1. February 16, Week # 6 NB-93 Learning Target: I will Homework: Agenda:
Define mutation.
Define mutagen.
Explain 3 different types of mutations.
Homework:
Read p
Answer questions 1-7 on p. 200
Agenda:
Homework (NB-92 & 89)
DNA mutations
Organize notebooks
Essential Question:
If both the father and mother are Tt, what are the chances of producing tt offspring?

2. Learning Target: I will
Complete a Punnett Square to predict
genotypes and phenotypes of offspring.
A genotype is
the DNA coding for a trait (EE)
A phenotype is
the trait we observe (free earlobes)
A percentage is
an amount compared to 100.
A ratio is a
relation between 2 numbers

3. Mutations
A change in DNA

4. Chromosomes and DNA

5. IIA. Mutations – Changes in DNA
Changes in DNA can cause changes in the amino acid sequence of proteins, which can have effects on the shape and function of proteins.
Transcription
Translation
Normal Functional Protein Shape
Normal DNA
Transcription
Translation
Different Shape Different Function No Function
Mutated DNA

7. Ex: Sickle Cell Anemia Sickle Cell RBC Normal RBC
Caused by single amino acid change in hemoglobin
Q: Is this a gene or a chromosomal mutation?
A: Gene mutation.
Sickle Cell
RBC
Normal RBC

8. Ex: Down Syndrome Caused by a 3rd copy of chromosome 21
Q: Is this a gene or a chromosomal mutation?
A: Chromosomal mutation.

9. Ex: Cancer
Cancer occurs when mutations cause cells to grow in an uncontrolled way

10. Famous Mutants

11. IIB. Causes of Mutations (mutagens)
1. Environment
sunlight
smoke
Chemicals
Radiation
2. Mistakes during replication.
AAT TGG ATC CTT ACC TAT ATT GGG GGG GCC CAA TAG
AAT TGG ATC CGT ACC TAT ATT GGG GGG GCC CAA TAG

12. Types of Mutations 1. What is the difference between a gene
mutation and a chromosomal mutation? A:
Gene Mutation
Chromosomal Mutation
--Changes in single gene/base
--3 types
--Changes in whole chromosomes
--5 types

13. 3 types of gene mutations
Deletion
Substitution
Insertion

14. IID. Types of Mutations – Substitutions
Replacement of 1 nucleotide and its partner with another pair of nucleotides.
Effects of base pair substitutions
no change
insignificant change
alteration in structure and thus function of protein

15. IID. Types of Mutations – Substitutions
Analogy of a Base Pair Substitution Mutation
1) A Point Mutation:
Normal Sample Gene:
The fat cat ate the wee rat.
Gene with a Point Mutation:
The fat bat ate the wee rat.
The meaning of the sentence has changed with a 1 letter difference.

16. Lets apply that knowledge to DNA & Proteins
Green Fluorescent Protein (GFP) is produced by a number of organisms, such as the jellyfish.
There are three amino acids which are critical for GFP’s green fluorescent color.
Only a 1 amino acid difference changes green to blue, and blue to cyan.
Why does this happen?
Aequoria victoria

17. Production of wild type Green Fluorescent Protein
Part of a normal GFP Gene
Transcription mRNA produced
Translation at ribosomes
Green Fluorescent Protein

18. A Base Pair Substitution Mutation Occurs…

19. A Base Pair Substitution Mutation Occurs…

20. A Base Pair Substitution Mutation Occurs…

21. A Base Pair Substitution Mutation Occurs…

22. A Base Pair Substitution Mutation Occurs…

23. A Base Pair Substitution Mutation Occurs…

24. A Base Pair Substitution Mutation Occurs…

25. A Base Pair Substitution Mutation Occurs…

26. A Base Pair Substitution Mutation Occurs…

27. Production of Blue Fluorescent Protein
Part of a mutated Gene
Base Pair Substitution Mutation
Transcription mRNA produced
Translation at ribosomes
Blue Fluorescent Protein

28. IIC. Analogy of a Frameshift Mutation
Normal Sample Gene:
The fat cat ate the wee rat.
Gene with a Deletion Frameshift Mutation- 1 letter deleted.
The fat caa tet hew eer at
Regardless of the changes in the DNA, the mRNA is always read in 3 letter increments in the ribosomes.
The meaning of the sentence has changed dramatically with a 1 letter difference.

29. A Deletion Mutation Occurs…

30. A Deletion Mutation Occurs…

31. A Deletion Mutation Occurs…

32. A Deletion Mutation Occurs…

33. A Deletion Mutation Occurs…

34. A Deletion Mutation Occurs…

35. A Deletion Mutation Occurs…

36. A Deletion Mutation Occurs…

37. A Deletion Mutation = Non functional protein
Site of Deletion
Transcription mRNA produced
Translation at ribosomes
Nonfunctional Protein no fluorescence

38. IIC. Analogy of a Frameshift Mutation
Normal Sample Gene:
The fat cat ate the wee rat.
Gene with an Addition Frameshift Mutation- 1 letter added.
The fat caa tat eth ewe era t
Regardless of the changes in the DNA, the mRNA is always read in 3 letter increments in the ribosomes.
The meaning of the sentence has changed dramatically with a 1 letter difference.

39. What type of mutation? Gene or chromosome?
Insertion, deletion, or substitution?

40. What type of mutation? Gene or chromosome?
Insertion, deletion, or substitution?

41. What type of mutation? Gene or chromosome?
Insertion, deletion, or substitution?

42. Not all mutations are harmful!

47. IV. Why are Mutations Important?
Mutations provide the raw material for natural selection.
Changes in the bases of DNA may cause a change in a protein which gives an organism an advantage:
Bigger teeth, faster runner, better vision, different fluorescent colors etc.
Organisms with advantages may leave more offspring…
Directed Evolution
Now possible to produce optimal mutations.
Let’s return to Fluorescent Proteins…..

48. Learning Target: I will
Complete a Punnett Square to predict
genotypes and phenotypes of offspring.
A genotype is
the DNA coding for a trait (EE)
A phenotype is
the trait we observe (free earlobes)
A percentage is
an amount compared to 100.
A ratio is a
relation between 2 numbers

49. Organize Notebooks 10 minutes

50. Learning Target: I will
Complete a Punnett Square to predict
genotypes and phenotypes of offspring.
A genotype is
the DNA coding for a trait (EE)
A phenotype is
the trait we observe (free earlobes)
A percentage is
an amount compared to 100.
A ratio is a
relation between 2 numbers

51. Fill out the weekly planner. Don’t forget the homework on NB-92!
Essential Question:
What is the difference between genotype and phenotype?