Cells: Structure & Replication of Prokaryotic Cells

Question 1

Differences Between Eukaryotic & Prokaryotic Cells

Answer 1

• Prokaryotic cells are smaller and simpler than eukaryotic cells
• Prokaryotic cells do not contain membrane-bound organelles in the cytoplasm
• Smaller ribosomes
• No nucleus; instead they have a single circular DNA molecule that is free in the cytoplasm and is not associated with histone proteins
• A cell wall that contains murein, a glycoprotein

Question 2

What are plasmids?

Answer 2

• Plasmids are small loops of DNA that aren’t part of the main circular DNA molecule
• Plasmids contain genes for antibiotic resistance
• Not always present in prokaryotes

Question 3

What is a slime capsule?

Answer 3

• Not found in all prokaryotic cells (found in bacteria)

- Helps to protect the prokaryotes from attack by cells of the immune system

Question 4

What is a flagella?

Answer 4

• Long hair-like structure that rotates to move the prokaryotic cell

Question 5

What is a cell wall?

Answer 5

• The cell wall supports the cell and prevents it from changing shape
• In prokaryotes, the cell wall is made of murein

Question 6

How do prokaryotic cells replicate?

Answer 6

• Prokaryotic cells replicate by a process called binary fission
• The cell replicates its circular DNA and plasmids
• Cytokinesis - the cytoplasm divides to produce two daughter cells - Each with a single copy of the circular DNA and a variable number of copies of plasmids