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26 Feb 2026

Introduction to Biotechnology Class 9 Science Chapter 17 Questions And Answers Maharashtra Board

1. 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.d. Striated muscles are also called involuntary muscles.e. Chloroplast is present in permanent tissue. Answer. a. False. Ciliated columnar epithelium is present in respiratory tract.b. False. Cuboidal epithelium is present in kidneys.c. False. Aerenchyma helps the plant to float in water.d. False. Striated muscles are also called voluntary muscles.e. False. Chlorenchyma is present in permanent tissue. 2.Identify the odd word and explain why it is odd. a. Xylem, phloem, permanent tissue, meristematic tissue. Answer. Meristematic tissue. It has the ability to divide whereas the others have lost the ability to divide. b. Epithelium, Muscle fibre, nerve fibre, the epidermis. Answer. Epidermis. It is a plant tissue whereas the others are animal tissues. c. Cartilage, bone, tendon, cardiac muscle. Answer. Cardiac muscle. 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. Answer. Squamous epithelium. b. Tissue joining muscles and bones. Answer. Tendon c. Tissue responsible for increasing height of plants. Answer. Apical meristem. d. Tissue responsible for increasing girth of stem. Answer. Lateral meristem. 4. Write the differences.Simple tissue and complex tissues in plants. Answer. Simple Tissue in plants Complex Tissues in plants (i) They are made up of only one type of cells. (i) They are made up of more than one type of cells. (ii) They are found in all parts of the plant. (ii) They are found in the vascular regions of the plant. (iii) They perform different functions like storage (iii) They mainly perform the function of of food, support, giving strength etc. conduction of water and food. (iv) Examples – Parenchyma, Collenchyma, Sclerenchyma. (iv) Example – Xylem and phloem. 5. Write short notes. a. Meristematic tissue. Answer. b. Xylem Answer. c. Striated muscles. Answer. d. Agro-complementary business. Answer. (i) The business that are complementary to agriculture and generate supplementary income for the farmers are called agro complementary business. (ii) These include: e. Genetic engineering Answer. f. Sericulture Answer. 6. Explain the meaning of biotechnology and its impact on agricultural management with suitable examples. Answer. 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. Impact of biotechnology on agricultural management: 7.Which two main techniques are used in biotechnology? Why? Answer. 8. Discuss ‘Agritourism’ in the class and write a project on an agrotourism centre nearby. Present it in the class in groups. Answer. 9. Define the term tissue and explain the concept of tissue culture. Answer. A group of cells having the same origin, same structure and same function is called tissue. Concept of tissue culture: 10. ‘Rearing of sheep is a livestock’. Justify this statement. Answer.

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Class 8 | Science | Textbook Solutions | Maharashtra Board

20 Feb 2025

Class 8 | Science | Chapter 17 | Man Made Material | Exercise Solution | Maharashtra Board

1. Try to find it: a. Plastic shows …………. property, hence it can be moulded to any shape.Answer:Plastic shows plasticity property, hence it can be moulded to any shape. b. Motor cars are coated with ……… .Answer:Motor cars are coated with Teflon. c. Thermocol melts at ………… °C.Answer:Thermocol melts at more than 100 °C (it is about 240 °C). d. …………….. glass dissolves in water.Answer:Alkali silicate or water glass dissolves in water. 2. Who is my partner? Column ‘A’ Column ‘B’ 1. Lead glass a. Plates 2. Bakelite b. Mattresses 3. Thermocol c. Electric bulb 4. Optic glass d. Electric switch 5. Polypropylene e. Lens Answer: Column ‘A’ Column ‘B’ 1. Lead glass c. Electric bulb 2. Bakelite d. Electric switch 3. Thermocol a. Plates 4. Optic glass e. Lens 5. Polypropylene b. Mattresses 3. Answer the following. a. Thermocol is produced from which material?Answer:Thermocol is made from polystyrene which is also a complex thermoplastic substance. b. Write uses of PVC.Answer:PVC or Polyvinyl chloride is used for making bottles, raincoat, pipes, handbags, shoes, electric cable insulation, furniture, ropes, toys, etc. c. Write the natural or man-made raw material of the following items.Mattress, beaker, bangle, chair, gunny bag, broom, knife, pen.Answer: Items Natural raw material Man-made raw materials Mattress Cotton, Coir (Jute fibres) Polypropylene Beaker ___ Glass (Silicate or borosilicate glass) Bangle Gold, silver, lac, copper Plastic, Glass Chair Wood Plastic (PVC) Gunny bag Jute, cotton Plastic (PVC) Broom Plant fibres Plastic fibres (PVC) Knife Metals such as iron Plastic Pen Metals Plastic d. Which are the main ingredients of glass?Answer:The main ingredients of glass are sand and silica. e. How the plastic is produced?Answer: 4. Distinguish between. a. Man-made material and natural materialAnswer: Man-made material Natural material 1. The man-made materials are obtained from processes in scientific laboratory. 1. Natural materials are obtained from nature. 2. Man-made materials are subjected to rigorous processing to alter the material for serving the intended purpose. 2. Natural materials are subjected to less treatment and processing. 3. Man-made materials are typically much more durable having a very long lifespan. 3. Natural materials have shorter lifespan, because these materials were once alive and so gradually perish over time. 4. Maintaining man-made materials require less care and attention. 4. Maintaining natural materials requires lots of care and continuous attention. 5. Man-made materials can have a negative environmental impact because they are not sustainable.E.g. Glass, plastic, Thermocol, soil, metals, rubber. 5. Natural materials do not have a negative environmental impact because they can be degraded easily.E.g. Cotton, silk, wood. b. Thermoplastic and Thermosetting plastic:Answer: Thermoplastic Thermosetting plastic 1. The plastic that can be moulded as per our wish is called thermoplastic. 1. The plastic in which a specific shape is given with the help of mould and this shape cannot be changed again on heating is called thermosetting plastic. 2. Thermoplastic substances can be recycled and reused.E.g. PVC – Polyvinyl chloride, PS – Polystyrene, PE – Polyethylene and PP – Polypropylene are types of thermoplastics. 2. Thermosetting plastic cannot be reused again.E.g. Bakelite, Melamine, Polyurethane and polyster are the types of thermosetting plastics. 5. Answer the following in your own words. a. Explain the effect of following materials on environment and human health.1. Plastic2. Glass.3. Thermocol.Answer:1. Plastic: 2. Glass: 3. Thermocol: b. Which measures will you arrange to minimize the environmental problems arising due to non-degradable plastic?Answer: 6. Write short notes. a. Glass production:Answer:The general preparation of the glass is as follows: b. Optic glass:Answer: c. Uses of plastic:Answer:Plastic, the man-made material is used in various forms in modern age. According to the type of plastic, its uses are different. I. Thermoplastic materials are used for manufacturing following articles: II. Thermosetting plastic is used in the manufacturing of the following items:

