I believe blood vessels constrict
<span>The sequence of alternation of generation is; gametes->zygote->sporophyte->spores->gametophyte->gametes.
The attached diagram shows clearly this looped cycle. Alternation of generation
occurs in a more advanced land plant that
has distinct
haploid and diploid phases in their life
cycle. The diploid phase usually involves
the sporophyte while the haploid phase involves the gametophyte</span>
Nucleus to the ribosomes, I think.
The mesenteric veins and the hepatic portal vein
