If both where Mm then we would have 25% MM,
50% Mm and 25% mm.Even though we can see the frequencies we
still do not know if the Pale green leaf trait
is Dominant or Recessive, but we can find this
out by performing A Test Cross.Now we are not going to go through the Test
Cross chapter again but we can show you how to
isolate the genotype that you need, which is
either MM or mm because we want to breed that
trait true. We must also keep track of the
parent plants been used.To keep parent plants alive, clone them!
The exact same genetic material will be passed
on from clone to clone.In this this cross do you see MM offspring
and the mm offspring? Well by their very nature
they can not be the same. By running several
Cross Tests we can isolate the plant that is
either MM or mm and break away any Mm from the
group. Whether it is MM or mm, we can still
breed the trait true by breeding it with other(^) M m
M MM Mm
m Mm mm