P-2 Towards Green Energy — Science STD 10 — Question

State one use each of the following non-metals:
Hydrogen, Carbon (as Graphite), Nitrogen, Sulphur

X and Y are two human beings. The organ A in the reproductive system of X releases a mature gamete B once a month which goes into a tube-like structure C through a funnel-like opening. The organ D in the reproductive system of Y makes and releases gametes E which pass through a duct F and are introduced by an organ of Y, into the body of X. B and E fuse together in C to form a new cell G. The cell G divides repeatedly to form a ball of cells H which gets embedded in the lining of organ I of reproductive system of X where it grows and develops into a baby.

1. Name (i) organ A, and (ii) gamete B.
2. Write two names of tube-like structure C.
3. Name (i) organ D, and (ii) gamete E.
4. Write two names of duct F.
5. Name (i) cell G (ii) ball of cells H, and (iii) organ I.
6. Out of X and Y, which one is (i) male, and (ii) female?

Read the passage and answer the questions based on it.
If heat is exchanged between a hot and cold object, the temperature of the cold object goes on increasing due to gain of energy and the temperature of the hot object goes on decreasing due to loss of energy. The change in temperature continues till the temperatures of both objects attain the same value. In this process, the cold object gains heat energy and the hot object loses heat energy. If the system of both the objects is isolated from the environment by keeping it inside a heat-resistant box then no energy can flow from inside the box or come into the box. In this situation, we get the following principle.
Heat energy lost by the hot object = Heat energy gained by the cold object. This is called the ‘Principle of heat exchange’.

1. Where does heat transfer take place?
2. In such a situation which principle of heat do you perceive?
3. How can this principle be explained in short?
4. Which property of the substance is measured using this principle?

With the help of suitable diagrams, explain the five stages of prophase-I of meiosis.

 Explain the Krebs cycle with reaction.

A man bought a device X which could cook pulses, vegetables and rice without using any fuel like wood, coal, kerosene or LPG, etc. This device did not work at night. It also took a lot of time for cooking.

1. Name the device X.
2. What is the source of energy which cooks food in this device?
3. What is the name of the process which traps energy in this device?
4. State one advantage (other than saving on fuel) or using such a device for cooking food.

Reorganize the following food chain. Describe the ecosystem to which it belongs.
Grasshopper – Snake – Paddy field – Eagle – Frog.