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

Explain the meanings of the following symbols:

explain the various effects of the disaster of railway accident.

Write short notes on: Magnetic separation method

When a female child is born, her ovaries already contain thousands of immature eggs (or ova) contained in immature structures A. On maturing, A bursts open and an egg shoots out of the ovary in a process called B. The process B starts in the females at puberty and occurs again and again after a time period x. Before every occurrence of process B, the inner lining of uterus becomes thick and soft with lots of blood vessels in it. When the egg cell gets fertilised by a sperm, then an event C occurs in the life of mature human female which lasts for time period y leading to the birth of baby. If, however, the egg cell released by the ovary does not get a sperm to fuse with, then the thick and soft inner lining of uterus breaks down and comes out of the female's body in an event called D. The occurrence of event D is controlled by chemical substances E.

1. What are A?
2. What is process B?
3. What is the time period x?
4. Name the event C.
5. How much is the time period y?
6. What is the name of process D?
7. Name the chemical substances E.

Describe the process of development and birth in humans.

Explain the following with the help of a diagram :
Compound microscope

A potted plant is growing in a transparent glass jar. In this plant, X and Y are the two growing parts having a lot of meristematic tissue. It is observed that the part X of this plant exhibits positive geotropism but negative phototropism. On the other hand, part Y of this plant exhibits negative geotropism but positive phototropism.

1. Name the part X of plant.
2. Name the part Y of plant.
3. Which part of the plant, X or Y, will exhibit positive hydrotropism?
4. Which part of the plant, X or Y, can have tendrils on it?
5. Which phytohormone causes the part X to exhibit negative phototropism?

Some hunters are roaming in the plush green forest of Africa. They spot a deer and kill it. They decide to roast the deer there and then and eat it. When the hunters had just finished enjoying the feast of roasted deer, a lion attacks them. The lion kills one of the hunters and eats his flesh.

1. Write a food chain which provides food to lion in this case.
2. Which animal (other than deer) the lion could look for food if he did not get the hunter as prey?
3. Which other animal in the forest could have been in place of lion?
4. How does the above food chain differ form the food chain such as: plants → goat → man?