Balbharti Maharashtra State Board Class 9 Science Solutions

 Maharashtra State Board Class 9 Science Solutions Chapter 17 Introduction to Biotechnology

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 Chapter 17 Introduction to Biotechnology Notes, Textbook Exercise Important Questions and Answers

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Q.1. Fill in the blank and rewrite the completed statements

1. Tissues which join different parts of the body are called tissues.

Ans Tissues which join different parts of the body are called connective tissues.

1. The cell body which contents the cytoplasm and the nucleus is the main part of each cell.

Ans The cell body which contents the cytoplasm and the nucleus is the main part of each nerve cell.

1. To bring about plant growth is the main function of tissue.

Ans To bring about plant growth is the main function of meristematic tissue.

1. The techniques of bringing about improvements in living organisms by artificial genetic changes and by hybridization for the welfare of human beings, are together called …………

Ans The techniques of bringing about improvements in living organisms by artificial genetic changes and by hybridization for the welfare of human beings, are together called ‘Biotechnology’.

1. Ex vivo growth of cells or tissues in an aseptic and nutrient-rich medium’ is called …………… .

Ans Ex vivo growth of cells or tissues in an aseptic and nutrient-rich medium’ is called tissue culture.

1. tissues are formed from special type of contractile proteins.

Ans Muscular tissues are formed from special type of contractile proteins.

1. Protective coverings in the animal body are called tissues.

Ans Protective coverings in the animal body are called epithelia. tissues.

Q. 2. Find the odd one out 5

1. Different types of animal tissues.

a. Squamous epithelium b. Stratified epithelium

c. Columnar epithelium d. Areolar Tissue.

Ans Areolar Tissue : It is a connective tissue while remaining are types of epithelium tissues.

1. Different types of animal tissues.

a. Blood b. Lymph c. Squamous Epithelial tissue d. Adipose Tissue.

Ans Squamous Epithelial tissue : It is a type of epithelial tissue while remaining are type connective tissue.

1. Types of plant tissues.

a. Xylem b. Parenchyma c. Sclerenchyma d. Collenchyma

Ans Xylem : It ius a complex tissue while others are simple tissues.

1. Type of permanent tissues.

a. Tracheids b. vessels c. Sieve tubes d. xylem fibres-dead cells

Ans Sieve tubes : Sieve tubes are part of phloem while remaining are the type of xylem.

1. Types of tissues in different organisms.

a. epithelial tissue b. meristematic tissue

c. connective tissue d. muscular tissue and nervous tissue.

Ans meristematic tissue

1. It is a plant tissue while remaining are animal tissues.

Q. 3. Find co-related terms 2

1. Exotic breed : Jersey : : Indian bread : …………… .

Ans Exotic breed : Jersey : : Indian bread : Khillari.

1. Cylindrical shape : cardiac muscles : : spindle shaped : …………… .

Ans Cylindrical shape : cardiac muscles : : spindle shaped : Non-striated muscles .

Q. 4. Match the pair 3

1

Column A	Column B
i. Muscular tissue	a. CNS, PNS, ANS
ii. Nervous tissue	b. Poultry and Cattle
	c. Xylem and phloem
	d. Striated and non-striated

Ans

i. Muscular tissue	Striated and non-striated
ii. Nervous tissue	CNS, PNS, ANS

2

Column A	Column B
i. Complex tissue	a. Epithelial tissue
ii. Simple tissue	b. Poultry
	c. Xylem
	d. Sericulture

Ans

i. Complex tissue	Xylem
ii. Simple tissue	Epithelial tissue

3

Column A	Column B
i. Indian poultry	a. Khillari
ii. Exotic cattle	b. Aseel
	c. Holstein
	d. Leghorn

Ans

i. Indian poultry	Aseel
ii. Exotic cattle	Holstein

Q.5. State True or False 6

1. Blood is a type of connective tissue.

Ans Blood is a type of connective tissue – True

1. Simple permanent tissues are made up of more than one type of cells.

Ans False – Simple permanent tissues are made up of only one type of cells.

1. Fully grown plants can be produced in shorter durations using biotechnology.

Ans Fully grown plants can be produced in shorter durations using biotechnology – True

1. In India, animal husbandry is practised for milk production and for using the catttle as help in farming operations.

Ans In India, animal husbandry is practised for milk production and for using the cattle as help in farming operations – True

1. Embryos formed by conventional hybridization technique between two or more varieties may not grow fully for some reasons.

