100+ Free HESI A2 Biology Practice Questions

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Question 1

Score: 0/0

Fungi are classified into their own kingdom in part because they:

Lack DNA

Are autotrophic like plants

Have cell walls of chitin and are heterotrophic

Are all unicellular prokaryotes

to track

2026 Statistics

Key Facts: HESI A2 Biology Exam

~25

Questions on Biology subsection

Elsevier handbook

25 min

Section time limit

Elsevier handbook

100

Free practice questions here

OpenExamPrep

Elsevier's HESI A2 Biology section covers about 25 multiple-choice items in 25 minutes, focusing on cell biology, genetics, biomolecules, cellular energetics, and mitosis/meiosis for nursing-school applicants in 2026.

Sample HESI A2 Biology Practice Questions

Try these sample questions to test your HESI A2 Biology exam readiness. Each question includes a detailed explanation. Start the interactive quiz above for the full 100+ question experience with AI tutoring.

1Which organelle is known as the powerhouse of the cell because it produces most of the cell's ATP?

A.Nucleus

B.Mitochondrion

C.Ribosome

D.Golgi apparatus

Explanation: The mitochondrion generates the majority of ATP through oxidative phosphorylation along its inner membrane. It is a double-membraned organelle with its own DNA and is the primary site of cellular respiration in eukaryotic cells.

2Which structure is found in plant cells but NOT in animal cells?

A.Mitochondrion

B.Nucleus

C.Cell wall

D.Ribosome

Explanation: Plant cells have a rigid cell wall made of cellulose that lies outside the plasma membrane. The cell wall provides structural support and protection and is absent in animal cells.

3What is the primary function of the rough endoplasmic reticulum?

A.Lipid synthesis

B.Protein synthesis and modification

C.ATP production

D.DNA replication

Explanation: The rough endoplasmic reticulum (RER) is studded with ribosomes that translate proteins destined for membranes, secretion, or organelles. The RER folds and adds initial modifications such as glycosylation before passing proteins to the Golgi.

4Which type of cell lacks a membrane-bound nucleus?

A.Plant cell

B.Animal cell

C.Prokaryotic cell

D.Fungal cell

Explanation: Prokaryotic cells, such as bacteria and archaea, lack a membrane-bound nucleus and instead house their circular DNA in a region called the nucleoid. They also lack membrane-bound organelles like mitochondria and the ER.

5Which type of membrane transport requires the cell to expend ATP?

A.Simple diffusion

B.Facilitated diffusion

C.Osmosis

D.Active transport

Explanation: Active transport moves substances against their concentration gradient and requires energy from ATP, often using pumps such as the sodium-potassium pump. Diffusion and osmosis move substances down their gradients and do not require ATP.

6Water moves across a semipermeable membrane from a region of low solute concentration to high solute concentration. What is this process called?

A.Diffusion

B.Osmosis

C.Active transport

D.Endocytosis

Explanation: Osmosis is the passive movement of water across a semipermeable membrane from an area of lower solute concentration to an area of higher solute concentration. It continues until equilibrium is reached or pressure prevents further flow.

7A red blood cell is placed in a hypotonic solution. What will most likely happen to the cell?

A.It will shrink (crenate)

B.It will remain unchanged

C.It will swell and possibly lyse

D.It will become more rigid

Explanation: In a hypotonic solution, the surrounding fluid has a lower solute concentration than the cytoplasm, so water moves into the cell by osmosis. Red blood cells lack cell walls, so they swell and may burst (hemolysis).

8Which organelle is the primary site of protein synthesis?

A.Ribosome

B.Lysosome

C.Peroxisome

D.Centriole

Explanation: Ribosomes are the molecular machines that read mRNA and assemble polypeptides from amino acids. They consist of small and large subunits made of rRNA and protein, and can be free in the cytosol or bound to the rough ER.

9Which organelle contains hydrolytic enzymes that digest worn-out organelles and engulfed material?

A.Vacuole

B.Lysosome

C.Smooth ER

D.Golgi apparatus

Explanation: Lysosomes contain acid hydrolases that digest proteins, nucleic acids, carbohydrates, and lipids. They fuse with phagosomes or damaged organelles to break down their contents in a process called autophagy.

10The fluid mosaic model describes the plasma membrane as a:

A.Rigid wall of cellulose

B.Bilayer of phospholipids with embedded proteins

C.Single layer of cholesterol

D.Continuous sheet of carbohydrate

Explanation: The fluid mosaic model describes the plasma membrane as a flexible phospholipid bilayer with proteins, cholesterol, and glycolipids embedded throughout. The hydrophilic heads face the aqueous environments while hydrophobic tails face inward.

About the HESI A2 Biology Exam

The HESI A2 Biology subsection covers cell biology, genetics, biomolecules, cellular energetics, and mitosis/meiosis. It is one of three science subsections (Biology, Chemistry, A&P) on the HESI Admission Assessment.

Questions

25 scored questions

Time Limit

25 minutes

Passing Score

School set (75-80%+)

Exam Fee

Bundled in HESI A2 registration (Elsevier / nursing school testing centers)

HESI A2 Biology Exam Content Outline

High

Cell Biology

Organelles, transport, prokaryote vs eukaryote

High

Genetics

Punnett squares, alleles, DNA/RNA, inheritance patterns

Medium

Cellular Energy

Photosynthesis and cellular respiration

Medium

Cell Division

Mitosis vs meiosis, chromosomes

Medium

Biomolecules

Carbs, lipids, proteins, nucleic acids

Low

Classification & Ecology

Taxonomy and ecosystem basics

How to Pass the HESI A2 Biology Exam

What You Need to Know

Passing score: School set (75-80%+)
Exam length: 25 questions
Time limit: 25 minutes
Exam fee: Bundled in HESI A2 registration

Keys to Passing

Complete 500+ practice questions
Score 80%+ consistently before scheduling
Focus on highest-weighted sections
Use our AI tutor for tough concepts

HESI A2 Biology Study Tips from Top Performers

1Master the organelles and their functions

2Practice Punnett squares until you can do them quickly

3Build a side-by-side comparison of mitosis and meiosis

4Memorize the steps of photosynthesis and cellular respiration

Frequently Asked Questions

Is Biology required for HESI A2?

Programs choose which sections to require. Many require A&P and Math but not necessarily Biology — check your program.

How long is the HESI A2 Biology section?

About 25 minutes for roughly 25 questions.

What biology topics are most tested?

Cell biology, genetics, mitosis vs meiosis, and biomolecules are the most heavily tested topics.