These AP 7th Class Science Important Questions and 6th Lesson Respiration in Organisms Class 7 Extra Questions will help students prepare well for the exams.
Class 7 Science Respiration in Organisms Extra Questions
Respiration in Organisms Class 7 Important Questions
Question 1.
Where does cellular respiration takes place?
Answer:
Cellular respiration takes place in cells of all organisms.
Question 2.
Name the two modes of respiration.
Answer:
The two modes of respiration are:
- Aerobic respiration
- Anaerobic respiration
Question 3.
What is respiration?
Answer:
Respiration is a biological process in which food is utilised to produce energy.
Question 4.
What is breathing?
Answer:
Breathing is the process in which air rich in oxygen is taken inside and air rich in CO2 is given out, with the help of respiratory organs.
Question 5.
Define the terms:
a) Inhalation
b) Exhalation
Answer:
a) Inhalation : Taking in of air rich in oxygen into the body is called inhalation.
b) Exhalation : Giving out air rich in carbon dioxide from the body to the external environment is called exhalation.
Question 6.
Our nostrils has hair and mucous. What is the need to have them in our nasal cavity?
Answer:
Our nostrils possess hair and mucous lining. These helps to filter the air that goes into the lungs. They stop the germs and dust from entering into our body.
Question 7.
Which group of organisms possess spiracles?
Answer:
Spiracles are plesent only in insects.
Question 8.
What do you mean by breathing rate?
Answer:
The number of times a person breathes in a minute is termed as breathing rate. An adult human being can inhale and exhale 15-18 times in a minute.
Question 9.
Which gas present in the air is essential for aerobic respiration? What is the role of oxygen during respiration?
Answer:
Oxygen present in air is essential for aerobic respiration and it help to break down food and release energy during respiration.
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.
What do you mean by diaphragm?
Answer:
A muscular partition separating the abdominal and thoracic activities is called diaphragm.
Question 12.
Why smoking should be avoided?
Answer:
Smoking damages lungs. Smoking is also linked to cancer. It must be avoided.
Question 13.
What are anaerobes?
Answer:
There are some organisms such as yeast that can survive in the absence of air. They are called anaerobes.
Question 14.
Name the parts of respiratory system of human?
Answer:
The respiratory system consists of the nose, pharynx, larynx, trachea, bronchi, diaphragm and lungs.
Question 15.
Where are the lungs of human beings are present?
Answer:
The lungs of the human beings are present in the chest cavity.
Respiration in Organisms Extra Questions
Question 1.
What are spiracles?
Answer:
Spiracles are small openings present on the sides of the body of insects, like cockroaches. The spiracles on the body of insects are connected to a network of thin air tubes called tracheae which spreads into the whole body of the insect, where the exchange of gases takes place.
Question 2.
Pick the odd one out from each of the groups given below on the basis of respiratory organs. Give reason for your answer.
a) Cockroach, grasshopper, snail, ant
b) Lizard, cow, earthworm, snake
c) Crocodile, whale, dolphin, fish
d) Snake, tadpole, crow, goat
Answer:
a) Snail is the odd one, as it does not breathe by means of tracheae.
b) Earthworm is the odd one, because it breathes through its skin and it does not have lungs.
c) Fish is the odd one, as most fish breathe through their gills and do not have lungs.
d) Tadpole is the odd one, as it breathes through gills and do not have lungs.
Question 3.
Insects and leaves of a plant have pores through which they exchange gases with the atmosphere. Can you write two points of differences between these pores with respect to their position, number and extension into the body?
Answer:
Spiracles in insects and stomata on the leaves of a plant are pores through which gaseous exchange takes place. The differences between spiracles and stomata on the basis of their position, number and extension into the body are as follows:
- Spiracles are present on the sides of insects body while stomata are present on the lower surface of leaves in the plants.
- Spiracles are lesser in number as compared to stomata.
- Spiracles are part of an extensive network of tracheal system which is absent in the leaves.
Question 4.
What is the Aerobic respiration?
Answer:
The process of respiration which takes place in the presence of oxygen is called aerobic respiration. During aerobic respiration, glucose is completely broken down into carbon dioxide and water and energy is released. Aerobic respiration takes place in mitochondria.
It can be shown by the following equation :
Aerobic respiration is seen in most of the organisms such as humans (man), dogs, cats, lions, elephants, cows, buffaloes, goats, snakes, earthworms, frogs, fishes, etc.
Question 5.
What do you mean by anaerobic respiration?
Answer:
The respiration which takes place in the absence of oxygen is called anaerobic respiration. In this procesș glucose is not completely broken down into carbon dioxide and water. An intermediate compound is formed with the release of less amount of energy during this process. It can be shown as follows:
Question 6.
What are yeasts? Write its uses.
Answer:
Yeast is a single-celled organism. During anaerobic respiration (also called fermentation), yeast produces ethanol or alcohol as a by product which is used in making wine and beer. The carbon dioxide produced by yeast is used in the bread making industry. The CO2 gas released during this process causes the bread dough to rise.
Question 7.
What causes muscle cramps? How can you relieve the pain from muscle cramps?
Answer:
The muscle cramps occur when cells respire anaerobically. The partial breakdown of glucose produces lactic acid. The accumulation of lactic acid causes muscle cramps. The pain from muscle cramps can be reduced by following methods:
- Massaging the area
- Bathing with hot water
- Resting
Hot water bath or massage improves circulation of blood. As a result, the supply of oxygen to the muscle cells increases. The increase in the supply of oxygen results in the complete breakdown of lactic acid into carbon dioxide and water.
Question 8.
Define respiration in plants.
Answer:
Plants take in oxygen from the air and give out carbon dioxide through tiny pores called stomata, situated in the back of the leaves. Oxygen is used to break down glucose into carbon dioxide and water inside the cell.
Question 9.
Explain the respiration in Earthworm.
Answer:
Earthworms breathe through their skins. The skin of an earthworm feels moist and slimy on touching.Oxygen enters the body of the earthworm through diffusion and exits in a similar way.
Question 10.
Observe the given diagram of human respiratory system. List the organs from (A) to (G).
Answer:
The human respiratory system have following organs:
- A – Ribs
- B – Trachea
- C – Pharynx
- D – Diaphragm
- E – Lungs
- G – Oral cavity
- F – Nasal passage
Question 11.
What are the stages of respiration?
Answer:
Respiration takes place in the following stages:
- External respiration or gaseous exchange: The exchange of gases between the environment and the body is called external respiration or gaseous exchange. This is also called breathing.
- Internal respiration : It is a biochemical process involved in respiration which breaks down the food using inhaled oxygen to release energy and takes place in the tissues within the cells of an organism.Thus, this is called the cellular or tissue respiration.
Question 12.
Describe the various types of respiratory organs found in animals?
Answer:
In animals, there are definite respiratory organs for exchange of gases.
- In earthworm and leech exchange of gases takes place through moist, thin and vascular skin.
- In insects the trachea are the respiratory organs.
- In fishes the gills are the respiratory organs.
- Higher animals like mammal and birds including man have lungs for respiration.
Question 13.
Explain the process of breathing.
Answer:
The air inhaled is transported to every part of the body and ultimately is transported to every cell in the body. The oxygen in the air helps in the breakdown of food in the cells to release energy. This process is called cellular respiration.
Question 14.
Define cellular respiration.
Answer:
The air inhaled is transported to all parts of the body and ultimately to each cell in the body. In the cells, oxygen in the air helps in the breakdown of food. The process of breakdown of food in the cell with the release of energy is called cellular respiration. Cellular respiration takes place in the cells of all organisms.
Extra Questions of Respiration in Organisms Class 7
Question 1.
Paheli participated in a 400 m race competition held at her school and won the race. When she came home she had mixed feelings of joy and pain as she had cramps in her leg muscles. After a massage, she was relieved of the pain. Answer the following questions related to situation.
a) What can be the possible reasons for the pain in her legs?
b) Why did she fell comfortable after a massage?
Answer:
a) The pain in her legs could be because of the accumulation of lactic acid in the muscles. During heavy exercise or running etc., the muscle cells respire anaerobically and produce lactic acid.
b) The massage or hot water bath gives relief from muscle cramps or pain, because it improves the circulation of blood leading to increased supply of oxygen to the muscle cells. It helps in complete breakdown of lactic acid into carbon dioxide and water.
Question 2.
Decribe the respiratory system in humans.
Answer:
Respiratory system is responsible for the process of respiration. It involves exchange of gases, i.e., oxygen and carbon dioxide between body and surrounding. When we breathe in, the air enters through our nostrils. Hair and the most inner lining of the nose prevent the dust and germs from entering the respiratory system. The air passing the nasal passage gets warm and moist and enter the lungs through trachea and bronchi. In lungs, each bronchus divided into smaller tubes called bronchioles.
