AQA Biology B2 Unit 2.1 - Cells Tissues and Organs
Animals and Plant Cells
All little things are made up of CELLS
The Cell is the basic
structural, functional
and biological unit of
all known living
organisms
Cells are small and can
only be seen with
microscopes
Animal Cells have:
NUCLEUS
Contains the genetic
material of the cell and
controls the cell's activities
CYTOPLASM
Water-based gel
which allows chemical
reactions to take
place within the cell.
Controlled by
enzymes
CELL MEMBRANE
Controls the
movement of materials
in and out of a cell
Holds the
contents of the
cell together
MITOCHONDRIA
This is where energy is released
during aerobic respitation
RIBOSOMES
Where protein
synthesis takes place
Plant Cells have:
CELL WALL
Made of CELLULOSE for
support and structure of
the cell. Strengthens the
cell.
CYTOPLASM
Water-based gel
which allows chemical
reactions to take
place within the cell.
Controlled by
enzymes
CELL MEMBRANE
Controls the
movement of materials
in and out of a cell
Holds the contents
of the cell together
NUCLEUS
Contains the genetic material of the cell and controls the cell's activities
CHLORPLASTS
Contains CHLOROPHYLL, which asorbs light energy for photosynthesis
VACOULE
Filled with cell
sap to keep the
cell TURGID
CELL SAP: a weak
solution of sugar and
salts
Bacteria and Yeast
Bacteria
Very small and can only be seen
by powerful microscopes
Bacterial cells have a CELL
MEMBRANE and CELL WALL which
surrounds CYTOPLASM
Do not contain a
NUCLEUS so therefore
all genetic material is
found in the
CYTOPLASM
When bacteria
multiply they form
BACTERIA COLONIES
which can be seem by
the naked eye
BACTERIA COLONIES: A
population of billions of bacteria
grown in culture
Examples
Lactobacillus Bularicus - A rod shaped
bacterium used to make yoghurt from
milk
Pneumococcus - A
spherical bacterium
that acts as the
pathogen that causes
pneumonia
BACTERIA: A single-celled
microorgansim that can reproduce
very rapidly. Many bacteria are useful
(for example, gut bacteria and
decomposing bacteria) but some can
cause disease
Yeast
A single celled organsim
Have a nucleus,
cytoplasm and a
membrane
surrounded by a
cell wall
Specialised Cells
As an organsim matures each cell develops into a
particular type. The structure of the cell is linked to
the function
Sperm Cells
Has many
mitochondria so
that it has more
energy
Has a tail so
that it is able to
move
The head contains
genetic material and
enzymes to help
penetrate the egg
cell membrane
It's function is to
fertilise an egg
cell - female
gamete
Muscle Cells
Gland Cells
Has many Ribosomes
so that it is making a
lot of protein
Leaf Cells
Root Hair Cell
Red Blood Cells
Absorbs water and
mineral ions from the
soil
Thin outer membrane to let oxygen diffuse
through easily. Shape increases the surface area to
allow more oxygen to be absorbed efficiently. No
nucleus, so the whole cell is full of Haemoglobin