During embryological development the unspecialised stem
cells of the early embryo differentiate into cells with
specialised functions
What are Stem Cells?
Stem cells are unspecialised somatic cells that
can divide to make copies of themselves & can
differentiate into specialised cells of one or more
types
How do Embryonic Stem Cells work?
Cells of the very early embryo, differentiate into
all the cell types that make up an organism.
They are said to be pluripotent.
How do Adult Stem Cells work?
Tissue stem cells are involved in the growth,
repair and renewal of the cells found in that
tissue. They are said to be multipotent
What are the main tissue types?
The main tissue types in the body are:
apithelial, connective, muscle and nerve.
The body organs are formed from a variety of
these tissues.
What cells types do Multipotent
haematopietic stem cells create?
Multipotent haematopietic stem cells in the red bone
marrow give rise to all the cell types in the blood: red
blood cells, platelets, and the various forms of
phagocytes and lymphocytes
What do Tissues work together to create?
Tissues work together to form more complex
organs, systems, and organisms such as humans.
How do somatic cells divide?
Somatic cells divide my
mitosis to form more
somatic cells, maintaining
the diploid chromosome
number.
What is Cellular Differentiation?
Cellular Differentiation is the process by which
a cell develops more specialised functions by
expressing the genes characteristic for that cell
type.
What happens when the cell becomes
differentiated?
Once a cell becomes differentiated it only expresses
the genes that produce the proteins characteristic for
that type of cell
How many pairs of chromosomes
does a Germline nucleus contain?
The nucleus of Germline cells
have 23 pair of chromosomes &
are said to be diplopd.
How do Germline Cells divide?
Germline cells divide by mitosis to produce new germline cells (diploid).
Germline cells can also divide by meiosis to produce
haploid gametes - these germline cells are known as
Gamete Mother Cells.
Where are Gamete Mother Cells found and what
do they produce?
Gamete Mother Cells are
found in the sex organs and
give rise to haploid gametes -
Sperm & Eggs
What is the difference between mutations that occur in
somatic cells & germline cells?
Mutations that occur in germline cells
are passed to offspring whereas
mutations in somatic cells will not.
What are stem cells used for?
Stem cell research provides information on how the cells
processes such as cell growth, differentiation & gene
regulation work.
Also used as model cells to study how diseases develop or for drug testing.
What are the therapeutic uses of stem
cells?
The therapeutic uses include repair of diseased or damaged organs; by bone
marrow transplants, skin grafts for burns & stem cells grafts for cornea
repair
What happens if Cancer cells divide excessively?
Cancer Cells divide excessively to produce a mass of abnormal cells (a
tumour) that do not respond to regulatory signals and may fail to attach
to each other.
If the cancer cells fail to attach to each other they
can spread throughout the body to form secondary
tumours.