I think it is b because it is a result of an environmental influence
Answer is: the part of an experiment that stays the same though out the experiment is constant.
<span>Constant is a quantity that does not change.
</span>Experimental variable<span>, which is the also part of an experiment, is affected by the experiment (have change).</span>
Explanation:
It sends message directly to muscles and glands
Cells divide for many reasons. For example, when you skin your knee, cells divide to replace old, dead, or damaged cells. Cells also divide so living things can grow. When organisms grow, it isn't because cells are getting larger.
1) Eubacteria.
https://upload.wikimedia.org/wikipedia/commons/thumb/7/78/Collapsed_tree_labels_simplified.png/400px...