Fibres are very thin, thread like strands from which fabrics are made. The fibres which are obtained from plants and animals are called natural fibres.

Cotton and jute are obtained from plants.

Wool and silk are obtained from animals.

A galaxy is a huge collection of gas, dust, and billions of stars and their solar systems. A galaxy is held together by gravity. Our galaxy, the Milky Way, also has a supermassive black hole in the middle. The Milky Way's disk spans at least 100,000 light-years and probably contains several hundred billion stars, which makes our home galaxy a giant. The smallest known galaxies in the Universe are actually tiny satellites of the Milky Way: objects like Segue 1 and Segue 3. They contain only a few hundred stars, orbiting their combined center of mass at less than the speed that Earth orbits the Sun: just 15 km/s.

Sirius is the brightest star in the night sky. Its name is derived from the Greek word Σείριος Seirios "glowing" or "scorching".Sirius, also called Alpha Canis Majoris or the Dog Star, brightest star in the night sky, with apparent visual magnitude −1.46. It is a binary star in the constellation Canis Major. Although white to blue-white in color, Sirius might be called a rainbow star, as it often flickers with many colors. 

Metamorphosis is a biological process in which a larva transforms into an adult. It involves sudden and abrupt changes in the body structure of the animal by cell growth and differentiation. It is generally observed in amphibians (e.g., frogs) and insects (e.g., butterflies), etc.
The life cycle of a frog has three life stages.

• Eggs Eggs are the result of external fertilisation which transform into fish like tadpoles.
• TadpoleTadpole has gills, small mouth and fish like tail to swim inside lakes and ponds.
• Frog: Tadpole grows and transforms into a small frog which is an amphibian by nature.

Following are the four ways to prevent water pollution:
1.Chemical industries which pollutes the water most should be set up away from rivers and water reservoirs.
2.Waste water of industries should not be directly disposed off in the rivers.
3.Water of industries should not only be purified but also used for irrigation.
4. People should not bathe in rivers and should not wash their clothes in rivers. 

Friction can be increased by the following methods:

1. Grooves are made in the soles of shoes to increase friction and prevent slipping.
2. Treads are made in the tyres of vehicles to increase friction and prevent skidding of vehicles on wet roads.
3. Spikes are provided in the shoes of players and athletes to increase friction and prevent slipping.
4. Gymnasts apply some coarse substance on their hands to increase friction for better grip.
5. Machine belts are made of special materials to increase friction and drive machine wheels properly.

(i) Buckets made of iron get rusted but those made of plastic are not rusted.
(ii) Food can be stored in plastic containers, as they are resistant to chemicals in the food
(iii) Teflon coated pans are used instead of metallic as it does not react with chemicals in the food.

All the crops need water for their growth which they absorb from the soil. The process of supplying water to the crop plants in the fields is called irrigation. The time and frequency of irrigation varies from crop to crop and season to season. Irrigation is necessary to provide moisture for the germination of seeds. It is also necessary for the absorption of nutrient elements by the plants from the soil. Crops are supplied water for irrigation from different sources like rivers, canals, wells, dams, ponds and lakes.

Sublimation is the transition of a substance directly from the solid to the gas state, without passing through the liquid state. Deposition is the phase transition in which gas transforms into solid without passing through the liquid phase. Deposition is a thermodynamic process. The reverse of deposition is sublimation and hence sometimes deposition is called desublimation. This causes the water vapor to change directly into a solid.

Bacteria are unicellular organisms belonging to the prokaryotic group where the organisms lack a few organelles and a true nucleus.

examples:  Streptococcus and Bacillus, Actinobacteria, Bacteroidetes, Firmicutes, Proteobacteria

The bacterium, Lactobacillus promotes the formation of curd from milk and the bacterium, Renin is used in cheese production.

The Kharif cropping season starts with the onset of monsoon and ends when the rainy season is over. 

Following are some of the examples of Kharif crops:

• Rice
• Maize
• Sorghum
• Millets
• Ragi
• Soybean
• Cotton

Microbes or microorganisms are tiny organisms which are so small that we cannot see them with an unaided eye. Some microorganisms can be seen with the help of a magnifying glass (such as fungus that grows on bread) while some can only be seen when you use a microscope (such as bacteria and protozoa). Microorganism were first observed by Anton Van Leeuwenhoek.

Our atmosphere has 78% of nitrogen but this atmospheric nitrogen cannot be utilised directly by plants or animals. It has to be first converted into nitrogen compounds. This process of converting nitrogen gas of atmosphere into compounds of nitrogen is called nitrogen fixation. The nitrogen gas of atmosphere can be fixed by

1. Certain nitrogen fixing bacteria present in the soil.
2. By Rhizobium bacteria present in the root nodules of leguminous plants
3. By blue-green algae
4. By lightning

The nitrogen fixing Rhizobium bacteria live in the root nodules of leguminous plants like peas, beans, etc. and show symbiotic relationship. When lightning takes place in the sky during thunderstorm, a high temperature is produced in the atmosphere and nitrogen gas combines with oxygen to form nitrogen compounds.

Static friction is defined as the frictional force that acts between the surfaces when they are at rest with respect to each other.

Sliding friction is defined as the resistance that is created between any two objects when they are sliding against each other.

Rolling friction is defined as the force which resists the motion of a ball or wheel and is the weakest types of friction.

Fluid friction is defined as the friction that exsits between the layers of the fluid when they are moving relative to each other.

Silos:

1. Silos are large tanks made of metals used to store silage.

2. It is used in the field of agriculture to store the crop in such a manner that it remains unaffected by pests and insects.

3. Huge quantity of seeds can be stored.  

4. Used by corporate companies.

Granaries:

1. Granaries are small hut like structures constructed with mud and a small cap like structure made up of leaf thatches which is used to store threshed grains.

2. It is used in the field of agriculture to store the crop in such a manner that it remains unaffected by pests and insects.

3. Compared to silos, less quantity of seeds can be stored.

4. Used by Farmers.

A liquid with a high solute concentration is called a concentrated solution. The dissolved salt from a well in the drinking water is a dilute solution. When adding more water, the concentration of a solution can be further decreased and diluted. On the other hand, the solution becomes more concentrated as more solute is applied to a solution. There is a significant amount of water in a concentrated solution.

Carriers are the organism which causes diseases....like anopheles is the feamale mosquito which causes malaria and akl

Combustion is a chemical process in which a substance reacts with oxygen and generates heat in the process.
Flame is a hot glowing body of ignited gas which is produced when something is on fire.

Microbiology is the study of a great variety of living organisms which are invisible to the naked eye like bacteria and fungi and many other microscopic organisms.

Bauxite is a rock formed from a reddish clay material called laterite soil and is most commonly found in tropical or subtropical regions. Bauxite is primarily comprised of aluminum oxide compounds (alumina), silica, iron oxides and titanium dioxide. Bauxite is the most important ore of aluminum which contains only 30–54% alumina, Al2O3; the rest is a mixture of silica, various iron oxides, and titanium dioxide along with trace amounts of zinc, phosphorous, nickel, vanadium etc., as indicated earlier.

Common agricultural implements used during crop cultivation:

• Hoe
• Plough
• Yoke
• Leveller
• Harrow
• Spade
• Axe
• Scythe
• Saw
• Winnower
• Thresher