Please enable JavaScript.
Coggle requires JavaScript to display documents.
Variation and Inheritance - Coggle Diagram
Variation and Inheritance
The possible genotypes and phenotypes of the offspring can be determined using a punnett square
Differences between individuals in a population, such as eye colour, height and body mas, are called
variation
An organisms characteristics are controlled by the genes it inherits from its parents
The genotypes of individuals can be identified by using pedigree charts
Phenotype
- the visible characteristics in an organism which occur as a result of its genes
Combining different versions of genes from two parents contributes to variation
Characteristic controlled by a single gene tend to have phenotypes that fall into different categories -
discrete variation
Hand used for writing, ability to roll tongue and blood group are all discrete variation
Most characteristics are controlled by more than one gene -
ploygenic
Polygenic characteristics have phenotypes that can show a wide range of values -
continuous variation
Height, body mass and plant root length are continuous variation
A
gene
is a location
on
a
chromosome
where there is a
DNA sequence
that
codes
for a
protein
that
codes
for a
particular characteristic
The different versions of a particular gene are called
alleles
If the
two alleles
for a particular gene are
identical
, then the individual is
homozygous
for that characteristic
If the two alleles for a particular gene are
different
, then the individual is
heterozygous
for the characteristic
A
monohybrid cross
is a genetics cross that shows the inheritance of one characteristic
The dominant gene of an allele is given a dominant letter and the recessive gene is given a lower case letter
A punnett square is a grid that shows the possible combinations of alleles that can result at fertilisation
A pedigree chart is a diagram that displays the phenotypes of individuals in several generations of family
The symbols
P
,
F1
and
F2
can be used to describe different generations when talking about genetic inheritance.
P
refers to the parent
F1
refers to the first generation of offspring
F2
refers to the second generation of offspring