Ragweed antigens bind ragweed and then bind mast cells which release histamine
<span>Allergies develop because of a Th2 response against the allergen. </span>
Answer:
B, A fossil found in rocks from one time period
Explanation:
Fossils are used to determine the ages of rock layers. Index fossils are the most useful for this. Index fossils are of organisms that lived over a wide area. They lived for a fairly short period of time. An index fossil allows a scientist to determine the age of the rock it is in. Hope that this helps you :)
The answer is Arteries
Arteries carry oxygen-rich blood from the heart to capillaries. On the contrary, veins carry blood without oxygen from the capillaries to the heart.
Arteries are very flexible and yet strong blood vessels so that efficient transport of oxygen-rich blood along the bloodstream through the organism is enabled.
False
Plants, animals, and fungi all have pro cells
