Question 1

Which of the following best explains why potassium (K$$^+) is a $$key player in establishing the resting membrane potential (RMP) of most cells?

Accepted Answer

K$$^+$$ diffuses out of the cell down its concentration gradient, leaving behind negatively charged proteins that cannot cross the membrane.

Question 2

A neuron is 'upset' from its steady-state RMP by the intentional opening of which channels?

Accepted Answer

Na$$^+$$ and K$$^+$$ channels

Question 3

Which of the following best describes the function of the mitochondria?

Accepted Answer

They produce most of the cell's energy (ATP) via aerobic respiration.

Question 4

A cell is observed to have an extensive network of microtubules and microfilaments. Which nonmembranous organelle is most likely being described, and what is its primary function?

Accepted Answer

Cytoskeleton; structural support and movement of cell components

Question 5

Which of the following is a correct sequence of events during transcription?

Accepted Answer

Initiation $$\rightarrow$$ Elongation $$\rightarrow$$ Termination

Question 6

During translation, what is the role of the anticodon on tRNA?

Accepted Answer

It binds to the complementary codon on mRNA, ensuring the correct amino acid is added to the polypeptide chain.

Question 7

A mutation causes a cell to lack functional peroxisomes. Which of the following processes would be most directly affected?

Accepted Answer

Breakdown of fatty acids and detoxification of toxins

Question 8

Which of the following best describes the function of the nucleolus?

Accepted Answer

It is the site of ribosomal RNA (rRNA) synthesis and ribosome assembly.

Question 9

Which of the following is true regarding the genetic code?

Accepted Answer

There are 64 possible codons, but only 20 amino acids, so some amino acids are coded by more than one codon.

Question 10

A scientist observes a cell with many rough endoplasmic reticulum (ER) structures. Which function is this cell most likely specialized for?

Accepted Answer

Protein synthesis for export or membrane insertion

Question 11

Which of the following best explains why Na$$^+$$ entry into a cell can bring the RMP up to around $$-70 mV$$?

Accepted Answer

Na$$^+ is $$attracted to the inside of the cell due to its negative charge, making the inside less negative when it enters.

Question 12

Which of the following is NOT a function of the cytoskeleton?

Accepted Answer

Synthesizing proteins for export

Question 13

A patient has a genetic defect that prevents the formation of cilia on respiratory epithelial cells. Which of the following symptoms would most likely result?

Accepted Answer

Difficulty moving mucus and debris out of the airways

Question 14

Which of the following best describes the process of elongation during translation?

Accepted Answer

Amino acids are added one by one to the growing polypeptide chain as tRNAs bring them to the ribosome, matching their anticodons to codons on the mRNA.

Question 15

Which of the following is a correct statement about the function of microvilli?

Accepted Answer

They increase the surface area of the cell for absorption.

Question 16

Which of the following best explains the role of the nuclear envelope?

Accepted Answer

It allows substances to pass into and out of the nucleus through nuclear pores.

Question 17

During active transport, the maintenance of electrochemical gradients is primarily achieved by which of the following mechanisms?

Accepted Answer

Active pumping of Na$$^+$$ out of the cell and K$$^+$$ into the cell by the Na$$^+/K$^+$$ ATPase

Question 18

Which of the following best describes the function of lysosomes?

Accepted Answer

They contain digestive enzymes that break down ingested bacteria, viruses, and toxins.

Question 19

A cell is observed to have a high number of free ribosomes. Which of the following is the most likely function of this cell?

Accepted Answer

Synthesis of proteins for use within the cytosol

Question 20

Which of the following best describes the process of DNA replication prior to cell division?

Accepted Answer

It creates an exact replica of DNA during interphase in preparation for mitosis/cytokinesis.

Cellular Structure, Organelles, and Protein Synthesis: Study Notes for Anatomy & Physiology

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