<span>The penguin population will decrease due to shorter and warmer winters.
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It's basically to reproduce. You are here because of reproduction from your parents.
<span>Observing that fibroblasts grew better in cell culture when blood serum was added to the growth medium instead of blood plasma. Thus proving that there was a substance in serum that made it easier for fibroblasts to grow.</span>
Answer:
intensity with which the rats pressed the lever
Explanation:
In research, there are two main variables which are <u>dependent</u> or <u>independent</u>.
Independent variables are controlled or manipulated by the experimenter and the independent variable in this experiment is the amount of light exposure.
The response or outcome, which is then measured is the dependent variable. In this experiment, the dependent variable is the intensity with which the rats pressed the lever with varying exposure to light.
In summary, the independent variable has a causal effect on the dependent variable so in this experiment the amount of light exposure has a casual effect on whether the rats would press a lever more.
