Download PP Cell Cycle and Mitosis

The CELL CYCLE
and MITOSIS
Introducing the cell cycle

Introduction to cell cycle
DNA IS ENCODES
OUR GENETIC
BLUEPRINT
DNA IS
PACKAGED INTO
CHROMOSOMES
RESULT: DNA MOLECULE
IS PACKAGED INTO A
CHROMOSOMES THAT IS
50,000X SHORTER THAN ITS
EXTENDED LENGTH
SEM of chromosomes (d/s)
Chromosome
structure
double
stranded (d/s)
chromosome
centomere
single
stranded
(s/s)
chromo
some
Chromatid
The cell cycle
Enters own
cell cycle
Enters own cell cycle
May exit from cell
cycle:
Ageing and
differentiation
pathway
Introducing the cell cycle

Details of the Cell cycle and Mitosis
Stages of Mitosis:
•Use the matching cards to form a table in the format
shown on the next slide:
•Finish the table in your notes by completing the
description of each phase and then drawing a simple
diagram of each phase.
Stage of
Mitosis
Interphase
Prophase
Metaphase
Anaphase
Telophase
Interphase
Description
Drawing
Photographed
Image
Real images: Stages of Mitosis
A
C
D
B
Cross Section Showing Cells in
various stages of the cell cycle.
Now complete the activity
Online garlic root tips:
webaddress and question on
work sheet.
http://www.biology.arizona.edu/
cell_bio/activities/cell_cycle/cell
_cycle.html
Read 79-83 qu 9-14
Additional slides that might help
answer question that crop up
DNA IS ENCODES
OUR GENETIC
BLUEPRINT
DNA IS
PACKAGED INTO
CHROMOSOMES
RESULT: DNA MOLECULE
IS PACKAGED INTO A
CHROMOSOMES THAT IS
50,000X SHORTER THAN ITS
EXTENDED LENGTH
SEM of chromosomes (d/s)
Chromosome
structure
double
stranded (d/s)
chromosome
centomere
single
stranded
(s/s)
chromo
some
Chromatid
DNA Replication
Mitosis in garlic root tip
If cells are overlapping, squash the slide again. Avoid moving the coverslip from side to side.
n Make sketches of (or take photographs of) cells that show any of the stages of mitosis.
o Calculate the mitotic index.
p Compare the mitotic index of root tips from alliums that have been sprouting for 1, 2, 5 and 10 days.
q If available, compare the allium meristem tissue with that from other species.
Teaching notes
Cell division in flowering plants takes place in particular regions of the plant called meristems. Cells in meristems are not specialized for any particular function and
Chromosomes in root tip tissue are made visible with the stain. Dividing cells (if present) will show up clearly with chromosomes in different forms according to the s
The links between the cellulose walls of plant cells are broken down by the treatment with hydrochloric acid. This ensures that the stain can penetrate the cells and
The mitotic index is calculated like this:
The duration of each stage of mitosis has been recorded and the data (see table below) could be used to compare the observed frequencies of the different stages
compare the observed frequencies of the different stages as recorded by student
Stage
Observed occurrence in
representative microscope
fields
Duration
number of cells % of total cells minutes
% of total time
Prophase
216
85.0
71
85.0
Metaphase
17
6.7
6.5
7.7
Anaphase
8
3.3
2.4
2.9
Telophase
13
5.1
3.8
4.4