P-2 Disaster Management — Science STD 10 — Question

Write short note: Pre-disaster management.

Explain the construction and working of the following. Draw a neat diagram and label it : Electric Generator (AC)

Classify the following into herbivores, carnivores and omnivores:
Lion, Man, Dog, Goat, Crow, Elephant, Snake, Hawk, Rabbit, Deer.

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.

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?

When a spherical mirror is held towards the sun and its sharp image is formed on a piece of a carbon paper for some time, a hole is burnt in the carbon paper.

1. What is the nature of spherical mirror?
2. Why is a hole burnt in the carbon paper?
3. At which point of the spherical mirror the carbon paper is placed?
4. What name is given to the distance between spherical mirror and carbon paper?
5. What is the advantage of using a carbon paper rather than a white paper?

The following diagram shows a part of the periodic table containing first three periods in which five elements have been represented by the letters a, b, c, d and e (which are not their chemical symbols):

1. Select the letter which represents an alkali metal.
2. Select the letter which represents a noble gas.
3. Select the letter which represents a halogen.
4. What type of bond is formed between a and e?
5. What type of bond is formed between d and e?

Explain why, though both a plane mirror and a sheet of paper reflect light but we can see the image of our face in a plane mirror but not in a sheet of paper.

There are two important fuels A and B both of which are extracted from deep inside the earth. Fuel A is a thick, dark, foul smelling liquid whereas fuel B is a black solid. Combustion of both the fuels produces products, C, D, E and F. The product C makes the rainwater only slightly acidic but it is mainly responsible for causing global warming. The product D is neither acidic nor basic. It is harmless and does not affect the environment in any way. Both E and F attack breathing system of humans and are mainly responsible for causing acid rain. In addition to combustion of fuels A and B, the product F is also formed when lightning occurs in the sky.

1. What are (i) fuel A, and (ii) fuel B?
2. Name (i) C (ii) D (iii) E, and (iv) F?
3. What is the process of formation of F during lightning known as?
4. Which fuel is supposed to be exhausted sooner : A or B?
5. Which fuel is mostly used for generating electricity at thermal power plants?

(translation, anticodon, tRNA, mRNA, amino acids, triplet codon, transcription, DNA)
The …….. formed in nucleus comes in cytoplasm. It brings in the coded message from DNA. The message contains the codes for amino acids. The code for each amino acid consists of three nucleotides. It is called as ‘………..’. Each mRNA is made up of thousands of triplet codons. As per the message on mRNA, ……… are supplied by the ………. For this purpose, tRNA has ‘…………’ having complementary sequence to the codon on mRNA. This is called ‘………..’.