Answer:
A
A because it is talking specifically about two different pieces within the human body which have two different functions
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).
To learn more about the antibody refer here:
brainly.com/question/13981216
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Neurotransmitters that have narcotic-like effects are called endorphins. These neurotransmitters are responsible for our feelings of excitement or satisfaction.
Answer:
Option C, Paramecium
Explanation:
Complete question
Which of these organisms contains no specialized cells?
a. Sea anemone
b. Jellyfish
c. Paramecium
d. Sponge
Solution -
Paramecium consists of only cell and hence the chance of it having specialized cells is nill. Its size is somewhere around between 50 to 300 micrometer. It belongs to kingdom Protista and is a single celled eukaryote. While on the other hand sea anemone, sponge and jelly fishes are multicellular with various special structures such as tentacles, cilia , flagella. Hence, these three must be having specialized cell.
