Key Area 1: Organisation Of DNA

Question 1

Define the term prokaryote

Answer 1

Prokaryotic cells are cells that do not contain a nucleus (bacteria)

Question 2

Define the term eukaryote

Answer 2

Eukaryotic cells are cells that do contain a nucleus (plant, animal, fungal)

Question 3

What are the two forms a double stranded DNA molecule can take?

Answer 3

Linear

Circular

Question 4

What form does DNA in prokaryotes take?

Answer 4

Circular

Question 5

What form does DNA in eukaryotes take?

Answer 5

Linear

Question 6

Describe the structure in prokaryotes

Answer 6

The structure is circular as a continuous loop which is not contained within a nucleus. There are also smaller circular sections of DNA called plasmids that are desperately from the main circular chromosome in the cell.

Question 7

Describe the structure of DNA in eukaryotes

Answer 7

The structure is linear and arranged in almost straight lines. Linear DNA is condensed into chromosomes as it is several thousand times longer than the cell it is in. Long strands of DNA are bound around special proteins.

Question 8

What eukaryotic cell may contain circular plasmids?

Answer 8

Yeast cells

Question 9

Which two organelles found in eukaryotes contain circular DNA?

Answer 9

Chloroplast and mitochondria