CLASS 8 MICROBIAL WORLD REVISION

MICROBIAL WORLD

REVISION

CLASS VIII

1. Which of the following reproduces only inside a host cell? 
(a) Bacteria (c) Amoeba (b) Virus (d) Fungus.
 2. A disease in human beings caused by virus is _______. 
(a) typhoid (c) dysentry (b) influenza (d) cholera
 3. Pathogenic micro-organisms present in host cells are killed by medicines called
 (a) pain killer (c) antibiotics (b) antibodies (d) vaccines 
4. The two micro-organisms which live in symbiotic association in lichens are
 (a) fungus and protozoa (c) bacteria and protozoa (b) alga and bacteria (d) alga and fungus 
5. The gas released during the preparation of bread is
 (a) oxygen (c) nitrogen (b) carbon dioxide (d) sulphur dioxide 
6. The disease caused by a protozoan and spread by an insect is _________. 
(a) dengue (c) polio (b) malaria (d) measles 
7. Paheli dug two pits, A and B, in her garden. In pit A, she put a polyhtene bag packed with some agricultural waste. In pit B, she dumped the same kind of waste but without packing it in a polythene bag. She, then covered both the pits with soil. What did she observe after a month?
 (a) Waste in pit A degraded faster than that in pit B. 
(b) Waste in pit B degraded faster than that in pit A. 
 (c) Waste in both pits degraded almost equally. 
(d) Waste in both pits did not degrade at all.
 VERY SHORT ANSWER QUESTIONS
 8. Unscramble the jumbled words underlined in the following statements. 
(a) Cells of our body produce santiidobe to fight pathogens. 
(b) curbossulite is an air-borne disease caused by a bacterium.
 (c) Xanrhat is a dangerous bacterial disease.
 (d) Yeasts are used in the wine industry because of their property of meronettinaf. 
9. Suggest a suitable word for each of the following statements. 
(a) Chemicals added to food to prevent growth of microorganisms. (b) Nitrogen-fixing microorganism present in the root nodules of legumes.
 (c) Agent which spreads pathogens from one place to another.
 (d) Chemicals which kill or stop the growth of pathogens. 
10. Match the names of scientists given in Column A with the discovery made by them given in Column B. 
 Column A                          Column B

 (a) Louis Pasteur              (i) Penicillin 
(b) Robert Koch                (ii) anthrax bacterium
 (c) Edward Jenner            (iii) Fermentation
 (d) Alexander Fleming     (iv) small pox vaccine
                                          (v) Typhoid 
11. Name one commercial use of yeast.
 12. Name the process in yeast that converts sugars into alcohol. 
13. In the soil, which nutrient is enriched by blue-green algae (cyanobacteria)?
 14. Why should we avoid standing close to a tuberculosis patient while he/she is coughing? 
15. Polio drops are not given to children suffering from diarrhoea. Why?
 16. Paheli watched her grandmother making mango pickle. After she bottled the pickle, her grand mother poured oil on top of the pickle before closing the lid. Paheli wanted to know why oil was poured? Can you help her understand why? 
SHORT ANSWER QUESTIONS 
17. Match the microorganisms given in the Column A to the group to which they belong in Column B. 
Column A                            Column B 
(a) Lactobacillus                  (i) Algae
 (b) Aspergillus                    (ii) Protozoa 
(c) Spirogyra                       (iii) Fungi 
(d) Paramecium                    (iv) Bacteria 
18. Classify the following into friendly and harmful microorganisms.
 Yeast, malarial parasite, Lactobacillus, bread mould, Rhizobium, Bacillus anthracis 
Friendly                                              Harmful 
________                                             ________ 
________                                             ________
 ________                                           ________
 ________                                           ________

 19. While returning from the school, Boojho ate chaat from a street hawker. When he reached home, he felt ill and complained of stomach ache and fell ill. What could be the reason? 
20. What will happen to ‘pooris’ and ‘unused kneaded flour’ if they are left in the open for a day or two? 
21. (a) Name two diseases that are caused by virus.
      (b) Write one important characteristic of virus.

CLASS 6 COMPONENTS OF FOOD REVISION

components of food     class 6

1.While using iodine in the laboratory, some drops of iodine fell on Paheli’s socks and some fell on her teacher’s saree. The drops of iodine on the saree turned blue black while their colour did not change on the socks. What can be the possible reason? 
2. Paheli and Boojho peeled some potatoes and cut them into small pieces. They washed and boiled them in water. They threw away the excess water and fried them in oil adding salt and spices. Although the potato dish tasted very good, its nutrient value was less. Suggest a method of cooking potatoes that will not lower the nutrients in them. 

