Year 9 Science

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Year 9 Science

• Organisation of the Human Body

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(a) ORGANISM
An individual living creature. Plant or animal.
A person is an example of an Organism.
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(b) BODY SYSTEMS
A group of body organs that work together. Body
systems Skin, Skeletal, Muscular, Lymphatic
(drains fluids), Urinary, Digestive, Circulatory,
Endocrine (hormones), Nervous, Respiratory
(breathing), Reproductive List 4 systems in your
books.
This is the Digestive System it breaks down our
food.
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(c) ORGANS
Two or more different tissues that work together
to perform a common function (job).
This is a picture of the stomach, an organ in the
Digestive System.
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This picture shows the wall of the stomach with
different tissue layers, including muscle.
Tissues are layers of similar cells that perform
special functions muscle, bone and nerves are
types of tissues.
(d) TISSUES
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(e) CELLS
A Cell is the basic structural and functional
unit for life. Humans are made up of approx. 60
to 100 trillions of cells. Different types of
cells perform different jobs in the body.
This is a picture of Muscle Cells from the
stomach.
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Bone Cells
These are some of the different cells in the
human body.
Red and White Blood Cells
Cheek Cells
List four different types of cells in your books.
Nerve Cell
Muscle Cells
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(f) PARTS OF CELLS (ORGANELLES)
Organelles are special parts of the cell. They
perform specific functions. E.g. The
nucleus of the cell is like its brain.
This is a picture of an Animal Cell with
Organelles labelled. Can you find the nucleus?
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CELLS ARE SMALL
An average cell is about 1/5 of the size of the
smallest dot you can make with your pen.
1cm 10mm 1mm 1000µm (µm is microns)
A red blood cell is an average sized cell. It is
approx. 8µm (0.008mm) in diameter you need a
microscope to see it.
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Fertilised Ovum (egg cells) are the largest cell
in the body at approx. 120µm (0.125mm) you may
be able to just see these without a microscope
Sperm cells are the smallest cells in the body
their heads are only 4µm (0.004mm) wide, but
their tails are about 25 µm long (0.025 mm).
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ANIMAL CELLS
White Blood Cells (fight infection)
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PLANT CELLS
Onion Cells
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ANIMAL CELLS
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PLANT CELLS
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COMPARISON BETWEEN ANIMAL AND PLANT CELLS
ANIMAL CELLS PLANT CELLS
Has a thin cell membrane that allows things like water to get through. Has a thick cell wall that gives the cell (and plant) its shape.
Has a flexible shape (usually rounded and fluid). Has a definite shape (usually rectangular or square).
Has very small vacuoles to store water for the animal. Has large vacuoles to store water for the plant.
Does not contain chlorophyll to produce food. Contain chlorophyll, a green substance, that is used to produce food in a process called photosynthesis. This is why they are called producers.