Cell Structure and Function — Hard Practice Quiz

Question 1

A newly discovered single-celled organism possesses a cell wall, ribosomes, and a single circular chromosome, but lacks a nuclear envelope, mitochondria, and chloroplasts. Based on the Unified Cell Theory and cellular characteristics, which of the following statements is the most accurate conclusion about this organism?

Accepted Answer

It is a prokaryotic organism, and its cells are the basic unit of life, capable of synthesizing proteins and reproducing from existing cells.

Answer

It is a eukaryotic organism, as it contains ribosomes for protein synthesis, and its cells are the basic unit of life.

Answer

It is a eukaryotic organism that has lost its nucleus and mitochondria, but still adheres to the principle that new cells arise from existing cells.

Answer

It is a prokaryotic organism, but it violates the Unified Cell Theory because it lacks membrane-bound organelles.

Question 2

An animal cell and a plant cell are both placed into separate beakers containing a solution that is significantly hypotonic relative to their internal cellular environments. Considering the structural differences between animal and plant cells, particularly regarding the cell wall and central vacuole, what is the most probable outcome for each cell?

Accepted Answer

The animal cell will undergo lysis, while the plant cell will become turgid due to the cell wall preventing excessive water intake and bursting.

Answer

Both the animal cell and the plant cell will swell and eventually lyse, as water rushes into both cells down its concentration gradient.

Answer

The animal cell will shrink due to water loss, while the plant cell will become flaccid as its central vacuole loses water.

Answer

Both the animal cell and the plant cell will become turgid, but only the plant cell's cell wall will prevent it from bursting.

Question 3

A eukaryotic cell is genetically modified to produce a specific protein destined for secretion outside the cell. However, a mutation occurs that prevents the proper formation and budding of transport vesicles from the trans-Golgi network. Which of the following would be the most direct and significant consequence for the fate of this secreted protein and the cell's overall function?

Accepted Answer

The protein would be correctly synthesized and modified in the Golgi apparatus but would accumulate within the Golgi lumen, unable to be transported to the plasma membrane for exocytosis.

Answer

The protein would accumulate in the Rough Endoplasmic Reticulum, leading to its degradation by peroxisomes.

Answer

The protein would be misfolded in the cytoplasm and subsequently targeted to lysosomes for digestion, preventing its entry into the endomembrane system.

Answer

The protein would be secreted directly from the ribosomes into the extracellular matrix without any further modification or packaging.

Question 4

Consider a scenario where a cell's ability to maintain its electrochemical gradient across the plasma membrane is severely compromised due to a lack of ATP. This gradient is crucial for various cellular processes, including the active transport of ions. If the cell's mitochondria are non-functional, leading to a complete cessation of ATP production, what would be the most immediate and profound impact on the cell's homeostasis and its ability to perform active transport?

Accepted Answer

The cell would immediately begin to swell or shrink uncontrollably as passive transport mechanisms become unregulated, leading to a rapid loss of internal ion balance and eventual cell death.

Answer

The cell would switch to anaerobic respiration to produce ATP, maintaining the electrochemical gradient and continuing active transport without significant disruption.

Answer

Only facilitated diffusion would be affected, while other forms of passive and active transport would continue normally, as they do not directly rely on ATP.

Answer

The cell's internal environment would become isotonic with the extracellular fluid, eliminating the need for an electrochemical gradient and active transport.

Question 5

A plant cell is transferred from an isotonic solution to a hypertonic solution. Describe the sequence of events and the final state of the cell, emphasizing the roles of the plasma membrane, cell wall, and central vacuole in this process.

Accepted Answer

Water will move out of the cell, causing the central vacuole to shrink and the plasma membrane to pull away from the cell wall (plasmolysis), but the cell wall will maintain the overall shape of the cell.

Answer

Water will move into the cell, causing the central vacuole to expand and the plasma membrane to press against the cell wall, leading to increased turgor pressure and potential lysis.

Answer

The cell wall will prevent any water movement, maintaining the cell's original volume and shape, while the central vacuole remains unchanged.

Answer

The plasma membrane will become impermeable to water, and the cell will maintain its turgid state due to the rigidity of the cell wall.

