Antibodies have a variable region that binds to a specific antigenic determinant.
Antibody
An antibody (Ab), also known as an immunoglobulin (Ig), is a large, Y-shaped protein used by the immune system to identify and neutralize foreign objects such as pathogenic bacteria and viruses. The antibody recognizes a unique molecule of the pathogen, called an antigen. Each tip of the "Y" of an antibody contains a paratope (analogous to a lock) that is specific for one particular epitope (analogous to a key) on an antigen, allowing these two structures to bind together with precision. Using this binding mechanism, an antibody can tag a microbe or an infected cell for attack by other parts of the immune system or can neutralize it directly (for example, by blocking a part of a virus that is essential for its invasion).
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C. Organelles. organelle are the small things in your cell like mitochondria that help work the cell.
Answer:
Describe two desert animals and the adaptation that help them survive?
Camel and Donkey
Explanation:
Both animals have two different types of stomach that enables them to store water for a very long time and makes them withstand drought
Answer:
D) Even a slight reproductive advantage will eventually lead to the elimination of the less well adapted of two competing species.
Explanation:
The competitive exclusion describes relationship between two species that compete for the limiting sources, and cannot coexist. It is enough for one species to have slightly advantage to be dominant over the other. As a consequence, other species (the weaker one) will be extincted (shift to a different ecological niche).