It is ecosystem !!!!!!!!!!!!!!!!!!!!
An increase in volume DECREASES the pressure in the chest (pressure and volume vary inversely when temperature is held constant -- Boyle's law). Gas can only flow from an area of higher pressure to an area of lower pressure. It can't go uphill -- ever. It can only go from high to low pressure. When the diaphragm and intercostals contract, the diaphragm flattens and the rib cage rises. That increases the volume of the chest. That increase in volume decreases the pressure inside the chest (temperature is held constant -- because the temperature of the chest cavity does not change appreciably. It remains at body temp.). Air then flows from the area of higher pressure (atmospheric) to lower pressure (intrathoracic). That continues until the pressures are equal.
When the diaphragm and intercostals relax, the chest cavity decreases in size, the pressure increases to above atmospheric, and gas flows again from the area of higher pressure (intrathoracic) to lower pressure (atmospheric) until they are again equal.
It has nothing to do with the concentration of oxygen. You can ventilate a lung with ANY gas. It has to do with the change in pressure and only the change in pressure -- which is a function of the volume of the chest cavity.
The cell wall and chlorophyll are not found in animal cells.
Hope this helps!
-Payshence
<span>The correct answer is A. atoms. Atoms are studied by physics and chemistry, not by ecology. Ecology studies organisms, populations, and the earth in terms of climate, pollution prevention, natural habitats and biomes, and all kinds of similar things that are related to living on earth. Atoms are irrelevant for the study of ecology.</span>
The cautions that can be given to the friend include the following:
Eating foods from different sources is very advantageous because it ensures that one gets all the necessary food nutrients that are needed for proper growth and development. Getting the necessary food nutrients on the other hand will boost one's immunity and enable one to develop resistance to diseases. Restricting one's food to a limited type of food is very bad and can have fatal consequences.