Cell Reproduction and Differentiation Flashcards
This is crucial because without it, we would have remained unicellular.
cell reproduction
Creatingmillionsofcellsisnot
enough; we can’t just keep creating. Differentiation is key. We assign them distinct purposes, functions, and roles.
cell differentiation
cell division = reproduction
unicellular organisms
Like us, they undergo cell division, PMAT, and have the ability to reproduce. When they divide to become another cell, it is a form of reproduction. The initial cell, upon giving birth, generates additional cells, leading to an increase in population.
unicellular organisms
cell division = development
multicellular organisms
As we age, our internal structures evolve into increasingly complex forms.
development
Every time our cells divide, it
involves growth, which can manifest in literal size.
★ Fertilized cell -> Baby
growth
Our bodies have the ability to self repair because of cell division.
regeneration
two phases of cell cycle
interphase and mitotic phase
→ Primary period of cell growth
→ The cells are starting to create the organelles
→ “Organelle Factory”
→ Here, we are developing our
mitochondria, chromosomes, nuclear membranes, and many more. The major organelles are created here.
G1phase
- “In between cell division”
- Long growth period between cell
divisions - Long portion of the Cell Cycle
- A lot of people say that everything
here is at rest but that is not correct. It is actually preparing for the main event which is the M Phase.
interphase
→ DNA is duplicated
→ Growth continues slowly
→ Creating the genetic material that could mean DNA and RNA
→ Central Dogma happens here
→ A composition of a cell is simply organelles inside then on the middle is the nucleus and inside that nucleus are the genetic material. So the G1 and S Phase are both equally important phases.
S phase
→ Cell prepares for division
→ Chromatin condenses into
chromosomes
→ Growth continues slowly
→ Preparing for the next step
→ Double checking the organelles
and genetic material because for the preparation for M Phase
→ Everything entering the M Phase needs to be perfect already.
G2 phase
Inside our bodies, there are cells that decode signals to cease reproduction; they become non-dividing. These cells retain the characteristics you have at a certain age until the day you die. If they get damaged, repairing them becomes nearly impossible.
G0
→ are cells that can be found in the bones
→ At some point in our life, our bones stop growing.
osteocytes
→ Permanent
→ At some point in our lifetime, our neurons stop reproducing. This will cause conditions related to memory and impaired brain function.
neurons (nervous system)
→ Temporary
→ These are for boys and this only
activates at a certain period of their life to generate sperm cells.
spermatocytes
→ Temporary
→ These are for girls that are
temporarily G0 and only activate when they experience menstruation.
oocytes
How long does the M phase take?
less than an hour
how long does g1 take?
5-6 hours
how long does s phase take?
10-12 hours
how long does g2 take?
4-6 hours
in human cells, complete cell cycle takes how long?
18-24 hours
- Not all cells divide at the same rate
- Internal surveillance and control
mechanism - Several key checkpoints where “go
ahead” signals must be received in order for the cycle to progress to the next phase - Outside influences can modify cell cycle
- Hormones, growth factors,
presence of other cells - These are for checking, controlling,
and regulating the different
processes - Located in between the phases
cell regulation
it checks the organelles
g1 checkpoint
it checks the genetic material
s checkpoint
it double checks the double checker to ensure that everything is perfect to produce a perfect and healthy cell
g2 checkpoint
the cell examines whether all the sister chromatids are correctly attached to the spindle microtubules
M checkpoint
this is continually being formed from deep layers of cells. the outermost layer of dead cell is constantly being sloughed off
skin cells