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(a) The larger molecules are of the solute (dye)

(b) The smaller molecules are of the solvent (water)

1. Thermoplastic: As these plastic are soften on heating, they can be recycled, reused, coloured, melted and moulded into different shape.
Some thermoplastic and their uses are mentioned below:
(a) FVC: one of the most commonly used plastic is PVC (polyvinyl chloride). PVC is used as a building material and to make enclosure for electronic item.
(b) Teflon: Teflon is a scratch proof, corrosion-resistant plastic, which is used to provide protective covering to materials.
(c) Polyethylene (PE): It has a wide range of inexpensive uses that include making supermarkets bags, plastic bottle, packing material for milk, and some other liquid.
(d) Polystyrene (PS): It is used for making disposable untensils, food container, cover for CD and cassettes.

2. Thermosetting: Such plastic once moulded cannot be heated and recanted into another. Some thermosetting plastic are:
(a) Bakelite: Bakelite is used for making plugs, sockets, switches and other electrical fitting.
(b) Melamine: It is used for making unbreakable kitchenware. Melamine plastic is also coated on the uniform of firemen.

Plastic is a polymer which is easily moulded or set into any desired shape when heated. It hardens on cooling to make a durable object.

(b) Bakelite

Mining of coal and stone releases coal dust and stone dust that cause air pollution.

The Archeological department declared that  \(2\frac{1}2\) km around Taj Mahal is no drive zone.

Testes are responsible for the production of male gametes i.e. sperms. The normal body temperature does not allow the maturation of the sperms. Being suspended outside the body cavity, the temperature in the scrotal sac is 2 to 3oC which is the suitable temperature for the maturation of the sperms

When it is too hot, the skin of the scrotum loosens so that the testes hang down away from the body. When it is too cold, the skin contracts in a folded manner and draws the testes closer to the body for warmth.

In an abnormal condition, in the embryonic stage, the testes do not descend into the scrotum. It can lead to sterility or incapability to produce sperms.

As the concentration of solvent molecules is more in the left side of the figure A. The cell membrane will act as semi permeable membrane and will allow only the solvent molecules of water to move owards the solute particles. So the solvent molecules will move towards the solute particles. This will show the phenomenon or process of osmosis.

Polyester is a synthetic fibre made from petroleum product which contain a large number of esters. It has the property of repelling water, known as hydrophobia. Blended fibres are more comfortable than synthetic fibres and are easier to maintain
than natural fibre. Properties of polyester:

• It is a very strong fibre. Polyester clothes are quite durable.
• Polyester clothes are easy to maintain their wrinkle free and resist wear and tear.
• Polyester is light in weight and elastic.

Uses of polyester:

• It is a popular fibre for making shirt, trouser, saree and other dress material.
• It is used to make sail of sailing boat as it is least.
• Hollow polyester fibre trap heat. Hence, they are used to mae jacket, sleeping bags, etc.
• In industry polyester is used to make bottle, jar, utensils, wire, films and many other useful product.

Extensive use of synthetic polymers has led to certain environmental hazards, making with a matter of global concern, plastic proved to be a magical material for the world because of its properties, but it has a negative side also.

They are:

1. Plastic cause health hazards and are very harmful to the environment, as they are non-biodegradable and cannot be decomposed by micro-organisms.
2. Hence they prevent rain water from seeping into the earth and affect plant growth.
3. Plastics lying on roadsides and floating in lakes and streams provide shelter for germs and animals causing diseases.
4. Toxic to aquatic life when placed in water.
5. Produce toxic gases when burnt, hence causing air pollution.
6. Take several years to decompose.
   To avoid these problems we should prevent-
7. By recycling which involved collecting, sorting and processing the plastic.
8. Follow 4R principal – reduce, reuse, recycle and recover.
9. Making use of cotton jute bags while shopping.
10. By dividing the garbage into biodegradable and non-biodegradable wastes and hence recycling the non-biodegradable wastes.

The motor vehicles and the Industries located in and around Agra for rubber processing, chemicals oil refinery of Mathura, iron foundries have been responsible for the colour change of Taj Mahal from white to yellow.

