Download mutations

Unit 3 genetics – Unit 12 Molecular Genetics: (12.4) Gene Regulation & Mutation-class key
Name: ________Class key_________
Period: ________________________
Website upload 2015
The Living Environment ’14-‘15
Mr. Murdoch
Unit 3 genetics – Unit 12 Molecular Genetics: (12.4) Gene Regulation & Mutation-class key
The Living Environment ’14-‘15
Mr. Murdoch
Topic 12.4 assignments
Pages/Sections
Website upload 2015
Date Assigned
Date Due
Unit 3 genetics – Unit 12 Molecular Genetics: (12.4) Gene Regulation & Mutation-class key
Topic:
The Living Environment ’14-‘15
Mr. Murdoch
Mutations
Objective: What is a genetic mutation?
 Any _change_ in DNA _sequence_ is called a _mutation_.
 Can be _caused_ by errors in _replication_, _transcription_,
cell _division_, or by _external_ agents.
 If _mutation_ occurs in _gametes_ (sex cells) it will be
__passed_ on to _offspring_.
 May _produce_ a new __trait_ or it may result in a _protein
that does _not_ work _correctly_.
 If the mutation results in a _protein_ that is _nonfunctional_,
the _embryo _ may _not _survive.
 In some __rare_ cases a gene _mutation_ may have
_positive_ effects.
Website upload 2015
Unit 3 genetics – Unit 12 Molecular Genetics: (12.4) Gene Regulation & Mutation-class key
Topic:
The Living Environment ’14-‘15
Mr. Murdoch
Mutations
Objective: What are mutations in a somatic cell?
 If _mutation_ takes place in a _somatic_ (body) cell, it is
__not_ passed on _to _an organism’s _offspring_.
 _Damage_ to a gene may_ impair_ the function of the cell.
 When that cell _divides_, the new cells also will __have the
same _mutation_.
 Some _mutations of DNA in body cells affect_ genes that
control cell _division__.
 This can _result in the cells _growing_ and _dividing_ rapidly,
producing _cancer.
Website upload 2015
Unit 3 genetics – Unit 12 Molecular Genetics: (12.4) Gene Regulation & Mutation-class key
Topic:
The Living Environment ’14-‘15
Mr. Murdoch
Mutations
Objective: What actually changes to cause mutations?
 __Changes to _DNA_ are called _mutations
o change the _DNA_
o changes the _mRNA_
o may change __protein_
o may change _trait_
Website upload 2015
Unit 3 genetics – Unit 12 Molecular Genetics: (12.4) Gene Regulation & Mutation-class key
Topic:
The Living Environment ’14-‘15
Mr. Murdoch
Point Mutations
Objective: Describe what happens in a point mutation.
 Changes to the letters (A,C,T,G _bases_ ) in the DNA
o _Point_ mutation
 _change_ to __ONE_ letter (_base_ ) in the DNA
 _may_ cause _change to protein, may not
o __One_ base _change_
 can _change_ the meaning of the whole _protein_
Website upload 2015
Unit 3 genetics – Unit 12 Molecular Genetics: (12.4) Gene Regulation & Mutation-class key
Topic:
Missense Mutations
Objective: Describe a point missense mutation.
 Missense mutation = changes amino_ _acid_
Website upload 2015
The Living Environment ’14-‘15
Mr. Murdoch
Unit 3 genetics – Unit 12 Molecular Genetics: (12.4) Gene Regulation & Mutation-class key
Topic:
The Living Environment ’14-‘15
Mr. Murdoch
Sickle Cell Anemia
Objective: Describe a specific point missense mutation.
 Sickle cell anemia__
 __Hemoglobin protein in red blood cells
o strikes 1 out of 400 African Americans
o limits activity, painful & may die young
Website upload 2015
Unit 3 genetics – Unit 12 Molecular Genetics: (12.4) Gene Regulation & Mutation-class key
Topic:
Silent Mutations
Objective: Describe a point silent mutation.
 Silent mutation = _no_ _change_ to protein
Website upload 2015
The Living Environment ’14-‘15
Mr. Murdoch
Unit 3 genetics – Unit 12 Molecular Genetics: (12.4) Gene Regulation & Mutation-class key
Topic:
The Living Environment ’14-‘15
Mr. Murdoch
Nonsense Mutations
Objective: Describe a point nonsense mutation.
 _nonsence_ mutation = __change__ to __STOP__
Website upload 2015
Unit 3 genetics – Unit 12 Molecular Genetics: (12.4) Gene Regulation & Mutation-class key
The Living Environment ’14-‘15
Mr. Murdoch
Frameshift Mutations
Topic:
Objective: Describe an addition or deletion mutation.
 Frameshift mutation
o _addition_ of a ___new___ letter (base) in the DNA
sequence
o __deletion__ of a letter (base) in the DNA sequence
o _both_ of these __shift__ the ___DNA___ so it changes
how the codons are read
o big __changes__ to __protein__ !
o ___add___ or __delete__ one or more __bases__
o __changes__ the meaning of the whole __protein__
Website upload 2015
Unit 3 genetics – Unit 12 Molecular Genetics: (12.4) Gene Regulation & Mutation-class key
Topic:
The Living Environment ’14-‘15
Mr. Murdoch
Frameshift Additions
Objective: Describe a frameshift addition mutation.
 Addition = ___add___ one or more __bases__
Website upload 2015
Unit 3 genetics – Unit 12 Molecular Genetics: (12.4) Gene Regulation & Mutation-class key
Topic:
The Living Environment ’14-‘15
Mr. Murdoch
Frameshift Deletions
Objective: Describe a frameshift deletion mutation.
 Deletion = ___lose___ one or more __bases__
Website upload 2015
Unit 3 genetics – Unit 12 Molecular Genetics: (12.4) Gene Regulation & Mutation-class key
The Living Environment ’14-‘15
Mr. Murdoch
Causes of Mutations
Topic:
Objective: What are some causes of mutations?
 Causes of Mutations
o Sometimes a __mistake__ in base __pairing__ during
DNA _replication_.
o Many _mutations_ are caused by __factors__ in the
_environment_.
o Any __agent__ that can cause a __change__ in DNA is
called a _mutagen_.
o _mutagens_ include _radiation_, _chemicals_, and even
high _temperatures_.
Website upload 2015
Unit 3 genetics – Unit 12 Molecular Genetics: (12.4) Gene Regulation & Mutation-class key
Name: ________________
The Living Environment ’14-‘15
Mr. Murdoch
Period: ____________________
Carefully remove this sheet from your packet to hand in.
Work silently and alone to complete this graded exercise.
Check for Understanding
1. Describe the basic idea of a mutation.
2. Explain how mutations in skin cells due to overexposure to
the Sun will be hazardous to offspring.
3. Give an example of a point mutation.
4. Give an example of a frameshift mutation.
Website upload 2015
Unit 3 genetics – Unit 12 Molecular Genetics: (12.4) Gene Regulation & Mutation-class key
Page intentionally blank
Website upload 2015
The Living Environment ’14-‘15
Mr. Murdoch
Unit 3 genetics – Unit 12 Molecular Genetics: (12.4) Gene Regulation & Mutation-class key
Notes page:
Website upload 2015
The Living Environment ’14-‘15
Mr. Murdoch