Question 1
A cell structure is described as a discrete subunit adapted to carry out a specific function. Which structure fits this description as an organelle in this syllabus?
A.
Cell wall
B.
Ribosome
C.
Cytoplasm
D.
Cytoskeleton
Question 2
The plasma membrane is considered an organelle in this syllabus because it is a defined cell structure with specific functions. Which function is most directly associated with it?
A.
Storage of cellulose outside animal cells
B.
Control of movement of substances into and out of the cell
C.
Production of chromosomes by translation
D.
Formation of a cell-wide filament network
Question 3
What is an advantage of separating the nucleus from the cytoplasm in eukaryotic cells?
A.
Ribosomes are prevented from synthesizing proteins.
B.
DNA leaves the nucleus to be translated directly.
C.
Translation can occur before transcription has finished.
D.
mRNA can be modified before meeting ribosomes.
Question 4
During cell fractionation, why are cells usually homogenized in a cold, buffered solution?
A.
To increase enzyme activity and dissolve organelle membranes
B.
To convert all organelles into ribosomes
C.
To slow enzyme activity and help maintain suitable pH
D.
To make the cytoplasm an extracellular structure
Question 5
Which statement gives a benefit of concentrating enzymes and metabolites in a membrane-bound compartment?
A.
It prevents all metabolic reactions from occurring.
B.
It makes metabolites identical to membranes.
C.
It removes the need for enzymes in metabolism.
D.
It increases the probability of enzyme–substrate collisions.
Question 6
In chloroplasts, where are photosystems located?
A.
Mitochondrial matrix
B.
Nuclear pores
C.
Thylakoid membranes
D.
Golgi cisternae
Question 7
A phagocytic vacuole fuses with a lysosome. What is the main benefit of this compartmentalization?
A.
It converts ribosomes into lysosomal enzymes.
B.
It allows digestion of engulfed material without releasing hydrolytic enzymes into the cytoplasm.
C.
It prevents any movement of water across membranes.
D.
It stores chromosomes away from the cytoplasm.
Question 8
A homogenate is centrifuged at increasing speeds. Which fraction would normally form a pellet before ribosomes?
A.
Nuclei
B.
Individual amino acids
C.
mRNA molecules
D.
Soluble enzymes
Question 9
What is the advantage of the small volume of the mitochondrial intermembrane space?
A.
Hydrolytic enzymes can digest engulfed bacteria.
B.
A proton concentration gradient can build up rapidly.
C.
Glucose can be stored as starch in the matrix.
D.
DNA can be translated before transcription.
Question 10
A protein is synthesized for secretion from a pancreatic cell. Where is its translation most likely to occur?
A.
In the thylakoid lumen
B.
On ribosomes attached to rough endoplasmic reticulum
C.
On free ribosomes for retention in the cytoplasm
D.
Inside nuclear pores
Question 11
What is the role of the trans face of the Golgi apparatus?
A.
Shipping processed proteins in vesicles to their destinations
B.
Binding mRNA during translation
C.
Pumping protons across cristae
D.
Receiving unprocessed proteins directly from free ribosomes
Question 12
During mitosis, what happens to the nuclear envelope in many eukaryotic cells?
A.
It breaks into vesicles that can later fuse to reform nuclear envelopes.
B.
It is translated by ribosomes into chromosomes.
C.
It becomes a permanent cell wall around the chromosomes.
D.
It converts to thylakoid membranes for photosynthesis.
Question 13
Why can translation begin on an molecule before transcription has finished in prokaryotes?
A.
Prokaryotic ribosomes are inside a double membrane.
B.
Prokaryotic transcription occurs on the rough endoplasmic reticulum.
C.
Prokaryotic mRNA is translated only after leaving the nucleus.
D.
Prokaryotes have no nuclear compartment separating DNA from ribosomes.
Question 14
What is a functional benefit of pores in the nuclear envelope?
A.
They prevent any protein from entering the nucleus.
B.
They allow controlled passage of large molecules such as and ribosomal subunits.
C.
They form clathrin coats on vesicles.
D.
They pump protons into thylakoids.
Question 15
What is the role of clathrin in vesicle formation?
A.
It catalyses peptide bond formation at ribosomes.
B.
It absorbs light energy in photosystems.
C.
It hydrolyses proteins inside lysosomes.
D.
It forms a coat that helps curve a membrane into a budding vesicle.
Question 16
The cristae of mitochondria are extensive in cells with high ATP demand. What explains this relationship?
A.
Cristae increase surface area for proteins involved in oxidative phosphorylation.
B.
Cristae digest worn-out organelles using hydrolytic enzymes.
C.
Cristae store mRNA before it leaves the nucleus.
D.
Cristae contain photosystems for light absorption.
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