Natural Selection
Natural Selection
changing attele frequency
: over
timewhich ma
a de
S.I units
Allele
frequency
=
proportion of one allele to the
total number
of alleles
.
1 There must be within
.
genetic variation a
population
↳ > mutation
random variation - >
- DNA replication
>
- sexual reproduction
>
-
meiosis
2 Population selection
.
is
subjected to a
pressure
.
e
.
g
-
introduction of predator
change in food source
-
competition
-
-
disease
-
climate
change
3a) Some individuals in the
population have an
advantageous allele
↳ random mutation
cause
by
-
DNA replication mistake
radiation
ionising
-
-
UV
-
Chemicals
b) codes advantageous phenotype
for an
.
4 . These individuals are more likely to survive and
reproduce
. Pass
5 advantageous
on allele to he
offspring
altere will
. Over
6
many generations frequency increase
for he
advantageous allele
Natural Selection
changing attele frequency
: over
timewhich ma
a de
S.I units
Allele
frequency
=
proportion of one allele to the
total number
of alleles
.
1 There must be within
.
genetic variation a
population
↳ > mutation
random variation - >
- DNA replication
>
- sexual reproduction
>
-
meiosis
2 Population selection
.
is
subjected to a
pressure
.
e
.
g
-
introduction of predator
change in food source
-
competition
-
-
disease
-
climate
change
3a) Some individuals in the
population have an
advantageous allele
↳ random mutation
cause
by
-
DNA replication mistake
radiation
ionising
-
-
UV
-
Chemicals
b) codes advantageous phenotype
for an
.
4 . These individuals are more likely to survive and
reproduce
. Pass
5 advantageous
on allele to he
offspring
altere will
. Over
6
many generations frequency increase
for he
advantageous allele
