ATI TEAS Science Exam 2026: ACTUAL EXAM
TESTBANK - 3 VERSIONS WITH VERIFIED
ANSWERS FINAL EXAM BUNDLE 2026/2027
(REAL EXAM QUESTIONS)
Which of the following statements is/are true regarding cells and tissues?
• A. Cells and tissues carry out all chemical activities needed to sustain life.
• B. Cells are the fundamental structural building blocks of all living things.
• C. Tissues are organized groups of specialized cells that are similar in structure and
function.
• D. All of the above are true.
Correct Answer: D
Rationale: Cells function as the baseline unit of all living biology, and matching cells group
together to form specialized functional layers called tissues. Both individual cells and combined
tissues work in tandem to coordinate the metabolic reactions that sustain life.
Question
Which of the following statements regarding saltatory conduction within the nervous system
are true?
• A. It occurs strictly within myelinated neurons.
• B. It is significantly faster than continuous nerve conduction.
• C. It occurs as the electrical impulse jumps from one node of Ranvier to the next.
• D. All of the choices are correct.
Correct Answer: D
Rationale: Saltatory conduction is an accelerated form of neural transmission where action
potentials "hop" or jump down an axon from one uninsulated node of Ranvier to the next. This
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mechanism is unique to myelinated fibers and drastically speeds up signal propagation
compared to unmyelinated pathways.
Question
What is the precise biological definition of cytokinesis?
• A. The mechanical division of the cell nucleus.
• B. The initial primary phase of active cell division.
• C. The stage of mitosis where genetic division halts.
• D. The physical division of the cytoplasm to form two daughter cells.
Correct Answer: D
Rationale: While mitosis refers explicitly to the division and separation of the nuclear genetic
material, cytokinesis is the distinct final step where the cell's cytoplasm splits, pinching the
plasma membrane to create two separate, independent daughter cells.
Question
What do you call the cellular process of producing a functional polypeptide chain from a
mature RNA template?
• A. Transcription
• B. Replication
• C. Translation
• D. Fabrication
Correct Answer: C
Rationale: Translation is the process by which ribosomes read the nucleotide sequence of a
messenger RNA (mRNA) transcript and convert that code into a specific sequence of amino
acids, building a polypeptide chain. Transcription is the alternative step where DNA is copied into
RNA.
Question
Which cytoplasmic organelle is characterized by an extensive network of fluid-filled tubules
and sacs designed for modifying, carrying, and transporting cellular substances?
• A. Nucleus
• B. Mitochondria
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• C. Endoplasmic reticulum
• D. Golgi apparatus
Correct Answer: C
Rationale: The Endoplasmic Reticulum (ER) is a vast continuous network of folded tubules and
flattened sacs (cisternae) that functions as the cell's manufacturing and transport highway. The
rough ER processes proteins, while the smooth ER synthesizes lipids and handles detoxification.
Question
Which of the following specific nucleic acids is responsible for carrying individual amino acids
directly to the ribosomes, where they are linked together one by one to form a polypeptide?
• A. tRNA
• B. DNA
• C. rRNA
• D. mRNA
Correct Answer: A
Rationale: Transfer RNA (tRNA) molecules act as molecular adaptors. Each tRNA molecule
carries a specific amino acid on one end and features a matching anticodon on the other,
allowing it to dock at the ribosome and deliver its payload according to the mRNA template
sequence.
Question
Which of the following options accurately describes the primary physiological function of the
mitochondria?
• A. Protein synthesis
• B. Cellular division
• C. Transport and storage
• D. Energy production
Correct Answer: D
Rationale: Mitochondria are known as the powerhouses of the cell because they house the
biochemical machinery for aerobic cellular respiration, utilizing oxygen and nutrients to generate
the cellular fuel molecule ATP (adenosine triphosphate).
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Question
Which statement correctly describes a core structural difference between the cytosol and the
mitochondrion?
• A. The cytosol is a functional part of the cytoplasm, but the mitochondrion is not.
• B. The mitochondrion is a membrane-bound organelle, but the cytosol is not.
• C. The mitochondrion is considered a part of the cytoplasm, but the cytosol is not.
• D. The cytosol is a specialized membrane-bound organelle, but the mitochondrion is not.
Correct Answer: B
Rationale: The cytosol is the fluid, semi-gelatinous liquid environment that fills the cell and
surrounds the internal structures. The mitochondrion is a distinct, physical, double-membrane-
bound organelle floating within that cytosol. Both are sub-components of the broader
cytoplasm.
🫁 Physiology, Pathophysiology & Homeostasis
Question
Which of the following are recognized as major homeostatic functions performed by the liver?
• A. Energy storage and glycogen use.
• B. Supporting the kidneys via the conversion of ammonia into urea for waste disposal.
• C. Producing bile to emulsify fats inside the lumen of the small intestine.
• D. Synthesizing blood clotting factors and maintaining plasma osmotic balance.
• E. All of the choices are correct.
Correct Answer: E
Rationale: The liver is a multi-functional organ critical to homeostasis. It manages energy
(glycogen storage), converts dangerous ammonia into urea to support kidney excretion, secretes
bile to assist lipid digestion, and manufactures essential plasma proteins like albumin (for
osmotic balance) and prothrombin (for clotting).
Question
The systematic protection of an organism's internal environment from disruptive fluctuations
in the outside external environment is termed:
• A. Homeostasis