The following links offer some useful revision on Cell Structure to support your learning:
Structure and Replication of DNA Quiz
Structure of DNA Wordwall Game
The Higher Biology Podcast: DNA, PCR & the Loch Ness Monster
At Higher, you will need to know the following:
- Structure of DNA — nucleotides contain deoxyribose sugar, phosphate and base.
- DNA has a sugar–phosphate backbone, complementary base pairing — adenine with thymine and guanine with cytosine.
- The two DNA strands are held together by hydrogen bonds and have an antiparallel structure, with deoxyribose and phosphate at 3′ and 5′ ends of each strand.
- All cells store their genetic information in the base sequence of DNA.
- The genotype is determined by the sequence of DNA bases. DNA is the molecule of inheritance and can direct its own replication.
- Chromosomes consist of tightly coiled DNA and are packaged with associated proteins.
- Prior to cell division, DNA is replicated by a DNA polymerase. This process occurs at several locations on a DNA molecule.
- Replication of DNA by DNA polymerase and primer. DNA is unwound and unzipped to form two template strands. DNA polymerase needs a primer to start replication and can only add complementary DNA nucleotides to the deoxyribose (3′) end of a DNA strand. This results in one strand being replicated continuously and the other strand replicated in fragments which are joined together by ligase.
