Every question from this NCERT chapter, with a detailed explanation.
With reference to cellular respiration, consider the following statements: 1. It is the process of synthesis of food within the cell using energy. 2. It takes place in the cells of all living organisms. 3. The breakdown of food always occurs in the absence of oxygen. Which of the statements given above is/are correct?
What is the biological term for the breakdown of glucose in the absence of oxygen?
Consider the following statements regarding yeast: 1. They are single-celled organisms. 2. They respire anaerobically to produce lactic acid. 3. They can survive in the absence of air. Which of the statements given above is/are correct?
What are the end-products of anaerobic respiration (fermentation) in yeast?
Consider the following statements about the diaphragm: 1. It is a rigid bony plate located in the chest. 2. It forms the floor of the chest cavity. 3. It moves downwards during the process of inhalation. Which of the statements given above is/are correct?
Why does lime water turn milky when exhaled air is passed through it?
Consider the following statements regarding the respiratory system of insects like cockroaches: 1. They have small openings on the sides of their body called spiracles. 2. They rely exclusively on lungs for the exchange of gases. 3. The tracheal system is also the primary respiratory organ in earthworms. Which of the statements given above is/are correct?
Which one of the following organisms primarily utilizes cutaneous respiration (breathing through skin)?
With reference to respiration in plants, consider the following statements: 1. Plants take in oxygen from the air and give out carbon dioxide. 2. Only the leaves are capable of exchanging gases with the atmosphere. 3. Roots absorb air from the spaces between the soil particles. Which of the statements given above is/are correct?
Which structure facilitates gaseous exchange in plant leaves?
What is the primary physiological reason for the death of a potted plant when it is overwatered?
Consider the following statements about anaerobic respiration in yeast: 1. It occurs only in the presence of oxygen. 2. It produces alcohol and carbon dioxide. 3. It is used in the commercial production of wine and beer. Which of the statements given above is/are correct?
With reference to the movement of air in insects, consider the following statements: 1. Oxygen-rich air rushes through spiracles into tracheal tubes. 2. Oxygen is transported to body tissues primarily through haemoglobin. 3. Carbon dioxide is converted into starch within the tracheal tubes. Which of the statements given above is/are correct?
Consider the following statements regarding the air we breathe: 1. The air we inhale contains a mixture of gases including nitrogen. 2. The air we exhale is devoid of any oxygen. 3. Both inhaled and exhaled air are mixtures of gases. Which of the statements given above is/are correct?
What is the significance of air spaces between soil particles for plant roots?
With reference to the breathing rate, consider the following statements: 1. An adult human at rest typically breathes 40–50 times per minute. 2. During heavy exercise, the breathing rate can increase up to 25 times per minute. 3. While exercising, deep breaths are taken to inhale more oxygen. Which of the statements given above is/are correct?
Which of the following is produced during anaerobic respiration in muscles?
Consider the following statements regarding the tracheal system: 1. It consists of a network of air tubes found in insects. 2. It relies on blood circulation to transport oxygen to tissues. 3. It is the primary respiratory system in humans. Which of the statements given above is/are correct?
Which one of the following represents the approximate percentage of oxygen in inhaled air?
Which one of the following values represents the approximate percentage of carbon dioxide in exhaled air?
With reference to the breakdown of food, consider the following statements: 1. The breakdown of food in the cell releases energy. 2. The breakdown of food always requires the presence of oxygen. 3. Cellular respiration takes place inside the cell. Which of the statements given above is/are correct?
Which of the following pairs is correctly matched? Organism | Feature 1. Yeast | Anaerobe 2. Frog | Tracheae 3. Fish | Spiracles 4. Insect | Gills
Consider the following statements regarding the effect of smoking: 1. It improves the efficiency of the lungs in gas exchange. 2. It is linked to lung cancer. 3. It reduces the capacity of the lungs to hold air. Which of the statements given above is/are correct?
Which one of the following reasons explains why aquatic animals, such as fish, rely on water for respiration?
Consider the following statements regarding the moisture on a mirror when we exhale onto it: 1. It comes from the water vapour present in the surrounding air. 2. It condenses from the moisture present in our exhaled breath. 3. It indicates that respiration consumes water. Which of the statements given above is/are correct?
Consider the following statements about "cellular respiration": 1. It is the process of breakdown of food in the cell. 2. It is an energy-absorbing process. 3. It occurs in both plants and animals. Which of the statements given above is/are correct?
Which of the following is a product of aerobic respiration?
What is the primary role of oxygen in the cellular metabolism of aerobic organisms?
Which of the following statements about "anaerobes" is correct?
Which one of the following is NOT a component of the human respiratory system?
Consider the following statements regarding the energy release in respiration: 1. Aerobic respiration consumes energy without releasing any. 2. Anaerobic respiration releases energy. 3. The breakdown of food in cells releases energy. Which of the statements given above is/are correct?
Which of the following statements about "yeast" is correct?
Which one of the following organisms possesses a respiratory system that is structurally and functionally most similar to that of humans?
Consider the following statements about "oxygen toxicity": 1. Oxygen is essential for the survival of every living organism. 2. For some organisms, oxygen is toxic. 3. Breathing pure oxygen for long periods is always beneficial for humans. Which of the statements given above is/are correct?