Molecular Genetics: Mutation

Question 1

genetic code is redundant

Answer 1

multiple codons for one amino acid

Question 2

genetic code is unambiguous

Answer 2

codon never specifies more than one amino acid

Question 3

genetic code is conservative

Answer 3

if redundant, the first and second bases typically the same

Question 4

genetic code is almost universal

Answer 4

same codons almost always code for same amino acids in all organisms

Question 5

mutation

Answer 5

permenant alteration of an organism’s DNA sequence

Question 6

point mutation

Answer 6

single base change, could alter protein primary structure or gene expression

Question 7

silent mutation

Answer 7

does not alter primary structure

Question 8

missense mutation

Answer 8

alters amino acid sequence

Question 9

nonsense mutation

Answer 9

results in an early stop codon - mRNA breakdown or truncated protein

Question 10

frame-shift mutation

Answer 10

insertion or deletion of one or two bases

Question 11

chromosome mutations

Answer 11

alter chromosome number (aneuploidy) or structure

Question 12

spectral karyotyping

Answer 12

allows simultaneous visualization of all chromosomes

Question 13

random mutagenesis

Answer 13

useful for genetic screening and creating genetic variation (expecially in crops)

Question 14

targeted mutagenesis

Answer 14

specific mutations placed at specific locations in the genome (site-directed, homologous recombination, CRISPR)

Question 15

CRISPR

Answer 15

immune mechanism in bacteria to destroy viral DNA

Question 16

cas9

Answer 16

protein destroys DNA - used in CRISPR to delete bits of DNA or insert DNA into cells