Emergent Properties

Multicellular organisms are capable of completing functions that unicellular organisms can’t

Collective actions of individual cells combining to create new synergistic effects

Cell Differentiation

Multi-cellular organisms made of specialized cells - physical and chemical properties to perform one job very well

Cell Differentiation - process by which a cell becomes specialized to perform a specific function via activation of some genes by chemical signals and not others

Gene Packing

Differentiated cells have different regions of DNA packaged as euchromatin and heterochromatin

Euchromatin - expanded form that is accessible for transcription (active gene)

Heterochromatin - condensed form that is not accessible for transcription (inactive gene)

Stem Cell

Stem Cell - animal cell that can differentiate into many types and continually replicate

Stem cells can be derived from 3 places:

Embryos

Umbilical Cord Blood

Adult Tissues

Types of Stem Cells

Totipotent - form any cell type and develop into entirely new organisms (ex - zygote) - embryonic

Pluripotent - form any cell type arising from 3 germ layers (ex - inner mass of blastocyst) - embryonic

Multipotent - only form closely related cell types (ex - bone marrow) - adult

Stem Cell Niches

Sites within body where pool of adult stem cells are maintained

Locations of stem cell niches:

• Bone Marrow

• Hair Follicles

• Heart

• Intestines

• Brain

Uses of Stem Cells/hea

Necessary for embryonic development - undifferentiated cell

source from which all other cell types may be derived

Viable therapeutic option when adult tissues become damaged

and cannot be regenerated