Prokaryotic and Eukaryotic Cells Practice Questions
20 free Prokaryotic and Eukaryotic Cells practice questions for the Zoology. Tap an option to answer — you get instant feedback, the correct answer, and a detailed explanation for every question.
Which feature is common to both prokaryotic and eukaryotic cells?
- A Membrane-bound nucleus
- B 80S ribosomes
- C Plasma membrane
- D Mitochondria
Correct answer: Plasma membrane
All living cells possess a plasma membrane that encloses the cytoplasm and regulates exchange with the environment. Prokaryotes lack membrane-bound organelles like the nucleus and mitochondria, which are found only in eukaryotes.
The genetic material in a typical prokaryotic cell is best described as:
- A Linear DNA enclosed within a membrane-bound nucleus
- B Circular DNA located in the nucleoid region
- C Multiple linear chromosomes associated with histones
- D RNA molecules dispersed throughout the cytoplasm
Correct answer: Circular DNA located in the nucleoid region
Prokaryotic DNA is usually circular and lies in a region called the nucleoid, not surrounded by a nuclear membrane. Histone-associated linear chromosomes are characteristic of eukaryotic cells.
Which organelle is responsible for energy production in eukaryotic cells but is absent in prokaryotes?
- A Ribosome
- B Chloroplast
- C Mitochondrion
- D Golgi apparatus
Correct answer: Mitochondrion
Mitochondria carry out aerobic respiration and ATP synthesis in eukaryotic cells. Prokaryotes lack mitochondria and perform respiratory processes at the plasma membrane.
Which statement correctly distinguishes eukaryotic cells from prokaryotic cells?
- A Eukaryotic cells completely lack ribosomes of any kind
- B Eukaryotic cells contain membrane-bound organelles
- C Eukaryotic cells are exclusively unicellular organisms
- D Eukaryotic cells carry only circular DNA like prokaryotes
Correct answer: Eukaryotic cells contain membrane-bound organelles
A defining feature of eukaryotic cells is the presence of membrane-bound organelles such as the nucleus, mitochondria, and endoplasmic reticulum. Prokaryotic cells do not have such compartmentalization.
Which structure is present in prokaryotic cells but absent in animal cells?
- A Plasma membrane
- B Rigid cell wall surrounding the cell
- C Ribosomes for protein synthesis
- D Cytoplasm as cellular medium
Correct answer: Rigid cell wall surrounding the cell
Most prokaryotes possess a rigid cell wall that provides shape and protection. Animal cells lack a cell wall and rely on the plasma membrane and cytoskeleton for structural support.
The ribosomes found in prokaryotic cells are typically:
- A 80S and attached to endoplasmic reticulum
- B 70S and free in the cytoplasm
- C 90S and membrane-bound
- D 60S and located in the nucleus
Correct answer: 70S and free in the cytoplasm
Prokaryotic ribosomes are smaller 70S ribosomes that float freely in the cytoplasm. Eukaryotic cells mainly contain larger 80S ribosomes in the cytosol and on the rough endoplasmic reticulum.
Which of the following best describes the nucleus of a eukaryotic cell?
- A A region without a membrane that holds genetic material
- B A membrane-bound organelle containing genetic material
- C A structure that forms only during cell division
- D An organelle that participates in protein synthesis
Correct answer: A membrane-bound organelle containing genetic material
The eukaryotic nucleus is enclosed by a double-layered nuclear membrane and houses the cell's DNA. This compartmentalization is absent in prokaryotic cells.
Which cellular process occurs in both prokaryotic and eukaryotic cells?
- A Photosynthesis in chloroplasts
- B Oxidative phosphorylation in mitochondria
- C Protein synthesis by ribosomes
- D Nuclear division through mitosis
Correct answer: Protein synthesis by ribosomes
Protein synthesis is a universal cellular process carried out by ribosomes in all cells. Structures like mitochondria, chloroplasts, and the mitotic apparatus are exclusive to eukaryotes.
Which feature allows eukaryotic cells to be larger and more complex than prokaryotic cells?
- A Presence of plasmids in the cytoplasm
- B Absence of a rigid cell wall
- C Internal compartmentalization by membranes
- D Circular arrangement of chromosomal DNA
Correct answer: Internal compartmentalization by membranes
Eukaryotic cells contain membrane-bound compartments that separate and regulate different metabolic activities. This organization supports greater size and functional complexity compared to prokaryotes.
Which of the following correctly matches a cell type with its typical example?
