differentiation is the process by
which a cell changes to become
specialised for its job
as cells change, they develop different subcellular structures and
turn into different types of cells. This allows them to carry out
specific functions.
most differentiation occurs as an organism develops. in
most animal cells, the ability to differentiate is then lost at
an early stage, after they become specialised.
however, losts of plant cells don't ever lose this
ability.
the cells that differntiate in mature animals are
mainly used for repairing and replacing cells, such
as skin or blood cells.
some cells are undifferentiated cells - they're called
stme cells
sperm cells are specialised for reproduction
The function of sperm is to get the male DNA to the female
DNA
It has a long tail and a streamlined head to help
it swim to the egg
There are a lot of mitochondria in the cell to
provide the energy needed
it also carries enzymes in its head to digest through the egg
membrane
Nerve cells are specialised for rapid signalling
the function of nerve cells is to carry electrical signals from one part of
the body to another
These are long and have branched connections at their ends to connect
to other nerve cells and form a network throught the body
muscle cells are specialised for contraction
the function of muscle cells is to contract quickly
these cells are long and contain lots of
mitochondria to generate the energy needed
for contraction.
root hair cells are specialised for absorbing water and minerals
root hair cells are cells on the surface
of plant roots, which grow into long
'hairs' that stick out into the soil
this gives the plant a big surface area for absorbing
water and mineral ions from the soil
phloem and xylem cells are specialised for
transporting substances
phloem and xylem cells form phloem
and xylem tubes, which transport
substances such as food and water
around plants.
to form the tubes, the cells are long and
joined end to end
xylem cells are hollow in the centre
phloem cells have very few subcellular structures,
so that stuff can flow through them.