Mutations
Vocabulary
• Right now, write your name and class period
on the top right corner of your packet.
• After that, look at the vocabulary words. You
will need to learn these words.
• Mark an X in the appropriate box next to the
vocabulary word. For example, if you do not
know what mutation means, but you have
heard the word before, you would mark an X
under Column 2 Heard it/Seen it
Popcorn Reading
• Mrs. Campbell will choose one person to start
reading. When that person finishes a
sentence, they will choose another student to
read the next sentence. We will continue this
until we have read the entire section, “Lesson
Introduction.”
• After this presentation, you will fill in the
section that says “Before Reading” and answer
the questions that follow.
Causes of Mutation
• Spontaneous Mutations vs.
Induced Mutations
• The X-men have spontaneous
mutations because their
mutations just happened with
no outside influence.
• Spiderman has an induced
mutation. He was bitten by a
spider, and something in that
spider’s venom caused his DNA
to change, which changed his
traits. He was exposed to a
mutagen.
• We will popcorn read this
section as well!
Mutagens
• A mutagen is anything in the environment that can cause a
mutation. Mutagens can be radiation, chemicals, or
infectious agents (viruses and bacteria that make you sick)
Germline Mutations
Germline mutations occur in gametes (sex cells).
These mutations are especially significant
because they can be transmitted to offspring
and every cell in the offspring will have the
mutation.
Somatic Mutations
Somatic mutations occur
in any of the cells of the
body besides gametes.
These mutations may
have little effect on the
organism because they
are confined to just one
cell and its daughter cells.
Somatic mutations
cannot be passed on to
offspring.
Chromosome Mutations (Alterations)
Chromosomal alterations are mutations that
change chromosome structure. They occur when a
section of a chromosome breaks off and rejoins
incorrectly or does not rejoin at all.
Point Mutations
• A point mutation is a
change in a single
nucleotide in DNA. This
type of mutation is usually
less serious than a
chromosomal alteration. An
example of a point
mutation is a mutation that
changes the codon UAC to
the codon UAU. Sometimes
point mutations occur in
noncoding regions of DNA,
so they may not have an
impact on the organism.
Point mutations that do
occur in coding regions can
be silent, missense, or
nonsense mutations