Activity:
Put some hot water in a plastic bucket and try to press it. You will feel that the bucket has become comparatively soft. Now at the time of cooking try to press the handle of the pressure cooker. You observe that handle neither becomes hot nor soft, that is both the bucket and handle made of plastics show different properties. This is because the internal structures of both are different. 

Thus plastics are of two types:

(a) Thermoplastic (thermally soft) i.e. it becomes soft on heating.
(b) Thermosetting plastic (thermally strong) i.e. it remains hard and retains its property even on heating.

Nylon is prepared by mixing of adipic acid and hexamethylene diamine. It is completely a synthetic fibre.

1. Nylon fibre is a strong plastic and light.
2. It is lustrous and easy to wash.
3. Clothes made from nylon does not get wrinkle and stable for long time.
4. This is durable.
5. They soak less water and dry up easily.
6. Clothes of nylon does not have threat of clothes worn.
7. They do not need extra care.

Incinerators: The instruments used for burning plastic.

Nylon: The polymer is made of chemical units called polyamides.

In the true sense or literally rayon is not considered as a synthetic fibre completely because, it involves the regeneration of cellulose from naturkl resources, in the synthesis, to improve the quality of fibre. Hence it is also called as modified natural fibre.

The correct answer is Whittaker.

D) Charles Darwin

Scientific reason behind why testes located in the scrotal sac because in testes sperm are produced. Sperm need an optimum temperature to form properly. The testes being located outside the body enable the whole system regulate temperature. Sperm production works best at temperatures slightly lower than body temperature. The scrotum allows for some regulation. When it's cold, the testes are pulled in close to the body. If it is hot, they hang real low. 

(a) Plants continuously absorb water through their roots. This water is sent up through the stem to all parts of the plant, including the leaves. Only a little amount, of water is retained in the plant or utilised by it in photosynthesis. The rest of it gets evaporated into the atmosphere as water vapour through the stomata present in the epidermis of the leaves and other aerial parts of the plant. This creates a suction pressure which pulls up water from xylem of the roots to the stem and then to the leaves. 

(b) Xylem tissues are in the form of capillary tubes (tracheids and fibres) where narrower the diameter, greater will be the force. Whenever the xylem vessels lay empty, such as during the loss of water by transpiration, the water from below rises into them by a capillary force. 

During day time, water is lost from the surface of the leaves by the process of transpiration. In this process, more and more water molecules are pulled up due to their tendency of rentainingjoined (cohesion). Such pulling force created by the leaves is very important in the case of tall trees where an upward conduction of water takes place.

1. What is environmental pollution? 

2. What are the natural disasters of pollution? 

3. What are the human activities that leads to pollution? 

4. What is the unforgettable industrial tragedy took place in Bhopal on second December 

5. Who is responsible for thepollution in Patancheru ? What are the interim orders, released by supreme court of India for the sake of people and environment? 

6. What is the sad story of River Musi? 

7. Can we save Taj Mahal from pollution? What is the present situation of Taj Mahal? 

8. Natural resources are the devine gift for us by nature. Can we keep these resources clean and healthy for the future generations? What is your role and response towards this?

Controlling measures of soil pollution:

1. Limit the use of fertilizers and pesticides. 

2. Awareness about biological control methods and their implementation. 

3. The grazing of cattle must be controlled and forest management should be done properly. 

4. The afforestation and reforestation must take place. 

5. Proper preventing methods like shields should be used in areas of wind erosion .and wind breakes. 

6. Remember to carry paper bags and minimising plastic bags. 

7. The soil binding grass must be planted and the large trees must be plant along the banks. 

8. Industrial waste must be dumped in the low lying areas. 

9. There should be a definite technic of cropping which does not allow weeds to settle on the fields.

10. The mining waste must be improved along with the transportation. 

11. The are must not be left barren and dry.

Melamine is versatile material. It resists fire and can tolerate heat better than other plastics. It is used for making floor tiles, kitchenware and fabrics which resists fire.

Melamine: It is a thermosetting plastic used for making utensils and groceries.

Bakelite and Melamine are examples of Thermosetting plastics.

