tetrad crossing over question (genetics) science people??

**IronReload04** · 03-19-2009, 11:23 PM

hey guys. FOr those of you that are confident in your answer, please reply, I have a test tomarrow morning. IF you feel like replying, mention how confident you are in your answer.

when you have a tetrad in prophase 1 of meiosis

can Crossing over occur between the outer chromatids? Can an Outer chromatid recombine with the inner homolougus chromatid? OR is crossing over just between the inner chromatids?

**jbm** · 03-19-2009, 11:25 PM

OMG! I'm lost...

***RAGE*** · 03-19-2009, 11:31 PM

**Phate** · 03-20-2009, 12:22 AM

Originally Posted by IronReload04

hey guys. FOr those of you that are confident in your answer, please reply, I have a test tomarrow morning. IF you feel like replying, mention how confident you are in your answer.

when you have a tetrad in prophase 1 of meiosis

can Crossing over occur between the outer chromatids? Can an Outer chromatid recombine with the inner homolougus chromatid? OR is crossing over just between the inner chromatids?

i don't get what you mean by outer chromatids, but i would say it is just the two inner chromatids because crossing over occurs when the tetrads are aligned like this:

therefore, the crossing over would always occur in the inner chromatids

**IronReload04** · 03-20-2009, 12:27 AM

yeah, I think you understand my question

)*( )*(

let that be homolougus chromosomes. each chromosome has 2 chromatids represented by the parenthesis, and the centromere represented by the star.

SO you think only the inner chromatids in each pair can cross over. That is my guess too. But I think the question if the outer ones can participate is a good question and I have never heard of it even being adressed.

**IronReload04** · 03-20-2009, 12:28 AM

Originally Posted by jbm

OMG! I'm lost...

Originally Posted by prone2rage

ehhhh, I'd be too if I was never taught it.

**peachfuzz** · 03-20-2009, 12:38 AM

i believe crossing over is only between the inner chromatids? not 100% tho. as no science is.

**IronReload04** · 03-20-2009, 12:38 AM

Originally Posted by Phate

i don't get what you mean by outer chromatids, but i would say it is just the two inner chromatids because crossing over occurs when the tetrads are aligned like this:

therefore, the crossing over would always occur in the inner chromatids

Right.....Thanks for the pic. I dont think I need to know this on any kind of level other than that picture. But I was just curious. This is not really a super important detail, but I am like 2/3's% sure that after chromosomes recombine, the sister chromatids themselves can swap genes, but dont quote me on it.

**peachfuzz** · 03-20-2009, 12:41 AM

maybe this will help you?

http://www.jimtrue.com/school/bsc2010/000068.html

**Phate** · 03-20-2009, 12:42 AM

Originally Posted by IronReload04

Right.....Thanks for the pic. I dont think I need to know this on any kind of level other than that picture. But I was just curious. This is not really a super important detail, but I am like 2/3's% sure that after chromosomes recombine, the sister chromatids themselves can swap genes, but dont quote me on it.

they can, i'm almost 100% sure

**Phate** · 03-20-2009, 12:43 AM

Originally Posted by peachfuzz

maybe this will help you?

http://www.jimtrue.com/school/bsc2010/000068.html

thank you, and we are correct iron, just the inner

**IronReload04** · 03-20-2009, 12:47 AM

Originally Posted by Phate

they can, i'm almost 100% sure

Ya, I remember that from the actual genetics class I took. This final I have tomarrow is just a repeat of a freshman year bios. Its a COMPREHENSIVE final which will be pretty broad. So I know this on a level way way way more than I need to which is good.

Originally Posted by Phate

thank you, and we are correct iron, just the inner

thanks for checking that dude. its 2:30, and I am gonna be studying straight through until my exam at 10

**peachfuzz** · 03-20-2009, 12:50 AM

crazy mofo

**IronReload04** · 03-20-2009, 12:56 AM

all nighters are clockwork for me now. I got an A going into this final, just trying to hang on to it. The final is comprehensive and its an absolute beast. But the questions are supposed to be kind of broad. I am just overdoing it to ensure I keep that A.

**peachfuzz** · 03-20-2009, 01:14 AM

nerd

**IronReload04** · 03-20-2009, 01:16 AM

HUAHAHhahahahahahah

I'm the steely eyed missile man!!!!!

**IronReload04** · 03-20-2009, 04:29 AM

still trucking but man is this a bitch.

**Matt** · 03-20-2009, 06:32 AM

Nough said...

**IronReload04** · 03-20-2009, 07:28 AM

lol we got it covered I think

I'm about to go take this bitch and make the class average look like clowns.

**Phate** · 03-20-2009, 07:31 AM

Originally Posted by IronReload04

lol we got it covered I think

I'm about to go take this bitch and make the class average look like clowns.

go get'em tiger, lol

**IronReload04** · 03-20-2009, 03:56 PM

My results:

final exam grade - 109.00% with the curve, 95% without the curve
class average: 70% with curve, 61% without curve

final grade- I finished with over a 100 percent, median and mode is a C for the course.

I get a huge pat on the back.

**J-Dogg** · 03-20-2009, 04:00 PM

So if I rape a small animal....it can't get preggers?

Congrats on the grade too bro, thumbs up.

**J-Dogg** · 03-20-2009, 04:03 PM

So if I rape a small animal....it can't get preggers?

Congrats on the grade too bro, thumbs up.

**Phate** · 03-20-2009, 04:46 PM

Originally Posted by J-Dogg

So if I rape a small animal....it can't get preggers?

Congrats on the grade too bro, thumbs up.

completely different reason, but no it can't get pregnant

**IronReload04** · 03-20-2009, 05:19 PM

lol

thanks guys. THis grade makes up for the other class in which I sucked balls on the final and evens things out nicely.

**Phate** · 03-20-2009, 05:24 PM

Originally Posted by IronReload04

lol

thanks guys. THis grade makes up for the other class in which I sucked balls on the final and evens things out nicely.

congrats bro, i understand how hard bio and such can be, all my biology, zoology and chemistry exams AND lab practicals are cumulative, sux balls

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