alleles and genetic diagrams

different genes control different characteristics

some characteristics are controlled by a single gene

eg fur colour of mice, or colour blindness in humans

an allele is an alternative version of a gene

gametes only have one allele

but all other cells in an organism have two-one on each chromosome in a pair

this is due to inheriting half of our alleles from our mother and half from our father

when an organism has two alleles for a particular gene that are the same then its homozygous

when an organism has two alleles for a particular gene that are different then its heterozygous

the allele for the characteristic thats shown is called the dominant allele and the other one is called recessive

for an organism to display a recessive characteristic both its alleles…