1.4 Flashcards
what is a mutation
a random change to an organisms dna
what are the possible effects of a mutation
- no protein being synthesised
- an altered protein
- no effect
what increases the chance of mutation
chemicals - eg mustard gas
radiation - eg uv light
what is a genetic disorder
a condition or disease related to an individuals phenotype
what causes genetic disorders
mutations causing either a protein to not be expressed or a faulty protein being expressed
what is a single gene mutation
a mutation involving the dna nucleotide sequence being altered in one gene on a chromosome
what are the types of single gene mutations and explain them
substitution -> replaced by another one
insertion -> added to a dna strand
deletion -> removed from a dna strand
what are the 2 types of substitution mutations and explain them
mis-sense -> one nucleotide is changed for another
nonsense -> one codon is changed for a stop codon
what is a splice site mutation
a mutation where exons are removed and introns are retained
what is the result of a splice site mutation
a protein which doesn’t function properly
what are the types of chromosome structure mutations & explain them
inversion -> a chromosome segment is reversed
duplication -> a segment is removed and added to its homologous partner
deletion -> a segment is removed
translocation -> a segment is removed & added to a non-homologous chromosome
what are the types of translocation mutations & explain them
non-reciprocal -> one chromosome has deleted genes and one has extra
reciprocal -> 2 genes are removed and swapped
what is the effect of chromosome structure mutations
lethal effect
