In a controlled experiment, an independent variable (the cause) is systematically manipulated and the dependent variable (the effect) is measured; any extraneous variables are controlled. The researcher can operationalize (i.e. define) the variables being studied so they can be objectivity measured.
Blood flows to the brain through the internal carotid and vertebral arteries and away from the brain through the internal jugular vein. The internal carotid artery supplies the brain, while the external carotid nourishes other portions of the head, such as the face, skull, scalp and the meninges. The vertebral arteries provide supply to the upper spinal cord, brainstem, cerebellum, and the posterior part of the brain.
C, because alleles are alternative forms of a gene that arise from mutation.
Answer:
The law of conservation of energy states that energy
Explanation:
It can neither be created nor destroyed or only converted from one form of energy to another. This means that a system always has the same amount of energy... unless it's added from the outside. I hope this helps.