1. Slogans towards biodiversity: 

2. Segregate the reusable waste. 

3. Don’t produce lot of waste. 

4. Don’t use plastic covers. 

5. Compost the wet waste. 

6. Turn the waste into compost. 

7. Make Compost out of fallen leaves. 

8. Never burn the fallen leaves of trees. 

9. Use bicycles if the destination is manageable. 

10. Plant trees in vacant places and take care to ensure their growth. 

11. Grow plants and protect them for fresh air and ventilation. 

12. Use cattle dung, organic fertilizers. 

13. Practice eco-friendly methods. 

14. Strictly follow environmental policies and laws. 

15. Limit the use of fire wood and use bio fuels for cooking. 

16. Plant a sapling on your birthday water it every day. 

17. Wash your hands, feet close to the trees and plants.

• In 1758, Carl Linneaus proposed a system that has dominated classification for centuries. 
• Linneaus gave each organism two names denoting genus and species. 
• He grouped genera into families, families into orders, orders into classes, classes into Phyla, and Phyla into kingdoms. 
• Linneaus identified two kingdoms. Animalia (animals) and Plantae (plants). 
• Linneaus classified organisms on the basis of the similarities and differences.

C) Class, Family

Boys begin to have thick hair growth on the face. Their voice begins to crack.

We can be prevented by sanitizing, using mask, and maintaining social distance.

a) No. Every leaf has its size, shape and colour are same in many of the leaves.

b) 

1. Length and breadth of the leaves are different for each leaf. 

2. Most of the leaves have reticulate venation but only in plantain parallel venation is present.

1. Stop pollution – Save life 

2. Polluting water – Ending our lives 

3. Save the nature – Nature will save you 

4. Live and let live. 

5. Nature is for humans need – Not for his greed. 

6. Solar energy – Forever energy

1. Melamine is used in making of utensils and other grocery of kitchen. 

2. It is used for making of floor and dress material (firemen dress) for their nature of fire resistance. 

3. Computer and T.V. cabinets are made by melamine.

B) Angiosperms

D) All the above

a) Body is covered with scales.

b) On the head, on the tail, fins and on the lower side of the fish.

c) Teeth are present in the mouth. Tongue is also present.

a) The outer body is covered with shell.

b) The animal creeps by its ventral muscular foot. The movement is gliding movement.

c) The body of the snail is soft.

d) Yes, Tentacles are present.

At the time of puberty, breast size begins to increase, with darkening of the skin of the nipples. Also, girls begin to menstruate at around this time.

a) Evil effects of smoking : 

Smoking is injurious to health. Say YES to NO SMOKING Be smart, Don’t start Smoking? You must be joking You don’t have to smoke to be hot! Be Cool – Don’t Be a Smoking Fool 

Don’t take smoke as a joke Smokers are jokers Don’t put your lips on fire 

b) COVID-19 prevention Follow the SMS always 

SMS means social distance, mask and sanitization 

Don’t neglect be cautious Wash the hand regularly Break the chain to kill the corona Minimum distance is maximum safe

B) Phylum, class, order, family, genus, species

Our basis of classification would be whether the organism. 

1. Has a prokaryotic or eukaryotic cell 

2. Is unicellular or multicellular 

3. Is autotrophic or heterotrophic 

4. Mode of reproduction. Like that, I classify the organism in an orderly manner.

Classification system has gone changes over the years due to the new discovered organisms, advancement in genetic science invention of powerful microscope.

Need of classification :

1. Classification gives better knowledge and better understanding of organisms that are studied.

2. It helps to study the organisms in a proper and systematic manner. 

3. Classification helps to make comparison in an easier way. 

4. It helps in understanding relationship among the organisms and their interdependence. 

5. Classification makes our study more focused and helps us to handle huge population of organisms. 

6. Classification gives us an idea of evolution.

Questions:

1. Who made the classification? 

2. What are the advantages of classification? 

3. What are the recent developments being done?

• What is the basis of classification? 
• Why should we consider evolution in classification of animals and plants? 
• How should we classify the organisms of the same species basing on their variations? 
• How should we classify the organisms scientifically?

Correct option is B) Indian

a) These are spiny skinned organisms. 

b) Exclusively marine animals. 

c) Water vascular system is present. 

d) They have hard calcium carbonate structures that they use as a skeleton.

Correct option is D) Ecology

The process in which the cytoplasm of a single eukaryotic cell is divided to form two daughter cells is known as Mitosis 

D) All the above