Respiration in Organisms Class 7 Extra Questions and Answers Science Chapter 10

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Class 7 Science Chapter 10 Extra Questions and Answers Respiration in Organisms

Extra Questions for Class 7 Science Chapter 10 Respiration in Organisms with Answers Solutions

Respiration in Organisms Class 7 Extra Questions Very Short Answer Type

Question 1.
Where does cellular respiration take place?
Answer:
Cellular respiration takes place in the cells of all organisms.

Question 2.
What is aerobic respiration?
Answer:
The process of breakdown of glucose with the use of oxygen is called aerobic respiration.

Question 3.
Define inhalation.
Answer:
The process of taking in of air rich in oxygen into the body is called inhalation.

Question 4.
Which gas do humans take in while breathing?
Answer:
Oxygen

Question 5.
Which gas do humans give out while breathing?
Answer:
Carbon dioxide

Question 6.
Define exhalation.
Answer:
The process of giving out of air rich in carbon dioxide is called exhalation.

Question 7.
Give one usage of yeast.
Answer:
Yeast is used for making alcoholic beverages like beer, wine, etc.

Question 8.
State aerobic respiration with the help of an equation.
Answer:

Question 9.
State anaerobic respiration with the help of an equation.
Answer:

Question 10.
When do our muscle cells respire anaerobically?
Answer:
When there is a temporary deficiency of oxygen in the muscle cells; they begin to respire anaerobically.

Question 11.
Give two therapies to release muscle cramps.
Answer:

• Hot water bath
• Gentle massage.

Question 12.
What are the functions of hair and mucus inside the nose?
Answer:
Hair and mucus present inside the nose prevent dust, dirt and germs from entering the respiratory system of our body.

Question 13.
Name the breathing organs of fish.
Answer:
Gills

Question 14.
Where are the lungs of human beings present?
Answer:
Chest cavity

Question 15.
Name one significant process of getting energy.
Answer:
Respiration

Respiration in Organisms Class 7 Extra Questions Short Answer Type

Question 1.
Define respiration.
Answer:
The process in living organisms involving the production of energy, typically with the intake of oxygen and release of carbon dioxide from the oxidation of complex organic substances is termed as respiration.

Question 2.
Define anaerobic respiration.
Answer:
The process of breakdown of glucose without the use of oxygen is termed as anaerobic respiration. In this process, glucose is used to get energy and carbon dioxide and alcohol are made as waste products.

Question 3.
What are yeasts?
Answer:
Yeasts are single-celled fungi that reproduce asexually by budding. They respire anaerobically and yield alcohol during the process. Hence, they are used in the making of alcoholic drinks, such as wine, beer, etc.

Question 4.
Why does anaerobic respiration take place in our muscles sometimes?
Answer:
During heavy physical work like cycling, running, jumping, etc., the demand of energy is high but the supply of oxygen is limited. Hence anaerobic respiration takes place in the muscle cells to fulfil the demand of energy.

Question 5.
What causes muscle cramps?
Answer:
Under anaerobic condition the partial breakdown of glucose produces lactic acid in the cells. The ac-cumulation of lactic acid causes muscles cramps.

Question 6.
What is breathing rate?
Answer:
The number of times a person breathes per minute is known as the breathing rate. A single breath means one inhalation and one exhalation; both take place alternatively.

Question 7.
Do we breathe only one gas at a time? If not, what amount of gases do we breathe respectively?
Answer:
No, we do not take in or give out only one gas at a time. The percentage of oxygen and carbon dioxide in inhaled and exhaled air are:

Question 8.
Why do we feel hungry after physical activity?
Answer:
During physical activity the demand of energy in the body increases. For the fulfilment of this energy requirement, we breathe faster, as a result of which oxygen is supplied to the cells. Hence, the rate of breakdown of food increases and more energy is released. So we feel hungry.

Question 9.
Explain the respiratory system in cockroaches.
Answer:
A cockroach has small openings on the sides of its body, called spiracles. It also has a network of air tubes called tracheae for gas exchange. Oxygen rich air rushes through spiracles into the tracheal tubes, diffuses into the body tissue and reaches every cell of the body. Similarly, carbon dioxide from the cells goes into the tracheal tubes and moves out through spiracles.

Question 10.
What are the harmful effects of smoking?
Answer:
Smoking damages lungs. Smoking is also linked to cancer.

Respiration in Organisms Class 7 Extra Questions Long Answer Type

Question 1.
Describe the mechanism of breathing in human beings with a suitable diagram.
Answer:

• During inhalation, diaphragm moves down and ribs move up and outwards this movement increases space in our chest cavity and air rushes into the lungs. The lungs get filled with air.
• During exhalation, diaphragm moves up to its former position and ribs move down and inwards. The space in the chest cavity decreases and thus air from the lungs is forced to get out of the body through the air passage. This is known as exhalation.

Question 2.
What are the differences between cellular respiration and breathing.
Answer:

Cellular respiration	Breathing
(i) Energy is released.	(i) Energy is not released.
(ii) It is a biochemical process.	(ii) It is a physical process.
(iii) The production of carbon dioxide gas takes place.	(iii) Carbon dioxide is given out and oxygen is taken in from the air.
(iv) It is an intracellular process.	(iv) It is an extracellular process.

