeds.
• Absence of taproot system
• Require more care.

Question 20.
Observe the picture of a branch which is separated from its parent plant after sprouting roots.

a) Write the name of this method of producing new plantlet.
b) Write down any two merits of plantlets produced through this method.
c) The steps of producing new plantlets in this method are given below write them in the correct order.
a. Cover with a polythene sheet.
b. Cut the branch and plant it in the soil.
c. Peel off the bark in a circular shape.
d. Select a branch of the plant from which plantlet is to be produced.
e. Cover the peeled off part with slightly moistened mixture of coconut fibre and soil.
Answer:
A) Layering
B) Merits of layering:

• Most of the plants can be grown this way
• The plantlets have the qualities of the parent plant.
• Through layering, we can produce more saplings within a short period.
• Flowering and fruiting of such plants are faster than those in plants formed from the seeds.

C)
d) Select a branch of the plant from which the plantlet is to be produced,
c) Peel off the bark in a circular shape.
e) Cover the peeled-off part with a slightly moistened mixture of coconut fibre and soil.
a) Cover with a polythene sheet.
b) Cut the branch and plant it in the soil.

Question 21.
Examine the given table indicating the peculiarities of the two varieties of plants.

a) Which variety can be selected as stock and which one as scion to produce good saplings with high yield?
b) What are the methods adopted to produce good saplings with high yields? Explain anyone.
c) Group the following varieties of seeds suitably.
Answer:
a) Rootstock – Variety 1, Scion – Variety 2.

b) Hybridization, Crop rotation, Intercropping.
Hybridization: Hybridization is the method of production of seeds by artificially pollinating two plants which have different qualities and belong to the same species. From the seeds thus produced, those with superior quality are collected. These are the hybrid seeds.

C)

Question 22.
a) You want a hibiscus plant having three different flowers in your biodiversity park. Which method do you adopt for this?
b) The following are the activities done by a student for this. Arrange the steps in the correct order.

c) Write two things to be considered when you select plants for budding.
Answer:
a) Budding
b)
c) Need or select good buds, Should know the qualities of the plant.

Question 23.
The following are the peculiarities of two types of guava.

Variety A	High resistance to disease	Fruits are less sweet	Fruits are small in size
Variety B	Low resistance to diseases	Fruits are more sweet	Fruits are big in size

a) Write the peculiarities of the saplings produced by the hybridization of these two varieties.
Sapling 1 Low resistance to disease, less sweet, big in size
Sapling 2
Sapling 3
Sapling 4
Sapling 5
b) Write the peculiarities of hybrid plants which have the most desirable qualities of these two varieties.
c) Write the names of any two hybrid paddy seeds.
Answer:
a) Sapling – 2 – High resistance, fruits are more sweet, fruits are small in size.
Sapling – 3 – Low resistance to disease, Fruits are less sweet, Fruits are small in size.
Sapling 4 – High resistance to disease, Fruits are less sweet, Fruits are big in size.
Sapling – 5 – Low resistance to disease, Fruits are more sweet, Fruits are big. .
b) High and Quick yield. Resistance to infections.
c) Pavitra, Annapurna, Hraswa

Question 24.
Features of two chilly plants are given below:
A) Which of the following methods can be used to produce a new plant with long chilly and high yield?
(i) Budding (iii)Grafting (ii) Hybridisation (iv) Tissue culture
B) Layering is another method to produce new saplings. Write down any two features of the plant produced by this method.
C) Observe the picture of grafting. Which of the following parts marked as 1, 2, 3 and 4 should be cut off? Why?

Answer:
A) (ii) Hybridization
B) Possess the qualities of the mother plant, Early flowering and fruiting.
C) 1,3 should be cut off. After grafting wait for one more month and cut and detach the part completely when it attains proper growth. It can be replanted in a more suitable place. Remove any new branches sprouting on the stock.

Question 25.
A. Which are the artificial plant breeding methods used to obtain planting materials?
B. Mention any two methods of layering.
Answer:
A. Budding, Grafting, Layering, Hybridization.
B. Air layering and serpentine layering are two types of layering methods.

Question 26.
a) What are hybrid seeds?
c) What are the main characteristics of hybrid varieties?
Answer:
c) The plants produced through hybridization have superior-quality seeds. These seeds are called hybrid seeds.
d) High yield, disease-resisting capacity, ability to give high yield within a short period, etc are the characteristics of hybrid varieties.

