12.4 Mutations
What are Mutations?
•
Changes in the _____________________________of DNA
(genetic material)
•
May occur in _________________________________ (aren’t passed to offspring)
•
May occur in __________________________________(eggs & sperm) and be
passed to offspring
Kinds of Mutations
Mutations that produce changes in___________________________________________
_________________________________________.
Mutations that produce changes in _______________________________are known as
___________________________________________________.
Gene Mutations
Gene mutations involving a change in one or a few nucleotides are known as
_____________________________because they occur at a single point in the DNA sequence.
Point mutations include_________________________________________________________.
Substitutions usually affect no more than a single amino
acid. _________________________________________
_____________________________________________.
An example of a disorder from substitution is:
The effects of insertions or deletions are more dramatic.
The addition or deletion of a nucleotide causes a shift in
the grouping of codons,
therefore______________________________________________________________.
Changes like these are called_____________________________________.
In an insertion, an
_____________________________________________________.
In a__________________, the loss of a
___________________________________and the reading
frame is shifted. Amino Acid Sequence Changed.
Chromosomal Mutations
Chromosomal mutations involve__________________
______________________________________, break or are
lost during mitosis or meiosis.
Chromosomal mutations include deletions, duplications,
inversions, and translocations.
Deletions involve the loss of all or part of a chromosome.
Duplications produce extra copies of parts of a chromosome (sequence repeated).
Inversions reverse the direction of parts of chromosomes.
Translocations occurs when part of one chromosome breaks off and attaches to another.
Are Mutations Helpful or Harmful?
•
Mutations happen ____________________________
•
Almost all mutations are ____________________
•
Chemicals & UV radiation cause mutations
•
Many mutations are ______________________________________.
– Do you remember the name of that enzyme?
•
•
_____________________________________
Some type of ________________________________result from
___________(body cell) mutations
•
Some mutations may _____________________________________(beneficial)
Q: The type of point mutation that usually affects only a single amino acid is called
a. a deletion.
b. a frameshift mutation.
c. an insertion.
d. a substitution.
Q: A mutation that affects every amino acid following an insertion or deletion is called
a(an)
a. frameshift mutation.
b. point mutation.
c. chromosomal mutation.
d. inversion.
Q: A mutation that affects every amino acid following an insertion or deletion is called
a(an)
a. frameshift mutation.
b. point mutation.
c. chromosomal mutation.
d. inversion.