Overview DNA stands for d Deoxyribose Nucleic Acid Thinking Points What is the structure of DNA? Why is DNA so important?

DNA Stands for Deoxyribose Nucleic Acid It’s a coiled double helix (like a twisted ladder)

Chromosomes Long strands of genetic info (DNA) found in nucleus Chromosomes come as identical homologous pairs. (Except sex chromosomes) 23 pairs in the human body (46 all together)

Genes Are sections of DNA (shown on the chromosome)… Genes code for a specific characteristics (e.g. Eye colour). Genes are inherited from our parents. Genes come in different forms, these are known as alleles. MumDad

1.Draw a pair of chromosomes. 2.What are chromosomes made of? 3.A section of DNA is also known as…? 4.Define the term “allele”? 5.How do we inherit our characteristics? LEARNING CHECKPOINT !

The Genetic Code The long strand of DNA are made up of combinations of 4 bases. A change in one of these bases is enough to totally change the structure of the protein and disrupt how it works.

DNA spells out a genetic code (the instructions for genes.) There are four bases that spell out the sequence of the genetic code. They MUST be paired in a certain way ADENINE CYTOSINE THYMINE GUANINE

Sugar Hydrogen bonds Phosphate