Maharashtra Board Class 9 Science Solution Chapter 17 – Introduction to Biotechnology
Balbharati Maharashtra Board Class 9 Science Solution Chapter 17: Introduction to Biotechnology. Marathi or English Medium Students of Class 9 get here Introduction to Biotechnology full Exercise Solution.
Std |
Maharashtra Class 9 |
Subject |
Science Solution |
Chapter |
Introduction to Biotechnology |
1.) Each of the following statement is wrong. Rewrite the 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.
d) Striated muscle are also called involuntary muscle.
e) Chloroplast is present in permanent tissue.
Ans:
a) Simple squamous epithelium is present in oesophagus.
b) Glandular epithelium is present in inner layer of skin.
c) Chlorenchyma helps the plant to perform photosynthesis.
d) Striated muscle are also called voluntary muscle.
e) Chloroplast is present in simple permanent tissue.
2.) Identify the odd word and explain why it is odd.
Ans:
a) Xylem, phloem, permanent tissue, meristematic tissue.
Odd word: meristematic tissue, because other xylem and phloem are the permanent tissue types.
b) epithelium, muscle fibres, nerve fibre, epidermis.
Odd word: epidermis, because epidermis is the outer layer of cell found in plants while remaining are the types of tissues.
c) cartilage, bone, tendon, cardiac muscle.
Odd word: cardiac muscle, because cardiac muscle is the muscular tissue while all the others are the connective tissue.
3.) Write the names of the following tissues.
Ans:
a) Tissue lining inner surface of mouth:
The tissue lining inner surface of mouth are squamous epithelium.
b) Tissue joining muscles and bones:
The tissue joining muscles and bones are tendons.
c) Tissue responsible for increasing height of plants:
The tissue responsible for increasing height of plants are apical meristem.
d) Tissues responsible for increasing girth of stem:
The tissue responsible for increasing girth of stem are lateral meristem.
4.) Write the differences.
- a) Simple tissue and complex tissue in plants
Ans:
Simple tissue in plants:
- Simple tissue are those tissue which are made up of only one type of cells.
- The types of simple permanent tissues are parenchyma, collenchyma and sclerenchyma.
- Sole tissue are found in all parts of the plant body.
- Parenchyma tissues has functions to support, storage of food and fills the vacant spaces.
- Collenchyma tissue has functions to support and gives flexibility to various plants.
- Sclerenchyma tissue gives strength and rigidity to parts of the plant body.
Complex tissue in plants:
- Complex tissue in plants are those tissue which are made from different types of cells.
- Complex tissue in plants mainly consist of xylem and phloem.
- The complex tissue in plant occurs only in vascular region of plant body.
- Xylem conducts water and minerals only in upward direction while the phloem conduct sugar, amino Acids from leaves to various parts in upward as well as downward direction.
5.) Write short notes.
a) Meristematic tissue:
Ans:
- Meristematic tissue are present in specific part of the plants and hence growth would be occured in those plants only.
- The meristematic cells contains the thick cytoplasm, a conspicuous nucleus and a thin cell wall which are completely packed together but vacuoles are absent in these cells.
- As these cells are highly active they brings the plant growth.
- There are three types of meristematic tissue in the basis of their location as given below.
- Apical meristem which are located at the tip of the root and stem and they increases the length of the root and stem.
- Intercalary meristem are located at the base of petiole of leaves and branches which helps in growing the branches, formation of leaves and flowers.
- Lateral meristem which are located at the lateral side of root and stem and increases the girth of the root and stem.
b) Xylem:
- The complex tissue in plants are those tissue which are made up of more than one type of cells.
- Xylem and phloem in plants are the complex permanent tissue.
- Xylem is having thick walled dead cells.
- The types of cells present in xylem are tracheids, vessels and xylem fibres dead cells and xylem parenchyma living cells.
- Xylem tubes are having the structure like interconnected tubes which conduct the water and minerals only in upward direction.
c) Striated muscle:
- Muscular tissue are made from long cells of muscle fibres and muscular movement occurs due to the contraction and relaxation of the contractile proteins in the cells.
- There are three types of muscular tissue namely striated muscle, non striated muscle and cardiac muscle.
- Striated muscle cells are the long, cylindrical, multinucleated and having no branches.
- On these muscles there are the alternate bright and dark bands are present which are attached to the bones and hence called as skeletal muscles.
- As there movement is according to our will hence they are called as voluntary muscle.
- These muscles brought the movement of arms and legs, also running and speaking.
d) Agro complementary business:
- Agro complementary business are developed to get more yielding breed with well economic benefits. Agro complementary business includes animal husbandry, poultry farming and sericulture.
- Animal husbandry is developed for producing more milk and for using cattle in helping the farming operations.
- In India, cows and buffaloes are raised for milk while bulls and male buffaloes are used for pulling heavy loads.
- In poultry farming, there is a egg rearing mad meat yilding chickens occurs.
