Organisation of DNA

Question 1

Prokaryotes (Bacterium)

Answer 1

A prokaryotic cell, such as a bacterium. Does not have a membrane-bound nucleus. They have a single, circular chromosome and smaller circular plasmids.

Question 2

Eukaryotes (Plant and Animal)

Answer 2

Eukaryotes all have linear chromosomes, in the nucleus, which are tightly coiled and packaged with the associated proteins called histones. They also contain circular chromosomes in their mitochondria and chloroplast.

Question 3

Where are the small, circular chromosomes found?

Answer 3

Circular chromosomes are found in the chloroplast and mitochondria of the plant cell, and the mitochondria of an animal cell.

Question 4

Eukaryotes (Yeast)

Answer 4

Yeast cells are eukaryotic, and contain linear chromosomes. They also contain plasmids.

Question 5

State how the organisation of DNA in prokaryotes differ from eukaryotic cells.

Answer 5

In prokaryotes (such as bacterium) chromosomes are circular. In eukaryotes (such as animal, plant and yeast cells) chromosomes are linear.