1. Pathogens enter the body through a cut in the skin
2. Cells recognize the foreign invaders
3. Histamine is released
4. White blood cells travel to the invaded area
Hope it helps.
Explanation:
some ppl change there color to many other colors and some time there shape
True! Hydrogen bonds hold two stands of DNA together by forming nitrogenous bases. <span>A (adenine) can </span>form hydrogen bonds<span> only with T (thymine)</span>
Answer:
The alveoli are sacks coated on their inner wall by white and sticky liquid, they can be more than a millimeter in diameter and surface active agent. In them there is the exchange of gases between O2 and CO2.
They are evaginations of the epithelium of the air ducts with a single opening for the gases to exit and enter, controlled by the action of a smooth muscle sphincter. Its walls, called alveolar septa, provide a large increase in the exchange surface.
The answer is A I hope this works
