Understanding how living things process energy is a foundational concept in Middle School Life Science. Whether you are prepping for a biology unit test or working through your homework worksheets, mastering the difference between how cells breathe is essential.
| Feature | Aerobic Respiration | Anaerobic Respiration |
|---|---|---|
| Presence of Oxygen | Takes place in the absolute presence of oxygen air. | Takes place in the complete absence of oxygen air. |
| Breakdown of Food | Glucose is completely broken down into simpler elements. | Glucose is partially or incompletely broken down. |
| End Products | Carbon Dioxide ($CO_2$), Water ($H_2O$), and Energy. | Alcohol/Lactic Acid, Carbon Dioxide ($CO_2$), and minimal Energy. |
| Energy Yield | Releases a very large amount of energy. | Releases a relatively small amount of energy. |
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Explore NEET Biology →To make your exam preparation smooth, we have compiled a comprehensive list of Respiration in Organisms Class 7 Questions and Answers. This guide covers multiple-choice queries, brief definitions, long-form explanations, and highly useful comparative tables to help you secure top marks in your science exams.
Middle School Life Science Review Questions
Q1: What is cellular respiration and where does it occur?
Answer: Cellular respiration is the biological process by which cells break down food molecules (like glucose) to release stored chemical energy. This vital metabolic process occurs inside individual microscopic cells of all living organisms.
Q2: What is the main difference between breathing and respiration?
Answer:
Breathing is a purely physical mechanical process involving the inhalation of oxygen-rich air and the exhalation of carbon dioxide via respiratory organs (like lungs or gills).
Respiration is a complex chemical, cellular process occurring inside cells where glucose is broken down and oxidized to release functional energy.
Q3: Why do human muscles cramp after intense exercise?
Answer: During heavy exercise or strenuous athletic workouts, the human body requires rapid energy delivery. When the local oxygen supply falls short of the demand, muscle cells temporarily break down glucose anaerobically (without oxygen). This incomplete metabolic breakdown leads to an accumulation of lactic acid, causing temporary muscle cramps and fatigue.
❓ Part 1: Short Answer Questions (2 Marks Each)
Q1: What is cellular respiration? Where does it occur?
Answer: The process of breaking down food (glucose) in the cell with the release of energy is called cellular respiration. This process occurs inside the microscopic cells of all living organisms.
Q2: Differentiate between breathing and respiration.
Answer:
Breathing is a purely physical process involving the inhalation of oxygen-rich air and the exhalation of carbon dioxide-rich air via respiratory organs.
Respiration is a complex biochemical process occurring inside cells, where glucose is oxidized to release chemical energy.
Q3: Why do we get muscle cramps after heavy or strenuous exercise?
Answer: During heavy exercise, our body requires rapid energy. When the oxygen supply falls short, our muscle cells break down glucose anaerobically (without oxygen). This incomplete breakdown leads to the accumulation of lactic acid, which causes temporary muscle cramps.
Q4: Why do we sneeze when we inhale a lot of dust-laden air?
Answer: When dust particles enter our nasal cavity, they irritate the sensitive lining of the nose. As a natural reflex mechanism to expel these unwanted foreign particles, our body triggers a sneeze to clear the nasal passage.
📊 Part 2: Long Answer Questions & Comparisons (3-5 Marks Each)
Q5: Compare Aerobic Respiration and Anaerobic Respiration.
Answer: Understanding the distinct differences between these two pathways is highly critical for school examinations. Here is the structured comparison:
❓ Part 1: Short Answer Questions (2 Marks Each)
Q1: What is cellular respiration? Where does it occur?
Answer: The process of breaking down food (glucose) in the cell with the release of energy is called cellular respiration. This process occurs inside the microscopic cells of all living organisms.
Q2: Differentiate between breathing and respiration.
Answer:
Breathing is a purely physical process involving the inhalation of oxygen-rich air and the exhalation of carbon dioxide-rich air via respiratory organs.
Respiration is a complex biochemical process occurring inside cells, where glucose is oxidized to release chemical energy.
Q3: Why do we get muscle cramps after heavy or strenuous exercise?
Answer: During heavy exercise, our body requires rapid energy. When the oxygen supply falls short, our muscle cells break down glucose anaerobically (without oxygen). This incomplete breakdown leads to the accumulation of lactic acid, which causes temporary muscle cramps.
Q4: Why do we sneeze when we inhale a lot of dust-laden air?
Answer: When dust particles enter our nasal cavity, they irritate the sensitive lining of the nose. As a natural reflex mechanism to expel these unwanted foreign particles, our body triggers a sneeze to clear the nasal passage.
📊 Part 2: Long Answer Questions & Comparisons (3-5 Marks Each)
Q5: Compare Aerobic Respiration and Anaerobic Respiration.
Answer: Understanding the distinct differences between these two pathways is highly critical for school examinations. Here is the structured comparison:
Inhalation:
When we breathe in, the ribs move up and outwards, while the dome-shaped diaphragm moves downwards. This coordinated movement increases the total space inside our chest cavity, lowering air pressure and causing air to rush into our lungs.
Exhalation:
When we breathe out, the ribs move downwards and inwards, while the diaphragm moves upward to its relaxed state. This decreases the space in the chest cavity, compressing the air and forcing it out of our lungs.
🌿 Part 3: Respiration in Plants
Q8: Do plants also respire? Explain how roots get oxygen.
Answer: Yes, plants are living organisms and require constant energy to survive, meaning they respire around the clock.
Leaves: Leaves contain microscopic pores called stomata on their surfaces, which allow for the exchange of oxygen and carbon dioxide.
Roots: Root cells need energy to absorb vital water and mineral nutrients from the ground. They absorb oxygen from the tiny air spaces present between the loose soil particles. If a plant is overwatered for a prolonged period, these air spaces fill up with water, cutting off oxygen and causing the roots to rot.
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