00:01
In order to answer this question, let's talk about inheritance.
00:02
You're handed a mystery plant with tall stems and axel flowers and asked to determine its genotype as quickly as possible.
00:10
You know that the allel for tall stems is dominant.
00:12
So this allel is the dominant.
00:17
And the recessive allele is the dwarf allele.
00:21
And also this allele is dominant, this is axel flowers, and the aggressive file is terminal flowers.
00:28
So you have a mystery pea plant with tall stems and axiol flower.
00:34
So you have this genotype here.
00:37
Okay, because you don't know if this plant is homocybous for both traits or heterotype.
00:42
Okay, because both can code for toll and also axial.
00:47
So it says, what are all the possible genotypes of your mystery plant? so the possible genotypes are going to be when both of them are homozygotics.
00:57
This is the first possibility.
00:58
The second possibility is that it is heterocygote for the gene and somocygous dominant for the a gene.
01:07
The third possibility is that it is homozygous dominant for the t gene and heterocygote for the a gene.
01:14
And the fourth possibility is that it is heterocygote for both genes.
01:20
So these are the four possibilities for our mystery p plan.
01:24
Question b says describe that one cross you would do out of your guard.
01:29
To determine the exact genotype of your mystery plant.
01:34
So this is called a test crop.
01:38
So you have your mystery plant, right? and you have here, in order to perform a test cross, you have to look for a plant with both recessive traits.
01:51
In this case, it would be a dwarf plant and also a plant with terminal flowers.
02:01
So a plant with terminal flowers and also dwarf is the plant that you're going to cross with your mystery plant.
02:10
Then it says while waiting for the results of your growth, you predict that the result of each possible genotype listed in part a.
02:17
How do you do this? why is this not called performing a cross? this is a test cross.
02:24
And in order for it to be easy for you to understand, let's look at both genes by separate.
02:30
Okay, so let's first look at this one here and the same is going to apply for the aj.
02:35
Okay, so let's use this one here and also here.
02:38
So you have this cross.
02:43
This is your test cross or one part at least of your test cross.
02:48
You're going to do a panel square here.
02:51
Well, this is long and here you have this one.
02:56
Or actually you don't even need to make a panel square like to understand this, okay? because remember that each individual inherits one allele for.
03:05
Of each parent.
03:06
These are the parents.
03:07
This is one parent and this is another parent.
03:11
So this parent only has excessive all of the offspring are going to have at least one withcessive allele that comes from this parent here that is the plant front of this cross...