### cell:

New cell
* Every new cell requires over a trillion new molecules.
* are added to the nest as the number of larvae grows.
* are created by other living cells by the process of cell division
  - through cell division, when one cell splits into two
* are formed by mitosis and so are exact copies of the cells being replaced
  - only from the pre-existing cells
  - needed throughout life
* are produced at the same rate as older cells die
  - from existing cells
* arise by mitosis in the deep crypts and migrate up the sides of the villi to the tips
  - from the division of pre-existing cells
* begin forming into chains.
* come from the division of old cells.
* form and take the place of old or injured cells.
* get their chromosomes from old cells through cell division, or mitosis.
* grow to replace the damaged ones.
* keep forming, however and a cyst filled with cells forms under the skin.
* originate in the lowest layer and become keratinized as they are pushed to the surface.

### cell:

Normal cell
* Most normal cells are able to recover quickly when the treatment is over
  - differentiated, that is, they have a specific appearance and function
  - grow, reproduce and die in response to signals inside and outside the body
* are able to recover from radiation damage better than cancer cells
  - capable of repairing damage to their DNA as a means of preventing mutation
  - genetically pre-programmed to produce new copies of themselves and then die out
  - subject to both positive and negative growth stimulii
* can only serve one function.
* die off as they compete against the cancer cells for nutrients.
* differ from cancer cells by their capacity to repair themselves.
* divide in a planned way, creating more cells only when needed
  - an orderly way, making more cells only when needed
* exposed to radiation begin to repair themselves hours after exposure.
* grow and die in a controlled manner
  - divide, but have a limited life span
* grow, divide and die in an orderly fashion
  - divide, and die in an orderly manner
* grown in culture tend to stick together causing movement to stop.
* have a defined life span, roughly a few weeks to a few months
  - greater ability to repair themselves than do cancer cells
  - protective coating of sugars around their core
  - telomere ladder, each containing partials up to seven subunits
* have two copies of each chromosome
  - very small nuclei
* live only so long and then die.
* react after proteolytic treatment.
* reproduce themselves and divide in two
  - throughout life, but in an orderly and controlled manner
* show low amounts and nuclear localization.
* stop dividing to create new cells when they reach the end of their natural life span
  - growing and dividing at appropriate times
* take up DNA and begin expressing the protein which induces an immune response.
* tend to lose their ability to proliferate during the process of differentiation.

Nurse cell
* make sure the egg has all the nutrients it needs before joining with the sperm.
* produce the bulk of the cytoplasmic contents of the mature oocyte.

Old cell
* detach more rapidly uncovering smoother, finer textured, and more supple skin.
* have short telomeres.