DNA – structure and function What is DNA made of and what is its role? Starter: Match the dates to the events.

1804 1865 1885 1953 Cellular nucleus described in detail. Gregor Mendel published his work on inheritance. 1865 1885 Watson and Crick work out the spiral structure of DNA. 1953 Chromosomes were seen through a microscope and drawn.

1804 1865 1885 1953 Cellular nucleus described in detail. Gregor Mendel published his work on inheritance. 1865 1885 Watson and Crick work out the spiral structure of DNA. 1953 Chromosomes were seen through a microscope and drawn.

Learning Outcomes 1) Describe the base pairing arrangement in DNA 2) Name the main location for protein synthesis in a cell 3) Explain why a copy of a gene needs to carry the genetic code to the cytoplasm

Think – Pair – Share What can you conclude about the base pairings from the following? DNA exists as a double helix – 2 strands twisted together. There are 4 bases, Adenosine (A), Guanine (G), Thymine (T) and Cytosine (C) There is the same amount of A as there is T. There is the same amount of G as there is C.

The rungs of the ladder are the pairs of bases held together by weak chemical bonds.

There are ten pairs of bases for each twist in the helix.

Check Point Which of the following is true? 1) A pairs with C 2) T pairs with A 3) T pairs with G 4) C pairs with T

Task Each gene on a strand of DNA ( chromosome) codes for 1 characteristic. This combination of genes is unique to you. For a gene to be useful, the bases have to be exposed. Make your own “designer” cartoon character by selecting features you want from the “gene pool”. Extension: complete the complementary strand.

Mitosis – How DOES that DNA replicate?

The two strands separate. Free bases form a second strand.

The structure of DNA (simplified).

Complete the worksheet to replicate your own DNA

Plenary Look at the plenary mat