Cell Biology Quiz

What component of the cell membrane is primarily responsible for its selective permeability?

• Cholesterol

• Phospholipid bilayer

• Cytoskeleton

• Ribosomes

What is the main function of the sodium-potassium pump (Na⁺/K⁺ ATPase)?

• To pump sodium into the cell and potassium out

• To pump 3 sodium ions out and 2 potassium ions into the cell

• To transport glucose across the membrane

• To equalize the concentration of Na⁺ and K⁺ inside and outside the cell

How does facilitated diffusion differ from active transport?

• Facilitated diffusion requires ATP, while active transport does not.

• Facilitated diffusion moves molecules against their concentration gradient.

• Facilitated diffusion does not require energy, while active transport does.

• Facilitated diffusion moves water, while active transport moves ions.

In receptor-mediated endocytosis, what is the primary role of membrane receptors?

• To expel waste materials from the cell

• To bind specific molecules and trigger vesicle formation

• To open ion channels for passive diffusion

• To transport water across the membrane

What is the primary composition of the cytoplasm within a cell?

• Lipids and carbohydrates only

• Water, ions, proteins, nutrients, and waste

• Nucleic acids and organelles only

• Gases and solids only

Which of the following ions is NOT commonly found in the cytoplasm?

• Sodium (Na⁺)

• Potassium (K⁺)

• Chloride (Cl⁻)

• Iron (Fe²⁺)

Which of the following is the primary component of the plant cell wall?

• Chitin

• Cellulose

• Peptidoglycan

• Pectin

What is the composition of the bacterial cell wall primarily made of?

• Cellulose

• Chitin

• Peptidoglycan

• Hemicellulose

Which of the following is produced in the nucleolus?

• DNA

• mRNA

• rRNA

• Proteins

What is the fluid inside the nucleus called?

• Cytoplasm

• Nucleoplasm

• Chromatin

• Riboplasm