4/25 reivew; genetic mutations
Upcoming SlideShare
Loading in...5
×
 

4/25 reivew; genetic mutations

on

  • 809 views

 

Statistics

Views

Total Views
809
Views on SlideShare
809
Embed Views
0

Actions

Likes
0
Downloads
18
Comments
0

0 Embeds 0

No embeds

Accessibility

Categories

Upload Details

Uploaded via as Microsoft PowerPoint

Usage Rights

© All Rights Reserved

Report content

Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
  • Full Name Full Name Comment goes here.
    Are you sure you want to
    Your message goes here
    Processing…
Post Comment
Edit your comment

4/25 reivew; genetic mutations 4/25 reivew; genetic mutations Presentation Transcript

  • Remember the central dogma…
    Cytoplasm
    Ribosome
    Nucleus
    Translation
  • Central Dogma
    Genetic information travels from
    DNA  RNA  Protein (made of amino acids)
    The sequences of amino acids in proteins is determined by base pairs in the DNA
  • Review
    What happens to the two DNA strands before replicating?
    They separate
    How is DNA replication different in prokaryotes vs. eukaryotes?
    Prokaryotes no nucleus, one starting point; eukaryotes occurs in nucleus, may different starting points
    What two processes would replication occur before?
    Mitosis or Meiosis
  • Review
    What process involves swapping of DNA between homologous chromosomes?
    Crossing Over
    During what cell process does this occur?
    Meiosis
    What controls the sequence of amino acids in protein?
    DNA sequences containing genes
    What carries messages from DNA to ribosomes?
    RNA
  • AIM: How do changes in DNA affect genes?
  • What are mutations?
    Cells make mistakes in copying their DNA
    The wrong base can be inserted: T-C? It can happen in mutations
    A base can be skipped or not put in
    The mistakes in the DNA bases are called MUTATIONS
  • Types of mutations
    Point mutations – occur at one point in a DNA sequence
    Examples:
    Substitutions
    One base in the DNA sequence is changed to a different base
    A-T-T-A-G-C-G-A-T… A-T-C-A-G-C-G-A-T…
    T-A-A-T-C-G-C-T-A… T-A-A-T-C-G-C-T-A…
  • Types of mutations
    Point mutations – occur at one point in a DNA sequence
    Examples:
    2. Insertions/Deletions
    One base is added or subtracted
    Alter amino acid sequence in protein – FRAMESHIFT MUTATION
    THESE CHANGE EVERY AMINO ACID AFTER THE MUTATION
    A-T-
    T-A- A -T-C-G-C-T-A …
    T
    -A-G-C-G-A-T…
    A-T-A-G-C-G-A-T-…
    T-A-A-T-C-G-C-T-A…
    INSERTIONS/DELETIONS can cause a protein to become dysfunctional because all the amino acids will be out of order…
  • Regents Review
    A change in the base sequence of DNA is known as
    a gene mutation
    a karyotype
    nondisjunction
    polyploidy
  • Regents Review
    A random change in the base sequence of DNA resulting in the production of a defective protein is called
    translocation
    addition
    deletion
    gene mutation
  • What causes mutations?
    Errors in replication
    Enzymes insert wrong bases about once every 10 million bases
    The environment - MUTAGENS
    Chemicals like pesticides, tobacco smoke
    RADIATION! X-ray, UV light (sunlight)
    Can be called MUTAGENIC AGENTS
    Radioactive Substances are very dangerous!!!!
  • Regents Review
    Although genetic mutations may occur spontaneously in organisms, the incidence of such mutations may be increased by
    radioactive substances in the environment
    lack of vitamins in the diet
    a long exposure to humid climates
    a short exposure to freezing temperatures
  • The effects of mutations
    They can have no effect
    Imagine an A gets deleted and another A gets inserted
    They can produce negative changes
    Maybe a mutations turns on cell division  CANCER
    They can produce beneficial changes (yes, really)
    A plant can become resistant to certain bacteria
    POLYPLOIDY – an organism has an extra set of chromosomes
    Typically, this make plants larger and stronger!
  • Regents Review
    Because x-rays and ultraviolet light can change the chemical nature of DNA, they are known as
    mutagenic agents
    growth regulators
    hydrolytic enzymes
    toxic wastes
  • Regents Review
    Strontium-90, a radioactive isotope found in nuclear fallout, is incorporated and used by the human body in much the same manner as calcium. Because of its radioactive nature, strontium-90 would probably
    cause disjunction of chromosomes
    take the place of phosphorus in chromosomes
    act as a mutagenic agent within bone cells
    inhibit the development of mutations
  • Regents Review
    Mutagenic agents are substances that
    increase the rate of gene mutations
    decrease the rate of gene mutations
    have no effect upon the rate of gene mutation
    cause gene mutations but not other chromosomal changes
  • Citations
    All pictures taken from Google Pictures