---
### 1. It is true that a eukaryotic cell:
A. Is smaller than a prokaryotic cell.
B. Lacks a well-defined nucleus.
C. Does not contain histones.
D. Contains organelles and has a well-defined nucleus.
Answer: D
Rationale: Eukaryotic cells are typically larger than prokaryotic cells, contain a well-
defined nucleus, and possess histones, which help package DNA into a compact
structure.
---
### 2. The function of a histone found in a eukaryotic cell focuses on cellular:
A. Division.
B. Movement.
C. Activities.
D. DNA packaging and organization.
Answer: D
Rationale: Histones are proteins that bind to DNA, facilitating the supercoiling and
organization of DNA into chromosomes, vital for cellular processes such as replication
and expression.
---
,### 3. An organelle that is responsible for the metabolism of cellular energy is
referred to as:
A. Golgi complex.
B. Endoplasmic reticulum.
C. Mitochondrion.
D. Nucleolus.
Answer: C
Rationale: Mitochondria are often called the powerhouses of the cell, as they are
primarily involved in cellular respiration and ATP production, converting energy stored
in food.
---
### 4. Which statement best describes a desmosome?
A. A desmosome is a barrier to diffusion.
B. A desmosome is a communicating tunnel.
C. Desmosomes function as a zona occludens.
D. Desmosomes hold cells together and provide structural stability.
Answer: D
Rationale: Desmosomes are specialized cell junctions that mechanically hold adjacent
cells together, providing structural integrity within tissues, particularly in areas subject
to stress.
---
### 5. Which statement describes the function of a second messenger?
A. Extracellular ligand that binds with membrane-bound receptors.
B. Chemical messenger that opens specific channels in the cell membrane.
,C. Chemical messenger that blocks a membrane-bound receptor signal.
D. Intracellular enzyme that triggers a cascade of intracellular events.
Answer: D
Rationale: Second messengers, like cyclic AMP (cAMP) and calcium ions, are activated
by receptor-ligand signaling, leading to a series of biochemical reactions within the
cell that ultimately result in specific cellular responses.
---
### 6. Which statement is correct regarding cellular energy?
A. Glycolysis is the building of sugar molecules.
B. Oxidative cellular metabolism is a single reaction making ATP.
C. Anaerobic glycolysis occurs in the presence of oxygen.
D. Glycolysis breaks down glucose, producing a net of two ATP.
Answer: D
Rationale: Glycolysis is a metabolic pathway that converts glucose into pyruvate,
resulting in the net production of two ATP molecules. Anaerobic glycolysis occurs
without oxygen, while oxidative phosphorylation occurs in aerobic conditions.
---
### 7. Movement of a solute molecule from an area of high concentration to an area
of low concentration is called:
A. Filtration.
B. Osmosis.
C. Hydrostatic pressure.
D. Diffusion.
, Answer: D
Rationale: Diffusion refers to the movement of molecules from areas of higher
concentration to areas of lower concentration until equilibrium is reached, while
osmosis specifically refers to the movement of water.
---
### 8. Which of the following is an example of an energy-releasing process?
A. Anabolism.
B. Catabolism.
C. Substrate-induced reaction.
D. Second messenger system.
Answer: B
Rationale: Catabolism is the metabolic process that breaks down molecules into
simpler ones, releasing energy in the process, while anabolism builds complex
molecules, requiring energy.
---
### 9. Which of the following describes the term chemotaxis?
A. Uses the second messenger system.
B. Cellular signal affecting the cell of origin.
C. Movement of cells along a chemical gradient.
D. Ligands bind with receptors triggering a second reaction.
Answer: C
Rationale: Chemotaxis is the movement of an organism or cell in response to a
chemical stimulus, often towards higher concentrations of attractants or away from
repellents.
### 1. It is true that a eukaryotic cell:
A. Is smaller than a prokaryotic cell.
B. Lacks a well-defined nucleus.
C. Does not contain histones.
D. Contains organelles and has a well-defined nucleus.
Answer: D
Rationale: Eukaryotic cells are typically larger than prokaryotic cells, contain a well-
defined nucleus, and possess histones, which help package DNA into a compact
structure.
---
### 2. The function of a histone found in a eukaryotic cell focuses on cellular:
A. Division.
B. Movement.
C. Activities.
D. DNA packaging and organization.
Answer: D
Rationale: Histones are proteins that bind to DNA, facilitating the supercoiling and
organization of DNA into chromosomes, vital for cellular processes such as replication
and expression.
---
,### 3. An organelle that is responsible for the metabolism of cellular energy is
referred to as:
A. Golgi complex.
B. Endoplasmic reticulum.
C. Mitochondrion.
D. Nucleolus.
Answer: C
Rationale: Mitochondria are often called the powerhouses of the cell, as they are
primarily involved in cellular respiration and ATP production, converting energy stored
in food.
---
### 4. Which statement best describes a desmosome?
A. A desmosome is a barrier to diffusion.
B. A desmosome is a communicating tunnel.
C. Desmosomes function as a zona occludens.
D. Desmosomes hold cells together and provide structural stability.
Answer: D
Rationale: Desmosomes are specialized cell junctions that mechanically hold adjacent
cells together, providing structural integrity within tissues, particularly in areas subject
to stress.
---
### 5. Which statement describes the function of a second messenger?
A. Extracellular ligand that binds with membrane-bound receptors.
B. Chemical messenger that opens specific channels in the cell membrane.
,C. Chemical messenger that blocks a membrane-bound receptor signal.
D. Intracellular enzyme that triggers a cascade of intracellular events.
Answer: D
Rationale: Second messengers, like cyclic AMP (cAMP) and calcium ions, are activated
by receptor-ligand signaling, leading to a series of biochemical reactions within the
cell that ultimately result in specific cellular responses.
---
### 6. Which statement is correct regarding cellular energy?
A. Glycolysis is the building of sugar molecules.
B. Oxidative cellular metabolism is a single reaction making ATP.
C. Anaerobic glycolysis occurs in the presence of oxygen.
D. Glycolysis breaks down glucose, producing a net of two ATP.
Answer: D
Rationale: Glycolysis is a metabolic pathway that converts glucose into pyruvate,
resulting in the net production of two ATP molecules. Anaerobic glycolysis occurs
without oxygen, while oxidative phosphorylation occurs in aerobic conditions.
---
### 7. Movement of a solute molecule from an area of high concentration to an area
of low concentration is called:
A. Filtration.
B. Osmosis.
C. Hydrostatic pressure.
D. Diffusion.
, Answer: D
Rationale: Diffusion refers to the movement of molecules from areas of higher
concentration to areas of lower concentration until equilibrium is reached, while
osmosis specifically refers to the movement of water.
---
### 8. Which of the following is an example of an energy-releasing process?
A. Anabolism.
B. Catabolism.
C. Substrate-induced reaction.
D. Second messenger system.
Answer: B
Rationale: Catabolism is the metabolic process that breaks down molecules into
simpler ones, releasing energy in the process, while anabolism builds complex
molecules, requiring energy.
---
### 9. Which of the following describes the term chemotaxis?
A. Uses the second messenger system.
B. Cellular signal affecting the cell of origin.
C. Movement of cells along a chemical gradient.
D. Ligands bind with receptors triggering a second reaction.
Answer: C
Rationale: Chemotaxis is the movement of an organism or cell in response to a
chemical stimulus, often towards higher concentrations of attractants or away from
repellents.