Question 6

A novel drug is discovered that specifically targets and inhibits the polymerization of actin filaments, a key component of the cytoskeleton, within a eukaryotic cell. Considering the diverse functions of the cytoskeleton, which of the following cellular processes would be most directly and severely impaired by this drug, leading to significant functional disruption?

Accepted Answer

The movement of vesicles and organelles within the cytoplasm, as well as changes in cell shape and cell division processes like cytokinesis.

Answer

Protein synthesis on ribosomes and lipid synthesis in the Smooth Endoplasmic Reticulum.

Answer

ATP production in the mitochondria and detoxification of poisons by peroxisomes.

Answer

The modification, sorting, and packaging of proteins and lipids in the Golgi apparatus.

Question 7

An epithelial tissue, such as the lining of the small intestine, requires both strong mechanical adhesion between cells to prevent leakage and efficient communication for coordinated absorption. Which combination of intercellular junctions and extracellular components would be most critical for enabling these specific functions?

Accepted Answer

Tight junctions to seal cells together and desmosomes for strong adhesion, along with gap junctions for rapid intercellular communication.

Answer

Plasmodesmata for communication and a thick cell wall for structural support, as seen in plant cells.

Answer

Gap junctions for mechanical strength and an extensive extracellular matrix of collagen for communication.

Answer

Only desmosomes for adhesion, as tight junctions would impede nutrient absorption, and communication is not essential.

Question 8

A large, polar molecule, such as glucose, needs to be transported into a cell from an area of lower concentration to an area of higher concentration. Given the properties of the plasma membrane as described by the Fluid Mosaic Model and its selectively permeable nature, which transport mechanism is absolutely required for this process?

Accepted Answer

Active transport, involving a specific protein pump that uses energy (e.g., ATP) to move the molecule against its concentration gradient.

Answer

Simple diffusion, as the plasma membrane is fluid and allows all molecules to pass through.

Answer

Facilitated diffusion, utilizing a carrier protein to move the molecule down its concentration gradient.

Answer

Osmosis, as water movement will indirectly pull the glucose molecules into the cell.

Question 9

A scientist observes a eukaryotic cell under a microscope and notes the prominent presence of both mitochondria and chloroplasts. Based on the functions of these organelles and the characteristics of different cell types, what can be definitively inferred about this cell's metabolic capabilities and its likely classification?

Accepted Answer

This cell is capable of both photosynthesis and cellular respiration, indicating it is most likely a plant cell or an algal cell.

Answer

This cell is an animal cell that has recently engulfed a photosynthetic bacterium, and it primarily relies on cellular respiration for energy.

Answer

This cell is a prokaryote, as it possesses organelles for energy production, but lacks a true nucleus.

Answer

This cell can only produce ATP through photosynthesis and cannot perform cellular respiration.

Question 10

Consider a scenario where a cell's lysosomes are non-functional due to a genetic defect, preventing them from breaking down macromolecules and recycling worn-out organelles. How would this defect impact the cell's overall health and the function of other organelles within the endomembrane system?

Accepted Answer

The cell would accumulate waste products and damaged organelles, leading to cellular dysfunction and potentially cell death, while the Golgi apparatus and ER would become overloaded with unprocessed materials.

Answer

The cell would compensate by increasing the activity of peroxisomes to take over the digestive functions of the lysosomes, maintaining cellular homeostasis.

Answer

Protein synthesis would cease entirely, as ribosomes would lack the necessary components for assembly due to the inability to recycle amino acids.

Answer

The plasma membrane would become excessively permeable, leading to uncontrolled entry of substances and disruption of the cell's internal environment.

Subjects

Print

Cell Structure and Function — Hard Practice Quiz

Formulas & key concepts

A cellular structure that carries out protein synthesis.

A plant cell organelle that carries out photosynthesis.

A process of passing material out of a cell.

Practice quiz

Select a subject

Subjects

Print

Cell Structure and Function — Hard Practice Quiz

Formulas & key concepts

A cellular structure that carries out protein synthesis.

A plant cell organelle that carries out photosynthesis.

A process of passing material out of a cell.

Practice quiz

Select a subject

[ CHOOSE YOUR LOBBY ]

Print PDF Options