Maharashtra State Board – Standard IX

Science

Chapter 17 – Introduction to Biotechnology

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

1. Simple squamous epithelium is present in respiratory tract.
Ans: Ciliated columnar epithelium is present in the respiratory tract.

2. Glandular epithelium is present in kidneys.
Ans: Cuboidal epithelium is present in the kidneys.

3. Chlorenchyma helps the plant to float in water.
Ans: Aerenchyma helps the plant to float in water.

4. Striated muscles are also called in-voluntary muscles.
Ans: Striated muscles are also called voluntary muscles.

5. Chloroplast is present in permanent tissue.
Ans: Chlorenchyma is a type of permanent tissue.

🔹 2. Identify the odd word and explain why it is odd.

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

Ans: Meristematic tissue is the odd word because it has the ability to divide, whereas the others are permanent tissues and do not divide.

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

Ans: Epidermis is the odd word because it is a plant tissue, whereas the others are animal tissues.

c. Cartilage, bone, tendon, cardiac muscle.

Ans: Cardiac muscle is the odd word because it is a muscular tissue, whereas the others are connective tissues.

🔹 3. Write the names of the following tissues.

a. Tissue lining inner surface of mouth.

Ans: Squamous epithelium.

b. Tissue joining muscles and bones.

Ans: Tendon.

c. Tissue responsible for increasing height of plants.

Ans: Apical meristem.

d. Tissue responsible for increasing girth of stem.

Ans: Lateral meristem.

🔹 4. Write the differences.

Simple tissue and complex tissues in plants.

Simple TissuesComplex Tissues
(i) They are made up of only one type of cell.(i) They are made up of more than one type of cell.
(ii) They are found in different parts of the plant.(ii) They are mainly found in the vascular region of the plant.
(iii) They perform functions like storage of food, support, and strength.(iii) They mainly perform the function of conduction of water and food.
(iv) Examples: Parenchyma, Collenchyma, Sclerenchyma.(iv) Examples: Xylem and Phloem.

🔹 5. Write short notes.

a. Meristematic tissue

Ans:

  1. Meristematic tissue is present in specific regions of a plant where growth takes place.
  2. The cells of meristematic tissue have dense cytoplasm, a prominent nucleus, and thin cell walls.
  3. These cells are compactly arranged and usually lack vacuoles.
  4. They actively divide and help in plant growth.
  5. Based on location, meristematic tissues are of three types: apical meristem, intercalary meristem, and lateral meristem.

b. Xylem

Ans:

  1. Xylem is a complex permanent tissue in plants.
  2. It mainly consists of thick-walled dead cells.
  3. The components of xylem are tracheids, vessels, xylem fibres (dead cells), and xylem parenchyma (living cells).
  4. Xylem conducts water and minerals from the roots to other parts of the plant in an upward direction.

c. Striated muscles

Ans:

  1. The cells of striated muscles are long, cylindrical, multinucleate, and unbranched.
  2. These muscles show alternate dark and light bands.
  3. They are attached to bones and are therefore called skeletal muscles.
  4. They work according to our will and are called voluntary muscles.
  5. They help in movements such as walking, running, and speaking.

d. Agro-complementary business

Ans:

  1. Agro-complementary businesses are activities related to agriculture that provide additional income to farmers.
  2. These include animal husbandry, poultry farming, and sericulture.

Examples:

  • Animal husbandry: Rearing cows and buffaloes for milk and bulls for farming work.
  • Poultry farming: Rearing chickens for eggs (layers) and meat (broilers).
  • Sericulture: Rearing silkworms for silk production.

e. Genetic engineering

Ans:

  1. Genetic engineering is the deliberate modification of an organism’s genetic material to change its characteristics.
  2. Organisms produced by this method are called genetically modified organisms (GMOs).
  3. It is used in agriculture, medicine, research, and industry.
  4. In agriculture, it helps to develop high-yield and stress-resistant crops.
  5. In medicine, it is used for vaccine production, disease diagnosis, organ transplant research, and the production of artificial tissues.

f. Sericulture

Ans:

  1. Sericulture is the rearing of silkworms for the production of silk.
  2. Bombyx mori is the most commonly used silkworm species.
  3. The life cycle includes four stages: egg, larva, pupa, and adult.
  4. The larvae feed on mulberry leaves.
  5. They secrete silk from their salivary glands and spin a cocoon around themselves.
  6. The cocoons are processed to obtain silk fibres, which are woven into silk fabric.

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

Ans:

Biotechnology is the use of living organisms or their components to develop useful products and improve plants and animals for human welfare.

Impact on agricultural management:

  1. Genetically modified (GM) crops are developed by altering the DNA of plants.
  2. GM crops can tolerate environmental stresses like drought and temperature changes.
  3. These crops are resistant to pests and diseases, reducing the use of pesticides.
  4. Biotechnology improves the nutritional value and yield of crops.
  5. It reduces crop losses and increases farmers’ income.

🔹 7. Which two main techniques are used in biotechnology? Why?

Ans:

  1. The two main techniques used in biotechnology are genetic engineering and tissue culture.
  2. These techniques help to improve living organisms through artificial genetic changes and controlled growth.
  3. They are used in agriculture, medicine, research, and industry for the welfare of human beings.

🔹 8. Discuss ‘Agritourism’ in the class and write a project on an agro-tourism centre nearby. Present it in the class in groups.

Ans:

  1. Agritourism is a form of tourism where people visit farms to experience rural life and agricultural activities.
  2. An agritourism centre may include fruit orchards, vegetable gardens, and ornamental plants.
  3. It can also have a butterfly garden, medicinal plant garden, and organic farming area.
  4. Visitors can purchase fresh fruits, vegetables, and plant saplings.
  5. Agritourism provides additional income to farmers and promotes awareness about agriculture.

🔹 9. Define the term tissue and explain the concept of tissue culture.

Ans:

A tissue is a group of cells having the same origin, structure, and function.

Concept of tissue culture:

  1. Tissue culture is the growth of cells or tissues outside the organism in a sterile, nutrient-rich medium.
  2. A complete plant can be developed from a single cell using this technique.
  3. The medium contains nutrients and growth substances necessary for development.
  4. Tissue culture helps in producing disease-free and high-quality plants in a short time.
  5. It is widely used in agriculture and horticulture.

🔹 10. ‘Rearing of sheep is a livestock’. Justify this statement.

Ans:

  1. Sheep are reared to obtain useful products like wool, meat, and milk.
  2. These products can be sold in the market to earn income.
  3. Wool obtained from sheep is used to make woollen clothes.
  4. Since sheep provide economic benefits, their rearing is considered a part of livestock farming.
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