“Cell division generally takes place asexually by mitosis, a process that allows each daughter nucleus to receive one copy of each chromosome. Most eukaryotes also have a life cycle that involves sexual reproduction, alternating between a haploid phase, where only one copy of each chromosome is present in each cell and a diploid phase, wherein two copies of each chromosome are present in each cell. The diploid phase is formed by fusion of two haploid gametes to form a zygote, which may divide by mitosis or undergo chromosome reduction by meiosis. There is considerable variation in this pattern. Animals have no multicellular haploid phase, but each plant generation can consist of haploid and diploid multicellular phases.”

https://en.wikipedia.org/wiki/Eukaryote

I’d honestly never thought of it in that way before: an alternation between phases of life: haploid generating diploid, diploid generating haploid.

dv said:

“Cell division generally takes place asexually by mitosis, a process that allows each daughter nucleus to receive one copy of each chromosome. Most eukaryotes also have a life cycle that involves sexual reproduction, alternating between a haploid phase, where only one copy of each chromosome is present in each cell and a diploid phase, wherein two copies of each chromosome are present in each cell. The diploid phase is formed by fusion of two haploid gametes to form a zygote, which may divide by mitosis or undergo chromosome reduction by meiosis. There is considerable variation in this pattern. Animals have no multicellular haploid phase, but each plant generation can consist of haploid and diploid multicellular phases.”

https://en.wikipedia.org/wiki/Eukaryote

I’d honestly never thought of it in that way before: an alternation between phases of life: haploid generating diploid, diploid generating haploid.

> I’d honestly never thought of it in that way before: an alternation between phases of life: haploid generating diploid, diploid generating haploid.

I first became aware of that with ferns. A spore grows into a free-living haploid gametophyte by mitosis.

It was expressed in that form in a little zoology book from the 1970s that i loved, and still have.

http://www2.nau.edu/~bio372-c/class/sex/lfcc.htm

SCIENCE said:

http://www2.nau.edu/~bio372-c/class/sex/lfcc.htm

> REPRODUCTIVE DIVERSITY IN THE PLANT KINGDOM

The further back you go, the more diversity there is in the way that organisms reproduce.

“For instance, if looking for information about sex, the Guide suggests reading “chapters seven, … twenty-one to eighty-four inclusive, and in fact most of the rest of the Guide”.”