MCQ 11 Mark
The percentage of $CO2$ in inhaled air is:
- ✓$0.04\%$
- B$21\%$
- C$16.4\%$
- D$4.4\%$
Answer
View full question & answer→Correct option: A.
$0.04\%$
The percentage of carbon dioxides in inhaled air is $0.04\%$
50 questions · timed · auto-graded
The percentage of carbon dioxides in inhaled air is $0.04\%$
At rest, an adult human inhales about $6 - 8$ litres of air per minute, of which two - third gets to the alveoli thus, takes part in gas exchange and the rest remaining in the air passages.
Fresh air contains $21\%$ oxygen and almost no carbon dioxide.
Here, all these statements are correct.
At rest, an average-sized adult will take up about $250ml$ of oxygen each minute, and exhale about $200ml$ of carbon dioxide.
The key to aerobic respiration lies within the mitochondria.
The mitochondrion is an organelle with a complex series of chemical reactions similar to the chloroplast.
The mitochondria, like the chloroplast, contains its own $DNA$, and it is has a double - membrane system.
The outer membrane is similar to any other organelle, but the inner membrane is folded, creating a lot of surface area.
The chemical reaction for aerobic respiration occurs on the surface of the inner mitochondrial membrane.
In insects, the respiratory system has a network of the trachea.
They are opened through $10$ pairs of spiracles that are present on the lateral sides of the body.
The trachea has network of air tubes for gaseous exchange.
So the correct answer is 'Trachea'.
Tobacco smoke contains more than $4,000$ chemicals.
Many are known to be harmful substances, including tar, nicotine, carbon monoxide, benzene, formaldehyde and hydrogen cyanide.
More than 50 of these chemicals cause cancer.
The process of releasing energy from food is called respiration.
Respiration occurs in all the living cells.
The process of respiration involves taking in oxygen into the cells, using it for releasing energy by burning food, and then eliminating the waste products carbon dioxide and water from the body.
The percentage of oxygen in inhaled air is $21\%$
During heavy exercise, anaerobic respiration takes place in our muscle cells.
This happens as the oxygen gets used up faster in our muscle cells then can be supplied by the blood.
To produce extra energy for exercise, the muscle cells shift to anaerobic respiration.
Glucose + No oxygen (in muscles, anaerobic respiration) $\times $ Lactic acid $+$ Energy
The breathing rate of a person increases when he does gym or weightlifting.
Remember, the breathing rate of a person is a slowest when he is sleeping because minimum energy is required by the body during sleep which can be provided by a slow rate of breathing.
The breathing rate of a person increases with increased physical activity (like exercise, running, gym, weightlifting etc.).
When the breathing rate increases, greater amount of air goes into the lungs.
With more air going into the lungs, the blood can absorb oxygen at a faster rate.
Thus, faster breathing supplies more oxygen to the body cells for producing more energy or by the rapid breakdown of food needed for doing physical exercise etc.
Vital capacity is the maximum volume of air that a person can exhale after maximum inhalation.