Question

a group of students wanted to see what affect adding gingko biloba would have on the growth of young guppies (a type of fish). they fed a group of 10 guppies their regular diet. in another 10 guppies they fed them their regular diet but added 2 drops of gingko biloba to their food each day and measured their mass every day for three weeks. at the end of their experiment, the guppies given the gingko biloba had grown by 14 grams more than the guppies fed a regular diet. the students concluded that gingko biloba caused the guppies to grow larger.

1. identify the (a.) independent, (b.) dependent and (c.) control group.

a. ______________
b. ______________
c. ______________

Explanation:

Part (a) Independent Variable:

The independent variable is the factor that is manipulated or changed in an experiment. Here, the students added Gingko biloba to the diet of one group of guppies while the other group received the regular diet. So the presence or addition of Gingko biloba (specifically, the 2 drops of Gingko biloba added to the food) is the independent variable as it's what the experimenters are changing to observe its effect.

Part (b) Dependent Variable:

The dependent variable is the factor that is measured or observed to see how it changes in response to the independent variable. In this experiment, the students measured the growth (mass) of the guppies. So the growth (mass) of the guppies (specifically, the amount they grew, like the 14 grams more in the Gingko - fed group) is the dependent variable because it depends on whether Gingko biloba was added to their diet.

Part (c) Control Group:

The control group is the group in an experiment that is not exposed to the independent variable and is used for comparison. In this case, the group of 10 guppies that were fed their regular diet (without the addition of Gingko biloba) is the control group. This group allows the experimenters to see what the normal growth of the guppies is like without the influence of the independent variable (Gingko biloba), so they can compare it to the group that received the independent variable.

Answer:

a. The addition of Gingko biloba (or the presence of Gingko biloba in the diet)
b. The growth (mass) of the guppies
c. The group of 10 guppies fed their regular diet (without Gingko biloba)