Hardy-weinberg equation :D

[sweetxd]

hey!
i have 2 questions.

1. In a certain population, the dominant phenotype of a certain trait occurs 91% of the time. What is the frequency of the dominant allele?

i got 0.7 or 70%…
it’s either that or 0.91
i’m not sure.
which one do u think it is?

2. The allele for the hair pattern called widows peak is dominant over the allele for no widow’s peak. In a population of 1000 individuals, 510 show the dominant phenotype. How many individuals would you expect of each of the possible three genotypes for this trait?

Okay so i got
homozygous dominant 90
heterozygous 420
homozygous recessive 490

it’s that.. or…

510, 410, 80 (respectively)

can someone please check my answers… and check which ones are right?

thank you so much! i appreciate it greatly 🙂

Here are some of hte equations
p + q = 1
p^2 + 2pq + q^2

[MrMistery]

1. it’s 0.7. i can explain if you want
2. P-dominant; p-recessive
PP-90
Pp-420
pp-490

I can also explain. It is easy. Or do you understand?

[sweetxd]

thanks! yeah i understand… i just got confused at first. when they say dominant – that includes heterozygotes too.
i just wanted to make sure my answers were correct. thank you again! 🙂

[MrMistery]

hey no prob, i like to see people that actually do the work by themselves 😆

[sweetxd]

lol yeah

one more thing,

if
AA – 6
Aa – 9
aa – 0
———
15

then how do u find p and q.
because… since the recessive is 0.. there shoudl still be a q. but if u find the square root of 0 it’ll be 0. but there should still be q in the heterozygotes. so q can’t be = to 0… the recessive allele should never completely be removed bc of the heterozygotes… can someone clarify i’m confused 😥

would u do 9/15 = 0.6 / 2 = 0.3/ 0.4 = 0.75?.. ahah i.. idk

[mith]

9/30?

[sweetxd]

ohh.. is that for p or q? lol thanks

[MrMistery]

that does not follow Hardy Weinberg

[sdekivit]

quote sweetxd:

lol yeah

one more thing,

if
AA – 6
Aa – 9
aa – 0
———
15

now p and q are allel frequencies, thus theallele frequency q vcomes from the heterozygous individuals 9/30 as already said

[MrMistery]

hey sdekivit. haven’t seen you around for some time..

[sdekivit]

quote MrMistery:

hey sdekivit. haven’t seen you around for some time..

true –> was very,very busy studying the mechanisms of metabolic regulation the past 7 weeks. It was very annoying to get it all in my brains 🙄 😆

[Oscerot]

Wow.

I just learned this yesterday in my grade 12 Academic Biology class. 😆 Got a bunch of questions to go along with it. 😆

[Oscerot]

Okay I have a question. I have a "snow day" today, so I thought I’d finish up my biology homework. Here’s a question;

quote :

Twenty-one percent of a population is homozygous dominant, 50 percent is heterozygous, and 29 percent is recessive. What percentage of the next generation is predicted to be recessive. Explain

So here are the variables I got;

p^2 = 0.21
q^2 = 0.29
2pg = 0.50

So now I am lost as to how to get the second generation. Help?

[MrMistery]

well it depends on the way the species reproduces: sexually, asexually.

Generally, if the species is in HW equilibrium(which never happens) the next generation will have the same gene percentages. so the answer should be 29%

[Oscerot]

I thought so too. There isn’t enough information given so I at first assumed that it must be in equillibrium.

Here’s another one;

quote :

The allele for a hitchikers thumb is dominant over a straight thumb. In a pop. of 1,000 people, 510 show the dominant phenotype. How many individuals would you expect for each of the three possible genotypes for this trait?

[Author]

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