Section 2-2 Prokaryotes and Eukaryotes

Question 1

Define a prokaryote.

Answer 1

A cell with no membrane bound organelles.

Question 2

What are the main cell shapes?

Answer 2

Cocci (spherical)
Bacilli (Rod shaped)
Spiral

Question 3

What is the difference between a gram positive and a gram negative cell?

Answer 3

A gram positive cell has a thick peptidoglycan cell wall that retains the violet stain.

Gram negative cells have less peptidoglycan and is located in a layer between plasma membrane and the outer membrane. The violet stain is easily washed away.

Question 4

What features are found in a Eukaryote but not a prokaryote?

Answer 4

• Nucleus and nuclear membrane
• Mitosis
• Golgi, ER, Cytoskeleton
• Organelles
• Membrane bound sterols (Cholesterol is not found in prokaryotes)

Question 5

When approximately was the first Eukaryotic cell formed?

Answer 5

About 2.7 billion years ago.

Question 6

What are the 2 major features of how eukaryotes could have formed?

Answer 6

Complex membranes could have evolved from infolding.

-Specialized double membrane organelles (Mitochondria, Chloroplast) probably have exogenous origin.