Question 3.
How does exchange of gases take place in fish? Draw a diagram of breathing organs in fish.
Answer:

Fish have gills for respiration. Gills are feathery organs full of blood vessels. A fish breathes by taking water into its mouth and forcing it out through the gill passages. As water passes over the thin walls of the gills, dissolved oxygen moves into the blood and travels to the fish’s cells. Likewise carbon dioxide from the fish’s cells moves into the blood and is eliminated out through gills into the water.

Question 4.
Differentiate between photosynthesis and respiration.
Answer:

Photosynthesis	Respiration
(i) Only green plants carry out this process.	(i) It takes place in all the animals and plants.
(ii) Oxygen is given out as waste material.	(ii) Carbon dioxide is given out as waste mate­rial.
(iii) Conversion of light energy into chemical energy takes place.	(iii) Breakdown of food takes place with the release of energy.
(iv) Carbohydrate is synthesised.	(iv) Carbohydrate is broken down.
(v) It occurs only in presence of light.	(v) It occurs in both light and dark.
(vi) Carbon dioxide is taken in this process.	(vi) Carbon dioxide is liberated in this process.

Question 5.
Draw a well-labelled diagram
Answer:

Question 6.
Describe the process of breathing in human beings.
Answer:
When we breathe in, air enters through nasal cavity. The hair and mucus present in the nasal cavity traps dust and other particles present in air. Air from nasal cavity then reaches the pharynx in the neck region and the larynx. Below the larynx is the trachea. The trachea divides into two bronchi, right and left, which leads to the lungs.

In the lungs, each bronchus branches into smaller tubes called bronchioles. At the end of the bronchioles, small rounded structures called air sacs or alveoli are present. Each alveolus is made up of a very thin membrane surrounded by blood vessels. Exchange of gases occur in air sacs through the process of diffusion.

In short passage of air from nose can be depicted as:
Nose ➝ Nasal cavity ➝ Pharynx ➝ Larynx ➝ Trachea ➝ Bronchi ➝ Bronchioles ➝ Alveoli (air sac)

Respiration in Organisms Class 7 Extra Questions HOTS

Question 1.
Why do we yawn, especially when we feel drowsy and sleepy?
Answer:
When we feel drowsy or sleepy our breathing rate slow down. The lungs do not get enough oxygen from air resulting in yawning. Yawning brings extra oxygen into the lungs.

Question 2.
Why do people often breathe out on the spectacles to clean them?
Answer:
The warm and moist exhaled air condenses on the surface of spectacles as water vapour. Thus, making spectacles wet helps, to clean them easily with the help of a cloth.

Question 3.
On a very cold morning Radhika was amused and wondered to see that the air coming out of her mouth looked like smoke. Help her to find the answer.
Answer:
On a cold day, when warm and moist air comes in contact with the cold air outside, it condenses into mist. This look like smoke.

Question 4.
Why do we feel relieved after a massage of the pain in the leg muscles due to cramps?
Answer:
Massage improves the circulation of blood leading to increased supply of oxygen in the muscle cells which helps in complete breakdown of lactic acid into C02 and water. Thus, help in relieving of the pain.

Question 5.
Pick the odd-one-out from each of the groups given below on the basis of respiratory organs. Give reason for your answer.

1. cockroach, grasshopper, snail, ant
2. lizard, cow, earthworm, snake
3. crocodile, whale, dolphin, fish
4. snake, tadpole, crow, goat

Answer:

1. Snail; as other breathe through tracheae
2. Earthworm; as other breathe through lungs
3. Fish; as other have lungs for respiration
4. Tadpole; as other breathe through lungs

Question 6.
What is difference between pores present in insects and leaves of a plant?
Answer:
Pores in insects are known as spiracles whereas pores in the leaves of a plant is known as stomata. The differences between these two pores are:

1. Spiracles are present on the sides of insects’ body whereas stomata are present more on the lower surface of leaves and fewer on the upper surface of leaves.
2. Spiracles lead to an extensive network of tracheal system which is absent in the leaves.
3. Spiracles are fewer in number as compared to stomata.

Respiration in Organisms Class 7 Extra Questions Value Based (VBQs)

Question 1.
A food stall owner for preparing dough for making bhaturas, added a pinch of yeast and sugar to the dough. He kept the mixture in a warm place. After few minutes, the dough increases in volume.
(a) Why did the dough increase in volume?
(b) Do you think there is any change in smell and taste of dough?
(c) Why was sugar added to the dough?
(d) What would have happened if the dough was kept in the refrigerator, soon after it was prepared?
(e) Name some similar phenomenon we observe in making other food items?
(f) Can we use some previous dough of bhatura instead of yeast to leaven the dough?

Answer:
(a) The C02 released during respiration by the yeast gets trapped inside the dough and result in increase in volume.
(b) The smell and taste of dough will change to sour due to formation of alcohol and acid by yeast.
(c) Sugar acts as source of carbohydrate for yeast.
(d) The dough would not have increased in volume. In low temperatures, yeast would not multiply and respire. Thus, affecting the process of fermentation.
(e) We use the same phenomenon in making bakery items and idli and dosa.
(f) Yes, because previous dough will also have yeast to leaven the dough.