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NCERT Solutions for Class 7 Science Chapter 10 Respiration in Organisms are part of NCERT Solutions for Class 7 Science. Here we have given NCERT Solutions for Class 7 Science Chapter 10 Respiration in Organisms.

NCERT Solutions for Class 7 Science Chapter 10 Respiration in Organisms

Question 1.
Why does an athlete breathe faster and deeper than usual after finishing the race?
Answer:
During running, the athlete uses a lot of energy. So, he/she needs more energy and breathes faster.

Question 2.
List the similarities and differences between aerobic and anaerobic respiration.
Answer:
Similarities:

 Differences:

Question 3.
Why do we often sneeze when we inhale a lot of dust-laden air?
Answer:
The air around us has various types of unwanted particles, such as smoke, dust, pollens, etc. When we inhale, the particles get trapped in the hair present in our nasal cavity. However, sometimes these particles may get past the hair in thç nasal cavity. Then they irritate the lining of the cavity, as a result of which we sneeze. Sneezing expels these foreign particles from the inhaled air and dust-free, clean air enters our body.

Question 4.
Take three test-tubes. Fill 3/4th of each with water. Label them A, B and C. Keep a snail in test-tube A, a water plant in test-tube B, and in C keep snail and plant both. Which test-tube would have the highest concentration of CO₂?
Answer:
The exchange of gases in three test-tubes can be shown as in Fig.

Fig. (A) In test tube A; CO₂ is produced by the respiration of snail (No consumption of CO₂).
(B) In test tube B; CO₂ is produced by the respiration of the plant and a much higher amount of CO₂ is consumed during photosynthesis.
(C) In test tube C; CO₂ is produced by the respiration of snail and plant and CO₂ is consumed during photosynthesis.
It is clear from the above observation that the highest concentration of CO₂ will be in test tube A.

Question 5.
Tick the correct answer:
(a) In cockroaches, air enters the body through
(i) lungs
(ii) gills
(iii) spiracles
(iv) skin

(b) During heavy exercise, we get cramps in the legs due to the accumulation of
(i) carbon dioxide
(ii) lactic acid
(iii) alcohol
(iv) water

(c) Normal range of breathing rate per minute in an average adult person at rest is:
(i) 9-12
(ii) 15-18
(iii) 21-24
(iv) 30-33

(d) During exhalation, the ribs
(i) move outwards
(ii) move downwards
(iii) move upwards
(iv) do not move at all
Answer:
(a) (iii) spiracles
(b) (ii) lactic acid
(c) (ii) 15 – 18
(d) (ii) move downwards

Question 6.
Match the items in Column I with those in Column II :

Answer:

 Question 7.
Mark ‘T’ if the statement is true and ‘F’ if it is false :
During heavy exercise, the breathing rate of a person slows down. (T/F)
Plants carry out photosynthesis only during the day and respiration only at night. (T/F)
Frogs breathe through their skins as well as their lungs. (T/F)
The fishes have lungs for respiration. (T/F)
The size of the chest cavity increases during inhalation. (T/F)
Answer:
(i) F
(ii) F
(iii) T
(iv) F
(v) T

Question 8.
Given below is a square of letters in which are hidden different words related to respiration in organisms. These words may be present in any direction—upwards, downwards, or along the diagonals. Find the words for your respiratory system. Clues about those words are given below the square.

(i) The air tubes of insects
(ii) Skeletal structures surrounding the chest cavity
(iii) Muscular floor of the chest cavity
(iv) Tiny pores on the surface of the leaf
(v) Small openings on the sides of the body of an insect
(vi) The respiratory organs of human beings
(vii) The openings through which we inhale
(viii) An anaerobic organism
(ix) An organism with a tracheal system
Answer:
(i) TRACHEA
(ii) RIBS
(iii) DIAPHRAGM
(iv) STOMATA
(v) SPIRACLES
(vi) LUNGS
(vii) NOSTRILS
(viii) YEAST
(ix) ANT
These names are indicated by arrows and their serial number are indicated at starting point of the arrow.

Question 9.
The mountaineers carry oxygen with them because:
(a) at an altitude of more than 5 km, there is no air.
(b) the amount of air available to a person is less than that available on the ground.
(c) the temperature of the air is higher than that on the ground.
(d) the pressure of air is higher than that on the ground.
Answer:
(b) The amount of air available to a person is less than that available on the ground.

