The structure of DNA: including nucleotides
I can describe the structure of DNA and how DNA is copied during mitosis.
The structure of DNA: including nucleotides
I can describe the structure of DNA and how DNA is copied during mitosis.
Lesson details
Key learning points
- DNA is made of two strands, each a long polymer of nucleotides, wound together in a double helix shape.
- DNA is a polymer of four different nucleotides (A, C, G and T).
- Nucleotides in each strand of DNA pair up in a complementary way; A pairs with T, and C pairs with G.
- The DNA in chromosomes is unwound & copied during interphase, then the copies separate and the cell divides by mitosis.
- Complementary base pairing allows an exact copy of each ‘unzipped’ DNA strand to be made from free nucleotides.
Common misconception
Students may think that each strand of DNA is the same without recognising one strand is inverted.
The slides specifically mention the second strand is inverted and this is also reinforced using diagrams of inverted nucleotides wherever possible.
Keywords
DNA - A polymer with a double helix structure that carries the genetic information.
Mitosis - A type of cell division that produces genetically identical cells.
Nucleotides - Individual subunits that make up DNA.
Polymer - A long chain of repeating subunits.
Complementary base pairing - Bases form pairs with one other base: A pairs with T, and C pairs with G.
Licence
This content is © Oak National Academy Limited (2024), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).
Video
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Starter quiz
6 Questions
Contains DNA and controls cell activities.
Made from coiled DNA; humans have 23 pairs in their nuclei.
A polymer with a double helix structure; carries the genetic material.
Exit quiz
6 Questions
phosphate
base
sugar