Plant cells contain: Chloroplast,
a cell wall, and a vacuole. While
animal cells do not. Both contain:
Cytoplasm, a nucleus, a cell
membrane, mitochondria and
ribosomes.
Bacteria & Yeast
A bacterium is a
single celled
organism. Genetic
material in a
bacterial cell is in
no distinct nucleus.
Both have cytoplasm and
a membrane surrounding
a cell wall; but unlike a
bacterial cell, a yeast cell
has a nucleus. A yeast cell
is also a single celled
organism.
Specialised Cells
Cells may be specialised for a particular
function. Their structure will allow them to carry
this function out. For example, the function of a
leaf cell is to absorb light energy for
photosynthesis - this cell is packed with
chloroplasts. Regular shaped and has closely
packed cells which form a continuous layer for
efficient absorption of sunlight.
Diffusion
Dissolved substances have
to pass through the cell
membrane to get into or out of
a cell. Diffusion is one of the
processes that allows this to
happen. Diffusion occurs
when particles spread. They
move from a region where
they are in high concentration
to a region where they are in
low concentration. Diffusion
happens when the particles
are free to move.