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Class 7 | Science | Textbook Solutions | Maharashtra Board

8 Jul 2024

Class 7 | Science | Chapter 17 | Effects Of Light | Maharashtra Board | Solution

1. Fill in the blanks. a. When the beams from the headlights of a car fall on an object in the night, the shadows – called ………. and ………… . can be seen.Answer:umbra, penumbra b. During a lunar eclipse the shadow of the …………. falls on the ………. .Answer:earth, moon c. During a solar eclipse the shadow of the ………. falls on the ………… .Answer:moon, earth d. Various shades of colour are seen in the sky at sunrise and sunset due to ……….. .Answer:scattering of light 2. Give reasons. a. Space beyond the earth’s atmosphere appears dark.Answer: b. We are able to read while sitting in the shade.Answer: c. We should not observe the solar eclipse with naked eyes.Answer: 3. Give some examples of scattering of light that we come across in day-to-day life. Answer: 4. Why is the shadow of a bird flying high not seen on the earth? Answer: 5. Why is a penumbra not obtained from a point source? Answer: 6. Answer the following questions in your own words. a. What is meant by scattering of light?Answer: b. Does the shadow really vanish in the zero shadow condition?Answer:1. Yes, the day on which the sun reaches exactly overhead, at noon, shadow completely disappears.‘This event can be seen in the region between the Tropic of Cancer (23.5°N) and Tropic of Capricorn (23.5°S).2. The shadow diminishes and eventually disappears for a while only to reappear later. c. Will the laser beam be seen if it passes through a glass box which contains a lighted incense stick?Answer:Yes, it will be seen. 7. Discuss and write: a. Write a science based paragraph on ‘What if the sun did not rise’?Answer: b. What efforts will you make to remove the misconceptions about eclipses?Answer:Solar, lunar eclipse have been traditionally observed as an ominous sign and therefore superstitions are prevalent in association with these natural phenomena.1. All these misconceptions should be removed by explaining scientifically the process of eclipse how it happens: (a) Explain with the help of diagram and models of sun, moon and earth, (b) Explain how special glasses which will protect us from UV rays, and excess heat can be used to observe eclipses safely.2. Also inform that eclipses are natural phenomena and can be predicted in advance. c. Various eclipses and the conditions during that period.Answer:There are two eclipses: 1. Solar eclipse:There are two types of Solar eclipse, (a) Total solar eclipse (b) Partial solar eclipse a. Total solar eclipse: In total solar eclipse, the moon is between the sun and the earth and the moon shadow covers the sun disc fully by perfect alignment. The part of the earth that lies in the umbra of the moon experiences total solar eclipse. b. Partial solar eclipse: In partial solar eclipse, the moon is between the sun and the earth arid the moon shadow does not cover the sun disc fully, because of imperfect alignment. The part of the earth that lies in the penumbra of the moon experiences partial solar eclipse. c. The solar eclipse occur on a new moon day.d. Solar eclipse last for few minutes. 2. Lunar eclipse:There are two types of Lunar eclipse, (a) Total lunar eclipse (b) Partial lunar eclipse a. Total lunar eclipse: In total lunar eclipse, the earth comes in between the sun and the moon and the earth’s shadow covers the moon’s surface fully because of perfect alignment. b. Partial lunar eclipse: In partial lunar eclipse, the earth’s shadow does not cover the moon’s surface fully because of inperfect alignment. A small part of the moon’s surface is covered by umbra part of earth’s shadow. c. The lunar eclipse occurs on a full moon night.d. Lunar eclipse last for few hours. 8. Explain the difference: a. Point sources and Extended sources.Answer: Point sources Extended sources 1. A source of radiation light that is concentrated at a point and considered as having no spatial extension. 1. An extended source is a source consisting of many point sources separated internally. 2. Shadow we get from a point source is dark called umbra. 2. Shadow we get from extended source of light is faint called penumbra and dark called umbra b. Umbra and Penumbra.Answer: Umbra Penumbra 1. The umbra is a central core of darkness which tapers away. 1. The penumbra is an outer cone of partial shadow which diverges, instead of tapering. 2. Umbra is shadow formed from a point source of light. 2. It is the shadow formed from the extended source of light. 3. It is dark 3. It is faint 4. Umbra is the area of total shadow 4. Penumbra is the area of partial shadow.

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