Microtubules are hollow tubes of protein that maintain cell shape and permit movement of cell organelles.
Answer;
D. controlled
An experiment in which only one variable is changed is a controlled experiment.
Explanation;
-A control experiment is an experiment where the researcher only changes one variable at a time in order to isolate the results.
In a controlled experiment, most conditions are constrained so that they do not change. One or two other conditions are then changed and measured by the experimenter. These are known as the independent variables.
For example; An experiment where all subjects involved in the experiment are treated exactly the same except for one deviation.
Ionic bond is the correct answer
Naturally occurring compounds in the earth are called minerals.
Cancer is an abnormal and uncontrolled multiplication of cells.
<span>Cancer also involves abnormal cell growth with the potential to spread to other parts of the body via blood and to form metastasis. Cancer cells avoid apoptosis (programmed cell death), have the limitless number of cell divisions and promote blood vessel construction. There are more than 100 types of cancers that affect humans with different signs and symptoms and with many different causes. </span>
