I believe the answer is B because the egg becomes fertilized by the sperm inside the body.
using seeds from the same source.
using the same kind of soil for both groups.
giving the control and experimental groups the same volume of water.
keeping the light the same for the experimental and control groups.
measuring plant height the same way and at the same time for both groups.
Testosterone and oxytocin
<span>A cross-sectional study examines all of the participants at one time. So for a cross-sectional study of cancer survivors, we would gather some sample of former patients and find out how long they have been in remission.
The problem with that cross-sectional design is we would be missing the people whose cancer had returned and caused them to die before our experiment started; we would have introduced a problem called "survivor bias" by only counting people who were STILL in remission and still alive.
A better experiment will use a longitudinal design of enrolling people whose cancer has just gone into remission, and following them to see how long they stay healthy.</span>
