Experiment: What is the effect of drinking coffee on a person's score on a memory test? Which of the following would be the INDEPENDENT VARIABLE?
O Coffee
O Decaf coffee
O Memory test score
O Type of cup used

The independent variable would be the coffee.

Explanation:

In an experiment, the independent variable is something that is added or changed by the scientist in order to see if there will be a response.

In this case, the memory test score would be the dependent variable (something that changes as a result of a change in the independent variable).

Decaf coffee could be a control group, or a group that is treated the same as the independent variable but without being exposed in order to account for any outside factors.

Finally, the type of cup used would be a constant between the control group (using the decaf coffee) and the experimental group (the group with regular coffee).

Hope this helps!

genetic variation can be caused by mutation (which can create entirely new alleles in a population), random mating, random fertilization, and recombination between homologous chromosomes during meiosis (which reshuffles alleles within an organism's offspring).