Spring Semester in 90 Minutes or maybe a little more…

1. Spring Semester in 90 Minutesor maybe a little more…

2. Part I mutations

3. mutation basics… • Definition: a change in the genetic material of a cell • Note: not all mutations are bad • Can occur in 2 types of cells: • Germ Mutations: occur in germ-line (sex) cells • Somatic mutations: occur in somatic cells • Some are inherited and some are developed during embryonic development.

4. Question 1 What is the difference between and gene mutation and a chromosomal mutation?

5. 2 types of gene mutations: • Gene mutations: • involve individual genes within a chromosome • Point Mutation: the swapping of one base pair • Frameshift Mutation: the insertion or deletion of a base pair

6. Types of Chromosomal Mutations • Chromosomal mutations: • involve segments of chromosomes, whole chromosomes, and even entire sets of chromosomes • Types: • Deletion • Duplication • Inversion • Translocation • Nondisjunction

7. Part IIBiotechnology

8. Uses of Biotechnology • Analyzing human DNA • Finding and Identifying Genetic diseases • DNA fingerprinting • Forensics • The Human Genome Project • Identifying all genes in the human genome • Gene therapy • Curing disease • Create Transgenic animals

9. Genetic Engineering • Definition: introducing a set of genetic information directly into an organisms DNA • How is this done? • With use of restriction enzymes

10. Question 2 What is a restriction enzyme and what are the two types of cuts?

11. Restriction Enzymes • Proteins originally made to protect against viruses • RE’s chop DNA at specific sequences called recognition sites • Cuts can create sticky or blunt ends

12. Plasmids • Circular double-stranded DNA (bacterial) • Used in biotechnology because they are circular, small, and replicate on their own • Useful for creating recombinant DNA

13. Question 3 What is recombinant DNA?

14. DNA fragments + DNA from a living cell = Recombinant DNA Steps: using insulin (for sufferers of diabetes) as an example a) Cut open plasmid and DNA with gene encoding for insulin with same RE b) Mix cut plasmid with cut DNA (they have the same sticky ends) c) Seal with ligase d) Insert recombinant DNA into bacteria e) Recombinant DNA replicates and bacteria divides f) DNA is transcribed and translated = insulin Creating Recombinant DNA

15. Part IIIRegulating Gene Expression

16. What is gene regulation and why do we do it? Question 4

17. What is it? • Activating the expression of a particular piece of DNA only when needed • Why do we need it? • DNA is expensive and delicate • Transcription and translation take lots of energy… • be efficient! Only create proteins when needed! • How do we do it? • Transcribing only portions of the DNA that are needed • mRNA is created • Then mRNA is modified Regulating Gene Expressionin Eukaryotes…

18. G-cap: • a backwards guanine on the front of the mRNA • Poly-A tail: • a chain of adenine nitrogen bases on the end of the mRNA • Intron splicing: • remove portions of DNA that do not code for proteins: introns (remember  introns are IN the way) • Exons are joined together exon intron exon intron exon exon exon exon mRNA Modification G AAAAAAA exon exon exon

19. Why do we modify mRNA? • It’s all for the regulation of gene expression… • Takes out unnecessary nucleotides • G-cap helps ribosome recognize mRNA • Poly-A tail: promotes export from the nucleus and translation, and protects the mRNA mRNA Modification terms…

20. operator gene regulator gene promoter RNA Pol. If the repressor is in place: gene wont be expressed because the RNA polymerase cannot binder to the operator Prokaryotes: How it works….If the gene IS NOT being expressed Repressor

21. RNA Pol. operator gene regulator gene promoter How it works….If the gene IS being expressed Repressor Lac Inducer Enzymes that break down lactose

22. Operator: regions on a chromosome which regulate transcription of gene clusters by providing a site for a repressor to bind to, thereby turning off the operon • Promoter: region on a chromosome next to the operator to which RNA polymerase binds at the beginning of transcription • Repressor: a special protein that binds to the operator, preventing polymerase from attaching. This turns the operon off • Inducer: chemical substance that causes the production of proteins Operon terms…

23. Part IVpGLO

24. Question 5 What is transformation?

25. GFP Bacterial chromosomal DNA Amp Resistance pGLO plasmids What is transformation? Uptake of foreign DNA, often a circular DNA called a plasmid

26. Question 6 What are the three special genes in the pGLOplasmid?

27. What did we do in our lab? • We are going to “transform” bacteria by making them take up a commercially prepared plasmid that contains three genes of interest, amp, araC and GFP. • Genetically modified organisms are “transgenic”

