Class: 7th. Subject : Science
Short Answer Questions
1. What do you mean by respiration?
Ans: Respiration is the process in which food is broken in the presence of oxygen to release energy.
2. What is the need for respiration in living organisms?
Ans: Respiration is important for all living organisms on the earth including human's, animals and plants to respire in order to live.
3. How does respiration process take place in leaves?
Ans: Exchange of gases in the leaves take place through the opening in the leaves and stem called stomata.
4. What is a diaphragm?
Ans: A muscular partition separating the abdominal and thoracic cavities.
5. Define aerobic and anaerobic respiration.
Ans:
Aerobic respiration is the process of respiration that takes place in the presence of oxygen.
Anaerobic respiration is the process of respiration that takes place in the absence of oxygen.
6. What is the similarity between breathing in an earthworm and a frog?
Ans: A frog and an earthworm both breathe through their skin.
Q 7.How is breathing similar in a fish and a tadpole?
Ans: Fish breathes in water using gills. Water flows across the gills and blood is allowed to exchange oxygen and carbon dioxide. Tadpoles breathe the same way as fish during that stage of life before maturing into frog that use their lungs to breathe
Q 8.How do gills help in respiration in aquatic animals?
Ans; Fishes and other aquatic animals respire through gills . Gills are covered by an opening called operculum. Operculum let's the water to pass through the gills. The gills absorb oxygen from the water . The filaments in the gills contain blood capillaries that helps in the exchange of gases.
LONG ANSWER QUESTIONS
1. Describe the process of respiration in human beings.
Ans:
In humans, lungs are the organs of respiration, which are present inside the chest and protected by the rib cage. The ribs support the lungs and help in pumping air in and out while breathing. Underneath the lungs, there is a dome shaped muscle called diaphragm. When the diaphragm contracts, oxygen rich air is pulled inside the lungs. Exchange of gases takes place in the lungs and carbon dioxide is pumped out from the lungs when the diaphragm relaxes.
2. Describe respiratory system in animals.
Ans: There are different respiratory systems in animals, which include
Skin – In some animals respiration takes place with their moist and slimy skin surface. E.g., leeches and earthworms. Amphibians respire with skin when in water and with lungs when on land. E.g., frogs, newts.
Air holes – In insects, there are air holes or spiracles present on their body, which enable the entry of oxygen rich air and giving out carbon dioxide rich air. E.g., cockroaches
Gills – Many aquatic animals have gills, which are made up of filaments having blood vessels or capillaries. The blood in capillaries helps to absorb oxygen in water, transports in the body and gives out carbon dioxide. E.g., Fish
Lungs – Most mammals respire with lungs, which are sac like spongy organs in the body. E.g. ,monkeys, cats, human beings, etc.
3. How do plants respire? State the role of various plant parts in this process.
Ans: Plants respire with the help of openings or tiny holes called stomata that are present on the underside of the leaves. Stomata are able to trap air containing oxygen and carbon dioxide and exchange of gases occurs within the plant cells.
4. Explain exchange of gases in plants.
Ans: Exchange of gases in the leaves take place through the opening in the leaves and stem called stomata. If we look at a leaf , we find that it contains lots of small holes inside it. These holes are known as stomata. Stomata look like opening and have two cells.These cells are known as guard cells.It is due to the expension and contraction of guard cells that exchange of gases take place in the leaves.
5 Differences between
a) breathing and cellular respiration:
Breathing Cellular Respiration
It is a physical process in which exchange of gases takes place.
It does not involve any chemical reaction. It is oxidation of food, thus involves a chemical reaction.
It occurs outside the cells.
It occurs inside the cells.
No energy is liberated in the process.
b) Aerobic and anaerobic respiration. ANSWER: Aerobic respiration Anaerobic respiration
1) There is slow release of energy.
1) There is sudden release of energy. 2)Energy is released in a form that can be used by the organism. 2) Energy is released in a form of heat or light. Energy is stored in the body in the form of (adenosine triphosphate) ATP molecules. Energy cannot be stored as ATP.
3)Energy is liberated during the process.
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