NCERT CLASS 6 CH 2

Fill the blanks with appropriate answers:

1) Deficiency of Vitamin D causes ________

2) A disease known as beriberi is caused due to the deficiency of _______

3) _______ is caused due to the deficiency of Vitamin C.

4) Deficiency of _________ in our food causes night blindness.

Answers:

Deficiency of Vitamin D causes Rickets.

A disease known as beriberi is caused due to the deficiency of Vitamin B1.

Scurvy is caused due to the deficiency of Vitamin C.

Deficiency of Vitamin A in our food causes night blindness.

CLASS 6 SCIENCE CH1

1. What is food?

Ans. Food is the edible substance which are consumed by humans and other animals to absorb energy for various activities like physical movement, growth and development.

2. Why is it advised that we should prefer eating cooked food?

Ans. It advised that we should prefer eating cooked food because by cooking harmful germs will be destroyed and becomes germless. Cooked food can be easily digested and absorbed by our digestive system in our body. Cooking will also enhance the taste of food.

3. Illustrate the significance of food for living organisms.

Ans. The importance of food is:

(i) They are converted into energy which is required to do various activities.

(ii) It helps in growth of living organisms.

(iii) It helps in the process of repair and replace of damaged parts of the body of living organisms.

(iv) It safeguards us from various diseases and infections.

4. Illustrate the different sources of food items and ingredients with the help of examples.

Ans. There are mainly two sources of ingredients of various food items:

(a) Plants: Plants provide us vegetables, pulses, fruits, cereals, grains etc.

(b) Animals: Animals provide us meat, eggs, and milk etc.

5. Explain the term herbivores.

Ans. Herbivores are the animals which eat only plants or plant products. For instance, cow, goat and buffalo are herbivores.

NCERT CLASS 6 SOLUTION SCIENCE

1. Do you believe that all living beings need the same kind of food?

Ans. No, each species requires a different kind of food.

2. Name five plants and their parts that we eat.

Ans. Names of plants and their parts that we eat are:

(a) Brinjal Plant: Fruits

(b) Carrot plant: Root

(c) Cabbage: Leaf

(d)Potato Plant: Stems

(e)Wheat: Seeds

3. Match the items in column I and Column II.

Column I	Column II
Milk, curd, paneer, ghee Spinach, cauliflower, carrot Lions and tigers Herbivores	eat other animals eat plants and plant products are vegetables are all animal products

Ans.

Column I	Column II
Milk, curd, paneer, ghee Spinach, cauliflower, carrot Lions and tigers Herbivores	are all animal products are vegetables eat other animals eat plants and plant products.

4. Fill up the blanks with the words given:

Herbivore, plant, milk, sugarcane, carnivore.

(a) Tiger is a _______ because it eats only meat.

(b) Deer eats only plant products and so it is called a _______

(c) Parrots eat only _______

(d) The _______ that we drink, which comes from cows, buffaloes and goats is an animal product.

(e) We get sugar from _______

Ans. (a) carnivore (b) herbivore (c) plant (d) milk (e) sugarcane

Extra Questions:

Very short answer type questions:

1. Mention any two examples where two or more parts of the same plant are consumed as food.

Ans. Mustard – Leaves and seeds, Pumpkin – Flowers and fruit.

2. Mention any one plant which grows in water and is consumed as food.

Ans. The stem of the lotus flower is consumed as food.

3. Portrait any three ways which can be very effective to prevent wastage of food.

Ans. (i) Prevent leaving food unconsumed in meals.

(ii) Follow the phrase “Eat to live” and not “live to eat” – eating more than required should be avoided

(iii) Raw edibles like grains, pulses should be stocked well.

4. Name any two plants that produce sugar.

Ans. (i) Sugarcane

(ii) Sugarbeet.

5. Mention at least one non-green plant that we consume as food.

Ans. Mushroom.

6. What do we call every individual’s habit to of eating a peculiar type of food items generally?

Ans. Food habit.

7. Compare the food habits of a person living in North India to a person living in Tamil Nadu.

Ans. North Indian food habits: Chapatti, lassi, pulses, vegetables, rice, mustard oil.

Food habits of a person in Tamil Nadu: Dosa, Idli, sambhar, upma, rasam, and puri, etc.

8. What are the ingredients used to prepare cooked rice?

Ans. Raw rice and water.

9. Compare the ingredients of different food items. Are they having any common food ingredients?

Ans. Yes, they do have some ingredients in common like salt, water and ghee or oil.

10. Identify the two common sources of most of the ingredients of food items that we eat.

Ans. (i) Plants

(ii) Animals

11. Name any three products provided by plants and animals individually.

Ans. Plant products: Cereals, grains and vegetables.

Animal products: Egg, meat and milk.

