HESI A2 Biology Practice Exam 2025: Questions
with Answers & Rationales
Question 1
Which organelle is responsible for protein synthesis?
A: Mitochondrion
B: Ribosome
C: Lysosome
D: Golgi apparatus
Correct Answer: B
Rationale: Ribosomes synthesize proteins by translating mRNA into amino acid chains.
Mitochondria produce energy, lysosomes digest waste, and the Golgi apparatus modifies
proteins.
Question 2
Why is yeast used to make bread rise?
A: It produces oxygen
B: It produces carbon dioxide
C: It releases nitrogen
D: It breaks down starch
Correct Answer: B
Rationale: Yeast ferments sugars, producing carbon dioxide gas that forms bubbles, causing
bread to rise.
Question 3
How is mitosis different from meiosis?
A: Mitosis produces gametes
B: Mitosis produces identical daughter cells
C: Mitosis reduces chromosome number
D: Mitosis occurs in gametes only
Correct Answer: B
Rationale: Mitosis produces two identical diploid cells for growth, while meiosis produces four
non-identical haploid gametes for reproduction.
Question 4
What is the scientific name for a house cat?
A: Canis lupus
, B: Felis catus
C: Panthera leo
D: Ursus arctos
Correct Answer: B
Rationale: Felis catus is the genus and species name for a house cat, following binomial
nomenclature.
Question 5
What type of molecule is beeswax?
A: Carbohydrate
B: Lipid
C: Protein
D: Nucleic acid
Correct Answer: B
Rationale: Beeswax is a lipid, specifically a wax, used for energy storage and structural
purposes.
Question 6
What process occurs in a lysosome?
A: Energy production
B: Digestion of cellular waste
C: Protein synthesis
D: DNA replication
Correct Answer: B
Rationale: Lysosomes contain digestive enzymes that break down cellular waste and food
particles.
Question 7
Which organism reproduces via binary fission?
A: Yeast
B: Salmonella
C: Hydra
D: Fern
Correct Answer: B
Rationale: Salmonella, a bacterium, reproduces asexually by binary fission, splitting into two
identical cells.
Question 8
In which phase of cell division do chromosomes replicate?
A: Prophase
with Answers & Rationales
Question 1
Which organelle is responsible for protein synthesis?
A: Mitochondrion
B: Ribosome
C: Lysosome
D: Golgi apparatus
Correct Answer: B
Rationale: Ribosomes synthesize proteins by translating mRNA into amino acid chains.
Mitochondria produce energy, lysosomes digest waste, and the Golgi apparatus modifies
proteins.
Question 2
Why is yeast used to make bread rise?
A: It produces oxygen
B: It produces carbon dioxide
C: It releases nitrogen
D: It breaks down starch
Correct Answer: B
Rationale: Yeast ferments sugars, producing carbon dioxide gas that forms bubbles, causing
bread to rise.
Question 3
How is mitosis different from meiosis?
A: Mitosis produces gametes
B: Mitosis produces identical daughter cells
C: Mitosis reduces chromosome number
D: Mitosis occurs in gametes only
Correct Answer: B
Rationale: Mitosis produces two identical diploid cells for growth, while meiosis produces four
non-identical haploid gametes for reproduction.
Question 4
What is the scientific name for a house cat?
A: Canis lupus
, B: Felis catus
C: Panthera leo
D: Ursus arctos
Correct Answer: B
Rationale: Felis catus is the genus and species name for a house cat, following binomial
nomenclature.
Question 5
What type of molecule is beeswax?
A: Carbohydrate
B: Lipid
C: Protein
D: Nucleic acid
Correct Answer: B
Rationale: Beeswax is a lipid, specifically a wax, used for energy storage and structural
purposes.
Question 6
What process occurs in a lysosome?
A: Energy production
B: Digestion of cellular waste
C: Protein synthesis
D: DNA replication
Correct Answer: B
Rationale: Lysosomes contain digestive enzymes that break down cellular waste and food
particles.
Question 7
Which organism reproduces via binary fission?
A: Yeast
B: Salmonella
C: Hydra
D: Fern
Correct Answer: B
Rationale: Salmonella, a bacterium, reproduces asexually by binary fission, splitting into two
identical cells.
Question 8
In which phase of cell division do chromosomes replicate?
A: Prophase
