Answer:
The answer would be A, only chloroplasts and vacuoles are found in plant cells. :)
The term for the type of key that biologists used in separating<span> groups of organisms that are based on couplets is called taxonomic key. This key is very useful in the identification and classification of a </span>specific organism and it usually has an analytical characteristic.<span> </span>
This might have been the cause of not being exposed to this specific pollen during his years in Chicago. Allergic reactions can develop when the stimuli presented even when its not contagious causes the immune system to trigger and act in a defensive stance. This delayed effect may have been the cause of the sudden expression of the immune system.
The biome that usually have this type of vegetation are tundras or polar grasslands.
Hope this helps!