lollypenguin
Badges: 18
Rep:
?
#1
Report Thread starter 1 year ago
#1
A population of summer plants produced only green and yellow plants. The percentage of plants producing yellow fruit in this population was 36%.
Use Hardy-Weinberg equation to calculate number of plants that were heterozygous for gene B

I've tried but I can't do it can anyone help?
The one alleles that code for yellow are aaBB, aaBb & aabb
The answer is 32%
Last edited by lollypenguin; 1 year ago
0
reply
SBB887
Badges: 1
Rep:
?
#2
Report 1 year ago
#2
P^2 2pq q^2 = 1 P^2 = 0.64 so P = 0.8 q =0.2 so 2pq = 2× (0.2 × 0.8) = 0.32then ×100 as it is a percentage to get 32%
0
reply
Maryyam Moazzam
Badges: 9
Rep:
?
#3
Report 1 year ago
#3
(Original post by SBB887)
P^2 2pq q^2 = 1 P^2 = 0.64 so P = 0.8 q =0.2 so 2pq = 2× (0.2 × 0.8) = 0.32then ×100 as it is a percentage to get 32%
how do you know that P squared is 0.64
0
reply
Trumbles
Badges: 12
Rep:
?
#4
Report 1 year ago
#4
(Original post by Maryyam Moazzam)
how do you know that P squared is 0.64
This question is pretty hard to understand out of context.
I think this is the paper it's from - part of question 7. In that it seems to be clear that to be yellow phenotype the squashes need a B allele. The green ones are bb.
(And they're all aa – any with an A allele would be white.)

So if 36% are yellow (or 0.36 out of 1) then 64% (or 0.64 out of 1) must have the bb genotype.
0
reply
ZombieTheWolf
Badges: 22
Rep:
?
#5
Report 1 year ago
#5
p^2 2pq q^2=1

Where p^2 2pq=0.36, because yellow flowers are caused by either the BB (p) allele combo or Bb (2pq) combo. bb is q.

So, 1-0.36=0.64 (q^2).

Use the equation p q=1 to find p, then subtract q and p squared from 1 to find 2pq

(ps where there are spaces there should be pluses, TSR randomly removed them)
Last edited by ZombieTheWolf; 1 year ago
0
reply
X

Quick Reply

Attached files
Write a reply...
Reply
new posts
Back
to top
Latest
My Feed

See more of what you like on
The Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

Personalise

Which of these would you use to help with making uni decisions?

Webinars (34)
13.99%
Virtual campus tours/open days (53)
21.81%
Live streaming events (24)
9.88%
Online AMAs/guest lectures (24)
9.88%
A uni comparison tool (56)
23.05%
An in-person event when available (52)
21.4%

Watched Threads

View All
Latest
My Feed