Gene Mutations

Which statement best defines a mutation?

• A random change in an organism's DNA

• A planned improvement to an organism's traits

• A temporary change in protein shape only

• A predictable shift in chromosome number every generation

Tags

NGSS.HS-LS3-2

Which of the following is identified as a mutagen?

• Ionizing radiation such as gamma rays

• Seasonal temperature changes

• Normal cell division

• Dietary water intake

Tags

NGSS.HS-LS3-2

A substitution mutation is described as which of the following?

• One base is exchanged for another base in the DNA strand

• One or more bases are inserted, making the DNA strand longer

• One or more bases are deleted, making the DNA strand shorter

• A whole chromosome is duplicated during mitosis

Tags

NGSS.HS-LS3-2

Which of the following best illustrates an insertion mutation?

• A guanine is added before the fourth base, lengthening the strand

• The fifth base is exchanged for cytosine, keeping strand length the same

• The second base is removed from the DNA strand, shortening it

• A thymine is swapped with uracil to form RNA

Tags

NGSS.HS-LS3-2

Which description matches what happens with a deletion mutation?

• One or more bases are removed from the DNA strand, making it shorter

• A base is replaced with its complementary partner, keeping length constant

• Extra copies of all chromosomes are added to the nucleus

• A base is chemically modified but not added or removed

Tags

NGSS.HS-LS3-2

A student suggests that exposure to sunlight cannot cause genetic mutations because it is a natural part of the environment. Is this student's suggestion true or false?

• The statement is false; sunlight contains UV rays, which are known mutagens

• The statement is true; only artificial sources of radiation are mutagenic

• The statement is true; natural factors cannot act as mutagens

• The statement cannot be evaluated; there is not enough research on the relationship between sunlight and mutations

Tags

NGSS.HS-LS3-2

Which statement best explains why a DNA mutation can impact the protein synthesized in a cell?

• Mutations only change sugars in DNA, so translation is unaffected.

• Mutations alter the mRNA codon sequence, which can change the amino acid and thus protein structure and function.

• Mutations occur only in tRNA, so they change ribosome size but not proteins.

• Mutations make transcription skip over bases, leaving the amino acid sequence identical.

Tags

NGSS.HS-LS3-2

NGSS.HS-LS1-1

What is the effect of a silent mutation on the amino acid coded for by a codon?

• No change in the amino acid because many amino acids are coded by multiple codons.

• A change to a completely different amino acid, altering protein function.

• A shift in the reading frame that changes many amino acids.

• Creation of a stop codon that ends translation early.

Tags

NGSS.HS-LS3-2

NGSS.HS-LS1-1

A single base substitution changes one codon so that it now specifies a different amino acid from the original base sequence. Which mutation type does this describe?

• Silent mutation

• Missense mutation

• Frameshift mutation

• Nonsense mutation

Tags

NGSS.HS-LS3-2

Insertion of one nucleotide into a coding sequence causes the reading frame of mRNA codons to move forwards or backwards, changing many downstream amino acids. Which mutation does this describe?

• Silent mutation

• Missense mutation

• Frameshift mutation

• Nonsense mutation

Tags

NGSS.HS-LS3-2