Question 1

Which of the following statements best explains why eukaryotic cells can be much larger than prokaryotic cells?

Accepted Answer

Eukaryotic cells have organelles that compartmentalize functions, increasing efficiency and allowing larger cell size.

Question 2

A scientist discovers a cell with the following features: a single circular chromosome, ribosomes, a cell wall made of peptidoglycan, and no membrane-bound organelles. To which domain does this cell most likely belong?

Accepted Answer

Bacteria

Question 3

Which of the following best describes the function of the nuclear localization signal (NLS) in eukaryotic cells?

Accepted Answer

It serves as a 'zip code' that directs proteins into the nucleus through the nuclear pore complex.

Question 4

A mutation prevents the addition of mannose-6-phosphate tags to proteins in a cell. Which process would be most directly affected?

Accepted Answer

Targeting of acid hydrolases to the lysosome

Question 5

Which of the following is a function of the smooth endoplasmic reticulum (SER)?

Accepted Answer

Synthesis and breakdown of lipids, and storage of Ca$$^{2+}$$ ions

Question 6

During the pulse-chase experiment, what was the main conclusion regarding the movement of newly synthesized proteins?

Accepted Answer

Proteins move from the rough ER to the Golgi apparatus and then to secretory vesicles or the cell surface.

Question 7

Which of the following best describes the process of autophagy in eukaryotic cells?

Accepted Answer

Damaged organelles are enclosed in a membrane and delivered to the lysosome for digestion.

Question 8

Which cytoskeletal element is primarily responsible for the separation of chromosomes during mitosis and meiosis?

Accepted Answer

Microtubules

Question 9

A cell is observed to have a large number of mitochondria. Which of the following is the most likely function of this cell?

Accepted Answer

Production of large amounts of ATP for energy-demanding processes

Question 10

Which of the following statements about the endosymbiosis theory is correct?

Accepted Answer

It suggests that mitochondria and chloroplasts were once free-living bacteria engulfed by ancestral eukaryotic cells.

Question 11

Which of the following best explains why plant cells can maintain turgor pressure and animal cells cannot?

Accepted Answer

Plant cells have a large central vacuole and a cell wall that provides structural support.

Question 12

Which of the following is a key difference between prokaryotic and eukaryotic flagella?

Accepted Answer

Prokaryotic flagella rotate, while eukaryotic flagella move in a whip-like fashion and have a '9+2' microtubule arrangement.

Question 13

A protein is synthesized in the cytosol and contains an ER signal sequence. What is the correct order of events for this protein to be secreted from the cell?

Accepted Answer

Cytosol → Rough ER → Golgi apparatus → Secretory vesicle → Plasma membrane

Question 14

Which of the following best describes the function of peroxisomes in eukaryotic cells?

Accepted Answer

They are the site of reduction-oxidation (redox) reactions and detoxification of hydrogen peroxide.

Question 15

Which of the following cell junctions allows for the direct passage of ions and small molecules between adjacent animal cells?

Accepted Answer

Gap junctions

Question 16

Which cytoskeletal element is most directly involved in muscle contraction and cell crawling?

Accepted Answer

Actin filaments (microfilaments) interacting with myosin

Question 17

A vesicle containing newly synthesized proteins is observed moving from the rough ER to the Golgi apparatus. Which motor protein is most likely responsible for this movement along microtubules?

Accepted Answer

Kinesin

Question 18

Which of the following best describes the process of receptor-mediated endocytosis?

Accepted Answer

Specific molecules bind to receptors on the plasma membrane, are internalized in vesicles, and delivered to endosomes and lysosomes.

Question 19

Which of the following is a function of the Golgi apparatus?

Accepted Answer

Processing, sorting, and shipping proteins received from the rough ER

Inside the Cell: Structure and Function of Cellular Components

Guida di studio - Domande di pratica

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