Early in mitosis, during prophase and prometaphase, the nucleus, nucleolus and nuclear envelope begin to dissolve in preparation for cell division. During telophase, which is the final stage in mitosis,, there is a reversal of effects of prophase and prometaphase; nucleus, nucleolus and nuclear envelope are again formed.
phytoplankton falls on the first trophic level which is are "primary producers", it is because even smallest to smallest creatures like zooplankton feed on phytoplankton.