Ans Embryos formed by conventional hybridization technique between two or more varieties may not grow fully for some reasons – True

1. Muscular tissues are made up of the long cells of nerves.

Ans False – Muscular tissues are made up of the long cells of muscle fibres.

Q.6. Name the following 6

1. Name the Tissue lining inner surface of mouth.

Ans Squamous epithelium

1. Name the Two types of tissues.

Ans simple and complex

1. Name the Tissue responsible for increasing girth of stem.

Ans Lateral meristem

1. NameTissue responsible for increasing height of plants.

Ans Apical meristem

1. Name the Tissue joining muscles and bones.

Ans Tendons

1. Name the Two techniques used in biotechnology.

Ans genetic engineering and tissue culture

Q.7. Multiple Choice Questions 14

1. In most animals, action in response to a stimules occurs due to the integrated functioning of Which of the two?

a. nervous tissue and excretory tissue b. nervous tissue and muscular tissue

c. nervous tissue and circulatory tissue d. circulatory tissue and muscular tissue

Ans Option b.

2

The figure shows the process of

a. genetic engineering b. tissue culture c. totipotency d. soil-less farming

Ans The figure shows process of tissue culture

1. Which of the following are branched?

• 1. Nerves b. Non- Straited muscles

c. Cardiac muscles d. Straited muscles

Ans Option c.

1. Some cells in the body of living organisms are ‘. ’, that is if provided a proper environment, a new

organism can grow from these cells.

a. simple b. omnipotent c. impotent d. totipotent

Ans Option d.

1. …………… transports waste materials generated all over the body to the kidney for excretion.

a. Serum    b. Muscles c. Nerves d. Blood

Ans Option d.

1. Outermost layer is called ‘. ’

a. mesodermis b. peridermis c. endodermis d. epidermis

Ans Option d.

1. A group of cells having the same origin, same structure and same function is called ‘. ’

a.. cellulose b. tissue c. multicellular d. unicellular

Ans Option b.

1. Which of the foll is not a local variety of cattle?

a. jersey b. sahiwal c. gir d. lal kandhari

Ans Option a.

1. ‘. growth of cells or tissues in an aseptic and nutrient-rich medium’ is called tissue culture.

a. Ex vitro b. In vitro c. In vivo d. Ex vivo

Ans Option d.

1. Which meristem Increases girth (diameter) of the root and stem?

a. outercalary b. Intercalary c. Apical d. Lateral

Ans Option d.

1. Which Cells contain vesicles packed with secretory material?

a. Lower epithelium b. Stratified epithelium

c. Upper epithelium d. Glandular epithelium

Ans Option d.

1. Which of the foll contains Erythrocytes, leucocytes and platelets in a liquid plasma?

a. Blood b. Lymph c. Adipose Tissue d. Lungs

Ans Option a.

1. Which of the following is not a part of Xylem tissue?

a. Tracheids b. Vessels c. Sieve tubes d. Xylem parenchyma

Ans Option c.

1. is present Below the skin and around internal organs.

a. Areolar Tissue b. Blood c. Adipose Tissue d. Lungs

Ans Option c.

Q.8. Write Short Notes 10

1. Striated muscles.

Ans i. Muscle cells are long, cylindrical, multinucleate and have no branches.

1. Structure: There are alternate dark and light bands on these muscles at they are attached to bones, they are also called skeletal muscles.2. They move as per our will, hence they are called voluntary muscles.3. Function: These muscles bring about movements of arms and legs, running, speaking, etc.

2. Xylem.

Ans i. Xylem is a type of complex permanent tissue.

1. Presence of thick-walled dead cells is the characteristic feature of Xylem
2.  It consists of following types of cells: Tracheids, vessels and xylem fibres-dead cells Xylem parenchyma- living cells.
3.  It forms a structure like interconnected tubes and functions to conduct water and minerals only in upward direction.

3. Genetic engineering

Ans 1. The techniques of bringing about improvements in living organisms by artificial genetic changes is called as Genetic engineering.

1. In agriculture, it is use in the production of cash crops, improvement in varieties of cash crops, increase in abilities of plants to withstand environmental stresses etc.
2. In medicine, it is use for vaccine production, early diagnosis of congenital diseases, organ transplant, cancer research, production of artificial skin, cartilage, etc.

