Answer:
The correct answer is:
Includes at least two groups, one of which does not receive the experimental treatment. (B)
Explanation:
A controlled experiment is made up of at least two groups of participants (subjects). One group (the test group) receives the experimental treatment, which can be an intervention or a new drug to be tested etc, and the effect of the treatment on the subjects is measured, while the second group of similar subjects also known as the control group acts as a baseline and do not receive the treatment or intervention. They act as a baseline to ensure that the change observed in the treatment group was brought about as a result of the treatment.
<em>Note that repeating the experiment several times does not ensure accuracy of the result, rather it ensures reliability of the results hence option D is not correct</em>
Answer:
The cell membrane is selectively permeable and able to regulate what enters and exits the cell, thus facilitating the transport of materials needed for survival. ...
Explanation:
Because the membrane acts as a barrier for certain molecules and ions, they can occur in different concentrations on the two sides of the membrane.
They are made of DNA so it's B