Question

1. what process moves molecules from high to low concentration without energy?

a. active transport
b. osmosis
c. facilitated diffusion
d. passive transport

part b: short answer (2 - 4 pts each)

1. describe three major differences between prokaryotic and eukaryotic cells.

Explanation:

• Question 7:
• Active transport (A): Requires energy (ATP) to move molecules against the concentration gradient (low to high). So it's not the answer.
• Osmosis (B): Specifically the movement of water molecules across a semi - permeable membrane from a region of high water concentration (low solute concentration) to low water concentration (high solute concentration). It is a type of passive transport but is too specific (only for water).
• Facilitated diffusion (C): A type of passive transport where molecules (usually polar or large non - polar) move through protein channels from high to low concentration. But it is a subset of passive transport.
• Passive transport (D): General term for the movement of molecules from high to low concentration without the use of energy. It includes simple diffusion, facilitated diffusion, and osmosis.
• Question 8:
• Nucleus: Prokaryotic cells lack a true nucleus (have a nucleoid region with circular DNA), while eukaryotic cells have a membrane - bound nucleus with linear DNA.
• Membrane - bound organelles: Prokaryotes have no membrane - bound organelles (e.g., mitochondria, endoplasmic reticulum), while eukaryotes have various membrane - bound organelles.
• Cell size: Prokaryotic cells are generally smaller (0.1 - 5 μm) compared to eukaryotic cells (10 - 100 μm).

Answer:

• Question 7: D. Passive transport
• Question 8:
• Prokaryotes lack a true nucleus (nucleoid instead), eukaryotes have a membrane - bound nucleus.
• Prokaryotes have no membrane - bound organelles, eukaryotes have them (e.g., mitochondria).
• Prokaryotes are generally smaller (0.1 - 5 μm) than eukaryotes (10 - 100 μm).