4. Agro-complementary business.

Ans i. It includes following – Animal husbandry, Poultry farming, Sericulture.

• 1. In India, animal husbandry is practised for milk production and for using the catttle as help in farming operations.
  2. Rearing of egg and meat yielding chickens is called poultry farming.
  3. Silkworms (moths) are reared for production of silk. Bombyx mori is the most commonly used variety for this purpose.

1. Meristematic tissue.

Ans i. As meristematic tissue is present in specific parts of a plant, growth occurs in those parts only.

• 1. Cells of meristematic tissue contain thick cytoplasm, a conspicuous nucleus and a thin cell wall and are compactly packed together.
  2. Vacuoles are usually absent in these cells. These cells are highly active. To bring about plant growth is the main function of meristematic tissue.
  3. According to the location, meristematic tissue is of three types as given below.
     1. Apical meristem : At the tip of the root and stem
     2. Intercalary meristem : At the base of the petiole of leaves and of branches.
     3. Lateral meristem : Lateral sides of root and stem

Q. 9. Attempt the following. 4

1. Which two main techniques are used in biotechnology? Why?

Ans 1. Two main techniques used in biotechnology are genetic engineering and tissue culture.

1. These techniques are use for bringing improvements in living organisms by artificial genetic changes and by hybridization for the welfare of human beings.

2. Each of the following statements is wrong. Rewrite them correctly by changing either one or two words.

a. Striated muscles are also called involuntary muscles.

b. Chloroplast is present in permanent tissue.

Ans a. Striated muscles are also called voluntary muscles.

b. Chloroplast is found in chlorenchyma tissue.

Q.10. Complete the given flow chart / table / diagram 6

1. Label the Diagram Nervous tissue

Ans:

 

2.

Ans

3

Tissue	Type of animal tissue
Blood	……………
Glandular epithelium	……………
Adipose tissue	……………
Cardiac muscles	……………

Ans

Tissue	Type of animal tissue
Blood	Connective tissue
Glandular epithelium	Epithelial tissue

Adipose tissue	Connective tissue
Cardiac muscles	Muscular tissue

Q.11. Distinguish between 4

1. Xylem and Phloem

Ans

Xylem		Phloem
i.	It consists of thick-walled dead cells	It consists of cytoplasm containing living cells
	Type of cells includes Tracheids, vessels and xylem fibres-dead cells.	Type of cells includes tubes, companion cells, phloem parenchyma- living cells..
ii.
	It conduct water and minerals only in upward direction.	It conduct sugar and amino acids from leaves to various parts in upward and downward direction.
iii.

2. Simple tissues or Complex tissues

Ans

Simple tissues		Complex tissues
i.	They are made up of only one type of cells.	They are made up of more than one types of cells.
ii.	Found in all plants and animals.	Found in higher plants and animals.
iii.	They usually perform the function of division.	They usually perform complex functions like translocation in plants and circulation, excretion, etc. in animals.
iv.	Example Meristemetic tissue in plants, Epithelial tissue in animals.	Example Conducting tissues in plants, Connective and nervous tissue in animals.

Q.12. Give scientific reasons 6

1. Plants and animals have different types of tissue.

Ans 1. Plants being sedentary, most of their tissues are of the type that give support.

1. Growth of the plants occurs in specific parts of their body where the tissues contain dividing cells.

2. As animals have to move from place to place in search of food, shelter and partners, their energy needs are greater.

4.Uniform growth occurs through out the body of an animal and they do not have different dividing and non- dividing tissue.

That is why plants and animals have different types of tissue to performing the necessary functions.

3. Rearing of sheep is a livestock.

Ans 1. Livestock is defined as keeping farm animals and raising them for profit or for use.

1. Sheep are raised by the people in order to get meat, milk & wool from them. Hence, Rearing of sheep is a livestock.

3. The contraction and relaxation of muscles at every movement is possible.

Ans 1. Muscle fibres and muscular tissues are formed from special type of contractile proteins.

2.Muscular tissues are made up of the long cells of muscle fibres.

1. Muscular movement occurs due to contraction and relaxation of the contractile proteins in these cells. Hence, the contraction and relaxation of muscles at every movement is possible.