We hope the NCERT Solutions for Class 7 Science Chapter 10 Respiration in Organisms help you. If you have any query regarding NCERT Solutions for Class 7 Science Chapter 10 Respiration in Organisms, drop a comment below and we will get back to you at the earliest.

NCERT Solutions for Class 7 Science Chapter 9 Soil are part of NCERT Solutions for Class 7 Science. Here we have given NCERT Solutions for Class 7 Science Chapter 9 Soil.

NCERT Solutions for Class 7 Science Chapter 9 Soil

Tick the most suitable answer in questions 1 and 2.
Question 1.
In addition to the rock particles, the soil contains
(i) air and water
(ii) water and plants
(iii) minerals, organic matter, air and water
(iv) water, air and plants
Answer:
(iii) minerals, organic matter, air and water

Question 2.
The water holding capacity is the highest in
(i) sandy soil
(ii) clayey soil
(iii) loamy soil
(iv) mixture of sand and loam
Answer:
(ii) clayey soil

Question 3.
Match the items in Column I with those in Column II :

Answer:

Question 4.
Explain how soil is formed?
Answer:

1.  The big and heavy rocks are broken into smaller pieces that come on the surface of the earth.
2. Soil is formed by breaking down of rocks by the action of wind, water, and climate. This process is called weathering.
3.  The smaller particles of the rocks obtained due to weathering get further decomposed on long exposure to air and moisture.
4.  Finally, the decomposed parts of dead plants and animals get mixed up with soil formed by the above processes. This gives the soil enough energy in the form of organic matter.

Question 5.
How is clayey soil useful for crops?
Answer:
Clayey soil retains water to a great extent. Thus the crops which require more water grow well in clayey soil.

Question 6.
List the differences between clayey soil and sandy soil.
Answer:

Question 7.
Sketch the cross-section of soil and label the various layers.
Answer:

Fig. A soil profile. Various horizontal zones indicate the stages in soil formation

Question 8.
Razia conducted an experiment in the field related to the rate of percolation. She observed that it took 40 min for 200 mL of water to percolate through the soil sample. Calculate the rate of percolation.
Answer:
Given, amount of water = 200 mL
Time taken = 40 min
Rate of percolation (mL/min) = \(\frac { Amount of water(mL) }{ Amount of water(mL) }\)
= \(\frac { 200 ml}{ 40 Min }\)
= 5 mL / min .

Question 9.
Explain, how soil pollution and soil erosion could be prevented.
Answer:
Prevention of soil pollution:

1. There should be a ban on polythene bags and plastics.
2. Waste products and chemicals should be treated before they are released into the soil.
3. The use of pesticides should be minimized

Prevention of soil erosion:

1. By growing trees.
2. Avoid deforestation.
3. Maintaining the porous structure of the soil.
4. Control and reclamation of ravines and shifting of cultivation.

Question 10.
Solve the following crossword puzzle with the clues given below:

Across
2. Plantation prevents it.
5. Use should be banned to avoid soil pollution.
6. Type of soil used for making pottery.
7. Living organism in the soil.
Down
1. In desert, soil erosion occurs through.
3. Clay and loam are suitable for cereals like.
4. This type of soil can hold very little water.
5. Collective name for layers of soil.
Answer:

We hope the NCERT Solutions for Class 7 Science Chapter 9 Soil help you. If you have any query regarding NCERT Solutions for Class 7 Science Chapter 9 Soil, drop a comment below and we will get back to you at the earliest.

NCERT Solutions for Class 7 Science Chapter 8 Winds, Storms and Cyclones are part of NCERT Solutions for Class 7 Science. Here we have given NCERT Solutions for Class 7 Science Chapter 8 Winds, Storms and Cyclones.

NCERT Solutions for Class 7 Science Chapter 8 Winds, Storms and Cyclones

Question 1.
Fill the missing word in the blank spaces in the following statements :

1. The wind is ……… air.
2. Winds are generated due to ……….. heating on the earth.
3. Near the earth’s surface …………. air rises up whereas ………. air comes down.
4. Air moves from a region of ……….. pressure to a region of ……….. pressure.