3. Paheli avoids eating vegetables but likes to eat biscuits, noodles and white bread. She frequently complains of stomachache and constipation. What are the food items that she should include in her diet to get rid of the problem? 
Give reason for your answer. 
 (a) List all those components of food that provide nutrients.
 (b) Mention two components of food that do not provide nutrients. 4. ‘Minerals and vitamins are needed in very small quantities by our body as compared to other components, yet, they are an important part of a balanced diet.’ Explain the statement. 
5. ‘Water does not provide nutrients, yet it is an important component of food.’ Explain?
 LONG ANSWER QUESTIONS
 6. Boojho was having difficulty in seeing things in dim light. The doctor tested his eyesight and prescribed a particular vitamin supplement. He also advised him to include a few food items in his diet. 
(a) Which deficiency disease is he suffering from? 
(b) Which food component may be lacking in his diet? 
(c) Suggest some food items that he should include in his diet. (any four) 

class 7 revision nutrition in plants.

NUTRITION IN PLANTS REVISION QUESTIONS.

1.Potato and ginger are both underground parts that store food. Where is the food prepared in these plants?

 2. Photosynthesis requires chlorophyll, and a few other raw materials. Add the missing raw materials to the list given below: Water, minerals, _____________, ______________. 

SHORT ANSWER QUESTIONS

 3. A goat eats away all the leaves of a small plant (balsam). However, in a few days, new leaves could be seen sprouting in the plant again. How did the plant survive without leaves.

 4. Unscramble the following to form terms related to modes of nutrition. 

(i) RASPAEIT

 (ii) ROPEHYTSAP 

(iii) TOROPHAUT 

(iv) SIBIOMSYS 

5. Nitrogen is an essential nutrient for plant growth. But farmers who cultivate pulse crops like green gram, bengal gram, black gram, etc. do not apply nitrogenous fertilizers during cultivation. Why? 

6. Wheat dough if left in the open, after a few days, starts to emit a foul smell and becomes unfit for use. Give reason. 

7. Sunlight, chlorophyll, carbon dioxide, water and minerals are raw materials essential for photosynthesis. Do you know where they are available?

 Fill in the blanks with the appropriate raw materials.

 (a) Available in the plant : _______________ 

(b) Available in the soil : _______________, _______________

 (c) Available in the air : _______________ 

(d) Available during day : _______________

 8. Observe the diagram  and write its importance

9.Wild animals like tiger, wolf, lion and leopard do not eat plants. Does this mean that they can survive without plants? Can you provide a suitable explanation?

10. Define the following terms

a. Autotrophs        b. Photosynthesis      c. saprophytes.      d. parasites.

MEASUREMENT AND MOTION

REVISION QUESTIONS

1.Height of a person is 1.75 m. express his height in cm and mm.
2.The distance between Delhi and Kanpur is usually expressed in
 a. Metre b. Centimeter c. Kilometer d. Hectometer 
3. Which of the following does not represent a time-interval? 
a. A day b. A minute c. A second d. Time of sunrise. 
4. One kilometer is equal to
a. 100 m b. 1000 m c. 10 m d. 1000 cm 

5.What is unit? Write S.I. unit of mass. 
6. How periodic motion is different from circular motion? 
7. Three students measured the length of same wall. The results of these students are different. What might be the possible reasons? 
8. Saina and Megha are friends. They were riding on their bicycle. Saina said that motion of wheel of cycle is rectilinear but Megha argued that motion of cycle wheel is circular. Who was correct? Why? 

 9.Fill in the blanks.
 a. The standard unit of length is ----------------. 
b. The motion described by a simple pendulum is --------------- motion.
 c. Length more than one thousand meters are measured in -------------.
 d. Motion of a car on straight road is -------------- motion. 
e. Hectare is the unit of ----------------. 
10. Define curvilinear motion? Give one example.
 11. What is the S. I. unit of length and what is their symbol?
 12. What is difference between periodic and non-periodic motion. Give example. 
13. Classify the following motion as uniform motion, non-uniform motion and oscillatory motion. 
Car moving with constant speed, 
Bus moving on city road,
 rotation of earth, 
riding of cycle in crowded road, 
pendulum of clock, a swing.    

notes of electricity

                       Lesson Notes

Electric Current and Its Effects

Electric Current:

The flow of electric charge is called electric current.

