Fruits detached from a tree fall down due to the force of gravity. We know that a force arises due to interaction between two objects. Name the objects interacting in this case.

Arrange the following in order to show how deforestation leads to water pollution.
I. The roots of the trees no longer have a firm grip on the soil.
II. Rainfalls onto the ground.
III. The trees of a forest are cut down
IV. The loose soil gets washed away into a nearby body of water.

Study the following structure.

Which of the organisms have been classified wrongly?

Given in figure you find that the bulb glows when an iron nail is placed between two ends of wire. Complete the following sentences on the basis of this fact.

(a)......... is a metal.
(b) Metals are good.......... of electricity.

Iron metal reacts slowly with the oxygen and moisture of damp air to form rust. What is rust chemically known? State whether the rust formed is acidic, basic or neutral.

Petroleum is called black gold. Why?

Which synthetic fibre contains the organic group similar to those which give fruits their sweet smell?

In the soil, which nutrient is enriched by blue-green algae (cyanobacteria)?

Explain the process of formation of petroleum.

Read the following statements and write the appropriate term against each statement.
(a) I control the functions of a cell. Who am I?
(b) I am like a policeman. I do not allow anything and everything to get in and out of the cell. Who am I?
(c) I transfer characters from parents to offsprings. Who am I?

In the following situation, identify the agent exerting the force and the object on which it acts. State the effect of the force in each case.
(a) Squeezing a piece of lemon between the fingers to extract its juice.
(b) Taking out paste from a toothpaste tube.
(c) A load suspended from a spring while its other end is on a hook fixed to a wall.
(d) An athlete making a high jump to clear the bar at a certain height.

Give reasons for the following:
(a) Aluminium foils are used to wrap food items.
(b) Immersion rods for heating liquids are made up of metallic substances.
(c) Copper cannot displace zinc from its salt solution.
(d) Sodium and potassium are stored in kerosene.

Sunita loves to wear the clothes made up of synthetic fibres because these clothes dry up quickly, are durable, less expensive, readily available and easy to maintain. Once, she was working in kitchen. her mother advised her not to wear the synthetic clothes while working in the kitchen. She changed her clothes. Now, give the answer of the following questions.
(a) Why Sunita's mother advised her not to wear synthetic clothes while working in kitchen?
(b) Why Sunita loves to wear the clothes made up of synthetic fibres?
(c) What are the values of Sunita and her mother?

Polio drops are not given to children suffering from diarrhoea. Why?

Tashu saw her mother keeping the wheat grains on the terrace, before storing them. She was confused to see this as she thought the grains will get dirty if kept in open and approached her mother for clearing her doubts. Her mother explained Tashu the reason behind her act. Tashu then helped her mother carry the grains to the terrace happily.
(a) The grains were kept on the terrace. Can you suggest a reason.
(b) Is it necessary to keep the grains in the sun? Why or why not?
(c) Mention the values shown by Tashu.

Read the following terms and select the pair that is related to inheritance of characters

Rayon is different from synthetic fibres because:

The fishes swim easily in the water because they have

A toy car released with the same initial speed will travel farthest on

A brick is kept in three different ways on a table as shown in figure. The pressure exerted by the brickon the table will be

In figure, two boys A and B are shown applying force on a block. If the block moves towards the right, which one of the following statements is correct?

Which one of the following statements is true about a biosphere reserve?

Which of the following statements are true for eukaryotic cells?
(i) They do not have a nuclear membrane.
(ii) They have a well organised nucleus.
(iii) They have a nuclear membrane.
(iv) Blue-green algae are eukaryotic cells.

Boojho has learnt that non-metals on beating with a hammer are generally broken into pieces.Which of the following is non-metal?

Which substance is formed by the carbonisation of dead vegetation?

Various materials which are obtained from nature are called natural resources. Which of the following is not a natural resource?

The material similar to silk in appearance is

Which of the following reproduces only inside a host cell?

The term used for the process of separation of grains from chaff is

A paper can be recycled __________________ times.

...............is a unicellular aquatic animal.

The North pole of a magnet _________ the North pole of another magnet.

Coal is one of the _____________used to cook food

A plastic used for making crockery is.........

Paramecium is a slipper- shaped ___________________

Millet belongs to the........... crops

In physics classroom a teacher told to his students that when a cricket player want to catch a ball then first he rub the hands. Thus, there is less chance of slipping the ball from hands. 
(a) Explain the reason of not slipping of ball from hand
(b) If the player makes his hands oily instead of rubbing them. Would he be able to catch the ball?
(c) Mention the type of teaching skills of teacher is being represented here?

Observe the vessels A, B, C and D as shown in figure carefully.

Volume of water taken in each vessel is as shown. Arrange them in the order of decreasing pressure at the base of each vessel. Explain.

(a) A jelly-like substance is present in a cell. What is it called as? Also give its function.
(b) Give the meaning of protoplasm. Name the four elements which make up major part of protoplasm.

The substance A is a fossil fuel. It occurs deep below the earth's crust in certain areas. Another fossil fuel B is found above the substance A. When A is subjected to a process C, a number of different products (fractions) are collected at different temperature ranges which have different uses. A special grade of product D obtained in this process is used as aviation fuel in jet aeroplanes. The product D is also used in stoves, lamps, etc
Now give the answer of the following questions.
(a) What are the substances, A and B?
(b) Write the physical states of substances A and B.
(c) What is the process C called?
(d) Name the product D.

Friction does not cause any wastage of energy.

Liquids and gases do not exert pressure on the walls of the container.

A synthetic fibre is a chemical substance of single unit.

Pachmarhi biosphere reserve consists of one national park and two wildlife sanctuaries

Human cell is an eukaryotic cell.

Plasma membrane is dead.

What makes it difficult to walk on wet floor?

Various components are present in cytoplasm.Name them

Name a solution which should be added to make onion peel slide.

What is infiltration rate?

Name two non-contact forces.

Why is immersion rod used for heating liquids made of metallic substances?

Define cellulose.