Section 10-1 & 10-2
Learning Target:
Know the reasons for why cells divide.
Learning Outcome:
I will know limitations to cell growth
and structure of chromosomes.
https://www.youtube.com/watch?v=xuG4Z
Z1GbzI
Cells divide rather than get larger
because…….
1. Demands on DNA would be too great.
2. Cell would have trouble moving food
and waste across the cell membrane.
Volume increases faster than surface area.
 Made
up of DNA
wrapped around
proteins!
 Each
cell of an
organism has a
specific number
• Ex. Fruit flies = 8
• Ex. Austin Powers= 46
• Ex. Carrots - 18
 During
cell division chromatin condenses into
chromosomes.
 In order for each cell to get the right number
the chromosomes have to double
Learning Target:
Know the phases of Cell Division.
Learning Outcome:
I will complete the “Mitosis Flipbook.”
 Cell
cycle – The series of events that cells
go through as they grow and divide.



G1 – Growth phase #1.
Cells increase in size and
make new proteins and
organelles.
S – Synthesis.
Chromosomes are
replicated.
G2 – Growth Phase #2
Cell division organelles are
produced. Short phase.
Cell division is made up of 2 parts.
1. Mitosis – division of the nucleus.
Divided into 4 phases.
2. Cytokinesis – division of the
cytoplasm.




Chromosomes are visible.
Centrioles separate
Spindle fibers form
Nuclear membrane breaks down.
 Chromosomes
the cell
line up in the middle of
 Chromosomes
are pulled apart/away
from each other.




The opposite of prophase occurs.
Chromosomes disappear back to chromatin
Nuclear membrane reforms
Spindle fibers break apart and disappear
 Cytokinesis
occurs right after Mitosis and
is the division of the cytoplasm.
 Therefore, since
cells can not become too large
they need to divide into “daughter cells”
 To
do this the DNA first copies itself so each
daughter cell receives exact copies of the
genetic info needed for the cell
 Also
the ratio of surface area to volume
increases which is a very good thing!
1.
2.
3.
4.
Identify the phases in the diagrams
before cutting out.
Cut out the diagrams.
Glue diagrams to flashcards.
On the back write the following:
1. Phase of cell cycle
2. What is occurring in the diagram.