 In an electric circuit, the charge is often carried by moving electrons. 

The SI unit of electric current is Ampere (A). 

The SI unit of electric charge is Coulomb.

Electric Circuit:

The path through which electric charge moves is called electric circuit.

Symbols in Electric Circuit:

Different components of electric circuit are shown by certain symbols. 

Use of symbols makes it easy to represent an electric circuit. Use of standard symbol makes it easy to understand for anybody. 

For example; a TV mechanic can identify different components of a TV by looking at its circuit diagram.

Electric Cell: It is a device which produces electric charge because of some chemical reactions. 

The cell which is used in a torch is called dry cell. 

The wet cells are used in car batteries. 

A normal dry cell gives an output of 1.5 Volt (V).

Battery: A group of cells is called battery.

 More than one cell is used in most of the devices; because these devices need more than 1.5 V of power.

Closed Circuit: When the circuit is complete, it is called closed circuit. Current flows only in a closed circuit.

Open Circuit: When the circuit is incomplete, it is called open circuit. Current does not flow in an open circuit.

class 7 revision question of electric current and simple circuits.

    ELECTRIC CURRENT AND SIMPLE CIRCUITS 
                  REVISION QUESTION



1. Electric current is the flow of
 a. Proton b. Electron c. Neutron d. Nucleus
 2. Which of the following materials is a conductor?
 a. Silver b. Plastic c. Cloth d. Rubber
 3. A device which prevents or allow the current to flow through it a. Motor b. Conductor c. Switch d. Terminal
 4. When two or more cells are joined together it forms a
 a. Dynamo b. Transistor c. Battery d. Insulator

5. Fill in the blanks.
 a. ----------- is the best conductor of electricity.
 b. A -------------- is used to protects appliances from damage due to excessive current.
c. A short occurs when a -------------- comes in direct contact with neutral wire.
 d. Live wire is covered with ------------- coloured insulation. 
e. Connecting many appliances with single circuit may lead to -------------. 
6. What is short-circuiting? How it occurs? 
7. What is electromagnetic induction? Write its application.
 8. Write 3 application of electromagnet. 
9. Name the following 
a. Device used to measure the amount of current.
 b. A piece of thin wire of high resistance, used in electric bulb.
 c. A device which offers resistance to an electric current.
 d. A number of cells joined together.
 e. Safety device used to protect us from electric shocks.

10. What is electromagnet? Write its two applications.
 11. What is electric bell? Name its main components. 
12. What is difference between open and closed circuit?

13. What is electromagnetic effect of electric current? 
14. What is electric current? How its flows? 
15. Write difference between electromagnet and permanent magnet? 
16. Rearrange the jumbled letters to form meaningful words related to Electricity. 
a. RECURNT
 b. BYATTRY
 c. UFSE
 d. CTROLENETMAG 
e. ICRITUC  

PRACTICE QUESTIONS OF TIME AND MOTION

PRACTICE QUESTIONS OF TIME AND MOTION



1. Classify the following as motion along a straight line, circular or oscillatory motion:

• Motion of our hands while running
• Motion of a horse pulling a cart on a straight road.
• Motion of a kid in a merry-go-round.
• Motion of a child on a see-saw.
• Motion of the hammer of an electric bell.
• Motion of a train on a straight bridge.
• 2. child is on see-saw, what kind of motion he have and why? Explain.
• 3.Give an example when objects undergo combinations of different types of motion?
• 4.How the shape of the distance-time graph for the motion in the following cases when a car is moving with a constant speed.
• Show the shape of the distance-time graph for the motion when a car parked on a side road.

TIME AND MOTION NOTES

 TIME AND MOTION

• An object is said to be moving slowly if it covers less distance in a given time.
• An object is said to be moving fast if it covers more distance in a given time.
• The distance covered by an object in a unit time is defined as speed
• The basic unit for time is second, and it can be calculated in minutes and hours, too, depending on the need. The basic unit for distance is metre. So, the unit for speed is metres per second (m/s)
• Objects that move in a straight line and maintain the same speed throughout the distance covered are said to be in uniform motion
• The time period of a pendulum is the time taken for one full oscillation
• The graph for a body in uniform motion will be straight line making angle horizontally, the speed of a body at rest speed is zero at any point of time. Hence, its graph is a straight line along the X-axis
• The speed of a moving body at any particular instant of time is called instantaneous speed