5) Draw and label a simple diagram to show how DNA is constructed from sugars, phosphates and bases [6]

The two strands of DNA are antiparallel, meaning that they are oriented in different directions. One proceeds in the 3’ to 5’ direction while the other is oriented in the 5’ to 3’ direction. One can identify the 5' end of DNA as that is where the exposed phosphate is.

The weak hydrogen bonds between the complementary nitrogen base pairs hold both strands together.