Q.13. Give examples 16

1. Give any 4 names of Chickens raised for eggs.

Ans Leghorn, Minorca, Ancona, Lehman

1. Give any 4 example of connective tissue.

Ans Blood, Lymph, Areolar Tissue, Adipose Tissue, Cartilage, Bones, Tendons and ligaments

1. Give any 4 examples of epithelial tissue.

Ans Squamous epithelium, Stratified epithelium, Glandular epithelium, Columnar epithelium, Ciliated Epithelium, Cuboidal epithelium.

1. Give Any 4 exotic breed cattle.

Ans jersey, brown Swiss, Holstein, etc.

1. Give any 4 examples of Local Indian varieties of cows.

Ans sahiwal, sindhi, gir, lal kandhari, devni, khillari, dangi, etc.

1. Give any 4 examples of varieties of chicken reared in poultry.

Ans Aseel, leghorn, Rhode Island Red, New Hampshire, Plymouth Rock, Black Rock, etc.

1. Give Any 4 Indian breed cattle.

Ans sahiwal, sindhi, gir, lal kandhari, devni, khillari, dangi, etc.

1. Give any 4 Chickens raised for meat.

Ans Brahma, Long, Cochin, Aseel

Q.14. Explain the statement 9

1. Biotechnology has proved to be very useful.

Ans i. With the help of the technique it has become possible to produce plants and animals bearing some new characteristics in addition to their natural ones.

ii. The techniques of bringing about improvements in living organisms by artificial genetic changes and by hybridization for the welfare of human beings, are together called ‘Biotechnology’.

iii. It includes the techniques of genetic engineering and tissue culture.

iv. Its uses are in the production of cash crops, improvement in varieties of cash crops, increase in abilities of plants to withstand environmental stresses.

v. Also, vaccine production, early diagnosis of congenital diseases, organ transplant, cancer research, production of artificial skin, cartilage, etc. in laboratories is possible due to Biotechnology.

2. If sufficient land is available, the emerging field of ‘Agri-tourism would be a good business.

Ans i. If sufficient land is available, the emerging field of ‘Agri-tourism would be a good business.

ii. Plantlets of flowering, medicinal, ornamental, vegetable plants and fruit trees can be produced on a large scale by the tissue culture technique.

iii. And, by growing some of the plants fully a selfsufficient agritourism centre can be developed.

• Mango, chikoo (sapota), guava, coconut, custard apple and some other regional fruit trees.

• • Shade giving local or exotic attractive plants.
  • Ornamental and flowering plants.
  • Butterfly garden.
  • Medicinal plant garden.
  • Organic vegetables and fruits.

iv. People visit places with such attractions in large numbers.

v. Selling plantlets / seedlings, fruits, vegetables at such place can be quite profitable.

3. Plants and animals have different types of tissue to performing the necessary functions.

Ans i. . Plants being sedentary, most of their tissues are of the type that give support.

ii. There are dead cells in some tissues and these do not need much attention.

iii. Growth of the plants occurs in specific parts of their body where the tissues contain dividing cells.

iv. As animals have to move from place to place in search of food, shelter and partners, their energy needs are greater.

v. Most of the tissues of animals are made up of living cells. Uniform growth occurs through out the body of an animal and they do not have different dividing and non-dividing tissue.

vi.This means that plants and animals have different types of tissue to performing the necessary functions.

Q.15. Attempt the following. 9

1. Label the diagram and explain any two of the animal tissue.

Ans:

Connective tissue – Tissues which join different parts of the body are called connective tissues. Cells in this type of tissue are loosely arranged with a ground substance in the free spaces in between.

Epithelial tissue – Protective coverings in the animal body are called epithelial tissues. Cells in this tissue are closely packed and form continuous layers. Any material that enters the body first encounters epithelial tissue.

2. Each of the following statements is wrong. Rewrite them correctly by changing either one or two words.

a. Simple squamous epithelium is present in respiratory tract.

b. Glandular epithelium is present in kidneys.

c. Chlorenchyma helps the plant to float in water.

Ans a. Ciliated epithelium is present in respiratory tract.

b. Cuboidal epithelium is present in kidneys.

c. Aerenchyma helps the plant to float in water.

3. Identify the odd word and explain why it is odd.

a. Xylem, phloem, permanent tissue, meristematic tissue.

b. Epithelium, Muscle fibre, nerve fibre, epidermis.

c. Cartilage, bone, tendon, cardiac muscle.

