Transcript Cell Growth and Division

Cell Growth and Division
Chapter 10
Why do cells divide?
• Cells divide to allow the organism to
grow and to repair damaged tissue
• Cells grow, then divide. Why don’t they
keep growing?
• Large cells do not have enough DNA to
function.
• Large cells could not diffuse oxygen
and nutrients efficiently. *Agar block
lab*
Cell division in Prokaryotes and Eukaryotes:
• Prokaryotes – single chromosome is
copied and the cell splits. Binary
fission.
• Eukaryotes – All chromosomes must be
copied into sister chromatids, held
together by a centromere. The copies
are then split apart in a process called
MITOSIS. The cytoplasm is then split
by CYTOKINESIS.
The Cell Cycle
Cell cycle
Main steps of mitosis:
“IPMAT”
• Interphase – The cells grows and replicates
DNA and centrioles.
• Prophase – DNA wraps up into chromosomes.
The nuclear membrane dissolves.
• Metaphase – Chromosomes line up. Spindle
fibers created by the centrioles attach to the
centromere..
• Anaphase – The will spindle fibers will pull
the sister chromatids apart
• Telophase – chromosomes at opposite ends,
the nuclear membrane re-forms.
Live video of mitosis:
•Cell division
•Newt cell division
Mitosis Lab Microscope Images
• Onion Root
tip
• Low Power
Onion Root tip – High Power
Whitefish blastula – Low Power
Whitefish blastula – High Power
• What
phase
is this
cell in?
Duration of mitosis phases…