Question 27.
Important agricultural centres are given in column A and the researches taking place there are given in column B. Match them suitably.
Answer:
a – iii, b – iv, c – i, d- ii.

Question 28.
The Kerala Agricultural University is situated in …… ?
Answer:
Mannuthy, Thrissur

Question 29.
a) Prepare a questionnaire for conducting an interview with the agricultural officer (minimum 6 questions) related to crop management (Pest control, intercropping, organic farming).
b) Explain the method of preparation of any one of the biopesticides.
Answer:
a)
1) Where is the Kerala Agricultural University situated?
2) Which crops will affect the disease ‘Mandari’?
3) What are biopesticides?
4) What is the rotation of crops?
5) What is biological pest control?
6) Which bio-fertilizers are used in paddy cultivation?
b) Tobacco Decoction:
Chop 100 grams of tobacco and soak it in one and a half liters of water for a day. Squeeze it and filter it. Dissolve 10 grams of washing soap in it. The tobacco decoction is ready now. Dilute it by adding twice the quantity of water and spray on plants.

Question 30.
Listen to the words of earthworm.

A. How does the overuse of chemical pesticides and chemical fertilizers affect the soil, men, and other living things?
B. Write the method of preparation of a biopesticide.
C. Name any two biofertilizers.
Answer:
A. Fertilizers boost crop yields, but their excessive usage has hardened the soil, reduced fertility, strengthened insecticides, polluted air and water, and emitted greenhouse gases, creating health and environmental risks.

B. Tobacco Decoction: Chop 100 grams of tobacco and soak it in one and half litres of water for a day. Squeeze it and filter it. Dissolve 10 grams of washing soap in it. Dilute it by adding twice the quantity of water and spray on plants.

C. Kiriyath emulsion, Compost.

Question 31.
The data collected by visiting the fields of two farmers practicing integrated farming is given below.

a) Which farmer interrelatedly utilizes the resources to the maximum?
b) Justify your opinion.
c) Give two suggestions to the farmers who practice integrated farming
Answer:
a) Farmer – 1

b) The integrated farming of crop cultivation and animal husbandry, increases their income. Through integrating methods, they can avoid expenses needed for each sector, save space, and get money from all days, from any field.

c) Use cow dung for paddy fields as an organic manure. The straw obtained from paddy cultivation, the bran obtained from husking paddy grains, etc can be given to cattle as fodder, and the organic wastes from homes and agricultural fields can be utilized towards the gas plant.

Question 32.
a) What is Pisciculture?
b) Name the agricultural sector involved in the rearing of cattles.
Answer:
a) Pisciculture is a branch of farming that involves rearing fish and prawns on a commercial basis by adopting scientific and technical means.
b) Livestock rearing (Animal husbandry).

Towards A Hundredfold Yield Class 7 Notes

. Seeds are defined as small plants, present in their embryonic nature that are covered in a strong and protective covering. They are formed as the result of reproduction that occurs in plants.
. Good quality seeds should be selected for better yield. For this, the respective plant and fruit should also have good quality.
. New plants are formed from parts like roots, stems, leaves, and underground stems, besides seeds. Saplings can be formed not only from seeds but also from these parts.
. The process of production of new saplings from the vegetative parts of plants like root, stem, leaf, and underground stem is called vegetative propagation.
. Different vegetative propagation methods in plants are Layering, Grafting, and Budding.
. Hybridization is the method of productidn of seeds by artificially pollinating two plants which have different qualities and belong to the same species.
. Pollination is the transfer of pollen grains from the anther of one flower to the stigma of the same or another flower. It is divided into self-pollination and cross-pollination.
. The seeds produced from artificial pollination are called Hybrid seeds. They possess the characteristics of both the parent plants.
. There are so many agricultural research centres are there in India as well as in Kerala.
. Proper application of fertilizers is required for better yield. Fertilizers can be classified into organic fertilizers and chemical fertilizers.
. Many pest control measures are used by farmers to control the pest infestation in their fields like biological control, Mechanical control, chemical and organic pesticides, etc.
. There are various agricultural sectors prevailing in our country for helping farmers and make better benefits.