ILS
Topic Author
Posts: 2291
Joined: Fri Nov 09, 2001 2:34 am

Biology

Sat Dec 01, 2001 2:02 pm

OK, I have a dilema. This is the 3rd 6 weeks of the three-six week grading period that makes up a semester. The previous 2 six weeks I got both 84s. This six weeks I got an 80 on a test. On Thursday I took a quest (quiz/test) that counted 40% of a real test. I got a 50/100 on it. It was on Mendelian genetics and punnet squares. I have the real test on Tuesday. Does anyone know a lot about this that can help me like on incomplete dominance, etc. and dihybrid crosses? Thanks!
 
G Dubya
Posts: 387
Joined: Wed Nov 01, 2000 1:10 am

RE: Biology

Sat Dec 01, 2001 2:06 pm

 
IHadAPheo
Posts: 5499
Joined: Mon Sep 17, 2001 3:26 pm

RE: Biology

Sat Dec 01, 2001 2:08 pm

Sorry ILS biology is but a dim memory from the past, however if your lucky Mirrodie might see your post and help you out, i'm sure his biology knowledge is both fresher and superior than mine. Mirrodie is well on his way to be an OD so I think he might help you out.

Pray hard but pray with care For the tears that you are crying now Are just your answered prayers
 
ILS
Topic Author
Posts: 2291
Joined: Fri Nov 09, 2001 2:34 am

RE: Biology

Sat Dec 01, 2001 2:10 pm

Thanks very much G Dubya! That is just what I needed! Keep the info coming! Any books and other references are appreciated as well!
 
mls515
Posts: 2954
Joined: Mon Jun 26, 2000 5:56 am

RE: Biology

Sat Dec 01, 2001 2:13 pm

I remember the genetics part was a beeotch, but other than that it was ok. My teacher, also the head football coach, was pretty easy. Learned a lot about football during that class. Our exams had matching sections that spelled out "Merry Christmas" and stuff like that, it was a riot.
 
ILS
Topic Author
Posts: 2291
Joined: Fri Nov 09, 2001 2:34 am

RE: Biology

Sat Dec 01, 2001 2:17 pm

Well our teacher is a fricking 50 year old ragged weed smoking hippie who know WAY too much about biology.
 
IHadAPheo
Posts: 5499
Joined: Mon Sep 17, 2001 3:26 pm

RE: Biology

Sat Dec 01, 2001 2:21 pm

Mls515, I'm in awe, where was your school, my biology teacher was evil.. If you couldn't come up with the proper answer (for him) he would start calling you a "maggot" and if you didn't move quick enough you might have had an eraser bounce off your head..but that was wayyyyyyy back in 1980. Love the post !!
Pray hard but pray with care For the tears that you are crying now Are just your answered prayers
 
L-188
Posts: 29881
Joined: Wed Jul 07, 1999 11:27 am

RE: Biology

Sat Dec 01, 2001 5:18 pm

E-mail me....I got a 94 on the Mendel test I had about a month ago.

College level course.

It isn't hard once you realize what is going on.
OBAMA-WORST PRESIDENT EVER....Even SKOORB would be better.
 
L-188
Posts: 29881
Joined: Wed Jul 07, 1999 11:27 am

The Four Block Punit Square + Incomlete Dominance

Sat Dec 01, 2001 6:04 pm

Actually I have a final two weeks from now in that college class. So may trying to explain it will be a good refresher for me.

We are going to do some breeding with flowers. Assume the following.

R is a dominant red gene
W is a dominant white gene
r is a recessive red gend
w is a recessive white gene

Oversimplified, Dominance just means that one gene has more, if you will power over an recessive one. If the genes are of equal power or strenght to each other they will cancel each other out

Remember that for purposes of this discussions genes are in pairs. One from the father and one from the mother.

So lets say if we have a red flower that has a pair of genes that are both "R" and we mate it with a white flower that has both "w" as it's genes

We would make up the square like this

Fathers Gene Mothers Gene
R R
---------------------------------------------------
Fathers Gene w| Rw | Rw
----------------------------------------------------
Mothers Gene w| Rw | Rw
-----------------------------------------------------

In this case the four offspring from this mating each receive one gene from each plant a dominat red and a recessive white. Because the red is dominant all of the offspring is red(Rw).

Now lets pretent we are in Arkansas and two of the baby plants(Brother and Sister?) from the above example mate

Fathers Gene Mothers Gene
R w
---------------------------------------------------
Fathers Gene R | RR | Rw
----------------------------------------------------
Mothers Gene w| wR | ww
-----------------------------------------------------

What has happened here is that three of the four baby plants will be red (RR, wR, Rw) and one will have a white(ww) flower. This is because red is the dominate gene and overpowers the influence of the white gene.

Incomplete dominiance means that a gene will not overpower the influnce of another gene. Basicly you have two genes of equal dominance.

Fathers Gene Mothers Gene
R W
---------------------------------------------------
Fathers Gene R | RR | RW
----------------------------------------------------
Mothers Gene W| RW | WW
-----------------------------------------------------

Since both the white and red genes are equally dominant, neither one is completly dominant....and therefore we have "incomplete dominance"

The results of this mating is that if we where to have four baby plants. One would have red flowers (RR) one would have white flowers (WW) and two of them since they have equal strenght red and white genes (RW) would have PINK FLOWERS.


I hope this helps. I have to get back to work. I hope this explains dominace, incomplete dominace and the four square punit square. Do you know if you are going to cover a 16 square punit square?
OBAMA-WORST PRESIDENT EVER....Even SKOORB would be better.
 
ILS
Topic Author
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Joined: Fri Nov 09, 2001 2:34 am

RE: Biology

Sun Dec 02, 2001 3:25 am

Wow, thanks a lot everyone! Thanks a lot L-188.

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