Lecture 16 Flashcards
1
Q
What lines the inner surface of the nuclear envelope?
A
nuclearr lamina
2
Q
What are the nuclear lamina composed of?
A
Intermediate filaments which:
- maintain nucleus shape
- organise the packing of the DNA
3
Q
What is the function of nuclear pores?
A
Allow nuclear cytoplasmic exchange
4
Q
What goes IN to the cell through the nuclear pores?
A
- Energy
- materials
- control signals
5
Q
What leaves, goes OUT of the nuclear pores?
A
- mRNA
- tRNA
- rRNA
6
Q
What is the structure of the nuclear envelope?
A
- composed of two membranes
- nuclear pores
7
Q
During interphase regions of chromatin are either called:
A
- Euchromatin
- Heterochromatin
8
Q
What does euchromatin mean?
A
DNA is not as tightly condensed
- less dense
- active DNA, used right now
9
Q
What does heterochromatin mean?
A
DNA is tightly condensed
- dense
- inactive DNA, used for later
10
Q
What do histone proteins do to DNA?
A
Condenses DNA hellix to form ‘nucleosomes’ beads on string
then to chromatin fibres
DNA condenses from 2nm - 10nm - 30nm - 300m metaphase chromosome
