Cell differentiation

what is a simple definition of organs

communities of specialised cell types

what is cell differentiation

the process by which unspecialised cells become specific cell types

how do cells differ

based on the presence of different proteins, different metabolites, different morphologies and behaviours

where are chromaffin cells found

within the adrenal glands

give a brief overview of chromaffin cells

produce the hormone epinephrine, contain large numbers of vesicles containing epinephrine, contain the enzyme that converts tyrosine into norepinephrine and epinephrine

when do chromaffin cells release epinephrine into the bloodstream

upon simulation from the autonomic nervous system

what do cell lineages refer to

the developmental history of the cell

what does lineage restriction refer to

as cells become more specialised, the number of cells they can become is restricted

what is developmental potency

unspecialised cells in the early embryo are pluripotent, can form any cell type, multipotent cells can differentiate into many different cell types but not all

what is terminal differentiation in simple terms

when differentiation ends, the final cell form

what are the different germ layers

ectoderm, mesoderm, endoderm

when are germ layers formed

during gastrulation

how are mesoderm cells more differentiated

by the presence of specific proteins, characteristic cell behaviour, restricted future differentiation potential

do mesoderms exist in the final organism

no

what is gastrulation

the formation of germ layers by invagination

where are HSCs found

in the bone marrow

what does the endoderm develop into

several different internal organs

can the nucleus of differentiated cells support the development of a new organism

yes, this was first shown in frogs but can be done in plants and mammals

what is gene constancy

all cells in multicellular organisms have a full complement of genes

how can gene expression be controlled

DNA may be transcribed from all genes but RNA is degraded in cells that do not require it or the DNA may just not be transcribed