4.2 Flashcards
what are the three ways mutations occur
deletion, addition,substitution
deletion
one base is missing
addition
an extra base added
substitution
one base is substituted for an other
what are the three types of mutation
positive,negitive,neutral
neutral mutation
this mutation change does not effect the organism . this mutation does not increase or decrease the organisms survival rate
positive mutation
a mutation that benefits an individual
negative mutation
small changes in the sequence of bases can also cause harmful or negative mutations. negative mutations reduce the probability that the organisms with the mutation will produce offspring or survive in there environment
example of negative mutation
cystic fibrosis is when the mucus builds up because the protein can’t transport it out of the cell
example of positive mutation
some plants have developed resistance to bacteria and Fungle infections
example of neutral mutation
spirit bear. its a white bear but it lives here. so it doesn’t decrease or increase its cancellation of survival.
another example is a hairless rat. there note effected by there difference of look or colour.
mutagens
substances or factors that can cause mutations in DNA
examples of mutagens
cigarette smoke, radiation from x-rays, UV rays, pollutants such as mercury, even house hold chemicals, some pesticides that can cause mutation
gene therapy
in one form of here therapy, researchers replace a mutated gene whir a healthy copy of a gene.
