AQA GCSE Structure of DNA(Biology)
Structure of DNA
DNA is a polymer, it is made up of two polynucleotide strands that form a double helix.
As each strand is a polynucleotide, this means it is made up of many nucleotides joined together.
A nucleotide is made up of a phosphate group, deoxyribose sugar and one of 4 bases (A,C,T or G).
Below is a single nucleotide:
The diagram below shows how the nucleotides are joined together along with the overall structure of DNA
DNA has two long strands
The strands have a sugar-phosphate backbone
Bases stick out from the sugar phosphate backbone.
Practice Questions
1.Explain what is meant by DNA being a polymer.
2.Describe the structure of a nucleotide.
3.Why is DNA described as a “repeating structure”?
Factors affecting the rate of photosynthesis
Measuring & calculating rates of photosynthesis
Inverse square law and photosynthesis
Economics of enhancing the conditions in greenhouses
Investigating the effect of light intensity on the rate of photosynthesis
Data analysis and nervous system
The effect of a factor on human reaction time
Controlling blood glucose concentration
Regulating water and nitrogen levels in the body.
Hormones and human reproduction
Using hormones to treat infertility
Control and coordination in plants using hormones
Investigating the effect of light or gravity on the growth of newly germinated seedlings