HESI A2 Biology 2024/2025 V1–V3 Edition –
100% Correct Answers with Core Biological
Concepts Explained
Introduction
This guide provides 80 unique multiple-choice questions for the HESI A2 Biology
exam (V1–V3), covering cell biology, genetics, evolution, ecosystems, and molec-
ular biology. Each question includes four answer choices, with the correct an-
swer marked and a concise explanation to reinforce core concepts. The content
is formatted for professional PDF export, ensuring clarity and no repetition.
Biology Questions
Question 1: What is the primary function of the mitochondria in a cell?
A. Synthesize proteins
B. Store genetic material
C. Produce ATP (Correct)
D. Regulate cell division
Explanation: Mitochondria are the powerhouses of the cell, producing
ATP through cellular respiration, providing energy for cellular processes.
Question 2: Which molecule carries genetic information in cells?
A. RNA
B. DNA (Correct)
C. Protein
D. Lipid
Explanation: DNA (deoxyribonucleic acid) contains the genetic blueprint
for an organism, stored in the nucleus and passed during cell division.
Question 3: What process divides a cell into two identical daughter cells?
A. Meiosis
1
, B. Mitosis (Correct)
C. Binary fission
D. Apoptosis
Explanation: Mitosis is the process of cell division in somatic cells, pro-
ducing two identical daughter cells for growth and repair.
Question 4: Which organelle is responsible for protein synthesis?
A. Golgi apparatus
B. Ribosome (Correct)
C. Lysosome
D. Endoplasmic reticulum
Explanation: Ribosomes, either free or bound to the endoplasmic reticu-
lum, synthesize proteins by translating mRNA into polypeptide chains.
Question 5: What is the term for a gene’s specific position on a chromosome?
A. Allele
B. Locus (Correct)
C. Genotype
D. Phenotype
Explanation: A locus is the specific location of a gene on a chromosome,
determining its position for genetic mapping.
Question 6: Which process converts DNA to mRNA?
A. Translation
B. Transcription (Correct)
C. Replication
D. Mutation
Explanation: Transcription is the process where DNA is copied into mRNA
in the nucleus, initiating protein synthesis.
Question 7: What is the primary source of energy for Earth’s ecosystems?
A. Geothermal heat
B. Sunlight (Correct)
C. Fossil fuels
D. Wind
Explanation: Sunlight drives photosynthesis, the primary energy source
for ecosystems, converting solar energy into chemical energy in plants.
Question 8: Which molecule is the main component of cell membranes?
2
, A. Carbohydrate
B. Protein
C. Phospholipid (Correct)
D. Nucleic acid
Explanation: Phospholipids form a bilayer in cell membranes, with hy-
drophilic heads and hydrophobic tails, regulating cell entry and exit.
Question 9: What is the term for an organism with two identical alleles for a gene?
A. Heterozygous
B. Homozygous (Correct)
C. Dominant
D. Recessive
Explanation: A homozygous organism has two identical alleles (e.g., AA or
aa) for a specific gene, unlike heterozygous (Aa).
Question 10: Which structure controls what enters and exits a cell?
A. Nucleus
B. Cell membrane (Correct)
C. Cytoplasm
D. Mitochondrion
Explanation: The cell membrane, a selectively permeable barrier, regu-
lates the movement of substances in and out of the cell.
Question 11: What is the role of chlorophyll in photosynthesis?
A. Transport oxygen
B. Absorb light (Correct)
C. Store glucose
D. Break down water
Explanation: Chlorophyll absorbs sunlight, capturing energy to drive pho-
tosynthesis, converting carbon dioxide and water into glucose and oxygen.
Question 12: Which type of cell lacks a nucleus?
A. Eukaryotic
B. Prokaryotic (Correct)
C. Plant
D. Fungal
Explanation: Prokaryotic cells, like bacteria, lack a nucleus, with genetic
material free in the cytoplasm, unlike eukaryotic cells.
