When a pathogen comes in contact with your body, it has to breach the first line of defense to get inside. Your skin and mucus membranes are the main barrier here. Mucus traps the pathogens, and then is forced out of your body when you cough or blow your nose. Your skin also secretes chemicals that have antiviral properties, killing viruses on contact. If the pathogens get through that defense, the next line is non-specific immunity cells that patrol your tissues engulfing pathogens. There are other cells that do this, like macrophages, but the dendritic cells are most important for activating the third line of defense in your body.
Dendritic cells reside in your tissues, waiting for an invader to arrive. When they do find one, they engulf it and digest it. After they do this, they select pieces of the invader called antigens and put them on their surfaces. The dendritic cells migrate back to lymph nodes, key locations in your body filled with immune cells. There, they show the antigens, called antigen presentation, to two types of lymphocytes, T-cells and B-cells, activating them for a full immune response.
Answer: <em>I think is point a), not sure.</em>
Explanation:<em> if they drive at the same speed, they be closests to a).</em>
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Adaptations are
the result of evolution in different living organisms. This process occurs amazingly
through gene mutation but it takes a very long period in time. Adaptation
processes occur to help species survive and thrive in the ecological balance of
life. Structural adaptations are physical features of an organism that adapted
through time. An example of this are the bills of a bird and the fur of bears
that they generally need for their survival; birds for hunting, and bears to
protect them from low climate areas.
<span>
Functional or
Behavioral adaptations refer to particular things that an organism or organisms
do to survive. In the example above, behavioral adaptations that birds do is
through certain bird calls and migration, while bears hunt during warmer
seasons and hibernate during winter season. </span>
I think it just shows how many people care about the cause and think it’s important. It can also raise money and awareness about it.
