Answer:
The fish did not yet exist when the old layers of rocks were deposited. In fact, animals with hard parts did not evolve until about 600 million years ago, which is only about 13% of the 4.5 billion year age of the Earth. Multicellular animals without hard parts left tracks in older sediments, but had no fossilize-able body parts.
Explanation:
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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Answer:
p = 20
Explanation:
to get p alone you have to do the oposite of what your doing with p
ex) its being divided so you would have to multiply both sides by 4 to get p alone
p = 5x4
Answer:
Cell is the basic , functional unit of life
An atom is the smallest unit of ordinary matter that forms a chemical element .
D. Decrease in the amount of carbon dioxide in the air
Explanation:
i hope this is right have a nice day God bless u
