Models of an axiomatic system are isomorphic if there is a one-to-one correspondence between their elements that preserves all relations. That is, the models are abstractly the same; only the notation is different. An axiomatic system is categorical if every two models of the system are isomorphic.
The Nucleus. The largest and most clearly visible of the cell's constituents is the nucleus. Within the nucleus, DNA molecules, the cell's genetic machinery, are stored, repaired, transcribed and eventually replicated. Around the outside of the nucleus is an envelope consisting of two layers of membrane.
Report Abuse. DNA is found in the nucleus, and mitochondria and chloroplasts, cytoplasm too, but not very frequently.... RNA is found pretty much everywhere-nucleus, nucleolus, mitochondria, chloroplasts, ribosomes, cytoplasm... hrm_i_am_focking_bored Â· 9 years ago. Thumbs up. 8. Thumbs down. 0. Comment.