Escherichia coli (commonly abbreviated E. coli) is a Gram-negative, rod-shaped bacterium that is commonly found in the lower intestine of warm-blooded organisms (endotherms).Most E. coli strains are harmless, but some serotypes can cause serious food poisoning in humans.The harmless strains are part of the normal flora of the gut, and can benefit their hosts by producing vitamin K2, and by preventing the establishment of pathogenic bacteria within the intestine.ost E. coli strains are harmless, but some serotypes can cause serious food poisoning in humans. The harmless strains are part of the normal flora of the gut, and can benefit their hosts by producing vitamin K2, and by preventing the establishment of pathogenic bacteria within the intestine.
In flowering plants the gametophytes are very reduced in size, and are represented by the pollen and the embryo sac. The sporophyte produces spores (hence the name) by meiosis, a process also known as reduction division that reduces the number of chromosomes in each spore mother cell by half.The resulting meiospores develop into a gametophyte.n flowering plants the gametophytes are very reduced in size, and are represented by the pollen and the embryo sac. The sporophyte produces spores (hence the name) by meiosis, a process also known as reduction division that reduces the number of chromosomes in each spore mother cell by half.
Alternation of generations overview. the gametophyte produces haplod gametes by mitosis; two gametes unite and form a diploid zygote; the zygote develops into a multicellular diploid sporophyte; the sporophyte produces haploid spores by meiosis; the spores develop into multicellular haploid gametophytes.porophyte. in organisms (plants and some algae) that have alternation of gnerations, the multicellular diploid form that results from the union of gamtes; it produces haploid spores by meiosis that develop into gametophytes.