PROFESSIONAL BIOLOGIST
CERTIFICATION EXAM QUESTION AND
CORRECT ANSWERS (VERIFIED
ANSWERS) PLUS RATIONALES 2026 Q&A
INSTANT DOWNLOAD PDF
1. Which macromolecule is primarily responsible for catalyzing biochemical
reactions in cells?
A. Lipids
B. Carbohydrates
C. Nucleic acids
D. Proteins
Rationale: Enzymes are proteins that speed up biochemical reactions by
lowering activation energy.
2. The fluid mosaic model describes the structure of the:
A. Cell wall
B. Cytoskeleton
C. Plasma membrane
D. Nuclear envelope
Rationale: The plasma membrane consists of a phospholipid bilayer with
embedded proteins that move laterally.
3. Which organelle is the primary site of ATP production in eukaryotic cells?
A. Ribosome
B. Golgi apparatus
C. Chloroplast
, D. Mitochondrion
Rationale: Mitochondria generate ATP through oxidative phosphorylation.
4. DNA replication is best described as:
A. Conservative
B. Dispersive
C. Semiconservative
D. Random
Rationale: Each new DNA molecule contains one parental strand and one
newly synthesized strand.
5. Which phase of mitosis involves alignment of chromosomes at the cell’s
equatorial plane?
A. Prophase
B. Metaphase
C. Anaphase
D. Telophase
Rationale: During metaphase, chromosomes align at the metaphase
plate.
6. The primary function of ribosomal RNA (rRNA) is to:
A. Carry amino acids
B. Store genetic information
C. Form the structural and catalytic core of ribosomes
D. Regulate gene expression
Rationale: rRNA makes up ribosomes and catalyzes peptide bond
formation.
7. Which molecule serves as the universal energy currency of the cell?
A. NADH
B. FADH₂
C. ATP
D. Glucose
Rationale: ATP directly provides energy for cellular processes.
, 8. Photosynthesis occurs primarily in which plant cell organelle?
A. Mitochondrion
B. Vacuole
C. Chloroplast
D. Peroxisome
Rationale: Chloroplasts contain chlorophyll and enzymes for
photosynthesis.
9. The light-dependent reactions of photosynthesis produce:
A. Glucose and oxygen
B. ATP and NADPH
C. Carbon dioxide and water
D. Pyruvate and ATP
Rationale: Light reactions generate ATP and NADPH for the Calvin cycle.
10.Which enzyme unwinds the DNA double helix during replication?
A. DNA polymerase
B. Ligase
C. Helicase
D. Primase
Rationale: Helicase separates DNA strands by breaking hydrogen bonds.
11.Natural selection acts directly on an organism’s:
A. Genotype
B. DNA sequence
C. Phenotype
D. Allele frequency
Rationale: Selection favors phenotypic traits that improve survival and
reproduction.
12.Genetic drift has the greatest effect in populations that are:
A. Large and stable
B. Highly diverse
CERTIFICATION EXAM QUESTION AND
CORRECT ANSWERS (VERIFIED
ANSWERS) PLUS RATIONALES 2026 Q&A
INSTANT DOWNLOAD PDF
1. Which macromolecule is primarily responsible for catalyzing biochemical
reactions in cells?
A. Lipids
B. Carbohydrates
C. Nucleic acids
D. Proteins
Rationale: Enzymes are proteins that speed up biochemical reactions by
lowering activation energy.
2. The fluid mosaic model describes the structure of the:
A. Cell wall
B. Cytoskeleton
C. Plasma membrane
D. Nuclear envelope
Rationale: The plasma membrane consists of a phospholipid bilayer with
embedded proteins that move laterally.
3. Which organelle is the primary site of ATP production in eukaryotic cells?
A. Ribosome
B. Golgi apparatus
C. Chloroplast
, D. Mitochondrion
Rationale: Mitochondria generate ATP through oxidative phosphorylation.
4. DNA replication is best described as:
A. Conservative
B. Dispersive
C. Semiconservative
D. Random
Rationale: Each new DNA molecule contains one parental strand and one
newly synthesized strand.
5. Which phase of mitosis involves alignment of chromosomes at the cell’s
equatorial plane?
A. Prophase
B. Metaphase
C. Anaphase
D. Telophase
Rationale: During metaphase, chromosomes align at the metaphase
plate.
6. The primary function of ribosomal RNA (rRNA) is to:
A. Carry amino acids
B. Store genetic information
C. Form the structural and catalytic core of ribosomes
D. Regulate gene expression
Rationale: rRNA makes up ribosomes and catalyzes peptide bond
formation.
7. Which molecule serves as the universal energy currency of the cell?
A. NADH
B. FADH₂
C. ATP
D. Glucose
Rationale: ATP directly provides energy for cellular processes.
, 8. Photosynthesis occurs primarily in which plant cell organelle?
A. Mitochondrion
B. Vacuole
C. Chloroplast
D. Peroxisome
Rationale: Chloroplasts contain chlorophyll and enzymes for
photosynthesis.
9. The light-dependent reactions of photosynthesis produce:
A. Glucose and oxygen
B. ATP and NADPH
C. Carbon dioxide and water
D. Pyruvate and ATP
Rationale: Light reactions generate ATP and NADPH for the Calvin cycle.
10.Which enzyme unwinds the DNA double helix during replication?
A. DNA polymerase
B. Ligase
C. Helicase
D. Primase
Rationale: Helicase separates DNA strands by breaking hydrogen bonds.
11.Natural selection acts directly on an organism’s:
A. Genotype
B. DNA sequence
C. Phenotype
D. Allele frequency
Rationale: Selection favors phenotypic traits that improve survival and
reproduction.
12.Genetic drift has the greatest effect in populations that are:
A. Large and stable
B. Highly diverse
