WALT: To understand the role and structure of DNA.
~ State what part of the cell where DNA is found.
~ Name the four bases that make up the DNA molecule.
~ Describe how the DNA molecule is structured by
complementary base pairing and weak hydrogen bonds.
~ Explain the importance of DNA and how each gene codes
for a particular protein. (B)
~ Evaluate the ethical issues relative to DNA. (A/A*)
What is DNA?
Genes contain instructions for
specific proteins that are used in your
One gene contains the instructions
for one protein.
e.g. eye colour, blood group, shape of
The structure of DNA
Complementary base pairing:
Adenine with thymine
Cytosine with guanine
These bases are held together by weak hydrogen bonds.
Making a DNA model
• Choose four different colours (one for each base)
• Colour in your bases.
• Now cut out all your base pairs. Then fold along the
dotted lines so they are ready to stick.
• Cut out spines A and B. Stick your base pairs to one of
the DNA spines so that one strand of your DNA
molecule has bases in this order:
AT GT C AT G G CT A G C
• You might need to use paperclips to hold them on and
help them stick.
• Let the glue dry completely before you stick the base
pairs to the other DNA strand.
What’s the question?
Choose two of
and write a