Name: ______Date: ______Period: ______

3.1 DNA Mutations

Do First: Answer in your Do First Answer Document

  1. In snapdragons, the allele for tall plants (T) is dominant to the allele for dwarf plants (t), and the allele for red flowers (R) is dominant to the allele for white flowers (r). If ttrr is crossed with TtRr, what would be the probable frequency for offspring that are dwarf and red?
  1. O%
  2. 75%
  3. 50%
  4. 25%
  5. 100%
  1. ______In cats, the allele for black fur (B) is dominant over the allele for white fur (b), and the allele for yellow eyes is dominant (E) over brown eyes (e). What percentage of the offsping from bbEe x BBee cross would be expected to express the phenotype black fur and brown eyes?
  2. 0%
  3. 25%
  4. 50%
  5. 75%
  1. ______In mountain lions, having stripes is a dominant trait compared to no stripes. Which genotype, and phenotype are paired correctly?
  2. Ss: no stripes
  3. ss: stripes
  4. SS: no stripes
  5. Ss: stripes

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Name: ______Date: ______Period: ______

Mutation / Definition / Examples
Substitution Mutations
THE FAT CAT ATE THE RAT

THE FAT HAT ATE THE RAT / single base ______
One nitrogenous base must be ______by another base pair. /
…CAT CAT CAT… →
…CGT CAT CAT…
Frameshift Mutations
THE FAT CAT ATE THE RAT

THE FAT HCA TAT ETH ERA T / Insertion:One nitrogenous base pair is ______in the DNA, shifting each base pair to the ______.
Deletion:One nitrogenous base pair is ______in the DNA, shifting each base pair to the ______. /

…CAT CAT CAT… →
…CAT CGA TCA T…
…CAT CAT CAT… →
…CAT CTC AT…
Chromosomal Mutations
/ A change to the genetic make up of a specific ______. / Note: Each letter (A, B, C,..) stands for one gene (which codes for one protein)
Deletion

Mutation:______

  1. Blood and other ______contain ______from the body.
  1. Mutations ______within a species population.
  1. Mutation can be ______
  • Mistakes when ______

Examples: Carcinogen:______-causing mutagen

 these abnormal cells begin multiplying and forming tumors

  • Radiationgamma rays, ______, ultraviolet rays

Chemicals______, bases, some metals

  1. Mutation can be ______from parents if a mutation affects ______.

Complete the boxes below. Classify each as Deletion, Insertion (both frameshift) or Substitution.

Original DNA Sequence: T A C A C C T T G G C G A C G A C T …
Mutated DNA Sequence #1T A C A T C T T G G C G A C G A C T …
What type of mutation is this? ______
Original DNA Sequence: T A C A C C T T G G C G A C G A C T …
Mutated DNA Sequence #2T A C G A C C T T G G C G A C G A C T …
What type of mutation is this? ______
Original DNA Sequence: T A C A C C T T G G C G A C G A C T …
Mutated DNA Sequence #3T A C A C C T T G G G A C G A C T …
What type of mutation is this? ______
Original DNA Sequence: T A C A C C T T G G C G A C G A C T …
Mutated DNA Sequence #4T A C A C C T T A G C G A C G A C T …
What type of mutation is this? ______

Which of these changes to the DNA will NOT affect the protein produced?
T A C C C T A G C
mRNA:
Amino Acid
Mutated DNA Sequence #4 T A C C T A …
What’s the mRNA sequence?
What will be the amino acid sequence?
What type of mutation is this? ______
MutatedDNA Sequence#5 T A G C C T …
What’s the mRNA sequence?
What will be the amino acid sequence?
What type of mutation is this? ______

\

Mutated DNA Sequence #6 T A C C C A T …
What’s the mRNA sequence?
What will be the amino acid sequence?
What type of mutation is this? ______
  1. A geneticist found that a particular mutation had no effect on the protein coded by a gene. What do you think is the most likely type of mutation in this gene?______Why? ______

______

  1. Using the amino acid chart name one amino acid that has more than one codon.______Name an amino acid that has only one codon. ______
  1. Look at the following sequence: THE FAT CAT ATE THE RAT. Delete the first H and regroup the letters in groups of three, write out the new sentence ______Does the sentence still make sense?______What type of mutation is this an example of?______

Extension:

  1. You have a DNA sequence that codes for a protein and is 105 nucleotides long. A frameshift mutation (insertion) occurs after the 84th base.
  1. How many total amino acids are being coded for? ______
  2. How many amino acids will remain the same? ______
  3. How many amino acids might be changed? ______
  1. You have a DNA sequence that codes for a protein and is 99 nucleotides long. A frameshift mutation (deletion) occurs after the 75th base.
  1. How many total amino acids are being coded for? ______
  2. How many amino acids will remain the same? ______
  3. How many amino acids might be changed? ______

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