$\mathrm{AGC\text{-}UAU\text{-}CCG}$

Question 1

Which of the following best describes the principle of complementarity as it applies to human cells?

Accepted Answer

The structure of a cell determines its function.

Question 2

A scientist observes a cell with a large number of mitochondria. Which of the following is the most likely function of this cell?

Accepted Answer

Producing large amounts of ATP for energy-demanding processes.

Question 3

Which of the following statements about the plasma membrane is correct?

Accepted Answer

It is composed of a double layer of phospholipids with hydrophilic heads facing outward and hydrophobic tails facing inward.

Question 4

During osmosis, water moves across a selectively permeable membrane. In which direction does water move?

Accepted Answer

From an area of low solute concentration to an area of high solute concentration.

Question 5

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

Accepted Answer

The cell will shrink as water leaves the cell.

Question 6

Which organelle is primarily responsible for the synthesis of proteins that are exported from the cell?

Accepted Answer

Rough endoplasmic reticulum

Question 7

Which of the following best describes the function of lysosomes?

Accepted Answer

They contain digestive enzymes that break down worn-out organelles and cellular debris.

Question 8

Which process requires ATP to move substances across the plasma membrane against their concentration gradient?

Accepted Answer

Active transport

Question 9

A cell is actively secreting large amounts of hormones. Which process is most directly involved in this secretion?

Accepted Answer

Exocytosis

Question 10

Which of the following best explains why the sodium-potassium pump is essential for nerve impulse transmission?

Accepted Answer

It maintains the electrochemical gradient by moving $3 \ \mathrm{Na}^+$ out and $2 \ \mathrm{K}^+$ in per ATP hydrolyzed.

Question 11

Which of the following is a correct sequence of events during the cell cycle?

Accepted Answer

Interphase → Mitosis → Cytokinesis

Question 12

During which phase of mitosis do chromosomes align along the metaphase plate?

Accepted Answer

Metaphase

Question 13

Which of the following best describes the role of tRNA during translation?

Accepted Answer

It brings the appropriate amino acid to the ribosome by matching its anticodon to the mRNA codon.

Question 14

A DNA sequence of TCG-ATA-GGC is transcribed into mRNA. What is the resulting mRNA sequence?

Accepted Answer

$\mathrm{AGC	ext{-}UAU	ext{-}CCG}$

Question 15

Which of the following is an example of epigenetic regulation of gene expression?

Accepted Answer

DNA methylation that silences a gene without changing its sequence.

Question 16

Which of the following best describes the function of the Golgi apparatus?

Accepted Answer

It modifies, sorts, and packages proteins and lipids for secretion or delivery to other organelles.

Question 17

A cell in the small intestine is observed to have extensive microvilli. What is the primary advantage of this adaptation?

Accepted Answer

Increased surface area for absorption of nutrients.

Question 18

Which of the following is true regarding facilitated diffusion?

Accepted Answer

It requires a membrane protein to transport substances down their concentration gradient.

Question 19

Which of the following best explains why receptor-mediated endocytosis is highly selective?

Accepted Answer

It uses specific receptor proteins to bind and internalize only certain target molecules.

Question 20

A mutation prevents the formation of tight junctions between epithelial cells. Which of the following is the most likely consequence?

Accepted Answer

Substances may leak between cells, compromising tissue integrity.

The Human Cell: Structure, Function, and Regulation

Study Guide - Practice Questions