It is called coevolution, when two species influence each other's speciation.
RNA polymerase is guided to the correct place.
Phenotype; The expression of a particular trait, for example, skin color, height, behavior, etc., according to the individual's genetic makeup and environment.
Answer: 101 neutrons
An element's atomic number is the number of protons in its nucleus. X has 52 protons. The mass number is simply the number of protons AND neutrons in the nucleus. Since 52 is given, it's correct to assume that the remainder consists of neutrons. 153-52 will give you the number of neutrons.
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