00:01
We're looking at maize.
00:02
The allure for purple seeds is dominant over yellow.
00:05
So i'm going to have a capsule a for purple and little a for yellow.
00:11
The letter you use is completely arbitrary, as long as capsule is for dominant rate, lower case is for the recessive.
00:17
How can we determine the genotype of a purple -seated plant? we could test -cross it with a homozygous purple plant, test -cross with heterozygous yellow, test across with heterozygous purple, test -cross with heterozygous purple, test -crossed.
00:31
Of homozygous yellow.
00:33
Okay, so we have a plant.
00:35
We know it has a copy of a purple allele, because it has purple seeds.
00:40
We don't know what the second allele is.
00:42
It could be purple, it could be yellow, you'd still get a plant with purple seeds.
00:47
We want to work out what this is by crossing it with something else.
00:50
Question is here, what do you cross it with? and the answer to that is yellow.
00:57
So it's not going to be heterozygous yellow.
01:00
That's not possible.
01:02
You can't have heterozygous yellow because yellow is a recessive trait...