Answer:

1. moving
2. uneven
3. warm, comparatively cooler
4. high air, low air

Question 2.
Suggest two methods to find out wind direction at a given place.
Answer:
Two methods to find out wind directions are:
(i) using weathercock (Fig.).
(ii) one simple method used by common people is to hold some dust and release in the air. Dust will fly in the direction of air.

Fig. A weathercock

Question 3.
State two experiences that made you think that air exerts pressure (other than those given in the text).
Answer:
Experiment 1: When we fill the air in a balloon it flattens due to pressure exerted by air. Also when it is overfilled with air it bursts due to excess air pressure

Fig. Air exerts pressure
Experiment 2: When we hang a banner in a place of moving fast air, it tears due to the pressure exerted by the air.

Question 4.
You want to buy a house. Would you like to buy a house having windows but no ventilators? Explain your answer.
Answer:
No, a house which has no ventilators is not a safe or healthy house to live in. The air circulation is not present in such a house. So, it has no fresh air. Because warm air rises up and goes out through ventilators and fresh air comes in through windows.

Question 5.
Explain why holes are made in hanging banners and hoardings.
Answer:
We know that air exerts pressure. If there are no holes in the banners and hoardings they will be damaged. To make them safe, holes are made to give the air safe passage.

Question 6.
How will you help your neighbours in case a cyclone approaches your village/ town?
Answer:
I will help by following ways :

1. Warning everyone about the coming danger.
2.  Searching for shelter.
3. Keeping storage of water and food.
4. Setting up a first-aid facility.

Question 7.
What planning is required in advance to deal with the situation created by a cyclone?
Answer:
To deal with the situation created by a cyclone we must do the following planning in advance.
On the part of the government:

• Rapid communication of warnings to the government agencies, the ports, fishermen, ships, and to the general public must be ensured.
• There must be the construction of cyclone shelters in cyclone-prone areas and administrative arrangements for moving people fast to safer places.

On the part of the public following actions must be taken:

• keep ready the phone numbers of all emergency services like police, fire brigade, and medical centres.
• make necessary arrangements to shift the essential household goods, domestic animals and vehicles, etc., to safer places.

Question 8.
Which one of the following places is unlikely to be affected by a cyclone?
(i) Chennai
(ii) Mangaluru (Mangalore)
(iii) Amritsar
(iv) Puri
Answer:
(iii) Amritsar

Question 9.
Which of the statements given below is correct?
(i) In winter the winds flow from the land to the ocean.
(ii) In summer the winds flow from the land towards the ocean.
(iii) A cyclone is formed by a very high-pressure system with very high-speed winds revolving around it.
(iv) The coastline of India is not vulnerable to cyclones.
Answer:
(i) In winter the winds flow from the land to the ocean.

We hope the NCERT Solutions for Class 7 Science Chapter 8 Winds, Storms and Cyclones help you. If you have any query regarding NCERT Solutions for Class 7 Science Chapter 8 Winds, Storms and Cyclones, drop a comment below and we will get back to you at the earliest.

NCERT Solutions for Class 7 Science Chapter 7 Weather, Climate and Adaptations of Animals to Climate are part of NCERT Solutions for Class 7 Science. Here we have given NCERT Solutions for Class 7 Science Chapter 7 Weather, Climate and Adaptations of Animals to Climate.

NCERT Solutions for Class 7 Science Chapter 7 Weather, Climate and Adaptations of Animals to Climate

Question 1.
Name the elements that determine the weather of a place.
Answer:
Temperature, rainfall, humidity.

Question 2.
When are the maximum and minimum temperatures likely to occur during the day?
Answer:
The maximum temperature of the day generally occurs in the afternoon while the minimum temperature occurs generally in the early morning.

Question 3.
Fill in the blanks:
(i) The average weather taken over a long time is called …….
(ii) A place receives very little rainfall and the temperature is high throughout the year, the climate of that place will be …… and ………
(iii) The two regions of the earth with extreme climatic conditions are ……… and ……..
Answer:
(i) climate
(ii) dry, very hot
(iii) tropical, polar

Question 4.
Indicate the type of climate of the following areas:
(а) Jammu and Kashmir : ……….
(b) Kerala : ………
(c) Rajasthan : ………..
(d) Northeast India : ………
Answer:
(a) Moderately hot and moderately wet (very cold in winter).
(b) Very hot and wet.
(c) Hot and dry.
(d) Wet.