3
100% Correct Answers with Core Biological
Concepts Explained
Introduction
This guide provides 80 unique multiple-choice questions for the HESI A2 Biology
exam (V1–V3), covering cell biology, genetics, evolution, ecosystems, and molec-
ular biology. Each question includes four answer choices, with the correct an-
swer marked and a concise explanation to reinforce core concepts. The content
is formatted for professional PDF export, ensuring clarity and no repetition.
Biology Questions
Question 1: What is the primary function of the mitochondria in a cell?
A. Synthesize proteins
B. Store genetic material
C. Produce ATP (Correct)
D. Regulate cell division
Explanation: Mitochondria are the powerhouses of the cell, producing
ATP through cellular respiration, providing energy for cellular processes.
Question 2: Which molecule carries genetic information in cells?
A. RNA
B. DNA (Correct)
C. Protein
D. Lipid
Explanation: DNA (deoxyribonucleic acid) contains the genetic blueprint
for an organism, stored in the nucleus and passed during cell division.
Question 3: What process divides a cell into two identical daughter cells?
A. Meiosis
1
, B. Mitosis (Correct)
C. Binary fission
D. Apoptosis
Explanation: Mitosis is the process of cell division in somatic cells, pro-
ducing two identical daughter cells for growth and repair.
Question 4: Which organelle is responsible for protein synthesis?
A. Golgi apparatus
B. Ribosome (Correct)
C. Lysosome
D. Endoplasmic reticulum
Explanation: Ribosomes, either free or bound to the endoplasmic reticu-
lum, synthesize proteins by translating mRNA into polypeptide chains.
Question 5: What is the term for a gene’s specific position on a chromosome?
A. Allele
B. Locus (Correct)
C. Genotype
D. Phenotype
Explanation: A locus is the specific location of a gene on a chromosome,
determining its position for genetic mapping.
Question 6: Which process converts DNA to mRNA?
A. Translation
B. Transcription (Correct)
C. Replication
D. Mutation
Explanation: Transcription is the process where DNA is copied into mRNA
in the nucleus, initiating protein synthesis.
Question 7: What is the primary source of energy for Earth’s ecosystems?
A. Geothermal heat
B. Sunlight (Correct)
C. Fossil fuels
D. Wind
Explanation: Sunlight drives photosynthesis, the primary energy source
for ecosystems, converting solar energy into chemical energy in plants.
Question 8: Which molecule is the main component of cell membranes?
2
, A. Carbohydrate
B. Protein
C. Phospholipid (Correct)
D. Nucleic acid
Explanation: Phospholipids form a bilayer in cell membranes, with hy-
drophilic heads and hydrophobic tails, regulating cell entry and exit.
Question 9: What is the term for an organism with two identical alleles for a gene?
A. Heterozygous
B. Homozygous (Correct)
C. Dominant
D. Recessive
Explanation: A homozygous organism has two identical alleles (e.g., AA or
aa) for a specific gene, unlike heterozygous (Aa).
Question 10: Which structure controls what enters and exits a cell?
A. Nucleus
B. Cell membrane (Correct)
C. Cytoplasm
D. Mitochondrion
Explanation: The cell membrane, a selectively permeable barrier, regu-
lates the movement of substances in and out of the cell.
Question 11: What is the role of chlorophyll in photosynthesis?
A. Transport oxygen
B. Absorb light (Correct)
C. Store glucose
D. Break down water
Explanation: Chlorophyll absorbs sunlight, capturing energy to drive pho-
tosynthesis, converting carbon dioxide and water into glucose and oxygen.
Question 12: Which type of cell lacks a nucleus?
A. Eukaryotic
B. Prokaryotic (Correct)
C. Plant
D. Fungal
Explanation: Prokaryotic cells, like bacteria, lack a nucleus, with genetic
material free in the cytoplasm, unlike eukaryotic cells.
3
