EXERCISES
Mukul Sahgal Science Solutions for EXERCISES
Simple step-by-step solutions to EXERCISES questions of Respiration from Living Science 7. Also get 3D topic explainers, cheat sheets, and unlimited doubts solving on EMBIBE.
Questions from EXERCISES with Hints & Solutions
Trace the path of oxygen in humans during respiration by filling in the blanks with the main organs of the respiratory system:
Nostrils and nasal cavity _____ _____ lungs _____ _____ cells.
How do the nostrils contribute to the process of breathing?
How are combustion and cellular respiration similar to each other? In what ways are they different?
What is the difference between breathing and cellular respiration?
Why do mountaineers climbing high mountains carry oxygen cylinders with them?
When we run fast, we consume more oxygen. Each one of us has a maximum rate of oxygen consumption. Our bodies cannot consume more oxygen than this. A scientist conducted a study of the maximum rates of oxygen consumption per kilogram body weight in 4 athletes. He also studied how much time each of them took to run a 10 km race. The result is shown in the table.
| ATHLETE |
MAXIMUM RATE OF OXYGEN CONSUMPTION (mL per kg per min) |
TIME TO RUN 10 km RACE (min) |
| A1 | 65.5 | 33.2 |
| A2 | 70.3 | 31.5 |
| A3 | 55.8 | 38.1 |
| A4 | 75.1 | 28.3 |
Is there a relationship between the maximum rate of oxygen consumption and time taken to run 10 km?
When we run fast, we consume more oxygen. Each one of us has a maximum rate of oxygen consumption. Our bodies cannot consume more oxygen than this. A scientist conducted a study of the maximum rates of oxygen consumption per kilogram body weight in 4 athletes. He also studied how much time each of them took to run a 10 km race. The result is shown in the table.
| ATHLETE |
MAXIMUM RATE OF OXYGEN CONSUMPTION (mL per kg per min) |
TIME TO RUN 10 km RACE (min) |
| A1 | 65.5 | 33.2 |
| A2 | 70.3 | 31.5 |
| A3 | 55.8 | 38.1 |
| A4 | 75.1 | 28.3 |
Can you suggest an explanation for this relationship?
Jatin saw a little girl being swept away by floodwater. He immediately jumped into the water. Though the current was fast, he was able to save the girl and pulled her to safety. She had swallowed a lot of water. So Jatin gave her artificial respiration and restored her breathing.
What can you say about Jatin?
