Unit 1- Key Area 1.1

Question 1

Describe the structure of DNA

Answer 1

Each DNA molecule is very long and has two strands coiled into the shape of a double helix. Each strand of the double helix is made up from deoxyribose sugar.

Question 2

How are nucleotides linked?

Answer 2

By their deoxyribose sugars and phosphates to form a strand with a sugar-phosphate backbone.

Question 3

Describe what antiparallel means.

Answer 3

When strands run in opposite directions depending on the bonding through the carbon atoms of the sugar-phosphate backbone

Question 4

Describe the organisation of prokaryote cells

Answer 4

In prokaryote cells such as bacteria there is no distinct nucleus and the DNA is organised into circular chromosomes and plasmids.

Question 5

Describe organisation in eukaryote cells.

Answer 5

In the nuclei of the eukaryote cells, the DNA id found tightly coiled into linear chromosomes and associated with proteins that help keep the DNA strands untangled. They also have small circular chromosomes within their mitochondria, and within their chloroplasts in the case of plant cells.