I: | independent existence |
II: | performing the essential functions of life |
I: | The outer nuclear membrane usually remains continuous with the endoplasmic reticulum but does not bear ribosomes on it. |
II: | Nucleolus is a single membrane-bound structure. |
III: | Chromatin contains DNA and some acidic proteins called histones, but does not contain non-histone proteins and RNA. |
IV: | Every chromosome essentially has a primary constriction or the centromere on the sides of which disc-shaped structures called kinetochores are present. |