When microbial action during decomposition in aquatic ecosystems removes too much oxygen, the body of water experiences

N and P limitation is strongest in aquatic ecosystems (because light and water isn't) governed by same principles as terrestrial ecosystems radically different environmental controls streams have been treated as "sewers of terrestrial ecosystems" yet stream ecosystems have their own characteristics generated by the interaction of biota with the physical and chemical properties of the system unlike terrestrial ecosystems, nutrients "spiral" rather than cycle. The more limiting the nutrient, the tighter the spiral. Detritus/heterotrophs <---> autotrophs. 

answer; i believe that the correct answer is ; males are hemizygous for the x chromosome;

prophase: we can observe the chromosomes to coil up and condense. they become visible. nuclear membrane and envelope disintigrate.s

metaphase: chromosomes align at the center, the metaphase plate. spindle fibers attach to centromeres of the sister chromatids. they meet at kinetochores.

anaphase: sister chromatids are pulled towards each opposing centromere, set on different poles.

telophase: chromosomes are now clustered up only on either sides of the cell. nuclear membranes reform, and a new cell wall forms along the cell plate. this will lead to cytokinesis, the process that divides the cell membrane and forms the cell wall.