12. Mention any three edible parts of plants.

Ans. (a) Fruits (b) Roots (c) Leaves

13. Which part of the plants we generally eat?

Ans. We generally eat fruits from most of the plants.

14. Among normal seeds and sprouted seeds, from which do we get more energy?

Ans. We get more energy from sprouted seeds than from normal seeds.

15. What is honey?

Ans. Honey is a sweet substance in liquid state made by bees from the nectar obtained from flowers, i.e., sweet juice collected from flowers is called nectar.

16. What would you call the human beings based on the type of food that they eat or their food habit?

Ans. Omnivores.

SHORT ANSWER TYPE QUESTIONS

1. What is food?

Ans. Food is the edible substance which are consumed by humans and other animals to absorb energy for various activities like physical movement, growth and development.

2. Why is it advised that we should prefer eating cooked food?

Ans. It advised that we should prefer eating cooked food because by cooking harmful germs will be destroyed and becomes germless. Cooked food can be easily digested and absorbed by our digestive system in our body. Cooking will also enhance the taste of food.

3. Illustrate the significance of food for living organisms.

Ans. The importance of food is:

(i) They are converted into energy which is required to do various activities.

(ii) It helps in growth of living organisms.

(iii) It helps in the process of repair and replace of damaged parts of the body of living organisms.

(iv) It safeguards us from various diseases and infections.

4. Illustrate the different sources of food items and ingredients with the help of examples.

Ans. There are mainly two sources of ingredients of various food items:

(a) Plants: Plants provide us vegetables, pulses, fruits, cereals, grains etc.

(b) Animals: Animals provide us meat, eggs, and milk etc.

5. Explain the term herbivores.

Ans. Herbivores are the animals which eat only plants or plant products. For instance, cow, goat and buffalo are herbivores.

6. Explain the term omnivores.

Ans. Omnivores are the animals which eat both plants and animals. For instance, Bear, rodent, dog etc

CLASS 9 MOTION PART 2

Average Velocity:

    •  If a particular under goes a displacement s₁ along a straight line t₁ and a displacement s₂ in time t₂ in the same direction, then Average velocity = s1+s2t1+t2   .

    •  If a particle undergoes a displacement s₁ along a straight line with velocity v₁ and a displacement s_s with velocity  v₂ in the same direction, then

                                      Average velocity = (s1+s2)v1v2s1v2+s2v1   .

    •  If a particle travels first of the displacement along a straigh line with velocity v₁ and the next half of the displacement with velocity v₂ in the same direction , then

                                Average velocity = 2v1v2v2+v1  (in the case(b) put s₁ = s₂)

    •  If a particle travels for a time t1 with velocity v1 and for a time and for a time t2 with velocity v2 in the same direction, then

                                   Average velocity = v1t1+v2t2t1+t2    .

    •  If a particle travels first half of the time with velocity v₁ and the next half of the time with velocity v₂ in the same direction, then

                    Average velocity = v1+v22   (in the case d put t₁ = t₂) .

    •  Velocity of a particle is uniform if both it magnitude and direction remains unchanged.

    •  Velocity of a body changes when magnitude or direction or both change.

Acceleration

The rate of change in velocity is called acceleration and is measured in metre per square second in the international system of units.

             Acceleration, a = Final velocity - Initial velocityTime

Time 

Note: The negative acceleration is termed as retardation.

Differences Between Distance and Displacement

S.No.	DISTANCE	DISPLACEMENT
1.	It is defined as the actual path traversed a body	It is the shortest distance betweeen two points by between which the body moves.
2.	It is a scalar quantity.	It is a vector quantity.
3.	It can never be a negative or zero.	It can be negative, zero or positive.
4.	Distance can be equal to or greater than displacement.	Distance can be egaual to or less than distance.
5.	Distance travelled is not a unique path between two points.	Displacement is a unique path between two points.
6.	The distance between two points gives full information of the types of path followed by the body.	Displacement between two points does not give full information of the types of path followed by the body.
7.	Distance never decreases with time. For a moving body, it is never zero.	Displacement can decrease with time. For a moving body, it can be zero.
8.	Distance in SI is measured in metre.	Displacement in SI is measured in metre.

Differences Between Speed and Velocity

S.No.	SPEED	VELOCITY
1.	It is defined as the rate of change of distance.	It is defined as the rate of change of displacement.
2.	It is a scalar quantity.	It is a vector quantity.
3.	It can never be negative or zero.	It can be negative,zero or posituve.
4.	Speed is velocity without direction.	Velocity is directed speed.
5.	Speed may or may not be equal to velocity.	A body may possess different velocities but the same speed.
6.	Speed never decreases with time. For a moving body, it is never zero.	Velocity can decrease with time. For a moving body , it can be zero.
7.	Speed in SI is measured in ms-1	Velocity in SI, is measured in ms-1