Cell Structure and Function

What is the main difference between the primary and secondary cell walls in plants?

• The primary wall contains lignin while the secondary wall does not
• The primary wall is found only in young cells, while the secondary wall is found in all cells
• The primary wall is thicker than the secondary wall
• The primary wall allows growth while the secondary wall provides rigidity

What type of molecules typically use simple diffusion to cross the plasma membrane?

• Large polar molecules
• Charged ions
• Large proteins
• Nonpolar and small molecules

Which statement correctly describes passive transport?

• It requires ATP
• It moves molecules against the gradient
• It involves vesicle formation
• It does not require energy and moves molecules along the concentration gradient

Which of the following best describes the role of the endomembrane system?

• Produces ATP
• Facilitates DNA replication
• Stores genetic information
• Coordinates functions of different membranous organelles

Which of the following is NOT a component of the plant cell wall?

• Cellulose
• Hemicellulose
• Pectins
• Cholesterol