DNA
Humans inherit two
&
Mundi
THE
copies of
each gene
recessive
genes
characteristic individual inherits 2
an allele
it.
that only expresses its
(phenotype) when an copies of
Represented by lowercase letters
dominant
genes
inherited
an allele that is always expressed ,
even if only one
copy is
Represented by uppercase letters
Homozygous : an individual with two identical alleles for a trait (e g .
. At , aa)
Heterozygous : an individual with two different alleles for a trait (e g
.
Aa)
PHENOTYPE : is the observable
physical or biochemical characteristics of an organism
e .
g. eye/hair colour
GNOTYPf : the specific combination of alleles an individual possesses for a particular
gene
gametes
x
gender :
58
each sperm "%
I
XXXX
mum : XX
* is either X or Y chance
gameter
it can't &both
be
XYXY
dad : xy The dad (sperm) determines the gender
because he has the y chromosome which
could 'make' the
baby a
boy
PROBABILITY
H =
brown naiv
h= blonde hair
Dad-Hu
mum-hh
nh
50% 50%
H Ah Hh
chance
n he hh
Humans inherit two
&
Mundi
THE
copies of
each gene
recessive
genes
characteristic individual inherits 2
an allele
it.
that only expresses its
(phenotype) when an copies of
Represented by lowercase letters
dominant
genes
inherited
an allele that is always expressed ,
even if only one
copy is
Represented by uppercase letters
Homozygous : an individual with two identical alleles for a trait (e g .
. At , aa)
Heterozygous : an individual with two different alleles for a trait (e g
.
Aa)
PHENOTYPE : is the observable
physical or biochemical characteristics of an organism
e .
g. eye/hair colour
GNOTYPf : the specific combination of alleles an individual possesses for a particular
gene
gametes
x
gender :
58
each sperm "%
I
XXXX
mum : XX
* is either X or Y chance
gameter
it can't &both
be
XYXY
dad : xy The dad (sperm) determines the gender
because he has the y chromosome which
could 'make' the
baby a
boy
PROBABILITY
H =
brown naiv
h= blonde hair
Dad-Hu
mum-hh
nh
50% 50%
H Ah Hh
chance
n he hh
