2. BRAINSTORM In your group, brainstorm all your ideas about DNA. Include What is DNA? Where is DNA found? What is its function? Start Timer 3 1.5 0

3. National 5 Cell Biology Structure and Function of DNA

4. We are learning to: Describe the relationship between DNA, genes and chromosomes State where DNA is found within a cell State that chromosomes are made of DNA State the function of DNA Describe the structure of DNA Explain what is meant by complementary base pairing in DNA

5. What I'm looking for: Diagram relating DNA, chromosomes and genes Description of the function of DNA Labelled diagram of DNA Completed examples of complementary base pairing

6. Inside the nucleus

9. What is DNA? Watch the video Read information on page 21 pupil booklet Label and colour diagram of DNA to show – Two strands of DNA – Names of bases

10. Chromosomes and their genes are made of a molecule called DNA. DNA molecules carry the code that controls what cells are made of and what they do. DNA stands for deoxyribonucleic acid. Each chromosome is a very long molecule of tightly coiled DNA. What is DNA? The DNA molecule looks like a twisted ladder this spiral shape is called a DOUBLE HELIX

11. Strand Thymine Adenine Guanine Cytosine Chromosome

12. The double helix ‘ladder’ of a DNA molecule is held together by ‘rungs’ made from pairs of chemicals called bases. DNA Bases There are four types of bases, and they are usually identified by their initials. A T C G

13. Base pairs hold the two strands of the DNA helix together. It is the sequence of these bases along a DNA molecule that forms the genetic code – it’s that simple! DNA Bases AT CG CG AT

14. DNA bases Chromosomes

17. I can: Describe the relationship between DNA, genes and chromosomes State where DNA is found within a cell State that chromosomes are made of DNA State the function of DNA Describe the structure of DNA Explain what is meant by complementary base pairing in DNA