- In India, Aseeel and exotic varieties like Leghorn are used to produce quality chickens in large numbers.
- In sericulture, silkworms are reared for producing silk. Bombyx Mori is the variety used mostly for silk production.
- e) Genetic engineering:
- It has become possible to plants and also animals having some new characters along with their natural characters only by using the technology called as biotechnology.
- This can be done by bringing the artificial genetic changes and by hybridisation for the welfare of human beings which are collectively called as biotechnology.
- Biotechnology includes genetic engineering and also tissue culture.
- These techniques are used in producing cash crops, improvement in varieties of cash crops, to increase the ability of plants to withstand environmental stresses, vaccine production, early diagnosis of congenital diseases, organ transplant, cancer research, production of artificial skin, cartilage etc. in laboratories.
- Thus, there are huge applications of biotechnology in genetic engineering.
f) Sericulture:
- In Sericulture, silk worms are reared for producing silk. The most commonly used variety for this production is Bombyx Mori.
- The life cycle of silk moth has four stages namely egg, larva, pupa and adult.
- When thousands of eggs are deposited by female moth which are then incubated artificially and hence the incubation period is shortened.
- The hatching of larvae released from eggs will be takes place at mulberry plants. They get their nourishment through feeding on mulberry leaves.
- Larvae move to branches of mulberry plants after feeding for 3-4 days.
- And the silk thread is formed due to the secretion of their salivary glands.
- By spinning this thread around the larvae they forms the cocoon which may be spherical shape.
- The pups turns into adult before ten days of all the cocoon are transferred into the boiling water.
- As the water is boiling the pups get died in cocoon and silk fibres get loosed.
- After these fibres are unwound, processed and reeled and from this silk threads various types of fabrics are woven.
6.) Explain the meaning of biotechnology and its impact on agricultural management with suitable example.
Ans:
- It has become possible to plants and also animals having some new characters along with their natural characters only by using the technology called as biotechnology.
- This can be done by bringing the artificial genetic changes and by hybridisation for the welfare of human beings which are collectively called as biotechnology.
- Following are the impacts of biotechnology on agricultural management:
- Genetically modified crops are formed by introducing the changes in DNA of natural crops. But that types of varieties are not found in nature.
- Hence artificially these varieties are produced by introducing different useful characters.
- There are some natural occuring varieties which cannot withstand environmental stresses like changing temperature, wet and dry famines, changing climate etc while the genetically modified crops grown in any type of such adverse conditions.
- GM crops are resistant to insect pest, pathogens, chemical weedicides etc hence the use of harmful chemicals can be avoided.
- By using seeds of GM crops there will be increase in nutritive value and the decrease in loss of crops will occurs.
- Hence, due to better quality of crops are produced farmers are using GM crops cultivation all over the world on large scale.
- The high yielding varieties of GM crops are banana, maize, papaya, beet, rose, tobacco, wheat etc. are available.
- While the pest resistant genes are introduced in the some GM crops which are given below.
Maize: MON 810, MON 863
Potato: Amflora
Rice: Golden rice
Soyabean: Vistive gold
Tomato: Vaishali
Cotton: BT cotton
7.) Which two main techniques are used in biotechnology? Why?
Ans:
- It has become possible to plants and also animals having some new characters along with their natural characters only by using the technology called as biotechnology.
- This can be done by bringing the artificial genetic changes and by hybridisation for the welfare of human beings which are collectively called as biotechnology.
- Biotechnology includes genetic engineering and also tissue culture.
- These techniques are used in producing cash crops, improvement in varieties of cash crops, to increase the ability of plants to withstand environmental stresses, vaccine production, early diagnosis of congenital diseases, organ transplant, cancer research, production of artificial skin, cartilage etc. in laboratories.
- Thus, there are huge applications of biotechnology in genetic engineering.
8.) Define the term tissue and explain the concept of tissue culture.
Ans:
- The group of cells having the same origin, same structure and same function is called tissue.
- Ex vivo growth of cells or tissue in an aseptic and nutrient rich medium is called as the tissue culture.
- Now a days we can develop a complete organism from a single cell or single tissue by using tissue culture technique.
- The liquid, solid or gel like medium prepared from sugar which supplies the nutrients and energy necessary for tissue culture technique are used in this technique.
- In this method, under sterile condition some plant tissue are taken which are kept in tubes consisting of culture medium which helps in growing the cells fast and forms the unorganized mass of cells called as callus which transferred into another medium consisting of well growth hormones. Finally, small plant let’s are formed which are then placed in soil to grow into mature plants. And the technique is called as micro propagation.
9.) Rearing of sheep is livestock. Justify the statement.
Ans:
- Sheep are mainly reared as domestic animal for milk, meat and wool production.
- It is the traditional business which helps in many purposes and most of the people are based on these occupation also all over the world.
- The sheep rearing is nothing but the farming of sheep for various purposes and getting economic benefits also.