HESI Biology Practice Examination 100
Questions And Correct Answers
(Verified Answers) Plus Rationales
2026 Q&A Instant Download Pdf
Section 1: Cell Biology and Transport
1. Which organelle is responsible for protein synthesis?
A. Nucleus
B. Mitochondria
C. Ribosome
D. Golgi apparatus
C. Ribosome
Ribosomes are the sites of protein synthesis, translating mRNA into
polypeptides. The nucleus contains DNA, mitochondria produce ATP, and the
Golgi apparatus modifies and packages proteins.
2. What is the primary function of the cell membrane?
A. To produce energy
B. To control what enters and leaves the cell
C. To store genetic information
D. To synthesize proteins
B. To control what enters and leaves the cell
The cell membrane is selectively permeable, regulating the passage of
substances into and out of the cell. Energy production occurs in mitochondria,
genetic storage in the nucleus, and protein synthesis at ribosomes.
3. Which of the following is a prokaryotic cell?
,A. Human liver cell
B. Plant cell
C. Bacteria
D. Fungus
C. Bacteria
Prokaryotic cells lack a true nucleus and membrane-bound organelles.
Bacteria are prokaryotes, while human, plant, and fungal cells are eukaryotic.
4. Which organelle contains hydrolytic enzymes and is called the "suicide
bag"?
A. Ribosome
B. Golgi apparatus
C. Lysosome
D. Peroxisome
C. Lysosome
Lysosomes contain digestive enzymes capable of breaking down cellular
waste. If these enzymes are released, they can digest the cell itself, hence the
nickname "suicide bag."
5. Which particular structure is present in both eukaryotic and prokaryotic
cells?
A. Nucleus
B. Mitochondria
C. Cell membrane
D. Endoplasmic reticulum
C. Cell membrane
All living cells possess a cell membrane that encloses the cytoplasm and
regulates substance movement. Prokaryotes lack membrane-bound
organelles, but the plasma membrane is always present.
6. Plant cells differ from animal cells in the presence of:
A. Mitochondria
B. Ribosomes
, C. Cell wall
D. Nucleus
C. Cell wall
Plant cells possess a rigid cell wall made primarily of cellulose for support and
protection. Animal cells lack cell walls and rely on the cytoskeleton for shape.
7. What is the process by which cells divide to produce two genetically
identical daughter cells?
A. Meiosis
B. Mitosis
C. Binary fission
D. Budding
B. Mitosis
Mitosis produces two genetically identical diploid daughter cells for growth
and repair. Meiosis produces haploid gametes, binary fission is bacterial
division, and budding is a form of asexual reproduction.
8. A cell is in a solution in which the concentration of solutes is higher inside
the cell than outside the cell. What would you expect to happen to the cell?
A. It will shrink
B. It will swell and probably burst
C. It will remain unchanged
D. It will divide
B. It will swell and probably burst
This describes a hypotonic solution. Water moves by osmosis from an area of
lower solute concentration (outside) to higher solute concentration (inside),
causing the cell to swell and potentially lyse.
9. If bacteria are placed in a strong solution of salt water, they will shrink as
water moves out of the bacteria. What is this process called?
A. Active transport
B. Osmosis
Questions And Correct Answers
(Verified Answers) Plus Rationales
2026 Q&A Instant Download Pdf
Section 1: Cell Biology and Transport
1. Which organelle is responsible for protein synthesis?
A. Nucleus
B. Mitochondria
C. Ribosome
D. Golgi apparatus
C. Ribosome
Ribosomes are the sites of protein synthesis, translating mRNA into
polypeptides. The nucleus contains DNA, mitochondria produce ATP, and the
Golgi apparatus modifies and packages proteins.
2. What is the primary function of the cell membrane?
A. To produce energy
B. To control what enters and leaves the cell
C. To store genetic information
D. To synthesize proteins
B. To control what enters and leaves the cell
The cell membrane is selectively permeable, regulating the passage of
substances into and out of the cell. Energy production occurs in mitochondria,
genetic storage in the nucleus, and protein synthesis at ribosomes.
3. Which of the following is a prokaryotic cell?
,A. Human liver cell
B. Plant cell
C. Bacteria
D. Fungus
C. Bacteria
Prokaryotic cells lack a true nucleus and membrane-bound organelles.
Bacteria are prokaryotes, while human, plant, and fungal cells are eukaryotic.
4. Which organelle contains hydrolytic enzymes and is called the "suicide
bag"?
A. Ribosome
B. Golgi apparatus
C. Lysosome
D. Peroxisome
C. Lysosome
Lysosomes contain digestive enzymes capable of breaking down cellular
waste. If these enzymes are released, they can digest the cell itself, hence the
nickname "suicide bag."
5. Which particular structure is present in both eukaryotic and prokaryotic
cells?
A. Nucleus
B. Mitochondria
C. Cell membrane
D. Endoplasmic reticulum
C. Cell membrane
All living cells possess a cell membrane that encloses the cytoplasm and
regulates substance movement. Prokaryotes lack membrane-bound
organelles, but the plasma membrane is always present.
6. Plant cells differ from animal cells in the presence of:
A. Mitochondria
B. Ribosomes
, C. Cell wall
D. Nucleus
C. Cell wall
Plant cells possess a rigid cell wall made primarily of cellulose for support and
protection. Animal cells lack cell walls and rely on the cytoskeleton for shape.
7. What is the process by which cells divide to produce two genetically
identical daughter cells?
A. Meiosis
B. Mitosis
C. Binary fission
D. Budding
B. Mitosis
Mitosis produces two genetically identical diploid daughter cells for growth
and repair. Meiosis produces haploid gametes, binary fission is bacterial
division, and budding is a form of asexual reproduction.
8. A cell is in a solution in which the concentration of solutes is higher inside
the cell than outside the cell. What would you expect to happen to the cell?
A. It will shrink
B. It will swell and probably burst
C. It will remain unchanged
D. It will divide
B. It will swell and probably burst
This describes a hypotonic solution. Water moves by osmosis from an area of
lower solute concentration (outside) to higher solute concentration (inside),
causing the cell to swell and potentially lyse.
9. If bacteria are placed in a strong solution of salt water, they will shrink as
water moves out of the bacteria. What is this process called?
A. Active transport
B. Osmosis
