Chapter 10: Cell Growth & Division Flashcards
Mitosis and cell division produces two ______
identical daughter cells
3 goals of mitosis and cell division:
growth, repair, and development
1st problem: Cell size and material exchange
the larger a cell grows the surface area/volume ratio DECREASES which makes cells less efficient at…
- moving enough nutrients in
- moving waste out
Surface area of the membrane determines
the rate of exchange of materials
Volume of the cell determines
the rate material is used and discarded
As the cell increases, its volume increases faster than its SA, which ____ the ratio of SA:V.
decreases
2nd Problem: DNA Overload
as the cell gets larger, DNA stays the SAME, causing an information shortage.
- DNA demands cannot support the protein needs of large cells
Instead of growing too large, cells _______
divide in half!
- this increases SA/V ratio
- all organisms grow and change: worn-out tissues are replaced by newly produced cells
How does cell division solve the two growth problems?
- SA:V is increases, so efficient exchange of material can occur through the cell membrane
- Each daughter cell gets its own DNA so their is no information shortage.
10.2
.
Define The Cell Cycle.
series of events that cells go through as they grow and divide.
Two halves of the cell cycle:
- Interphase
- M Phase
Describe Interphase
the period of the cell cycle between cell divisions
Describe the M phase.
period of time when mitosis and cell division occurs
G_1 phase (Gap 1)
- growing
- synthesizes new proteins and organelles
- longest phase of the cell cycle
S Phase (Synthesis)
- Chromosomes (DNA) are replicated
- key proteins associated with replication are made (centromeres)
G2 Phase (Gap 2)
- shortest of the 3 phases of interphase
- organelles and molecules for cell division are produced (centrioles)
- checkup phase
What stage in the cell cycle would most likely be for a cancer-causing genetic mutation to occur? Why?
S Phase
- this is where DNAs are replicated
At what point in the cell cycle could the cell catch this mutation and either fix it or push the cell into apoptosis (programmed cell death)?
G_2 phase
- G2 phase is the checkup phase before mitosis, and organelles and molecules can be produced to kill the cell.
________ condenses into ________ before mitosis begins.
Chromatin; Chromosomes
Chromatin
a complex of DNA and proteins in the cell nucleus that condenses to form chromosomes
- messy and spread-out
Chromosomes
condensed chromatin