1. New York State Lab
Relationships and
Biodiversity
Pre-lab Review

2. Evolution
• Gradual change over time
• If two organisms share
similarities, they are likely
related – share a common
ancestor
• The more similarities, the
more closely related

3. Evidence of Evolutionary Relationships
• Structural evidence:
– Comparative anatomy
• Homologous structures
• Vestigial structures
– Comparative embryology

4. Evidence of Evolutionary Relationships
• Molecular evidence:
– Comparative Biochemistry
• Similar pigments (in plants)
• Similar enzyme-controlled chemical reactions
• Similarities in DNA structure
• Similar proteins

5. Structural Evidence in Plants
• External structure
• Seeds
• Internal structure:
– Conducting tissue – carries materials
– Xylem – carries water and nutrients
– Phloem – carries food

6. Molecular Evidence in Plants
• Pigments – absorb light
• Chromatography – lab technique to separate
pigments in plants

7. Molecular Evidence in Plants
• Enzymes – speed up chemical reactions
• Enzymes are specific

8. Molecular Evidence in Plants –
Enzymes

9. Molecular Evidence in Plants
• Gel electrophoresis – lab
technique to separate
fragments of DNA from
organisms

10. Molecular Evidence in Plants –
Gel Electrophoresis

11. Molecular Evidence in Plants
• Similarities in DNA code for amino acid
sequence in particular proteins

12. Molecular Evidence in Plants
Protein Synthesis

13. Molecular Evidence in Plants