Science

M. M: 90

Time:3hrs

General Instructions:

1. There are two sections in this paper. Section A contains Q 1-24 & section B contains Q25-36.
2. Marks are indicated against each question.
3. Read all questions carefully.
4. All questions are compulsory.

Section A

1 Why is an animal cell regarded as eukaryotic cell? 1

2 Give one method which we can adapt to use inexhaustible resources. 3 Give the direction of force of friction in the following cases. (i) (Arrows indicate the movement of the ball on the inclined plain) 4 Name the following 2

1. A female hormone
2. Male gamete in human beings
3. Process of formation of zygote
4. Part in the female reproductive system where implantation take place.

6 5 Compare any two properties of Rayon and Acrylic. Explain what happens to meteors when they enter into the Earth's atmosphere. 2 2

7 Discuss the various shapes of cells found in human body and write one example for each(any 3

three shapes) 8 Differentiate between thermoplastic and thermosetting polymers on the basis of : 3

1. nature
2. effect of high temperature
3. toughness

9 With the help of diagram, explain the causes of friction. 3

10 Explain the process of binary fission in amoeba with the help of well labeled diagram. 3

3 11 a) Write the principle involved in the given process.

110°C

180°C

260°C

Heated D

1. Label the parts A,B,C and D in the above diagram

12 Give reason for the following: 3

1. Heavy suitcases are provided with small wheels.
2. The body of a racing car is streamlined.
3. Thick groves are made in the tyres of heavy vehicles.

13 Explain how does the development of an embryo take place in a hen? 3

14 A string vibrates 60 times in 2 seconds. Find the frequency and time period of vibrations of the 3

string. Will this sound produced be audible to human ears or not? Give reason to support your answer. 15 a) What is carbonization. 3

1. Write conditions required for destructive distillation.

c)Give the relevant scientific term for the following:

1. A product used to make candles.
2. A fuel used in aero planes.

16 List any three changes that take place in females during adolescence. 3

17 a) What are sex chromosomes? 3

1. How is the sex determined in the human beings? Explain with the help of a flow chart.

18 Rohan read about the devastating effect of Oil Spills in the ocean and he wants to know more 3

about it. Help him by answering the questions given below:

1. What is an oil spill?
2. Give any two ill effects of oil spill.
3. How can it be prevented?

19 5

1. What is noise pollution?
2. Name any two sources of noise pollution.
3. Suggest two ways to reduce noise pollution

20 a) Differentiate between plant cell and animal cell on the basis of 5

1. Presence of cell wall
2. Size of the vacuole
3. Presence of plastids
4. Label the parts A,B,C & D in the given diagram