00:02
Hello there.
00:03
They want us to match each phenotypic ratio to the most appropriate description for the loci allele's dominance relationships genotypes of mating crosses that produces these ratios and offspring 121 9331 -1 -11 and 1 -1 -1 -1 so let's do our 1 -2 -1 so what can we say a bit about them well we can sit here and say that these are a cross of two f1 hybrids which is our fertilization the first fertilization one where they usually use heterocycone alleles for a single trait that displays and incomplete dominance what they mean by that so let's say we're dealing with traits where we have dominant teas to represent tall the minimum the big t little t represents people who are in the middle of the height and the two little t's represent being short since they're talking about more of a heterocycus alleles so let's focus on the medium the medium traits because they say heterocycus and this out of three of them this is only one that's heterocycus mean they're they're different from each other so we do our crosses you see you would get a punness you set up your punit square how many big t's we have you only have one so one over four which is 25 i mean 0 .25 or 25 percent that's how you get your big t's so or just seeing like you only found one of these that represents that one ratio for the heterocycus, how many heterocycus you see, we see one, two.
02:05
So we put the two on top, and that would be like 50 % or we put down two.
02:10
And then for the little t's, how many of them are there? just only one, and that's how you get your one -to -one ratio.
02:18
So let's move on to the next one.
02:22
So for the next one, let's do a 9 -33.
02:30
So what can we say about our 9 -3 -1? well, our 9331 is a classic mendelan ratio, and it represents a die hybrid cross, what they mean by that.
02:42
So let's say we have the set of big r little r, big y, little y, times big r little r, big w, little r.
02:53
So let's say the r is represent.
02:55
So to talk about mendelan, let's just stick with the p's where the big r represents being smooth, while the little r represents being wrinkled.
03:03
And then you got the big y represents yellow and the little y represents green.
03:09
So when they're counting, we're counting on what would be the dominant.
03:13
So that's why you see there's an r and it's blank because either or the dominant trait is going to supersede or basically overshadowed the recessive trait.
03:31
So that's why we'll count them because since the big one is dominant, they're going to focus on that dominant trade over the recessive.
03:39
That's why you see it 3 over 4 times 3 over 4.
03:43
But you get 9 over 16, which is why you get that 9 because that's the biggest one.
03:49
Next one that we see, we have our 2 little r's and our big y and whatever goes in there.
03:58
It doesn't matter.
04:00
Where you got your 1 over 4 ratio times 3 over 4.
04:09
That's how you get 3 over 16.
04:11
So that's where you get the 3.
04:13
Then the big r with blank is anything can go in there with the little y.
04:17
Same setup.
04:18
You get 3.
04:19
And then this one where you have it all being recessive.
04:22
You got 1 over 4 times 1 over 4.
04:25
And this is how you get 1 over 16.
04:28
That's how you get the 1...