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Unit B: Cells and Systems
Topic 5: Cell
Specialization and
Organization
Cells are Specialized in Multicellular
Organisms
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Specialized according to the need they meet.
Unicellular cells have to perform all the jobs
needed to stay alive.
A cell in a human being is like an ant in an
ant colony. Soldier ants are given the job of
protecting the colony. They are bigger than
worker ants and carry out their job until they
die.
A cell’s shape is based on its job
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Just like with the soldier
ant, a cell’s structure is
determined by what job
it has to do. A muscle
cell is stretchy and
flexible. A nerve cell
has many connections
so that signals can be
sent quickly to other
nerve cells.
Efficiency of Multicellular organisms
versus unicellular organisms
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Because multicellular organisms have
different kinds of cells performing different
jobs, they are much more adaptable to their
environment. They have a better chance at
surviving in different environments than
unicellular organisms.
Tissues and Cells
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Tissues are groups of the same kind of cell
doing the same kind of job.
A muscle tissue helps move the bones in
your body, causing you to move.
Bone tissue gives you the support and
strength you need to live.
Organs
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Are distinct structures in your body that
perform special functions in your body that
are VITAL in keeping you alive. (eg. heart
pumps blood, brain regulates your body’s
activities)
Having organ damage is much more critical
than general tissue damage.
Systems
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A system is a group of tissues and organs
working together to perform related activities.
Because a plant only needs sunlight, water,
and some minerals to survive, it only needs
three systems to survive and reproduce.
Animals have a greater challenge in getting
food and reproducing, and surviving so they
need more systems.