5. A plant can either have a smooth seed (p) or a rough seed (q). Rough seeds are recessive and smooth seeds are dominant. In a population of 100 plants, 32 of them have rough seeds.
p^2 + 2pq + q^2 = 1

a) What is q^2? (1 point)

b) What is q? (1 point)

c) What is p? (1 point)

d) If there are 19 plants with rough seeds in a population of 100, what is the allele frequency for smooth seeds? (1 point)

Question

5. A plant can either have a smooth seed (p) or a rough seed (q). Rough seeds are recessive and smooth seeds are dominant. In a population of 100 plants, 32 of them have rough seeds.
                           p^2 + 2pq + q^2 = 1

a) What is q^2? (1 point)

b) What is q? (1 point)

c) What is p? (1 point)

d) If there are 19 plants with rough seeds in a population of 100, what is the allele frequency for smooth seeds? (1 point)

anonymous · Answer

@marcoduuuh omg I haven't seen you in a long time! How's it going! :D

I can help you with your question. Do you understand the Hardy-Weinberg equation at all, or are you completely lost?

anonymous · Answer

Yeah it's been a long time haha! 

And no, I'm completely lost /:

anonymous · Answer

Sorry about that, I was dealing with some serious lag! I had to restart the computer. Okay, well, let's get started. 

Fisrt, you need to find the dominant and recessive alleles. Do you know how to do that?

anonymous · Answer

I think it's OpenStudy, it's lagging a lot. 

And yes, the rough seeds are recessive and smooth seeds are dominant.

anonymous · Answer

Great! Which means that smooth seeds are "p" and rough seeds are "q"

The first equation in Hardy-Weinberg is 

p + q = 1.

Since you have 100 plants, solving this will be a piece of cake! :)

we could write the expression like this:

p + q = 100

We already know q, because those are the recessive plants:

p + 32 = 100

If you solve that, you'll find that p is equal to 68. Do you understand how I did that?

anonymous · Answer

Okay, OS seems to be experiencing lag, so I will just have to move on. 

Since we figured out p + q = 1 (or, 68 + 32 = 100), we can solve for part a of your question now. By doing p + q = 1 we completed parts b and c already, so I'll let you fill those out. Now we're going to have to use the HW equation itself.

$$p^2 + 2pq + q^2 = 1$$ Since we already know what the values for p and q are, you could just plug them into the equation and you will get your answer. I would recommend simplifying it into decimal form, though. You can work it out on your calculator. 

$$.68^2 + 2(.68)(.32) + .32^2 = 1$$
Good luck! I hope this helped!

anonymous · Answer

Wow, thank you so much for all the help and explanation. 
Sorry I wasn't here, OS started lagging a lot and I couldn't log on to the site. 
Thank you again for everything, it really helped.

anonymous · Answer

Oh, you're welcome! Yeah,  the lag was terrible. I'm really glad that I was still able to help you, though! :D