Biology - Exam Revision

Question 1

What are the two main structural differences between prokaryotic and eukaryotic cells?

Answer 1

Eukaryotic Cells:

• Membrane-bound organelles
• DNA is linear

Prokaryotic Cells:

• No membrane-bound organelles
• DNA is circular

Question 2

What are the major structural differences between plant and animal cells?

Answer 2

Plant:

• Eukaryotic cells
• Cell wall & membrane
• Chloroplast

Animal:

• Eukaryotic cells
• No cell wall
• Centrioles (produces spindle fibres)

Question 3

Cytokinesis in plant & animal cells…

Answer 3

Plant:
- Grow a cell plate

Animal:
- Cleavage furrow develops

Question 4

What is binary fission?

Answer 4

• Prokaryotes use it
• No spindle fibres
• Single chromosome
• No nucleus division
• Used for reproduction
• No lining up
• Fast process (20 minutes)

Question 5

Define binary fission…

Answer 5

The division of a cell into two identical daughter cells without mitosis, used in prokaryotes.

Question 6

What is a mutagen?

Answer 6

An agent that causes mutations.

Eg. The suns UV rays, smoking, radiation, drugs, lead (heavy metals)

Question 7

What is a stem cell?

Answer 7

An undifferentiated cell that has the ability to produce different types of body cells.

Question 8

What are three types of stem cells used for research?

Answer 8

1. Umbilical Cord Cells
2. Adult Cells
3. Embryonic Cells (from the inner cell mass)

Question 9

Define epigenetics…

Answer 9

The chemical modifications altering the expression of DNA.
There is no change in the DNA, just the expression of it.
Eg. If you have the gene for fat storage but its not being expressed but you have an environmental pressure, your epigenetics can change and express the gene/s.