REX-PN EXAMINATION PRACTICE QUESTIONS
COMPLETE WITH CORRECT ANSWERS| AND
DETAILED RATIONALES NO QUESTION ARE
REPEATED.
BIOLOGY (Questions 1-75)
1. Which organelle is responsible for cellular respiration?
A) Chloroplast
B) Mitochondrion
C) Nucleus
D) Ribosome
Correct Answer: B
Rationale: Mitochondria are the sites of aerobic respiration, producing ATP
through the breakdown of glucose.
2. What is the main function of red blood cells?
A) Fight infection
B) Clot blood
C) Transport oxygen
D) Produce antibodies
,Correct Answer: C
Rationale: Red blood cells contain hemoglobin, which binds oxygen in the lungs
and releases it in tissues.
3. Which of the following is a prokaryotic organism?
A) Yeast
B) Amoeba
C) E. coli
D) Paramecium
Correct Answer: C
Rationale: E. coli is a bacterium, which is a prokaryote (lacks a nucleus and
membrane-bound organelles).
4. The human nervous system is divided into the central nervous system and the:
A) Somatic nervous system
B) Autonomic nervous system
C) Peripheral nervous system
D) Sympathetic nervous system
Correct Answer: C
Rationale: The nervous system has two main divisions: the central nervous system
(brain and spinal cord) and the peripheral nervous system (nerves throughout the
body).
5. Which vitamin is essential for blood clotting?
,A) Vitamin A
B) Vitamin B12
C) Vitamin K
D) Vitamin D
Correct Answer: C
Rationale: Vitamin K is necessary for the synthesis of clotting factors in the liver.
6. The semifluid matrix inside the cell membrane is called:
A) Nucleoplasm
B) Cytoplasm
C) Cell sap
D) Matrix
Correct Answer: B
Rationale: Cytoplasm is the gel-like substance inside cells, excluding the nucleus,
where organelles are suspended.
7. What is the role of the pancreas in digestion?
A) Produces bile
B) Produces digestive enzymes and insulin
C) Stores bile
D) Absorbs water
Correct Answer: B
Rationale: The pancreas secretes digestive enzymes into the small intestine and
hormones (insulin, glucagon) into the blood.
, 8. The structural unit of compact bone is the:
A) Osteon
B) Osteocyte
C) Lamella
D) Canaliculus
Correct Answer: A
Rationale: The osteon (Haversian system) is the microscopic structural unit of
compact bone.
9. Which of the following is NOT a function of the liver?
A) Detoxification
B) Production of bile
C) Storage of glycogen
D) Filtration of urine
Correct Answer: D
Rationale: Urine filtration is performed by the kidneys, not the liver.
10. The type of RNA that carries genetic information from the nucleus to the
cytoplasm is:
A) tRNA
B) rRNA
C) mRNA
D) snRNA
COMPLETE WITH CORRECT ANSWERS| AND
DETAILED RATIONALES NO QUESTION ARE
REPEATED.
BIOLOGY (Questions 1-75)
1. Which organelle is responsible for cellular respiration?
A) Chloroplast
B) Mitochondrion
C) Nucleus
D) Ribosome
Correct Answer: B
Rationale: Mitochondria are the sites of aerobic respiration, producing ATP
through the breakdown of glucose.
2. What is the main function of red blood cells?
A) Fight infection
B) Clot blood
C) Transport oxygen
D) Produce antibodies
,Correct Answer: C
Rationale: Red blood cells contain hemoglobin, which binds oxygen in the lungs
and releases it in tissues.
3. Which of the following is a prokaryotic organism?
A) Yeast
B) Amoeba
C) E. coli
D) Paramecium
Correct Answer: C
Rationale: E. coli is a bacterium, which is a prokaryote (lacks a nucleus and
membrane-bound organelles).
4. The human nervous system is divided into the central nervous system and the:
A) Somatic nervous system
B) Autonomic nervous system
C) Peripheral nervous system
D) Sympathetic nervous system
Correct Answer: C
Rationale: The nervous system has two main divisions: the central nervous system
(brain and spinal cord) and the peripheral nervous system (nerves throughout the
body).
5. Which vitamin is essential for blood clotting?
,A) Vitamin A
B) Vitamin B12
C) Vitamin K
D) Vitamin D
Correct Answer: C
Rationale: Vitamin K is necessary for the synthesis of clotting factors in the liver.
6. The semifluid matrix inside the cell membrane is called:
A) Nucleoplasm
B) Cytoplasm
C) Cell sap
D) Matrix
Correct Answer: B
Rationale: Cytoplasm is the gel-like substance inside cells, excluding the nucleus,
where organelles are suspended.
7. What is the role of the pancreas in digestion?
A) Produces bile
B) Produces digestive enzymes and insulin
C) Stores bile
D) Absorbs water
Correct Answer: B
Rationale: The pancreas secretes digestive enzymes into the small intestine and
hormones (insulin, glucagon) into the blood.
, 8. The structural unit of compact bone is the:
A) Osteon
B) Osteocyte
C) Lamella
D) Canaliculus
Correct Answer: A
Rationale: The osteon (Haversian system) is the microscopic structural unit of
compact bone.
9. Which of the following is NOT a function of the liver?
A) Detoxification
B) Production of bile
C) Storage of glycogen
D) Filtration of urine
Correct Answer: D
Rationale: Urine filtration is performed by the kidneys, not the liver.
10. The type of RNA that carries genetic information from the nucleus to the
cytoplasm is:
A) tRNA
B) rRNA
C) mRNA
D) snRNA
