Science MCQ (1 Marks)

A person can hold air in the lungs is $500ml.$

Passive smoking is the involuntary inhalation of smoke, called secondhand smoke $(SHS)$ or environmental tobacco smoke $(ETS).$
It occurs when tobacco smoke permeates any environment, causing its inhalation by people within that environment.
That's why Suresh is considered as a passive smoker.

On an average, an adult human being at rest breathes in and out $15 - 18$ times in a minute.
During heavy exercise, the breathing rate can increase upto $25$ times per minute.
While we exercise, not only do we breathe fast, we also take deep breaths and thus inhale more oxygen.

Breathing (or ventilation) is the process of moving air into and out of the lungs to facilitate gas exchange with the internal environment, mostly by bringing in oxygen and flushing out carbon dioxide.
The Normal range of breathing rate per minute in an average adult person at rest is $15-18.$

At rest, an adult human inhales about $6 - 8$ litres of air per minute, of which two - third gets to the alveoli thus, gas exchange takes place and the rest remains in the air passages.

Test tube $(A)$ contains a snail in water.
The snail will use of oxygen for respiration and produce carbon dioxide.
Test tube $(B)$ contains a “water plant” in water.
The water plant will do photosynthesis by using carbon dioxide and water and produce oxygen.
The water plant will use some of this oxygen for respiration and produce carbon dioxide.
This carbon dioxide will then be used by the plant in photosynthesis.
Test tube $(C)$ contains both, a snail and a water plant.
The carbon dioxide produced by the respiration is snail will be all used up by the water plant in photosynthesis.
We conclude that the test tube containing only snail will have the highest concentration of $CO_2$ because there is no plants to use up the carbon dioxide produced during the respiration in snail.