Introduction to Mutations

A scientist finds a single nucleotide change in a gene of a fish population living in low-oxygen water. Individuals with this change survive better. Which conclusion is most supported by this evidence?

• The mutation harms survival in low-oxygen water

• The mutation is beneficial in that environment

• The mutation is neutral in all environments

• The mutation only occurs in somatic cells

Tags

NGSS.HS-LS4-2

NGSS.HS-LS4-4

A chemical mutagen causes one extra nucleotide to be inserted early in a coding sequence. Predict the most likely consequence for the protein and select the corresponding mutation category.

• Substitution that preserves original reading frame

• Point change with a silent codon effect

• Frameshift and altered downstream amino acids

• Deletion that removes a noncoding intron

Tags

NGSS.HS-LS3-2

A viral infection leads to errors limited to a single nucleotide in a gene. Which listed category most precisely describes this pattern, and which causes are consistent with such mutations?

• Deletion from high-accuracy DNA repair only

• Insertion from nonmutagenic environmental factors

• Frameshift from normal replication fidelity

• Point mutation from copying errors or viruses

Tags

NGSS.HS-LS3-2

You are modeling a gene with the sentence THE FAT CAT ATE THE RAT. Choose the single change that represents a substitution point mutation while keeping the total number of letters unchanged.

• THE FIT CAT ATE THE RAT

• THE FATT CAT ATE THE RAT

• THE FAT CTA ATE THE RAT

• THE FA CAT ATE THE RAT

Tags

NGSS.HS-LS3-2

A DNA sequence is represented as THE FAT CAT ATE THE RAT. If one letter is inserted to create a frameshift, which option best shows an insertion point mutation?

• THE FAT CAT ATE THE TAR

• THE FATS CAT ATE THE RAT

• THE FAT CAT ATE THR RAT

• THE FAT CAT ATE THE RAT

Tags

NGSS.HS-LS3-2

Consider the idea that point mutations change a single nucleotide. Which scenario best illustrates a deletion mutation using the FAT CAT analogy?

• THE FAT CAT ATE THE RA

• THE FAA CAT ATE THE RAT

• THE FAT CAT ATE THE RAT

• THE FAT CAT ATE HER AT

Tags

NGSS.HS-LS3-2

A scientist wants to test how different point mutations may affect a protein. Using the FAT CAT analogy, which plan best compares substitution, insertion, and deletion for potential effect on meaning?

• Swap two letters in separate words, then add one letter at the end, then remove punctuation, noting minimal change to overall meaning

• Swap a whole word, then add one extra word, then remove a space, noting that all changes equally preserve meaning

• Compare three different letter colors, then add a capital letter, then remove bold formatting, noting that style changes mimic mutations

• Compare one letter swap, then add one letter, then remove one letter, noting that insertions or deletions can shift groups and often change downstream meaning

Tags

NGSS.HS-LS3-2

A diagram shows a normal mRNA read in codons: ATG GAA GCA CGT → Met Glu Ala Gly. After one nucleotide is deleted in the second codon, the new codons become ATG AAG CAC GT… Predict the most likely consequence for the protein.

• The reading frame stays exactly the same

• Many amino acids change after deletion

• Only the second amino acid changes slightly

• A stop codon appears immediately

Tags

NGSS.HS-LS3-2

NGSS.HS-LS1-1

You see a sentence analogy in a slide: THE FAT CAT ATE THE RAT. If one letter is inserted after the first space, which outcome best models a frameshift effect on meaning?

• THE TFA TCA TAT ETH ERA T…

• THE FAT CAT ATE THE MAT

• THE FAT BAT ATE THE RAT

• THE FAT CATS ATE THE RAT

A slide states: inserting or deleting nucleotides changes the reading frame and leads to proteins built incorrectly. Which reasoning best explains why this happens?

• Ribosomes group bases in triplets, so a shift redefines all codons

• Amino acids randomly attach, so any change is unpredictable

• tRNA molecules carry pairs of bases, so pairs control reading

• DNA polymerase replaces bases, so translation fully corrects

Tags

NGSS.HS-LS1-1