00:01
In order to answer this question, let's talk about inheritance.
00:04
It says, first flies with one allele for curly wings, it means one allele for curly wings and one allele for normal wings.
00:12
It means like this, have a curly wings.
00:15
So this is four curly wings.
00:20
And it says when two curly wings flies were crossed, it means, when you have a cross between one heterozygocles with another heterocygos, it says, there's 203 curly winged and 98 normal winged flies were obtained.
00:39
So in this case let's make our panel square first.
00:48
You get here homozygot for this allele, you get here heterozygose, let's place first this allele, okay? then you get this adroitrocygose and finally a homocygoyle for this allele here.
01:02
So here you have...
01:05
We don't know which allele is dominant to...
01:08
To the other but you get that at least or your phenotype rate is going to be three quarters and one quarter okay three quarters is about 0 .75 and this is about 0 .25 this is what you should find okay but in this case it says that you get 203 898 so let me write here 203 are curly 98 are normal wing so you have a total of 98 plus 203 is equal to 301 so what is your frequency for curly you have to divide 203 by 301 and this is going to be approximately 0 .67 okay see 0 .67 and in this case you have to do the same you have 98 divided by 3001 and this is equal to approximately 0 .33.
02:15
Okay.
02:16
So you can see here these ratios are not even close.
02:21
Okay, so practically this is there is something wrong with this.
02:25
Okay, because you should get a value or a frequency if this was true, you would get a frequency very similar or very close to these values here.
02:33
So then it says, in fact all courses between curly when flies produce nearly the same curly to normal ratio among the progeny.
02:39
So in this case as you can see here, you're getting more curly than normal.
02:45
The curly allele is this allele here.
02:50
This allele.
02:50
Okay, this is the curly allele and this is the normal allele.
02:54
So in this case, what is happening is that in order for you to have more curly than normal in this off -pring or in this panel square, this one here should be lethal.
03:08
Okay, so it means that this homozygoyles for the normal wing allele is lethal.
03:15
Okay, so in this case this is not going to be like this, but you don't have a total of four possibilities now...