00:01
So in beetles, eye color and presence may be determined by one gene with three alleles or two genes.
00:11
And if it's two genes, those two genes may be on autosomal chromosomes or they may be on x chromosomes.
00:19
And so the results of the pedigree are quite confusing.
00:23
For example, in one instance, a black -eyed fly was bred with a black -eyed fly.
00:30
And it yielded brown -eyed flies.
00:33
In the same line, if you take a brown -eye fly and you breed it with an eyeless fly, you get brown eyes.
00:40
And if you breed a brown -eyed fly with a black -eyed fly, you could get eyeless.
00:46
And so these results lead to a lot more questions than answers.
00:52
So the results are confusing.
00:54
And what i want to do is i want to start with using one gene to answer a -pol.
01:01
Heart and what i'm going to do is make the allele a1 the presence of black eyes.
01:08
A2 represents the presence of brown eyes and a3 represents the eyeless condition.
01:17
In addition, according to the information provided in the question, solid symbols yield black eyes or represent black eyes.
01:25
Open symbols represent brown eyes and i don't know, this x going through the symbol represents eyeless.
01:41
And so the other thing that we have to assume is that we have a dominance hierarchy, where black is dominant to brown and brown is dominant to eyeless.
01:53
And so now we can look at our pedigree.
01:55
So if we start with generation 1, generation 1 had a black, black eyed male fly.
02:02
So that individual has to be a1 something.
02:08
And that individual was bred to an eyeless female.
02:14
So she has to be a3, a3.
02:20
And she was also bred to a brown -eyed male.
02:26
So he must be a -2 something.
02:32
If we look at their offspring, let's start here, so this would be generation 2.
02:37
The offspring from this black -eyed male with an eyeless female yielded an offspring that was a female with brown eyes.
02:52
I'm sorry, black eyes.
02:54
And a second offspring that was a brown -eyed female.
03:04
Yeah, okay.
03:07
So there we have a1 something, a2 something.
03:14
And so we know that both of these are going to have a3 because their mom carried the eyeless trait.
03:24
What that also means since it produced this combination of breeding produced a brown -eyed offspring that this a1, the black -eyed male, must have a a brown -eyed allele hidden away.
03:38
Then this individual here, a1, a3, was bred to a black -eyed male.
03:54
So that individual has to be a1 -something.
03:59
And then these two were bred and produced a brown -eyed female.
04:04
So that means that this fly is a2 something.
04:08
And so this male, her dad, must have a hidden a -2, trait.
04:14
And so that's the third generation.
04:17
And so the other, her other allel must be a3 from this parent.
04:22
This offspring didn't produce any offspring from, from this breeding.
04:32
But she was bred instead to a male fly that was eyeless.
04:38
And so he's a3, a3.
04:47
And they produce an offspring for the third generation that was also a brown -eyed female.
04:55
So she must be a2, a3.
04:58
So here, the a2, and then the a3 allele came from dan.
05:03
And then this male was also bred to a female who had black eyes.
05:09
And so she was a1 something.
05:12
Their offspring, they had two groups, one black -eyed male, so a3, something and an eyeless female.
05:28
Oh, i'm sorry.
05:29
Wait, i've made a mistake here.
05:30
This should be a1.
05:34
This one's a3.
05:36
A3.
05:38
Okay, so based on these two individuals, this individual must be a3 and this individual female, his mom, must be a carrier for a3.
05:49
Then finally, these two were bred and generation 4 produced an eyeless male.
06:00
So a3, a3.
06:03
And so if there was one single gene, this is what it would look like.
06:09
It's a little bit crazy.
06:10
But you can see here, this black -eyed male produced both black -eyed offspring and brown -eyed offspring...