PAX Science NLN Exam Collection 2026/2027
Actual Practice Questions: Comprehensive
Assessment with Verified Solutions
BIOLOGY SECTION (Questions 1-32)
Cellular & Molecular Biology
Q1. Which cellular organelle is responsible for producing ATP through cellular
respiration?
A) Nucleus
B) Mitochondria
C) Ribosomes
D) Golgi apparatus
Correct Answer: B
Rationale: Mitochondria are the powerhouses of the cell, producing ATP through aerobic
cellular respiration (Krebs cycle and electron transport chain). The nucleus (A) contains
genetic material. Ribosomes (C) synthesize proteins. Golgi apparatus (D) modifies and
packages proteins.
Nursing Relevance: Understanding cellular energy production is fundamental to
physiology, pharmacology, and understanding tissue hypoxia in patients.
,Q2. During which phase of mitosis do the sister chromatids separate and move toward
opposite poles of the cell?
A) Prophase
B) Metaphase
C) Anaphase
D) Telophase
Correct Answer: C
Rationale: Anaphase is characterized by the separation of sister chromatids pulled apart
by spindle fibers toward opposite poles. Prophase (A) involves chromosome
condensation. Metaphase (B) aligns chromosomes at the equator. Telophase (D)
involves nuclear envelope reformation.
Clinical Connection: Understanding cell division is essential for oncology nursing and
chemotherapy mechanisms.
Q3. Which type of RNA carries amino acids to the ribosome during protein synthesis?
A) mRNA (messenger RNA)
B) rRNA (ribosomal RNA)
C) tRNA (transfer RNA)
D) snRNA (small nuclear RNA)
Correct Answer: C
,Rationale: tRNA (transfer RNA) has anticodons that pair with mRNA codons and carries
specific amino acids to the ribosome. mRNA (A) carries genetic code from DNA. rRNA
(B) forms ribosomal structure. snRNA (D) is involved in RNA splicing.
Application: Protein synthesis knowledge applies to understanding genetic disorders
and medication mechanisms.
Q4. What is the primary function of the cell membrane's phospholipid bilayer?
A) Protein synthesis
B) Selective permeability and barrier function
C) Energy production
D) Genetic information storage
Correct Answer: B
Rationale: The phospholipid bilayer creates a hydrophobic barrier that regulates what
enters and exits the cell (selective permeability). Protein synthesis (A) occurs at
ribosomes. Energy production (C) occurs in mitochondria. Genetic storage (D) occurs in
the nucleus.
Nursing Application: Cell membrane physiology is critical for understanding
fluid-electrolyte balance and medication transport.
Genetics & Heredity
Q5. In Mendelian genetics, if two heterozygous parents (Tt) for a single trait cross, what
percentage of offspring would be expected to express the recessive phenotype?
, A) 0%
B) 25%
C) 50%
D) 75%
Correct Answer: B
Rationale: Tt × Tt Punnett square yields: 25% TT (dominant), 50% Tt (dominant carriers),
25% tt (recessive phenotype). Only homozygous recessive (tt) expresses the recessive
trait = 25%.
Genetic Counseling: Essential for understanding inheritance patterns in family health
history assessments.
Q6. A genetic disorder appears in males with much higher frequency than females and
is never transmitted from father to son. Which inheritance pattern does this describe?
A) Autosomal dominant
B) Autosomal recessive
C) X-linked recessive
D) X-linked dominant
Correct Answer: C
Rationale: X-linked recessive traits affect males predominantly (hemizygous X), cannot
pass from father to son (Y-linked), but carrier mothers pass to sons. Examples include
hemophilia and Duchenne muscular dystrophy.
Actual Practice Questions: Comprehensive
Assessment with Verified Solutions
BIOLOGY SECTION (Questions 1-32)
Cellular & Molecular Biology
Q1. Which cellular organelle is responsible for producing ATP through cellular
respiration?
A) Nucleus
B) Mitochondria
C) Ribosomes
D) Golgi apparatus
Correct Answer: B
Rationale: Mitochondria are the powerhouses of the cell, producing ATP through aerobic
cellular respiration (Krebs cycle and electron transport chain). The nucleus (A) contains
genetic material. Ribosomes (C) synthesize proteins. Golgi apparatus (D) modifies and
packages proteins.
Nursing Relevance: Understanding cellular energy production is fundamental to
physiology, pharmacology, and understanding tissue hypoxia in patients.
,Q2. During which phase of mitosis do the sister chromatids separate and move toward
opposite poles of the cell?
A) Prophase
B) Metaphase
C) Anaphase
D) Telophase
Correct Answer: C
Rationale: Anaphase is characterized by the separation of sister chromatids pulled apart
by spindle fibers toward opposite poles. Prophase (A) involves chromosome
condensation. Metaphase (B) aligns chromosomes at the equator. Telophase (D)
involves nuclear envelope reformation.
Clinical Connection: Understanding cell division is essential for oncology nursing and
chemotherapy mechanisms.
Q3. Which type of RNA carries amino acids to the ribosome during protein synthesis?
A) mRNA (messenger RNA)
B) rRNA (ribosomal RNA)
C) tRNA (transfer RNA)
D) snRNA (small nuclear RNA)
Correct Answer: C
,Rationale: tRNA (transfer RNA) has anticodons that pair with mRNA codons and carries
specific amino acids to the ribosome. mRNA (A) carries genetic code from DNA. rRNA
(B) forms ribosomal structure. snRNA (D) is involved in RNA splicing.
Application: Protein synthesis knowledge applies to understanding genetic disorders
and medication mechanisms.
Q4. What is the primary function of the cell membrane's phospholipid bilayer?
A) Protein synthesis
B) Selective permeability and barrier function
C) Energy production
D) Genetic information storage
Correct Answer: B
Rationale: The phospholipid bilayer creates a hydrophobic barrier that regulates what
enters and exits the cell (selective permeability). Protein synthesis (A) occurs at
ribosomes. Energy production (C) occurs in mitochondria. Genetic storage (D) occurs in
the nucleus.
Nursing Application: Cell membrane physiology is critical for understanding
fluid-electrolyte balance and medication transport.
Genetics & Heredity
Q5. In Mendelian genetics, if two heterozygous parents (Tt) for a single trait cross, what
percentage of offspring would be expected to express the recessive phenotype?
, A) 0%
B) 25%
C) 50%
D) 75%
Correct Answer: B
Rationale: Tt × Tt Punnett square yields: 25% TT (dominant), 50% Tt (dominant carriers),
25% tt (recessive phenotype). Only homozygous recessive (tt) expresses the recessive
trait = 25%.
Genetic Counseling: Essential for understanding inheritance patterns in family health
history assessments.
Q6. A genetic disorder appears in males with much higher frequency than females and
is never transmitted from father to son. Which inheritance pattern does this describe?
A) Autosomal dominant
B) Autosomal recessive
C) X-linked recessive
D) X-linked dominant
Correct Answer: C
Rationale: X-linked recessive traits affect males predominantly (hemizygous X), cannot
pass from father to son (Y-linked), but carrier mothers pass to sons. Examples include
hemophilia and Duchenne muscular dystrophy.