Ans a. Meristematic tissue

It has the ability to divide, while the others have lost their ability.

b. Epidermis

It is a plant tissue, while others are animal tissue.

c. Cardiac muscle

It is a type of muscular tissue, while others are types of connective tissues.

Q.16. Complete the table/ web/ flow chart 9

1. Meristematic tissue.:

Types	Location	Function
Apical meristem :	…………………………………	…………………………………
Intercalary meristem :	………………………………….	…………………………………
Lateral meristem :	…………………………………	………………………………….

Ans

Figure	Location	Function
Apical meristem :	At the tip of the root and stem	Increases the length of the root and stem.
Intercalary meristem :	At the base of the petiole of leaves and of branches.	Growth of branches, formation of leaves and flowers.
Lateral meristem :	Lateral sides of root and stem	Increases girth (diameter) of the root and

stem.

2. Name the Types of connective tissue.

Type				Bones
Appearance

Ans

Type	Adipose Tissue	Adipose Tissue	Blood	Bones	Cartilage	Lymph	Tendons and ligaments
Appearance

3. Types of simple permanent tissues.

	Parenchyma	Collenchyma	Sclerenchyma
Location	……………	……………	……………
Functions	……………	……………	……………

Ans

	Parenchyma	Collenchyma	Sclerenchyma
Location	All parts like roots, stem, leaves, flowers and seeds	At the base of leaf petiole, branches and stem	Stem, veins of leaves, hard coats of seeds, outer covering of coconut
Functions	Support, storage of food and filling vacant spaces	Support and flexibility to various parts	Give strength and rigidity to parts of the plants.

Q.17. Complete the sentences in paragraph 9

1. Complete the paragraph.

(muscular, cytoplasm, nucleus, one meter, Dendrites, 1.5 meter, Nervous, Axon )

…………… tissue enables us to respond to stimuli like touch, sound, odour, colour, etc. Cells of this tissue are specially made to become excited and to conduct that excitation from one part of the body to other. Cell body containing the …………… and nucleus is the main part of the body to other are numerous, small,

branched fibres which arise from the cell body is extremely long fibre of the nerve cell. The length

of a nerve cell may even be up to Many nerve cells are bound together with the help of connective

tissue to form a nerve. This tissue is located in brain, spinal cord and the network of nerves spread all through the body. In most animals, action in response to a stimulus occurs due to the integrated functioning of nervous tissue and tissue.

Ans Nervous tissue enables us to respond to stimuli like touch, sound, odour, colour, etc. Cells of this tissue are specially made to become excited and to conduct that excitation from one part of the body to other. Cell body containing the cytoplasm and nucleus is the main part of the body to other. Dendrites are numerous, small, branched fibres which arise from the cell body. Axon is extremely long fibre of the nerve cell. The length of a nerve cell may even be up to one meter. Many nerve cells are bound together with the help of connective tissue to form a nerve. This tissue is located in brain, spinal cord and the network of nerves spread all through the body. In most animals, action in response to a stimulus occurs due to the integrated functioning of nervous tissue and muscular tissue.

2. Complete the paragraph.

( erythrocytes, opened, muscular, connective, solid, kidney, closed, liquid, filtration)

Blood is a type of …………… tissue. It helps in circulation i.e. transport of different materials. It transports oxygen, hormones and nutrients to all cells in the body and it also transports waste products generated in the body to the …………… for …………… . It is present in the …………… circulatory system. It consists of ,

leucocytes and platelets in a plasma.

Ans Blood is a type of connective tissue. It helps in circulation i.e. transport of different materials. It transports oxygen, hormones and nutrients to all cells in the body and it also transports waste products generated in the body to the kidney for filtration. It is present in the closed circulatory system. It consists of erythrocytes, leucocytes and platelets in a liquid plasma.

3. Complete the paragraph:

(in vivo, tissue culture, biotechnology, energy, exvivo, genetic engineering, aseptic, agar, temperature,

totipotency, tissue, collagen)

Techniques for bringing about improvements in living organisms for the welfare of human beings are together called …………… . It includes …………… and tissue culture. The growth of cells in an nutrient-rich and…………… medium is called tissue culture. In this process, a liquid, solid or gel like medium is prepared from………….. which supplies nutrients and necessary for the cells to grow.

