Byophylum are also known as air plants. In Bryophylum, reproduction occurs through asexual means, specifically, through vegetative propagation of leaves. The leaves of Bryophylum are broad possessing notches at its margins, these are the locations from which buds(notches) arise. The buds are termed as epiphyllous buds which have the potential to produce new plants having shoots, small leaves and adventitious roots. The newly formed plants can then detach from teh leaves to grow into a mature plant once it touches the soil. 

Octopuses have blue blood. To survive in the deep ocean, octopuses evolved a copper rather than iron-based blood called hemocyanin, which turns its blood blue. This copper base is more efficient at transporting oxygen than hemoglobin when water temperature is very low and not much oxygen is around.

Those materials which possess the characteristic of being hard, shiny, malleable, fusible, ductile, etc. are termed as metals. Few examples of metals are iron, gold, silver, aluminium, copper, etc.

Krishna-Godavari Delta region is historically called the “Rice Bowl of India”, although the same term is also used for Chhattisgarh. In Andhra Pradesh itself, East Godavari district is known as the rice bowl of Andhra Pradesh.

1. Force is a push or a pull that changes or tends to change the state of rest or uniform motion of an object or changes the direction or shape of an object. It causes objects to accelerate. SI unit is Newton. 

2. The force acting on per unit area of a surface is called pressure. We can say force per unit area is called pressure.
                                                              Pressure = Force / Area

4. Muscular force:
(i) Force due to the action of muscles is called muscular force. We can say force resulting because of action of muscle is called muscular force.
(ii) Muscular force is applied only after interaction with the object.
Examples:
(a) When we push the object like school bag or lift the bucket of water we use the muscular force.
(b) Animals also use of muscular force to carry out their task.

5.  Gravitational Force:
(i) Gravitation force is exerted by earth, moon, sun and other planets to others.
(ii) Earth and other planets attract all objects towards them. Since, earth attracts all objects even without coming in contact, thus gravitational force is a non-contact force.
Example: When we release an object from a height, it falls over the ground because of gravitational                attraction of earth.

6. 

Lemon pickle cannot be stored in aluminium utensils because lemon pickle contains acids, which can react with aluminium (metal) liberating hydrogen gas. This can lead to the spoiling of the pickle.

The chemical substances which are used to control , remove and kill the weeds are called weedicides.
Weeds are unwanted plants growing among wanted crops and compete with crop plants for sunlight, nutrients, water etc. 
Weedicides are the chemicals which are sprayed over field to get rid of weeds. They will not show any effect on crop plants. Two popularly used weedicides are   2,4-D Ethyl ester, Neem extract, Glyphosate etc.

Formation of petroleum

It was formed by the decomposition of the remains of tiny plants and animals buried under the sea millions of year ago.It is believed that millions of years ago,the tiny plants and animals which lived in sea,died.Their dead bodies sank to the bottom of sea and were soon covered with mud and sand.Due to high pressure,heat,action of bacteria,and in the absence of air,the dead remains of tiny plants and animals were slowly converted into petroleum.The petroleum thus formed got trapped between two layers of impervious rocks,forming oil deposit.

• Methane is a colorless, odourless and highly flammable gas which is the main component of natural gas.

• Carbon Monoxide (CO) is a colorless and odorless gas, which is produced by the combustion of materials that contain carbon.

Tiny disc-shaped cells that help regulate blood flow when any part of the body is damaged, thereby aiding in fast recovery through clotting of blood.

Density is the property of substance.
Mass of substance per unit volume is density.
If mass increases, density of substance increases.
Density is denoted by d or ρ. Thus,
 ρ = m/v

Rumination: Ruminants swallow the food without chewing. After feeding, they bring the food from the stomach back into the mouth and chew it leisurely. This process is called rumination and such animals are called as ruminants. Rumination is also called second chewing.

