Mutations Flashcards
what is mutation?
when a sequence of DNA bases is altered
how does mutation occur?
-the changes occur naturally and randomly
-some substances can increases the chance of mutation occurring
mutagons
increase the chance of mutation occurring
what are some examples of mutagons?
-ultra violet light
-some chemicals
-ionising radiation
when does mutation occur?
-they can randomly occur during DNA replication
-a base in the DNA sequence can be removed, replaced or added
what is a genetic variant?
a different version of an allele
what do all variants arise from?
mutation
what are the effects of mutation?
-mutation can have harmful effects (cancer)
-mutations can have beneficial effects
-mutations can result in new species occurring
what is a karyotype?
number and appearance of chromosomes in a nucleus
how is the female sex represented with chromosomes?
XX
how is the male sex represented wth chromosomes?
XY
what do the bands on chromosomes show?
genes
do genes come in pairs?
yes
why do genes come in pairs?
because chromosomes come in pairs
what are the only cells that don’t have pairs of chromosomes?
the sex cells (egg and sperm)