28. Genes of interest: amp, araC, GFP • amp – this gene will give our transgenic bacteria resistance to the antibiotic ampicillin • araC – this gene will produce a protein in the presence of arabinose that will allow the bacteria to turn on the GFP gene • GFP – in the presence of arabinose, this gene will “turn on” and cause the transformed (transgenic) bacteria to glow green

29. Explanation of agar plates • E. coli starter plate • This plate has the bacteria we will use growing in a luria broth (LB) agar plate. • These bacteria are normal (have NOT been transformed)

30. Question 7 For each Petri dish list: what the dish contains, the expected results, and an explanation

31. Explanation of agar plates • LB/-DNA • This is the control plate. These –DNA bacteria are not transformed and are in normal (LB) agar. • You should expect to see normal bacterial growth in this plate.

32. Explanation of agar plates • LB/amp/-DNA • These –DNA bacteria have not received the plasmid. • They have not been transformed, so they do not have resistance to the ampicillin that is in the agar. • No resistance, not growth in the presence of ampacillin

33. Explanation of agar plates • LB/amp/+DNA • This plate will have E. coli bacteria on LB agar to which ampicillin has been added. • The +DNA means that the bacteria may have been transformed (if your technique is good). • If they have been transformed, they will now have a plasmid with an ampicillin resistant site so they will not be killed by the ampicillin that has been added to the agar. • There will be bacteria growing in this plate, but they will not glow green.

34. Explanation of agar plates • LB/amp/ara/+DNA • This plate will have transformed bacteria (+DNA) growing on agar that has both ampicillin and arabinose added to it. • If your technique is good, you should expect to see green glowing bacteria in this plate.

35. Part V cladograms

36. Linnaean System: Old • Classifies organisms following: • kingdom, phylum, class, order, family, genus, and species • created before scientists understood that organisms evolved. • biologists are switching to a classification system that reflects the organisms' evolutionary history. • Still use the genus species to name organisms

37. Question 8 What system do we use now to classify organisms and why?

38. Cladistics: New System Based on evolution reconstruct evolutionary relationships a phylogeny. A Tree/Phylogeny is a hypothesis of relationships among organisms

39. Question 10 What is a clade?

40. Phylogeny • Organisms are grouped in clades • Clade: A group of organisms that includes all the descendants of a common ancestor and that ancestor. • built by collecting data about the characters • Characters shared by only one clade are called shared derived characters

41. Reading Cladograms Read like a family tree: show patterns of shared ancestry between lineages. • When an ancestral lineage splits: speciation is indicated due to the “arrival” of some new trait. Each lineage has unique traits to itself alone and traits that are shared with other lineages. each lineage has ancestors that are unique to that lineage and ancestors that are shared with other lineages — common ancestors.

42. Key to a good tree • We use homologouscharacters • characters in different organisms that are similar because they were inherited from a common ancestor that also had that character. • Bird and bat wings are analogous • Traits that have separate evolutionary origins, but are superficially similar • Evolved to serve the same function

43. Animal Body Plan Part VI

44. Ancestral characters can be preserved in an organism’s development. • Example: chick and human embryos • have a stage with slits anarches in their neck that are identical to the gill slits and gill arches of fish. • This observation supports the idea that chicks and humans share a common ancestor with fish. Learning about phylogeny from ontogeny

45. Sperm Entry Point Unfertilized Egg A. Polarity is the presence of distinct and opposite poles/sides B. Determined by the site of sperm entry C. Polarization: The development of symmetry Anterior Ventral Anterior Ventral Dorsal Posterior Dorsal Posterior

46. What are the three types of symmetry? Question 11

47. 1. Asymmetrical- not symmetrical • e.g. Porifera • 2. Radial- like a wheel • e.g. Star Fish • 3. Bilateral- (two sides, mirror images) • e.g. people, slugs • Cephalization Three types of symmetry

48. 1. Ectoderm- skin, nervous system • 2. Endoderm- digestive tissue • 3. Mesoderm (only present in bilateral)- muscles, reproductive system, circulatory vessels Embryo tissue layers

49. What is the difference between protostomes and deuterostomes? Question 12

50. A. Protostomia • 1. “mouth first” the blastoporebecomes mouth • 2. Cell’s fate is determined • Most invertebrates • B. Deuterostomia • 1. “mouth second” the blastopore becomes anus • 2. Cell’s fate not determined • Some invertebrates, most vertebrates Two types of Bilateral Animals: