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View Full Version : Interesting Bio question laundry 05-19-2007, 05:26 PM A neat question I came up with: Meiosis occurs only in: A. Sexual reproduction B. Asexual reproduction C. Mitosis D. Two of the above think twice and remember plants... blueyes34 05-20-2007, 09:24 AM Isn't it A? laundry 05-20-2007, 09:41 AM Kaplan blue book says that sporophyte generation reproduces asexually. Yet it undergoes meiosis...So that makes it D. Unless im overthinking something... jeezy 05-20-2007, 10:29 AM A poc91nc 05-20-2007, 10:37 AM Doesn't the sporophyte arise from the fussion of gametes? And the sporophyte undergoes meiosis to generate a spore which undergoes mitosis to give the gametophyte? Kinda confused....care to elaborate a little more? How is the sporophyte reproduced asexually if it arises from the fusion of gametes? laundry 05-20-2007, 10:37 AM :rolleyes: then what do you call sporophyte meiosis? it doesn't produce gametes... poc91nc 05-20-2007, 11:12 AM Not the most reliable source....but wikipedia says asexual reproduction is a form of reproduction not involving meiosis. Again...not the most reliable source, but wouldn't you agree that meiosis and asexual reproduction is a tad counter-intuitive? You're right...the sporophyte gives rise to a spore which undergoes mitosis to give the gametophyte which produces the gametes. Still the reproduction of the sporophyte itself invovles the fusion of two gametes (that doesn't seem asexual to me). We're you alluding to the context of two gametes from the same gametophyte coming together to give a sporophyte? I know there are asexual mechanisms in plants...but I don't think I've heard of two gametes from the same gametophyte coming together to give a sporophyte. Does anyone know if this is possible? cabbagebrain 05-20-2007, 11:16 AM This is off the top of my head, so I may have it wrong. But as I recall, the sporophyte generation of plants is diploid. They undergo meiosis to produce haploid spores. Those spores undergo mitosis, giving rise to the haploid gametophyte generation. It is the gametophyte generation that produces haploid gametes, which fuse to form a diploid zygote, which then grows into the sporophyte generation. So... Sporophyte (2n) --> spores (n, via meiosis) --> gametophytes (n) --> gametes (n) --> zygote (2n) --> sporophyte. Hopefully that's right and made sense. cabbagebrain 05-20-2007, 11:17 AM Oops, too slow and can't delete. Sorry! supraman 05-20-2007, 11:22 AM This is off the top of my head, so I may have it wrong. But as I recall, the sporophyte generation of plants is diploid. They undergo meiosis to produce haploid spores. Those spores undergo mitosis, giving rise to the haploid gametophyte generation. It is the gametophyte generation that produces haploid gametes, which fuse to form a diploid zygote, which then grows into the sporophyte generation. So... Sporophyte (2n) --> spores (n, via meiosis) --> gametophytes (n) --> gametes (n) --> zygote (2n) --> sporophyte. Hopefully that's right and made sense. Well done... thus it is A. I mean think about it; mitosis: 2n to 2n mieosis: 2n to n laundry 05-20-2007, 11:22 AM hm...i think it's a lil over DAT's margin for biology section...hopefully...hehe jackbauer! 05-20-2007, 11:53 AM hm...i think it's a lil over DAT's margin for biology section...hopefully...hehe think again :eek: jb!:) |