Question 5.
Which of the two changes frequently, weather or climate?
Answer:
It is the weather that changes frequently because it is such a complex phenomenon that it can vary over a very short period of time.

Question 6.
Following are some of the characteristics of animals:
(i) Diets heavy on fruits
(ii) White fur
(iii) Need to migrate
(iv) Loud voice
(v) Sticky pads on feet
(vi) Layer of fat under skin
(vii) Wide and large paws
(viii) Bright colours
(ix) Strong tails
(x) Long and large beak
Each characteristic indicates whether it is an adaptation for tropical rainforests or polar regions. Do you think that some of these characteristics can be adapted for both regions?
Answer:

 Question 7.
The tropical rainforest has a large population of animals. Explain why it is so.
Answer:
Because of continuous warmth and rain, this region supports wide variety of plants and animals.

Question 8.
Explain, with examples, why we find animals of certain kinds living in particular climatic conditions.
Answer:
Animals are adapted to survive in the conditions in which they live. Features and habits that help animals to adapt to their surroundings are a result of the process of evolution. Since to survive in a particular type of climate all the animals must have certain adaptive features, therefore we find animals of a certain kind living in a particular climatic conditions. For example, animals in the polar region are adapted to the extremely cold climate by having some special characteristics as in polar bear such as white fur, strong sense of smell, a layer of fat under the skin, wide and large paws for swimming and walking etc.

Question 9.
How does elephant living in the tropical rainforest adapt themselves?
Answer:
The elephant has adapted to the conditions of rainforests in many remarkable ways. It uses the trunk as a nose because of which it has a strong sense of smell. The trunk is also used for picking up food. Moreover, its tusks are modified teeth. These can tear the bark of trees that elephant loves to eat. So, the elephant is able to handle the competition for food rather well. The large ears of the elephant help it to hear even very soft sounds. They also help the elephant to keep cool in the hot and humid climate of the rainforest.

Choose the correct option which answers the following question:
Question 10.
A carnivore with stripes on its body moves very fast while catching its prey. It is likely to be found in
(i) polar regions
(ii) deserts
(iii) oceans
(iv) tropical rainforests
Answer:
(iv) tropical rainforests

Question 11.
Which features adapt polar bears to live in an extremely cold climate?
(i) A white fur, fat below the skin, keen sense of smell.
(ii) Thin skin, large eyes, white fur.
(iii) A long tail, strong claws, white large paws.
(iv) White body, paws for swimming, gills for respiration.
Answer:
(i) A white fur, fat below the skin, keen sense of smell.

Question 12.
Which option best describes a tropical region?
(i) Hot and humid
(ii) Moderate temperature, heavy rainfall
(iii) Cold and humid
(iv) Hot and dry
Answer:
(i) Hot and humid

We hope the NCERT Solutions for Class 7 Science Chapter 7 Weather, Climate and Adaptations of Animals to Climate help you. If you have any query regarding NCERT Solutions for Class 7 Science Chapter 7 Weather, Climate and Adaptations of Animals to Climate, drop a comment below and we will get back to you at the earliest.

NCERT Solutions for Class 7 Science Chapter 6 Physical and Chemical Changes are part of NCERT Solutions for Class 7 Science. Here we have given NCERT Solutions for Class 7 Science Chapter 6 Physical and Chemical Changes.

NCERT Solutions for Class 7 Science Chapter 6 Physical and Chemical Changes

Question 1.
Classify the changes involved in the following processes as physical or chemical changes:

1. Photosynthesis
2. Dissolving sugar in water
3. Burning of coal
4. Melting of wax
5. Beating aluminium to make aluminium foil
6. Digestion of food

Answer:

1. Chemical change
2. Physical change
3. Chemical change
4. Physical change
5. Physical change
6. Chemical change

Question 2.
State whether the following statements are true or false. In case a statement is false, write the correct statement in your notebook:
(a) Cutting a log of wood into pieces is a chemical change. (True/False)
(b) Formation of manure from leaves is a physical change. (True/False)
(c) Iron pipes coaled with zinc do not get rusted easily. (True/False)
(d) Iron and rust are the same substances. (True/False)
(e) Condensation of steam is not a chemical change. (True/False)
Answer:
(a) False
Correct statement: Cutting a log of wood into pieces is a physical change, ft, False
(b) True
Correct statement: The formation of manure from leaves is a chemical change.
(c) True
(d) False
Correct statement: Iron and rust are two different substances.
(e) True

Question 3.
Fill in the blanks in the following statements:

1. When carbon dioxide is passed through lime water, it turns milky due to the formation of …….
2. The chemical name of baking soda is ………
3. Two methods by which rusting of iron can be prevented are ……. and ……….
4. Changes in which only ………. properties of a substance change are called physical changes.
5. Changes in which new substances are formed are called ……. changes.

