Question

A group of scientists wants to determine if fin length variation is genetically or environmentally controlled. They think the presence of predator pressure may be an environmental determinant of fin length. The scientists take eggs from short-tailed parents and raise them in both low and high predator pressure environments. They also take eggs from long-tailed parents raise them in both low and high predator pressure environments. The scientists then evaluate the tail length of the fish hatched from the eggs at adulthood. Select the correct dependent variable for this experiment.

A.Level of predation pressure.

B.Tail length at adulthood.

C.Tail length of the parents of the eggs.

D.The eggs.

Answer 1

Answer :

Correct choice is B

Tail length at adulthood.

Dependent variables are variables which is being studied and measured in the experiment. Dependent variable depends on the independent variables. In a scientific experiment you cannot have a dependent variable without an independent variable. In an experiment researcher look for a possible effect on dependent variable by independent variables.

An independent variable in an experiment is the variable that is changed or controlled in a scientific experiment to test the effects on dependent variable.

Here in this experiment part 1 - independent variables are high and low predator pressure environments. In part 2 its tail length of parents either long or short.

The dependent variable is the tail length of the new fish that is is grown up in the experiment. The tail length of new fish depends on independent variables as predator pressure and parent tail length.