00:01
Tall plants are dominant to dwarf plants.
00:03
So if i write out two alleles, we have capital t for tall, little t, the dwarf.
00:11
Okay, so question one, a test cross is carried out on a homozygous tall plant.
00:18
So this is the plant we're looking at, homozygous for tall.
00:22
A test cross is when you cross it with a homozygous recessive.
00:27
So this is the cross we're doing.
00:29
There are 200 offspring, what will be the result? well, we don't even have to do a planet square here, because there's only one outcome.
00:37
Remember that each offspring gets one allele from each parent.
00:42
And this parent only has dominant alleles to pass on, so we'll always pass on this.
00:47
This parent only has recessive alleles to pass on, so we'll always pass on this.
00:53
So the only outcome here is 100 % heterozygous...