### cell:

Somatic cell
* Every somatic cell contains all the genetic information required for copying the whole organism.
  * are usually diploid, except where there is polyploidy. Either way, somatic cells have double the number of chromosomes that gametes in the same organism have. Somatic cells divide by mitosis and make identical copies of themselves, while gametes are made when germ cells divide by meiosis.
* accumulate oxidative damage as their fate is anyway death.
* are all the cells in a multicellular organism except the sex cells
  - rest
  - diploid in humans
  - eukaryotic cells
  - generally diploid, in constrast to gametes, which are haploid
* are produced by simple cell division called mitosis
  - from a zygote by mitosis
  - simply animal body cells present at low levels in normal milk
  - the second line of defense
  - usually diploid , except where there is polyploidy
* contain the full complement of chromosomes.
* contain two of each type of chromosome
  - pairs of each chromosome, while germ cells contain only one
* counts in bovine milk
  - relation to infection status of the goat udder
* divide using mitosis, for growth and repair.
* give rise to all non-germline tissues.
* have a limited lifespan, and they are difficult to manipulate genetically
  - the highest telomerase activity
* make up the rest of the body
  - skin, hair and muscle tissues
  - structural components of an animal, such as skin, muscle, and nerves
* replicate through mitosis and sex cells reproduce via meiosis.

Special cell
* help to take the food out of the water.
* line the inside of the nose.
* manufacture proteins, such as keratin, that make up the hair.
* receive stimuli and make appropriate responses.
* secrete the substances needed to form supportive or protective tissue.

Specialized cell
* act as receptors for certain chemical compounds.
* are more efficient than nonspecialized cells.
* arise by differentiation from unspecialized cells.
* can concentrate heavy metals, which are then deposited in the tunic.
* carry out both processes.
* help absorbed materials cross the intestinal lining into the bloodstream.
* perform specialized functions in multi-cellular organisms.
* protect the body from infectious disease.

Spermatocyte
* are a type of male gametocyte in animals
  - larger than spermatogonia, and in the early stage present synaptonemal complex
* includes cell membranes
  - corpi
  - cytoskeletons
  - lobes
  - nuclei
  - plasma membranes
  - sections
  - vacuoles
* undergo meiosis to produce spermatids that mature to become sperm cells.

### cell | spermatocyte:

Primary spermatocyte
* are arrested after DNA synthesis and prior to division
  - present in an irregular row toward the lumen
* go through the first meiotic division and become secondary spermatocytes.
* undergo a final round of DNA synthesis and enter meiosis.

Spindle cell
* are also like long thin cells that are mixed in with the muscle cells
  - dominant but there are also infiltrating inflammatory cells and vascular elements
* having eosinophilic cytoplasm resemble ordinary smooth muscle cells.

Sponge cell
* are very plastic and easily change from one type to another.
* obtain oxygen from water moving through the sponge by diffusion.

Stellate cell
* are the local circuit neurons.
* receive afferents and form intracortical networks.
* resemble smooth muscle but are of ectodermal origin.

Stromal cell
* are the cells that support the parenchymal cells in any organ.
* consist of fibroblasts, fat cells, endothelial cells, and mature macrophages.
* mediate retinoid-dependent functions essential for renal development.
* recruit cancer cells by producing soluble chemoattracting molecules.