Cells
What is a cell?
What is a cell?
A cell is the very smallest unit of living
matter.
All living things, including plants and
animals, are made up of cells.
What is a cell?
A cell is like a chemical factory.
What is a cell?
There are many different kinds of
cells, doing many different jobs in a
plant or animal.
Differences between plant and
animal cells?
Animal and plant cells
The two kinds you need to be most
familiar with are simple animal and plant
cells.
Cell membrane
One part found in all cells is the cell
membrane.
• What does the cell membrane do?
Cell membrane
The cell membrane surrounds the cell and holds the cell
together. It controls what chemicals can enter and leave
the cell.
Nucleus
Another part found in all cells is the
nucleus.
• What does the nucleus do?
Nucleus
The nucleus controls the cell. Inside the nucleus
is DNA which contains genetic information.
Cytoplasm
All cells also contain cytoplasm.
• What does the cytoplasm do?
Cytoplasm
Cytoplasm is a jelly-like mixture of chemicals
where most of the work of the cell takes place.
Plant cell parts
Plant cells may contain some extra parts.
Chloroplasts (plant cells)
Chloroplasts which are disc shaped and contain
chlorophyll for photosynthesis.
Cell wall (plant cells)
A cell wall which is a strong outer layer to support
the cell and give it shape.
Vacuole (plant cells)
A vacuole where the plant cell stores sap (the
food that it has made; a mixture of sugars, salts
and water).
To summarise:
More complicated!
In reality, most cells are much more
complicated than this!
Interesting cell facts:
Like all living things, cells die. If you watched a clock for
one minute, about three billion cells in your body die.
x 3000000000
Interesting cell facts:
In that same minute, about three billion
cells divided so that all the cells that died
were replaced.
x 3000000000
Interesting cell facts:
Dead skin cells flake off and dead cells
from internal organs will pass through and
out of the body with waste products.
Interesting cell facts:
The length of time cells live can vary. For example, white
blood cells only live for thirteen days, red blood cells live
for about one hundred and twenty days, liver cells live
about eighteen months, and nerve cells can live up to
one hundred years!
Palisade cell
Special cells
Nerve cell
There are many different types of cells to do different
jobs in plants and animals.
For the 5 cells on this slide can you answer the
questions below?
i. what they do
ii. How they are adapted to do their job
Root hair cell
Muscle
cells
Ciliated epithelial cell
Many of the same cells?
• What do you call a substance made of
many of the same kind of cell?
Tissues and organs
Cells of the same type can be grouped
together to form tissues
Muscle tissue
Muscle cells are grouped together to form
muscle tissue.
Root hair tissue
Root hair cells are grouped together to
form root hair tissue
Organs
Different kinds of tissue can be grouped
together to make organs
Heart
Leaf
Root
Organ systems
Organs can work together in organ
systems
What’s this system called?
Respiratory system
?
Excretory system
?
Circulatory system
?
Nervous system
?
Digestive system
What is the sex organ of a plant
called?
Flowers!
Do you know the names of the
parts of a flower?
Parts of a Flower
Stamen
(male)
Carpel
(female)