At the other end of these bronchioles, there are very small air sacs called alveoli. These air sacs are surrounded by blood vessels. These blood vessels absorb oxygen present in the air. we breathe in. Carbon dioxide present in the blood is released into the air sacs and is expelled out of our body when we breathe out. Thus during breathing, exchange of carbon dioxide and oxygen takes place in the lungs.
Question 3.
Differentiate between respiration and breathing.
Answer:
Differences between respiration and breathing are as follows :
| S.No | Respiration | Breathing |
| 1) | Respiration is a biological process in which food is utilised to produce energy. | Breathing is the process in which air rich in oxygen is taken inside & air rich in CO2 is given out, with the help of respiratory organs. |
| 2) | It takes place inside the cells, respiratory organs. | It takes place at the surface of the |
| 3) | The exchange of gases takes place between blood and the tissues of the body. | The exchange of gases takes place between the blood and the external environment. |
| 4) | Respiration takes place in cells and cell organelles, including mitochondria, etc. | Breathing occurs through respiratory organs, including the nose, lungs, etc. |
| 5) | In this process nutrients are oxidised to liberate energy. | The nutrients are not oxidised to liberate energy. . |
Question 4.
What is meant by breathing rate ? Explain the mechanism of inhalation and exhalation which are responsible for the breathing rate?
Answer:
The number of times a person breathes in a minute is termed as breathing rate. During breathing, inhalation and exhalation takes place alternatively. A breath means one inhalation plus exhalation. During inhalation two processes occur together, i.e., the muscles between the ribs contract causing the ribcage to move upward and outward, while the diaphragm contracts and moves downwards.
This upward and downward movement of ribcage and diaphragm respectively increases the space in the chest cavity and makes it larger. As the chest cavity becomes larger, it sucks air from outside the lungs and lungs get filled up with air and expand. During exhalation, ribs move down and inwards, while diaphragm moves up to its original position. This reduces the size of the chest cavity and air is pushed out of the lungs.
Question 5.
What are the differences between cellular respiration and breathing?
Answer:
The differences between cellular respiration and breathing are as follows :
| S.No | Cellular respiration | Breathing |
| 1) | The process of breakdown of food in the cell with the release of energy is called cellular respiration. | Breathing is the process in which air rich in oxygen is taken inside and air rich in CO2 is given out, with the help of respiratory organs. |
| 2) | Energy is released in this process. | Energy is not released in this process. |
| 3) | It is a biochemical process. | If physical process. |
| 4) | The production of carbon dioxide gas takes place. | Carbon dioxide is given out and it. oxygen is taken in from the air. |
| 5) | It is an intracellular process. | It is an extracellular process. |
Question 6.
Observe the given figures carefully and answer the following questions.
a. The amount of CO2 be the highest in which jar. Why ?
b. The amount of CO2 be the lowest in which one and why?
Answer:
a. Jar C has highest amount of CO2. lt is because the mice kept under the jar will breathe out CO2 continuously increasing its amount in the jar. In other jars, the CO2 present inside will be used up by the plants for photosynthesis. So, its amount will decrease.
b. The amount CO2 will be the lowest in jar A. It is because in jar A, CO2 released during respiration is used by the plant for the process of photosynthesis.
Case Based/Data – Based Questions
Mohan a stall owner was preparing dough for making Poori’s. He added a pinch of yeast and sugar to the dough and left it in a warm place. After few hours, the dough had risen. There was a sour smell too.
a) Why did the dough rise?
Answer:
The dough rose due to the release of carbon dioxide during anaerobic respiration by the yeast.
b) Why did the dough smell sour?
Answer:
Yeast, during anaerobic respiration also produces alcohol which results in the sour smell of dough.
c) Why was sugar added to the dough?
Answer:
Sugar is added into the dough, because it acts as a food for yeast, Yeast on incomplete breakdown of sugar or food produces CO2, alcohol and energy (in less amount).
d) What would have happened if the dough was kept in the refrigerator, soon after it was prepared?
Answer:
If the dough was kept in the refrigerator soon after it was prepared, then dough will neither rise nor become sour. Yeast requires high temperature to grow, multiply and to respire. At low temperature, the yeast will not multiply or respire and therefore, no CO2 or alcohol would be formed.