ACT Science Test

The ACT science test consists of 40 questions within 35 minutes. These questions cover the biological sciences, physical sciences, chemistry, and physics. You should average about 1 completed question per .8 minutes on this part of the ACT test.

It is not necessary to memorize scientific definitions, principles, and data to pass this part of the ACT test. You only have to review the passage or diagram and identify the relationships presented. This section of the ACT test focuses heavily on graphs and charts. Always read the title of the graph and chart. Identify the information presented on the x and y axis to help you understand the relationships of the data presented.


This sort of information could be covered on the ACT Science Test. Please review the following passage. On the ACT test there would 2-4 questions asking for an interpretation of the information in this passage. In addition, you have four answer choices on this part of the ACT test.

Circulatory System Review

The cardiovascular system is vital for providing oxygen and nutrients to tissues and removing waste. The heart is divided into four chambers-two atria and two ventricles-that communicate through orifices on each side. The right atrium receives blood from the venous system and then lets blood fall down into the right ventricle. Blood then goes to the lungs for a new supply of oxygen. Then the blood comes back from the lungs and goes to the left atrium. It then falls into the left ventricle and is pumped into the general circulation. The heart is composed of three layers: epicardium, myocardium and an endocardium. Heart sounds are due to the vibrations produced by blood and valve movements. Blood pressure is the force exerted by blood against the insides of the blood vessels. Heart rate is determined by physical activity, body temperature, and concentration of ions. The heart is controlled by impulses from the S-A node which passes to the A-V node.