The process of digestion in ruminants:

• Grass-eating animals swallow the food quickly and store it in the rumen. Rumen also inhabits cellulose digesting bacteria which establish a symbiotic relationship with the animal stomach.
• Digestion in ruminants is a good example of symbiosis. Microorganisms present in the stomach of ruminants help in digesting cellulose and in turn obtain shelter and nourishment form the animal. A symbiotic relationship exists between microorganisms and the ruminants.
• As rumen is full, the food is taken into second part of the stomach, the reticulum.
• Digestive juices of the reticulum partially digest the food. The partially digested food in the reticulum is called as cud.
• While resting, cow brings back the cud into the mouth for regurgitation.
• Food is chewed completely and swallowed into omasum for further digestion.
• Then the food moves into abomasum for digestion brought about by digestive juices.
• A large sac-like structure called the caecum lies between the small and large intestines.
• The symbiotic bacteria present in the caecum help in the complete digestion of cellulose. Digestion of food is completed in the intestine.
• As the symbiotic bacteria are not present in the human digestive system, humans cannot digest cellulose.

(i) The process of separating grain from chaff and hay with the help of wind is called winnowing.

(ii) When the grain mixed with chaff and hay is made to fall from a height in blowing wind, the grain, being heavy, falls straight to the ground, whereas the chaff and hay, being much lighter, are carried some distance away by the wind. In this way, the grains form a separate heap and can be collected and packed in gunny bags.

After harvesting the crop, the next step is threshing. The process of beating out the grains from the harvested crop plants is called threshing. Threshing is done to take take out the grain from its outer covering called chaff. A machine called thresher is also used for the threshing process.

Weedicides are uses to stop the growth if unwanted plants called weeds in rhe field along with the desirable crop. Weeds need to be cut as they compete with the crop for space, sunlight and nutrients. They thus reduce the yield. Weedicides need to be used with precautions as they harm the animals along with the farmers.

Two popularly used weedicides are   2,4-D Ethyl ester, Neem extract, Glyphosate etc.

 Drip system

There is network of narrow pipes with small holes in the fields.When water flows through the narrow pipes,it fall drop by drop at the position of roots of the plants.This water is absorbed by the soil in the root zone of the plants and utilised by the plant.There is no wastage of irrigation of water.

Advantages

1)It provides water to plants drop by drop.So water is not wasted at all.

2) It minimises the use of water in agriculture.It is useful in those regions where the availability of water is poor.

Sprinkler system

A main pipeline is laid in the field.Perpendicular pipes having rotating nozzles at the top are joined to the main pipelines at regular intervals.When water from a tube-well is allowed to flow through the main pipelines under pressure with the help of a pump,it escapes from the rotating nozzles.This water gets sprinkled on the crop plants as if it is raining.

Advantages

1)It is more useful for the uneven land where sufficient water is not available.

2)It is very useful for sandy soil

Manure is a nutrient-rich organic matter used as organic fertilizer in agriculture.
The advantages of adding manure to soil or in agricultural fields:-
1)  It helps to improve the soil structure.

2) It increases the nutrient content in the soil.

3)  It also helps to hold moisture in the soil and enhances the activity of micro-organisms.

Fossil fuels are exhaustible natural resources because fossil fuels require millions of years to form from the dead vegetation and animal that get buried deep inside the earth. They require high temperature and pressure for their formation, which cannot be provided in the laboratory. It is present in limited quantity beneath the earth, thus it will come to an end by human usage.

Chloroplasts are found only in plant cells because they contain a green pigment called chlorophyll. This green pigment is important for photosynthesis in green plants. This chlorophyll pigment traps solar energy and utilises it to manufacture food for the plant.

Cells constitute various components of plants and animals. A cell is the smallest unit of life and is capable of all living functions. Cells are the building blocks of life. This is the reason why cells are referred to as ‘the basic structural and functional unit of life’. All cells vary in their shapes, sizes, and activities they perform. In fact, the shape and size of the cell is related to the specific function it performs.

Plastics are non-corrosive in nature, they do not react even if they come in contact with strong chemicals. For example, the cleaning chemicals that we use at home are stored in plastic bottles, instead of metal containers.

The bread or idli dough rises because of growth of yeast.

It is because the yeast cells grow and by respiration, they fill the dough or idli with bubbles and increase it's volume.