alternation of generation.

[joonkimdds]

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I was studying plant chapter and I don't understand alternation of generation even after reading many diff explanations.

gametophytes(male and felmale) =>make sperm and egg that comebine and become =>zygote(2n)=>embryo(2n)=>sporophyte(2n) that makes=>spore👎=>becomes either gametophyte👎 and recycle again or sporophyte(2n).

is it correct?

if it is, i don't understand how spore can become sporophyte. spore is haploid and sporophyte is diploid.

 

[Mackchops]

sporophyte makes spores
gametophyte makes gametes

You know what gametes are from human repro, so you know they're 1n. Two 1n's get together, do the nasty, and make a 2n sporophyte. The sporophyte makes 1n spores via meiosis which become gametophytes.

I think you had it down, except I don't know where you got the last part -- a haploid spore will only produce a haploid gametophyte -- not a sporophyte! You need fertilization to get back to a diploid sporophyte via the gametes produced by the gametophyte! Maybe you're confused because a mature gametophyte can produce either/both antheridia (Male) or archegonia (Female)? I guess think of plant gametes being produced via mitosis (haploid produces haploid -- either gender) and spores are produced via meiosis (2n => n).

It's nasty, I know. Remember the top part though and remember that spores and gametes are haploid and that's really all you need.

Mack