I'll try to explain, because I've had tubes before. In fact, I still have them.
For me, tubes were put in because of too many ear infections, and excessive water in my ear. The tube helped drain the water out. You can see A picture I have in a file. The tubes can be put I believe in the ear drum. They're put there to help drain water that has trouble getting out on its own.
Like other succulent plants, most cacti<span> employ a special mechanism called "crassulacean acid metabolism" (CAM) as </span>part<span> of </span>photosynthesis<span>. Transpiration, during which carbon dioxide enters the plant and water escapes, </span>does<span> not </span>take place<span> during the day at the same time as </span>photosynthesis<span>, but instead </span>occurs<span> at night.</span>
Exocrine glands release secretions outside of the body.
One way to remember this is:
exo = outside
endo = inside
An example of an exocrine gland is a sweat gland. They release sweat (an excretion) to the outside of your body.
I hope this helps! I'm happy to answer any other questions you might have :)
External respiration (correct answer) involves the exchange of oxygen and carbon dioxide within the environment.
The exchange of wastes through the skin is just called excretion by sweating.
There is no exchange of nutrients that occur in the lungs but rather absorption of nutrients is the function of the gastrointestinal tract.
The exchange of oxygen and carbon dioxide within the cell is called cellular respiration and involves carrying oxygen from the blood to the cell then the cell uses it as the final electron acceptor in the electron transport chain. The metabolic wastes of the cell, primarily carbon dioxide, goes now to the bloodstream to be exchanged for oxygen in the lungs.
