I think I got this one right!!!!?

Question

Pea flowers may be purple (W) or white (w). Peas seeds may be round (R) or wrinkled (r). What proportion of the progeny from WwRr X WwRr will have purple flowers and wrinkled seeds?

I think it is 1/4 lol Please let this be right! I think I am starting to get the hang of it

Answer 1

Start by figuring the combinations formed from Ww x Ww. If you put them in a box, you get WW, Ww, wW, ww all with equal probability. Because purple(W) is dominant you have the following:

Combinations for W:
WW --> purple
Ww --> purple
wW --> purple
ww --> white

Similarly for Rr combined with Rr, you have RR, Rr, rR, rr with equal probability. Again round(R) is dominant.

Combinations for R:
RR --> round
Rr --> round
rR --> round
rr --> wrinkled

So 3/4 of the time the progeny will be purple. And 1/4 of the time the progeny will be wrinkled. The proportion that will be both is the product.

Multiplying you get:
3/4 * 1/4
= 3/16 will be round and wrinkled

You were very close with your answer which means you probably did it the long way enumerating all 16 combinations and checking which ones were purple and round. You can do that to, but it is prone to errors.

A hybrid method is to figure the characteristics separately as I did. So you have purple, purple, purple, white combined with round, round, round, wrinkled. If you put that in a box you get:

.... W .... W .... W .... w
R | WR | WR | WR | wR |
R | WR | WR | WR | wR |
R | WR | WR | WR | wR |
r . | Wr. | Wr. | Wr . | wr. |

9/16 = WR = Purple Round
3/16 = Wr = Purple wrinkled <--
3/16 = wR = white Round
1/6 = wr = white wrinkled

Either way the answer is 3/16 which is close to 4/16 = 1/4, so you must have just miscounted one combination.

I even had trouble keeping it all straight, especially when they chose to make W = Purple (when you might think it would stand for white or wrinkled)... :-)

Answer 2

So, purple wrinkled would be WWrr or Wwrr. So the answer is 3/16. You may be including the wwrr at the bottom right corner of the Punnett square which is wrinkled but white.

Answer 3

I think puzzled meant 3/4 will be PURPLE and 1/4 of those will be wrinkled.

Answer 4

Close, but it is 3/16.

Another way to approach this is to seperate the genes.

You have Ww x Ww and want to know how often you will get a W allele - 0.75 frequency (75% of the time)

Do the same thing with Rr x Rr --> 0.25

0.75*0.25 = 3/16

Answer 5

3/16

Here's how it goes

_____WR ____Wr____ wR____wr

WR WWRR WWRr WwRR WwRr
Wr WWRr *WWrr WwRr *Wwrr
wR WwRR WwRr wwRR wwRr
wr WwRr *Wwrr wwRr wwrr

The only combinations that give purple and wrinkled are WWrr or Wwrr

So as you can see, there are only 3 (marked with *) that fit.