Class 7 Science Chapter 6 Important Question Answers - Respiration in Organisms

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Very Short Answer Type Questions

Q1: What is the process by which cells release energy from glucose?
Ans: The process by which cells release energy from glucose is called respiration.

Q2: What is the product of glucose breakdown in the presence of oxygen?
Ans: In the presence of oxygen, glucose is broken down into energy, water, and carbon dioxide.

Q3: What is the product of glucose breakdown in muscle cells in the absence of oxygen?
Ans: In muscle cells in the absence of oxygen, glucose is converted into lactic acid and carbon dioxide.

Q4: How is yeast used in beverage industries?
Ans: Yeast is used in beverage industries to produce beer and wine by converting glucose into alcohol and carbon dioxide in the absence of oxygen.

Q5: When do plants release carbon dioxide, and when do they take in oxygen?
Ans: During the night, plants release carbon dioxide, and during the day, they take in oxygen for respiration.

Q6: What is the process in which glucose is broken down in cells to release energy called?
Ans: The process in which glucose is broken down in cells to release energy is called cellular respiration.

Q7: What is the term for the breakdown of glucose in the presence of oxygen?
Ans: The breakdown of glucose in the presence of oxygen is called aerobic respiration.

Q8: What is the role of red blood cells in the transportation of oxygen to cells?
Ans: Red blood cells absorb oxygen from the lungs and transport it to all the cells in the body.

Q9: What causes muscle cramps during strenuous exercises?
Ans: Muscle cramps during strenuous exercises are caused by the accumulation of lactic acid in the muscles during anaerobic respiration.

Q10: What is the term for organisms that respire in the absence of oxygen?
Ans: Organisms that respire in the absence of oxygen are called anaerobes.

Short Answer Type Questions

Q11: Explain the process of respiration in organisms.
Ans: Respiration is the process by which cells release energy from glucose. Glucose is broken down in the presence of oxygen to produce energy, water, and carbon dioxide. In the absence of oxygen, glucose can be converted into lactic acid and carbon dioxide, leading to muscle cramps.

Q12: How do plants exchange gases, and what is the role of stomata in this process?
Ans: Plants exchange gases through small openings called stomata, which are found on the leaves and stems. These stomata play a crucial role in the following ways:

• They allow carbon dioxide to enter the plant for photosynthesis.
• They enable the release of oxygen as a by-product of photosynthesis.
• At night, stomata facilitate the intake of oxygen and the release of carbon dioxide and water vapour.

Q13: Describe the role of cellular respiration in releasing energy from food.
Ans: Cellular respiration is the process that allows cells to break down glucose to release energy. This energy is essential for various activities, including:

• Growth
• Excretion
• Reproduction
• Everyday tasks like running, reading, and sleeping

During digestion, complex carbohydrates are converted into glucose. This glucose is then absorbed into the bloodstream and transported to cells, where it is used for energy production.

Q14: Explain the process of breathing in humans.
Ans: Breathing in humans consists of two main steps: inhalation and exhalation.

• During inhalation:
  • Air rich in oxygen enters the lungs.
  • The diaphragm contracts and the rib cage expands.
• During exhalation:
  • Air rich in carbon dioxide is expelled.
  • The diaphragm relaxes and the rib cage contracts.

The typical breathing rate is 15-18 breaths per minute.

Q15: How do insects and animals like frogs and earthworms respire?
Ans: Insects respire through small openings on their bodies called spiracles. This allows oxygen to enter directly into their cells via diffusion. They have a network of air tubes, known as tracheae, which transport oxygen and remove carbon dioxide. Frogs and earthworms breathe through their moist skin, which helps in gas exchange. Frogs also possess lungs, allowing them to breathe when on land.

Q16: What are the different respiratory organs in various organisms, and how do they obtain oxygen?
Ans: Different organisms have unique respiratory organs to obtain oxygen:

• Insects: Use small openings called spiracles to take in air.
• Frogs: Breathe through their skin and lungs.
• Earthworms: Respire through their moist skin.
• Fish: Use gills to extract dissolved oxygen from water.

Each organ functions to ensure that oxygen reaches the organism's cells efficiently.

Q17: How does the human respiratory system protect against unwanted particles in the air?
Ans: The human respiratory system protects against unwanted particles in the air through several mechanisms:

• Tiny hairs in the nasal cavity trap dust, smoke, and pollen.
• The mucous lining from the nasal cavity to the lungs helps to capture and remove these particles.
• If particles irritate the nasal lining, we may sneeze to expel them, allowing clean air to enter.

Q18: Explain the role of the diaphragm in the process of breathing.
Ans: The diaphragm is a large muscle that forms the base of the chest cavity. Its role in breathing includes:

• During inhalation, the diaphragm contracts and moves downwards.
• This contraction increases the space in the chest cavity, allowing air to flow into the lungs.
• During exhalation, the diaphragm relaxes and moves upwards.
• This movement decreases the chest cavity's size, pushing air out of the lungs.

These actions are essential for the breathing process, enabling the exchange of oxygen and carbon dioxide.

Q19: How do fish obtain oxygen for respiration, and what are their respiratory organs?
Ans: Fish obtain oxygen for respiration using gills. The process works as follows:

• Water enters the fish's mouth.
• It flows over the gills.
• Oxygen is extracted from the water.
• Carbon dioxide is released back into the water.

The gills are highly vascularised, allowing for efficient gas exchange.

Q20: How do insects respire, and what are their specialized respiratory structures?
Ans: Insects respire using special structures known as spiracles. These are small openings located on the sides of their bodies that:

• Allow air to enter directly into the insect's tracheal tubes.
• Facilitate the diffusion of oxygen to the cells.
• Enable carbon dioxide from the cells to exit through the spiracles.

The tracheal system is unique to insects and is not found in other animal groups.