$$3 \mathrm{Na}^+_{\text{out}} + 2 \mathrm{K}^+_{\text{in}}$$

Question 1

Which of the following best describes the primary function of the plasma membrane in a human cell?

Accepted Answer

It acts as a fragile barrier, controlling the movement of substances into and out of the cell.

Question 2

A red blood cell is placed in a hypotonic solution. What is the most likely outcome for the cell?

Accepted Answer

It will swell and may burst as water enters the cell.

Question 3

Which type of membrane protein is primarily responsible for transporting small molecules across the plasma membrane?

Accepted Answer

Integral proteins

Question 4

During active transport, which equation best represents the movement of sodium and potassium ions by the Na⁺/K⁺ pump?

Accepted Answer

$$3 \mathrm{Na}^+_{	ext{out}} + 2 \mathrm{K}^+_{	ext{in}}$$

Question 5

Which organelle is most abundant in cells that require large amounts of energy, such as muscle cells?

Accepted Answer

Mitochondria

Question 6

A cell is observed to be actively engulfing bacteria. Which process is most likely occurring?

Accepted Answer

Phagocytosis

Question 7

Which cytoplasmic organelle is responsible for modifying, packaging, and shipping proteins to their final destinations?

Accepted Answer

Golgi apparatus

Question 8

What is the main function of lysosomes within a cell?

Accepted Answer

Intracellular digestion of worn-out organelles and foreign substances

Question 9

Which of the following best describes the role of the nucleus in a eukaryotic cell?

Accepted Answer

It regulates passage of materials between the cytoplasm and nucleoplasm and contains genetic material.

Question 10

During DNA replication, which enzyme is responsible for building the complementary DNA strand?

Accepted Answer

DNA polymerase

Question 11

Which of the following best explains the genetic code?

Accepted Answer

It is a sequence of nucleotide triplets in DNA that specifies the order of amino acids in a protein.

Question 12

Which process involves the synthesis of mRNA from a DNA template?

Accepted Answer

Transcription

Question 13

A mutation changes the DNA triplet from $$\mathrm{TAC} to$$ $$\mathrm{TAT}. $$What is the most direct consequence of this mutation?

Accepted Answer

A different amino acid may be incorporated into the protein during translation.

Question 14

Which cytoskeletal element is primarily responsible for muscle contraction and generating forces within the cell?

Accepted Answer

Microfilaments (actin)

Question 15

Which of the following is a function of peroxisomes?

Accepted Answer

Detoxification of toxic substances

Question 16

A cell is exposed to a chemical that inhibits the Na⁺/K⁺ pump. What is the most likely effect on the cell's resting membrane potential?

Accepted Answer

The resting membrane potential will decrease toward zero.

Question 17

Which process is described as 'bulk-phase endocytosis' and involves the cell taking in extracellular fluid?

Accepted Answer

Pinocytosis

Question 18

During protein synthesis, which molecule brings amino acids to the ribosome for assembly into a polypeptide chain?

Accepted Answer

tRNA

Question 19

Which of the following best describes the role of centrioles during cell division?

Accepted Answer

They organize microtubule networks and form the mitotic spindle.

Question 20

Which extracellular material is most important for providing structural support and anchoring cells within tissues?

Accepted Answer

Extracellular matrix

Chapter 3: Cells – The Living Units (Anatomy & Physiology Study Notes)

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