Answer:

1. calcium carbonate
2. sodium hydrogen carbonate
3. painting or greasing, galvanization
4. physical
5. chemical

Question 4.
When baking soda is mixed with lemon juice, bubbles are formed with the evolution of a gas. What type of change is it? Explain.
Answer:
It is a chemical change. Here, a new substance carbon dioxide gas is formed.

Question 5.
When a candle burns, both physical and chemical changes take place. Identify these changes. Give another example of a familiar process in which both the chemical and physical changes take place.
Answer:
When candle bums, both physical and chemical changes occur as given below:
(i) Physical change: Melting of wax, vapourisation of melted wax.
(ii) Chemical change: Burning of the vapours of wax to give carbon dioxide, heat, and light.
The burning of LPG in our kitchen is another such example in which a physical change occurs when LPG comes out of the cylinder and is converted to hum a liquid state to a gaseous state and a chemical change occurs when this gas burns in air.

Question 6.
How would you show that the setting of curd is a chemical change?
Answer:
When some sour substance is added to milk or kept overnight, it turns into curd. The curd in no way can be converted into milk i.e. irreversible change. Curd is a different substance than milk. So, the formation of curd is a chemical change.

Question 7.
Explain why burning of wood and cutting it into small pieces are considered as two different types of changes.
Answer:
Burning of wood is a chemical change because in burning new substances are formed as given below:
Wood + Oxygen → Coal + Carbon dioxide + Heat + Light.
While cutting it into small pieces is physical change because by cutting we can only reduce the size of the log of wood and no change in its chemical properties occurs and no new substance is formed.

Question 8.
Describe how crystals of copper sulphate are prepared.
Answer:
A cup of water is taken in a beaker and a few drops of dilute sulphuric acid are added into it. The water is heated. When it starts boiling, copper sulphate powder is added slowly while stirring continuously. Copper sulphate powder is added continuously till no more powder can be dissolved. The solution is filtered and allowed to cool down. Crystals of copper sulphate slowly form at the bottom of the beaker.

Fig. Crystals of copper sulphate

Question 9.
Explain how the painting of an iron gate prevents it from rusting.
Answer:
We know that the process of rusting requires exposure to both oxygen and water (or moisture). Painting prevents the surface of the iron gate from coming in contact with oxygen and moisture thus prevents it from rusting.

Question 10.
Explain why rusting of iron objects is faster in coastal areas than in deserts.
Answer:
In coastal areas, there is more moisture in the air due to the presence of the sea. But in the desert, there is a scarcity of water and hence the air is almost dry there. Both air and moisture are necessary conditions for rusting. So, rusting is faster in coastal areas than in deserts.

Question 11.
The gas we use in the kitchen is called liquified petroleum gas (LPG). In the cylinder, it exists as a liquid. When it comes out from the cylinder it becomes a gas (Change – A) then it burns (Change – B). The following statements pertain to these changes. Choose the correct one.
(i) Process – A is a chemical change.
(ii) Process – B is a chemical change.
(iii) Both processes A and B are chemical changes.
(iv) None of these processes is a chemical change.
Answer:
(ii) Process – B is a chemical change.

Question 12.
Anaerobic bacteria digest animal waste and produce biogas (Change – A). The biogas is then burnt as fuel (Change – B). The following statements pertain to these changes. Choose the correct one.
(i) Process – A is a chemical change.
(ii) Process – B is a chemical change.
(iii) Both processes A and B are chemical changes.
(iv) None of these processes is a chemical change.
Answer:
(iii) Both processes A and B are chemical changes.

We hope the NCERT Solutions for Class 7 Science Chapter 6 Physical and Chemical Changes help you. If you have any query regarding NCERT Solutions for Class 7 Science Chapter 6 Physical and Chemical Changes, drop a comment below and we will get back to you at the earliest.