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.
Plants often photosynthesize during the day when they are exposed to sunlight. Hope this helps!
Light dependent reaction take place on the thylakoid membranes.
The model attached represents facilitated transport, which is answer choice D. In the model, there are protein channels, which allow molecules to pass through them if they're too large to fit through the aquaporins (making diffusion an incorrect answer.) We can eliminate active transport since ATP isn't used to control transport, and we can eliminate endocytosis as it is a form of active transport. The remaining answer would be facilitated transport, which is a form of passive transport. Hope this helps! :)
Nonrenewable resources are used commonly and are quickly running out, and it takes longer for us to form more of these.
