What is the unique feature of the biodiversity found in Pachmarhi Biosphere Reserve?

We do not sense any pain when we clip our nails or cut our hair. Why?

Name the metal
(a) which reacts with dilute hydrochloric acid to produce hydrogen gas.
(b) which does not react with dilute hydrochloric acid.

Name the polymer which is commonly used as a packaging material.

Ashish left an orange in his bag and forgot about it. After a week, when he looked in his bag, he found something growing on his orange.
(a) What was growing on Ashish's orange?
(b) What kind of organism is it?

You must have seen the farmer plough seedlings of paddy into the field from a nursery. Give the name of this process

What are contact and non-contact forces? Explain briefly with suitable examples.

Shruti's mother went to the market to buy new lunch box for Shruti. She saw different lunch boxes made up of plastics as well as steel. Plastic lunch boxes of different colours were very attractive but the steel lunch box was very simple. Shruti's mother told her to select a lunch box for her. She selected a lunch box made of steel instead of plastic one. Her mother purchased the steel lunch box for her.
Read the passage and answer the following questions:
(i) Why does Shruti prefer steel lunch box instead of plastic one?
(ii) Are plastic materials environment friendly? Explain.
(iii) What values are shown by Shruti?

The material X is a fossil fuel. It is formed from the buried large land plants (vegetation) by a very slow process Y. When X is heated in the absence of air, i. e. in the process called Z, it gives three products A, B and C. A is used as a reducing agent in the extraction of metals, B is used as an industrial fuel, whereas the product C has been traditionally used for metalling the roads. It is now replaced by a petroleum product, bitumen. Now give the answer of the following questions.
(a) What is the material X?
(b) What is the physical state and colour of X?
(c) Name the processes Y and Z.
(d) What are the products A, B and C?

Given below is a conversation between two farmers Heera and Beera
Heera Brother Beera, your maize crops look beautiful. They have grown pretty fast.
Beera Yes, I have sprayed urea this time. What about you?
Heera Well, I am still relying on good old cow dung. I am saving money for buying a tractor.
Beera That's good. Tractor saves a lot of time and labour.
Heera Yes, it's been very labour intensive for me and now these weeds have come up.
Beera Try weedicides, they are very effective
(a) List the practices which are not environment friendly and why? 
(b) What is the advantage of modern agricultural implements over traditional ones?
(c) Name one weedicide and the precaution, farmers must take during its application.

A black, tough and porous substance is :

Which of the following represents the correct match for items in Column A with those in Column B?

An agricultural implement used since ancient times for tilling the soil, adding fertilizers, removing weeds etc. is :

Which of the following statements is incorrect?

Two objects repel each other. This repulsion could be due to

The Red Data Book keeps a record of all the
(i) endemic species
(ii) endangered plants
(iii) extinct species
(iv) endangered animals

Of the following parts of a cell name the part that is common to plant cell, animal cell and a bacterial cell.

Which of the following non-metals reacts and catches fire on exposure to air?

Which of the following is not a constituent of petroleum?

The material which is commonly used for making kitchen containers is

The gas released during the preparation of bread is

Given below are statements about the harmful effects of weeds on crop plants.
(i) They interfere in harvesting.
(ii) They help crop plants to grow healthily.
(iii) They compete with crop plants for water, nutrients, space and light.
(iv) They affect the plant growth.
Choose the correct combination of statements.

Complete the crossword with the help of clues given below
Across: 
(1) This is necessary for photosynthesis.
(3) Term for component present in the cytoplasm.
(6) The living substance in the cell.
(8) Unit of inheritance present on the chromosomes.
Down:
(1) Green plastids.
(2) Formed by collection of tissues.
(4) It separates the contents of the cell from the surrounding medium.
(5) Empty space in the cytoplasm.
(7) A group of cells.

Complete the following word puzzle with the help of clues given below:
Down:
(1) Providing water to the crops.
(2) Crop grains have to be kept for a long time in
proper conditions.
(5) Certain plants of the same kind grown on a large scale.
Across:
(3) A machine used for cutting the matured crops.
(4) A rabi crop that is also one of the pulses.
(6) A process of separating the grains from chaff.

A father and son pushed their car to bring it to the side of road as it had stalled in the middle of the road. They experienced that although they had to push with all their might initially to move the car, the push required to keep the car rolling was smaller, once the car started rolling. Explain.

What are the disadvantages of using fossil fuels?

Polyester is synthetic fibre. Define chemical nature of polyester. Differentiate polywool and polycot.

Identify the organism given below. Where does it reproduce?

The main part of the plough is a long log of wood, which is called a________.

Static friction is ________ than the sliding friction.

Draper and rubber sucker work on the principle of ____________ pressure.

The shape and size of a cell are related to its...................

Sodium and potassium are kept in...............

Petroleum,_____________________ and ______________________are fossil fuels.

Use of lubricants increases the friction.

The force exerted by a magnet on a piece of iron is also a contact force.

There can be a wildlife sanctuary within a biosphere reserve.

Sulphite of iron is rust

Birds and fishes have streamlined shape.

Nerve cell is branched and long

Name the friction when wheels are used to carry heavy weights.

What are the basic components of a cell?

Name the first reserve forest of India.

What are the uses of diesel?

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

What is the process of loosening and turning of the soil called?