Ans:  Techniques for bringing about improvements in living organisms for the welfare of human beings are together called biotechnology. It includes genetic engineering and tissue culture. The ex vivo growth of cells in an nutrient-rich and aseptic medium is called tissue culture. In this process, a liquid, solid or gel like medium is prepared from agar which supplies nutrients and energy necessary for the cells to grow.

Q.18. Answer the following 15

1. Define the term tissue and explain the concept of tissue culture.

Ans A group of cells having the same origin, same structure and same function is called ‘tissue’.

Tissue culture:

1. ‘Ex vivo growth of cells or tissues in an aseptic and nutrient-rich medium’ is called tissue culture.

2. Nowadays, a complete organism can be developed from a single cell or from tissue with help of the tissue culture technique.

3 .A liquid, solid or gel-like medium prepared from agar, which supplies nutrients and energy necessary for tissue culture is used in this technique.

2. Explain the following terms:

4. Biotechnology

5. Tissue culture

6. Poultry farming

Ans 1. Biotechnology – The techniques of bringing about improvements in living organisms by artificial genetic changes and by hybridization for the welfare of human beings, are together called ‘Biotechnology’.

1. Tissue culture – ‘Ex vivo growth of cells or tissues in an aseptic and nutrient-rich medium’ is called tissue culture. Nowadays, a complete organism can be developed from a single cell or from tissue with help of the tissue culture technique.
2. Poultry farming – Rearing of egg and meat yielding chickens is called poultry farming. The objectives behind development of new hybrid varieties.

3. Explain nervous tissue.

Ans i. Nervous tissue enables us to respond to stimulii like touch, sound, odour, colour, etc.

ii. Cells of the nervous tissue are specially made to be come excited and to conduct that excitation form one part of body to other.

Iii. The cell body which contents the cytoplasm and the nucleus is the main part of each nerve cell.

iv. Numerous, small, branched fibres called dendrites arise from the cell body.

v. One of the fibres, however, is extremely long. It is called as the axon. The length of a nerve cell may even be up to one meter.

vi. Many nerve cells are bound together with the help of connective tissue to form a nerve.

vii. Nervous tissue is present in the brain, spinal cord and the network of nerves spread all through the body.

viii. In most animals, action in response to a stimules occurs due to the integrated functioning of nervous tissue and muscular tissue.

4.Mention any three changes that can be seen in agricultural management due to biotechnology.

Ans i. Genetically Modified Crops (GM crops) are being produced by introducing changes in DNA of natural crops. Normally, such varieties are not found in nature. Thus, new varieties are produced artificially. Different useful characters are introduced in such varieties.

ii. Ability to withstand environmental stress- Some naturally occurring varieties cannot withstand envioromental stresses like frequently changing temperature, wet and dry famines, changing climate, etc. However, GM crops can grow in any of such adverse conditions.

iii. As GM crops are resistant to insect pests, pathogens, chemical weedicides, etc, the use of harmful chemicals like pesticides can be avoided.

iv. Due to use of seeds of GM crops, there is improvement in nutritive value and decrease in loss of crops.

5. Explain about Agro-complementary occupations : Sericulture.

Ans i. Silkworms (moths) are reared for production of silk. Bombyx mori is the most commonly used variety for this purpose. The life cycle of the silk moth consists of four stages, namely egg, larva, pupa and adult.

ii. Thousands of eggs deposited by female moths are incubated artificially to shorten the incubation period. Larvae hatching out of eggs are released on mulberry plants.

Iii .Larvae are nourished by feeding on mulberry leaves. After feeding for 3 – 4 days, larvae move to branches of mulberry plant. The silk thread is formed from the secretion of their salivary glands.

Iv .Larvae spin this thread around themselves to form a cocoon. The cocoon may be spherical in shape.

Q.19. Extra data 30

1. Complete the paragraph.

(Conducting

Ans Tissues which join different parts of the body are called connective tissues. Cells of this tissues are loosely arranged with a ground substance which may be solid, liquid like water or jelly like present in the free spaces in between. There are different types of connective tissues which includes: blood, lymph, areolar tissues, adipose tissues, cartilage, bones, tendons and ligaments.

2. Poultry farming.

Ans Poultry farming – Rearing of egg and meat yielding chickens is called poultry farming. The objectives behind development of new hybrid varieties.

