Cells 2 Flashcards
how do we find heterochromatin?
tightly coiled DNA in storage
how do we find euchromatin?
it is diffuse and unraveled and in use or genetically active
identify the nucleolus, euchromatin, heterochromatin.
white is euchromatin
black small spots is heterochromatin
the nucleolus is the big black spot in the right
Do highly differentiated cells have euchromatin or heterochromatin? Many organelles, few organelles? small or prominent nucleoli?
euchromatin, many organelles, prominent nucleoli
Do highly undifferentiated cells have euchromatin or heterochromatin? Many organelles, few organelles? small or prominent nucleoli?
heterochromatin, few organelles, small nucleoli
how fast do undifferentiated cells divide?
very fast
how fast do differentiated cells divide?
rarely
how many membranes does the nuclear envelope have?
2; its a bi-layer
which layer of the nuclear membrane is continuous with the rough ER?
the outer
what does the nuclear membrane do?
it regulates mitotic activity
what is the nuclear membrane composed of?
intermediate filamentes and membrane proteins
how many histones does a nucleosome have?
9
what is the linker histone?
H1
what are the histones?
H2A,H2B, H3,H4
what does the nucleolus do?
synthesis of rRNA
What is the Pars Fibrosa of the nucleolus?
are genes undergoing transcription and filaments of rRNA
What is Pars Granulosa in the Nucleolus?
ribosomes taking shape
what is interphase?
cell prepares for division and has 3 stages: G1,S,G2
what happens in prophase?
nuclear membrane breaks, condensation of chromosomes
what happens in metaphase?
equtorial alignment of chromosomes
What happens in anaphase?
chromosomes separate to opposite poles
what happens in telphase?
nuclear membrane forms, decondensation of chromosomes
how are stem cells found? (differentiated or undifferentiated)
undifferentiated
