BIO 251: Final Exam fully solved &
updated | Latest!! BIO 251: Final Exam
fully solved & updated (latest version
verified for accuracy) | Latest!!
Questions 1–20: Cellular & Tissue Level
1. Which organelle is responsible for ATP production via
cellular respiration?
A) Ribosome
B) Golgi apparatus
C) Mitochondrion
D) Lysosome
Answer: C) Mitochondrion
Rationale: Mitochondria generate ATP through oxidative
phosphorylation. Ribosomes synthesize proteins, Golgi
modifies/sorts proteins, lysosomes digest waste.
2. Which process describes the movement of water across a
selectively permeable membrane?
A) Diffusion
B) Osmosis
C) Active transport
D) Phagocytosis
Answer: B) Osmosis
Rationale: Osmosis is the passive movement of water from low
,solute concentration to high solute concentration across a
membrane.
3. What is the correct order of structural organization from
simplest to most complex?
A) Tissue → Cell → Organ → Organ system
B) Cell → Tissue → Organ → Organ system
C) Organ → Tissue → Cell → Organ system
D) Cell → Organ → Tissue → Organ system
Answer: B) Cell → Tissue → Organ → Organ system
Rationale: Cells form tissues, tissues form organs, and organs work
together in organ systems.
4. Which tissue type covers body surfaces and lines cavities?
A) Connective tissue
B) Muscle tissue
C) Nervous tissue
D) Epithelial tissue
Answer: D) Epithelial tissue
Rationale: Epithelium provides protection, absorption, secretion,
and sensation; it forms the skin and linings.
5. What is the primary function of rough endoplasmic
reticulum?
A) Lipid synthesis
B) Protein synthesis and processing
C) ATP production
D) Detoxification of toxins
Answer: B) Protein synthesis and processing
Rationale: Ribosomes on RER synthesize proteins that are then
folded and modified within its lumen.
,6. Which junction forms a watertight seal between adjacent
epithelial cells?
A) Gap junction
B) Desmosome
C) Tight junction
D) Hemidesmosome
Answer: C) Tight junction
Rationale: Tight junctions prevent paracellular leakage of
substances, essential in the blood-brain barrier and intestinal
lining.
7. Which type of connective tissue stores energy and provides
insulation?
A) Areolar tissue
B) Adipose tissue
C) Dense regular connective tissue
D) Hyaline cartilage
Answer: B) Adipose tissue
Rationale: Adipocytes store triglycerides, providing energy
reserve, thermal insulation, and cushioning.
8. What is the extracellular matrix (ECM) primarily composed
of?
A) Collagen and elastin fibers embedded in ground substance
B) Only collagen fibers
C) Only elastin fibers
D) Lipids and carbohydrates
Answer: A) Collagen and elastin fibers embedded in ground
substance
Rationale: The ECM provides structural support; collagen gives
, tensile strength, elastin gives elasticity, and ground substance
(proteoglycans) resists compression.
9. Which organelle contains hydrolytic enzymes for
intracellular digestion?
A) Peroxisome
B) Lysosome
C) Nucleus
D) Ribosome
Answer: B) Lysosome
Rationale: Lysosomes break down macromolecules, old
organelles, and pathogens via acid hydrolases.
10. The process by which a cell engulfs large particles is
called:
A) Pinocytosis
B) Phagocytosis
C) Exocytosis
D) Receptor-mediated endocytosis
Answer: B) Phagocytosis
Rationale: Phagocytosis (“cell eating”) involves engulfment of
large solids; pinocytosis (“cell drinking”) takes in fluids.
11. Which tissue is characterized by striations, multinucleated
cells, and voluntary control?
A) Cardiac muscle
B) Smooth muscle
C) Skeletal muscle
D) Nervous tissue
Answer: C) Skeletal muscle
updated | Latest!! BIO 251: Final Exam
fully solved & updated (latest version
verified for accuracy) | Latest!!
Questions 1–20: Cellular & Tissue Level
1. Which organelle is responsible for ATP production via
cellular respiration?
A) Ribosome
B) Golgi apparatus
C) Mitochondrion
D) Lysosome
Answer: C) Mitochondrion
Rationale: Mitochondria generate ATP through oxidative
phosphorylation. Ribosomes synthesize proteins, Golgi
modifies/sorts proteins, lysosomes digest waste.
2. Which process describes the movement of water across a
selectively permeable membrane?
A) Diffusion
B) Osmosis
C) Active transport
D) Phagocytosis
Answer: B) Osmosis
Rationale: Osmosis is the passive movement of water from low
,solute concentration to high solute concentration across a
membrane.
3. What is the correct order of structural organization from
simplest to most complex?
A) Tissue → Cell → Organ → Organ system
B) Cell → Tissue → Organ → Organ system
C) Organ → Tissue → Cell → Organ system
D) Cell → Organ → Tissue → Organ system
Answer: B) Cell → Tissue → Organ → Organ system
Rationale: Cells form tissues, tissues form organs, and organs work
together in organ systems.
4. Which tissue type covers body surfaces and lines cavities?
A) Connective tissue
B) Muscle tissue
C) Nervous tissue
D) Epithelial tissue
Answer: D) Epithelial tissue
Rationale: Epithelium provides protection, absorption, secretion,
and sensation; it forms the skin and linings.
5. What is the primary function of rough endoplasmic
reticulum?
A) Lipid synthesis
B) Protein synthesis and processing
C) ATP production
D) Detoxification of toxins
Answer: B) Protein synthesis and processing
Rationale: Ribosomes on RER synthesize proteins that are then
folded and modified within its lumen.
,6. Which junction forms a watertight seal between adjacent
epithelial cells?
A) Gap junction
B) Desmosome
C) Tight junction
D) Hemidesmosome
Answer: C) Tight junction
Rationale: Tight junctions prevent paracellular leakage of
substances, essential in the blood-brain barrier and intestinal
lining.
7. Which type of connective tissue stores energy and provides
insulation?
A) Areolar tissue
B) Adipose tissue
C) Dense regular connective tissue
D) Hyaline cartilage
Answer: B) Adipose tissue
Rationale: Adipocytes store triglycerides, providing energy
reserve, thermal insulation, and cushioning.
8. What is the extracellular matrix (ECM) primarily composed
of?
A) Collagen and elastin fibers embedded in ground substance
B) Only collagen fibers
C) Only elastin fibers
D) Lipids and carbohydrates
Answer: A) Collagen and elastin fibers embedded in ground
substance
Rationale: The ECM provides structural support; collagen gives
, tensile strength, elastin gives elasticity, and ground substance
(proteoglycans) resists compression.
9. Which organelle contains hydrolytic enzymes for
intracellular digestion?
A) Peroxisome
B) Lysosome
C) Nucleus
D) Ribosome
Answer: B) Lysosome
Rationale: Lysosomes break down macromolecules, old
organelles, and pathogens via acid hydrolases.
10. The process by which a cell engulfs large particles is
called:
A) Pinocytosis
B) Phagocytosis
C) Exocytosis
D) Receptor-mediated endocytosis
Answer: B) Phagocytosis
Rationale: Phagocytosis (“cell eating”) involves engulfment of
large solids; pinocytosis (“cell drinking”) takes in fluids.
11. Which tissue is characterized by striations, multinucleated
cells, and voluntary control?
A) Cardiac muscle
B) Smooth muscle
C) Skeletal muscle
D) Nervous tissue
Answer: C) Skeletal muscle