3. Epithelial tissue.

Ans Epithelial tissue – Protective coverings in the animal body are called epithelial tissues. Cells in this tissue are closely packed and form continuous layers. Any material that enters the body first encounters epithelial tissue.

4.Tissue culture.

Ans Tissue culture – ‘Ex vivo growth of cells or tissues in an aseptic and nutrient-rich medium’ is called tissue culture. Nowadays, a complete organism can be developed from a single cell or from tissue with help of the tissue culture technique.

5.Write Short Note.

Ans i. Cells of the nervous tissue are specially made to be come excited and to conduct that excitation form one part of body to other.

ii. The cell body which contents the cytoplasm and the nucleus is the main part of each nerve cell. Numerous, small, branched fibres called dendrites arise from the cell body.

One of the fibres, however, is extremely long. It is called as the axon. The length of a nerve cell may even

Iii .be up to one meter. Many nerve cells are bound together with the help of connective tissue to form a nerve.

iv. Nervous tissue is present in the brain, spinal cord and the network of nerves spread all through the body.

6. Tissue

Ans Tissue – ‘A group of cells having the same origin, same structure and same function is called ‘tissue’.

Q. 20. Answer the following in detail 15

1. Explain the meaning of biotechnology and its impact on agricultural management with suitable examples.

Ans i. Tissue culture can be used to grow those plants on a large scale, which bear flowers, fruits of excellent quality.

1. Fully grown plants can be produced in shorter durations.
2. Plants can be grown on a large scale even if means of pollination or germinating seeds are not available. For example, orchids or pitcher plant do not germinate but these plants can easily be produced by means of tissue culture.
3. In a bioreactor, cells can be grown in a more nutritive medium and protected from pathogens. Bioreactors are useful for producing pantalets on a very large scale.
4. Large numbers of seedlings/pantalets can be produced in a short time using minimum resources and materials.
5. Usually, plants produced by tissue culture and genetic modification techniques are disease-free. Plantlets produced by tissue culture of the meristem are virus-free.
6. Embryos formed by conventional hybridization technique between two or more varieties may not grow fully for some reasons. However, embryos produced by tissue culture technique always complete their growth.
7. Rare and endangered plants can be grown by tissue culture technique and can thus be protected from extinction. Similarly, various parts and seeds of such plants can be preserved by tissue culture and those varieties can be protected.

2. In India, animal husbandry is practised for milk production and for using the cattle as help in farming operations. Explain.

Ans i. The number of cattle, their variety, total milk production, cleanliness in cattle-shed, arrangements for health care of cattle.

ii. In India, animal husbandry is practised for milk production and for using the catttle as help in farming operations. Ex. Cows and buffaloes are raised for milk and bulls and male buffaloes for pulling the heavy loads.

iii. Local Indian varieties of cows like sahiwal, sindhi, gir, lal kandhari, devni, khillari, dangi, etc. and exotic varieties like jersey, brown Swiss, Holstein, etc. are kept for their milk. Proper care of cattle is necessary for a clean and high yield of milk.

iv. A balanced diet i.e. which includes all constituents of food should be given to cattle. It must include fibre- rich coarse food, fodder, and sufficient water.

v. The cattle-shed should be clean and dry with proper ventilation and a roof.

vi. Cattle should be regularly vaccinated.

3. Application of biotechnology in floriculture, nurseries and forestry. [Any 5 points]

Ans i. Tissue culture can be used to grow those plants on a large scale, which bear flowers, fruits of excellent quality.

ii. Fully grown plants can be produced in shorter durations.

iii. Plants can be grown on a large scale even if means of pollination or germinating seeds are not available. For example, orchids or pitcher plant do not germinate but these plants can easily be produced by means of tissue culture.

iv. In a bioreactor, cells can be grown in a more nutritive medium and protected from pathogens. Bioreactors are useful for producing plantlets on a very large scale.

v. Large numbers of seedlings/plantlets can be produced in a short time using minimum resources and materials.

vi. Usually, plants produced by tissue culture and genetic modification techniques are disease-free. Plantlets produced by tissue culture of the meristem are virus-free.

vii. Embryos formed by conventional hybridization technique between two or more varieties may not grow fully for some reasons. However, embryos produced by tissue culture technique always complete their growth.

Viii. Rare and endangered plants can be grown by tissue culture technique and can thus be protected from extinction. Similarly, various parts and seeds of such plants can be preserved by tissue culture and those varieties can be protected.