Answer:
silicon dioxide Si02 and diamond
Explanation:
because it's commonly found in nature
The choices can be found elsewhere and as follows:
A. mature leaves
B. shoot apical meristem
C. cell elongation zone
<span>D. axillary buds
</span>
I think the correct answers are option B and D. It would be at the shoot apical meristem and the axillary buds that <span> a vascular plant would you expect to find totipotent cells. Hope this answers the question.</span>
The antigen-binding sites of an antibody molecule are formed from the molecule's variable regions which are described as so because their amino acid sequences can be different on different antibodies.
The specificity of antibodies is determined by the variable regions found at their endpoints. Antibodies are specialized proteins secreted by B-cells of the immune system. They are also called immunoglobulins. They contain four polypeptide chains that comprise two heavy chains and two light chains to form a Y-shaped molecule.
The variable regions, more specifically the hypervariable regions of an antibody, have a high ratio of different amino acids with the most common amino acids provided in one place. The variable region serves as the antigen-binding site while the constant region found below the variable region is determined to invade the antigen.
Antibodies are preserved in our body to identify the antigen the next time it encounters. They send the signals to the other body parts to reject the antigen and invade it.
To know more about variable regions of antibodies, refer to the following link:
brainly.com/question/17439586
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