TEAS Science Practice Questions with Explanations
8 min read · Updated
Science is 50 questions in 60 minutes — the largest section on the TEAS and the one nursing programmes scrutinise most closely. Human anatomy and physiology makes up the biggest share, so that is where preparation pays best.
Practice questions
Which chamber of the heart pumps oxygenated blood into the systemic circulation?
- ARight atrium
- BRight ventricle
- CLeft atrium
- DLeft ventricle
Explanation
The left ventricle receives oxygenated blood from the left atrium and pumps it out through the aorta to the body. It has the thickest wall of the four chambers because it works against the highest pressure. The right ventricle sends deoxygenated blood to the lungs, and the atria are receiving chambers rather than pumping chambers.
Which organelle is the primary site of ATP production?
- ARibosome
- BMitochondrion
- CGolgi apparatus
- DLysosome
Explanation
Mitochondria carry out oxidative phosphorylation, which produces the great majority of a cell's ATP. Ribosomes assemble proteins, the Golgi apparatus packages and ships them, and lysosomes break down waste.
What is the normal pH range of human arterial blood?
- A6.8 – 7.0
- B7.35 – 7.45
- C7.8 – 8.2
- D5.5 – 6.5
Explanation
Arterial blood is held between 7.35 and 7.45, slightly alkaline. Below 7.35 is acidosis, above 7.45 is alkalosis, and either state outside a narrow margin is life-threatening. This is one of the highest-yield numbers on the whole exam.
Which type of blood vessel carries blood away from the heart?
- AVeins
- BArteries
- CVenules
- DCapillaries
Explanation
Arteries carry blood away from the heart — the pulmonary artery does so even though its blood is deoxygenated, which is why 'away from the heart' is the reliable definition rather than 'carries oxygenated blood'. Veins return blood to the heart, and capillaries are where exchange happens.
Which macromolecule stores genetic information in living organisms?
- AProtein
- BLipid
- CNucleic acid
- DCarbohydrate
Explanation
Nucleic acids — DNA and RNA — store and transmit genetic information. Proteins do the structural and enzymatic work the genes encode, lipids form membranes and store energy, and carbohydrates are the body's readiest fuel.
Which part of the nervous system controls involuntary functions such as heart rate and digestion?
- ASomatic nervous system
- BAutonomic nervous system
- CCentral nervous system
- DPeripheral nervous system
Explanation
The autonomic nervous system governs involuntary processes, and divides into the sympathetic branch (fight or flight) and the parasympathetic branch (rest and digest). The somatic system controls voluntary muscle. Both the autonomic and somatic systems are subdivisions of the peripheral nervous system, which makes 'peripheral' too broad to be the best answer.
What to prioritise
- Cardiovascular system — chambers, valves, the path of blood, arteries versus veins.
- Respiratory system — gas exchange and how breathing is controlled.
- Nervous system — central versus peripheral, somatic versus autonomic.
- Cell biology — organelles and what each one does.
- Chemistry basics — pH, atomic structure, the four macromolecules.
Note the wording of question four
'Carries blood away from the heart' is correct for arteries; 'carries oxygenated blood' is not, because the pulmonary artery breaks that rule. TEAS Science questions are frequently decided by exactly this kind of distinction.