AORN BUNDLED EXAMS COMPLETE
QUESTIONS AND DETAILED SOLUTIONS
LATEST UPDATE
Question 1
Which organelle is the primary site of ATP synthesis in eukaryotic cells?
A) Nucleus
B) Ribosome
C) Mitochondrion
D) Golgi apparatus
E) Lysosome
Answer: C
Rationale: Mitochondria produce ATP via oxidative phosphorylation, utilising the
electron transport chain in the inner mitochondrial membrane. This chemiosmotic
process generates the vast majority of cellular ATP. The nucleus stores DNA,
ribosomes synthesise proteins, the Golgi modifies and packages secretions, and
lysosomes mediate intracellular digestion.
---
Question 2
Which structure is present in plant cells but absent in animal cells?
A) Plasma membrane
B) Cell wall
C) Nucleus
1
,D) Ribosome
E) Cytoplasm
Answer: B
Rationale: Plant cells have a rigid cellulose-based cell wall that provides
mechanical support and prevents osmotic lysis. Animal cells lack a wall and are
bounded only by a flexible plasma membrane. The nucleus, ribosomes, and
cytoplasm are common to both.
---
Question 3
During which phase of the cell cycle does DNA replication occur?
A) G₁ phase
B) S phase
C) G₂ phase
D) M phase
E) G₀ phase
Answer: B
Rationale: The S (synthesis) phase is dedicated to accurate duplication of
chromosomal DNA. G₁ is for growth and preparation, G₂ for final checks before
mitosis, M for nuclear and cytoplasmic division, and G₀ is a quiescent state.
---
Question 4
2
,What is the function of tRNA during translation?
A) Carries the genetic code from nucleus to ribosome
B) Forms the structural core of the ribosome
C) Transfers amino acids to the growing polypeptide chain
D) Catalyses peptide bond formation
E) Splicing introns from pre‑mRNA
Answer: C
Rationale: Transfer RNA (tRNA) molecules have an anticodon that pairs with the
mRNA codon and carry a specific amino acid at their 3′ end, delivering it to the
ribosome for peptide-chain elongation. mRNA carries the genetic message, rRNA
forms ribosome structure, and ribozymes catalyse peptide bonds.
---
Question 5
In a DNA double helix, adenine pairs with which base?
A) Guanine
B) Cytosine
C) Uracil
D) Thymine
E) Adenine
Answer: D
Rationale: Chargaff’s rules state that adenine (A) forms two hydrogen bonds with
thymine (T) in DNA. In RNA, adenine pairs with uracil. Guanine pairs with
cytosine via three hydrogen bonds.
3
, ---
Question 6
Which process produces the most ATP per glucose molecule under aerobic
conditions?
A) Glycolysis
B) Pyruvate oxidation
C) Citric acid cycle
D) Oxidative phosphorylation
E) Fermentation
Answer: D
Rationale: Oxidative phosphorylation, via the electron transport chain and ATP
synthase, generates approximately 28–34 ATP per glucose. Glycolysis yields only
2 net ATP, the citric acid cycle yields 2 GTP (equiv. to ATP), and fermentation
yields 2 ATP. Pyruvate oxidation produces no ATP directly.
---
Question 7
Which of the following is an example of a monosaccharide?
A) Sucrose
B) Lactose
C) Maltose
D) Glucose
E) Cellulose
4
QUESTIONS AND DETAILED SOLUTIONS
LATEST UPDATE
Question 1
Which organelle is the primary site of ATP synthesis in eukaryotic cells?
A) Nucleus
B) Ribosome
C) Mitochondrion
D) Golgi apparatus
E) Lysosome
Answer: C
Rationale: Mitochondria produce ATP via oxidative phosphorylation, utilising the
electron transport chain in the inner mitochondrial membrane. This chemiosmotic
process generates the vast majority of cellular ATP. The nucleus stores DNA,
ribosomes synthesise proteins, the Golgi modifies and packages secretions, and
lysosomes mediate intracellular digestion.
---
Question 2
Which structure is present in plant cells but absent in animal cells?
A) Plasma membrane
B) Cell wall
C) Nucleus
1
,D) Ribosome
E) Cytoplasm
Answer: B
Rationale: Plant cells have a rigid cellulose-based cell wall that provides
mechanical support and prevents osmotic lysis. Animal cells lack a wall and are
bounded only by a flexible plasma membrane. The nucleus, ribosomes, and
cytoplasm are common to both.
---
Question 3
During which phase of the cell cycle does DNA replication occur?
A) G₁ phase
B) S phase
C) G₂ phase
D) M phase
E) G₀ phase
Answer: B
Rationale: The S (synthesis) phase is dedicated to accurate duplication of
chromosomal DNA. G₁ is for growth and preparation, G₂ for final checks before
mitosis, M for nuclear and cytoplasmic division, and G₀ is a quiescent state.
---
Question 4
2
,What is the function of tRNA during translation?
A) Carries the genetic code from nucleus to ribosome
B) Forms the structural core of the ribosome
C) Transfers amino acids to the growing polypeptide chain
D) Catalyses peptide bond formation
E) Splicing introns from pre‑mRNA
Answer: C
Rationale: Transfer RNA (tRNA) molecules have an anticodon that pairs with the
mRNA codon and carry a specific amino acid at their 3′ end, delivering it to the
ribosome for peptide-chain elongation. mRNA carries the genetic message, rRNA
forms ribosome structure, and ribozymes catalyse peptide bonds.
---
Question 5
In a DNA double helix, adenine pairs with which base?
A) Guanine
B) Cytosine
C) Uracil
D) Thymine
E) Adenine
Answer: D
Rationale: Chargaff’s rules state that adenine (A) forms two hydrogen bonds with
thymine (T) in DNA. In RNA, adenine pairs with uracil. Guanine pairs with
cytosine via three hydrogen bonds.
3
, ---
Question 6
Which process produces the most ATP per glucose molecule under aerobic
conditions?
A) Glycolysis
B) Pyruvate oxidation
C) Citric acid cycle
D) Oxidative phosphorylation
E) Fermentation
Answer: D
Rationale: Oxidative phosphorylation, via the electron transport chain and ATP
synthase, generates approximately 28–34 ATP per glucose. Glycolysis yields only
2 net ATP, the citric acid cycle yields 2 GTP (equiv. to ATP), and fermentation
yields 2 ATP. Pyruvate oxidation produces no ATP directly.
---
Question 7
Which of the following is an example of a monosaccharide?
A) Sucrose
B) Lactose
C) Maltose
D) Glucose
E) Cellulose
4