- A Prokaryotic cell – Amoeba (unicellular protist)
- B Eukaryotic cell – Bacterium (single-celled organism)
- C Prokaryotic cell – Escherichia coli
- D Eukaryotic cell – Mycoplasma (wall-less bacterium)
Correct answer: Prokaryotic cell – Escherichia coli
Escherichia coli is a bacterium and therefore a prokaryotic cell. Amoeba is a unicellular eukaryote, while Mycoplasma is actually a prokaryote lacking a cell wall.
Which cellular component is involved in lipid synthesis and is found only in eukaryotic cells?
- A Smooth endoplasmic reticulum
- B Ribosome for protein assembly
- C Plasma membrane boundary layer
- D Nucleoid DNA-containing region
Correct answer: Smooth endoplasmic reticulum
The smooth endoplasmic reticulum synthesizes lipids and is a membrane-bound organelle found only in eukaryotic cells. Prokaryotes lack endoplasmic reticulum.
In prokaryotic cells, the respiratory enzymes are mainly located in the:
- A Mitochondria (absent in prokaryotes)
- B Outer cell wall layer
- C Plasma membrane
- D Nucleoid chromosomal region
Correct answer: Plasma membrane
Prokaryotes lack mitochondria, so respiratory enzymes are embedded in the plasma membrane. This membrane carries out functions analogous to mitochondrial membranes in eukaryotes.
Which statement about cell size is correct?
- A Prokaryotic cells are generally larger than eukaryotic cells
- B Both prokaryotic and eukaryotic cells are the same size
- C Eukaryotic cells are generally larger than prokaryotic cells
- D Cell size does not depend on cellular organization
Correct answer: Eukaryotic cells are generally larger than prokaryotic cells
Eukaryotic cells are typically larger due to internal compartmentalization and cytoskeletal support. Prokaryotic cells are usually much smaller and simpler in structure.
Which structure helps in the attachment of bacterial cells to surfaces?
- A Cilia
- B Pili (hair-like appendages)
- C Flagella
- D Centrioles
Correct answer: Pili (hair-like appendages)
Pili are hair-like appendages found in many prokaryotes that facilitate attachment to surfaces and conjugation between bacterial cells. Cilia and centrioles are eukaryotic structures not found in bacteria.
Which of the following is a true statement regarding DNA packaging?
- A Prokaryotic DNA is associated with histones like eukaryotes
- B Eukaryotic DNA is not associated with proteins
- C Eukaryotic DNA is packaged with histone proteins
- D Prokaryotic DNA is enclosed in a nuclear envelope
Correct answer: Eukaryotic DNA is packaged with histone proteins
In eukaryotes, DNA is tightly packaged with histone proteins to form chromatin. Prokaryotic DNA generally lacks histones and is not enclosed by a nuclear membrane.
Which organelle modifies and packages proteins in eukaryotic cells?
- A Rough endoplasmic reticulum
- B Golgi apparatus
- C Lysosome for waste digestion
- D Mitochondrion
Correct answer: Golgi apparatus
The Golgi apparatus modifies, sorts, and packages proteins received from the endoplasmic reticulum. This organelle is absent in prokaryotic cells.
Which feature is characteristic of all living cells?
- A Presence of a nucleus
- B Capacity to carry out metabolism
- C Membrane-bound organelles
- D Cell wall made of cellulose
Correct answer: Capacity to carry out metabolism
All living cells perform metabolic activities essential for survival. Features like nuclei, membrane-bound organelles, or cellulose cell walls are not universal to all cells.
Which structure is involved in maintaining cell shape in both prokaryotes and eukaryotes?
- A Cell wall
- B Cytoskeleton
- C Plasma membrane
- D Nuclear envelope
Correct answer: Plasma membrane
The plasma membrane helps maintain the integrity and basic shape of all cells. While cell walls and cytoskeletons vary among organisms, the plasma membrane is universal.
Which of the following correctly differentiates prokaryotic transcription from eukaryotic transcription?
- A Prokaryotic transcription occurs in the nucleus
- B Eukaryotic transcription occurs in the cytoplasm
- C Prokaryotic transcription and translation occur simultaneously
- D Eukaryotic transcription lacks RNA polymerase
Correct answer: Prokaryotic transcription and translation occur simultaneously
In prokaryotes, transcription and translation occur simultaneously in the cytoplasm. In eukaryotes, transcription occurs in the nucleus and is separated from translation in the cytoplasm.
Which of the following pairs is correctly matched?
- A Prokaryote – membrane-bound nucleus
- B Eukaryote – nucleoid region
- C Prokaryote – smaller 70S ribosomes
- D Eukaryote – absence of organelles
Correct answer: Prokaryote – smaller 70S ribosomes
Prokaryotic cells contain 70S ribosomes, which are smaller than the 80S ribosomes of eukaryotes. The other options incorrectly assign features between the two cell types.