Mitosis & Chromosomes
Histology SSN
September 22, 2004
Presented By:
Tresha Edwards & Nadia Goodwin
The Cell Cycle
What is the
ploidy of the
cell at stage
G2?
Cell during
Interphase
STAGES OF MITOSIS
Whitefish Mitosis
I
P
A
M
T
Key Structures: Nuclear Membrane, Chromosomes, Spindles,
Cytoplasmic membrane
Prophase
• Assembly of mitotic
spindle
• Chromosome
condensation
Prophase
Prometaphase
• Nuclear envelope
breakdown
• Attachment of
chromosomes to
spindle apparatus
Metaphase
Spindle poles
• Alignment of the
chromosomes at the
metaphase plate
• Rate-limiting step of
mitosis!
Metaphase plate
Kinetochore
microtubules
Anaphase
Anaphase A
• Sister chromatids
separate and move
towards poles
• Kinetochore
microtubules shorten
Anaphase B
• Spindle poles move
apart
• Cytokinesis begins
Telophase
• Nuclear envelope
reassembly
• Chromosome
decondensation
• Cytokinesis is
completed
Question 1
Put the numbered cells in sequential order.
4
1
3
2
5
Question 2
This structure could
be part of the
a) Kinetochore
b) Centromere
c) Microtubule
Organizing Center
(MTOC)
d) Cleavage furrow
e) Chromatid
Question 3
What characteristics
would you expect to
find in the cell at the
pointer:
I. Spindle apparatus
II. Nuclear envelope
III. Contractile ring
IV. Equatorial plate
a)
b)
c)
d)
I and II only
I, II, and IV
I and IV
All
Question 4
All of the following
pertain to the cell
labeled 1, EXCEPT:
a) Nuclear envelope has
disbursed
b) Mitotic spindle has
begun formation
c) Centrosomes have
separated
d) DNA has been
duplicated
1