Science Focus Topic 5 Notes: Cell Specialization & Organization | Print |

Specialized Cells

Different cells have different structures and functions:

Type of Cell

Shape (Structure)

Function
Muscle Elongated and tapered on either end Move parts of the body
Skin Flat and thin, brick-shaped or honeycomb Fit closely together to form a continuous protective layer
Nerve Long branched fibres running from the main part of the cell To carry nerve signals from one part of the body to another
Blood Thin, disc-like Carry oxygen in the bloodstream
(giving them a large surface area to collect oxygen)
Bone Thick, mineral matrix To provide support

Can you identify each?

The Advantages of Being Multi-cellular ?..  Size  ?.. Versatility

Multi-cellular organisms can:

-  live in a wide variety of environments
-
  grow very large
-
  obtain their energy from a wide variety of foods
-
  have complex bodies
-
  specialize functions and work in harmony with other cells

Cells with the same structure and function form tissue

Tissues form organs

Organs work together in organ systems

Systems work together to form an organism

Tissues

Tissues are groups of similar cells that work together, having similar structure and function.
(Figure 2.22 and Figure 2.23 ? page 141)

Organs

Each organ is made up of several tissues all working together.  They are distinct structures in the body that perform particular functions. (Plants have organs as well ? roots, stem and leaves)

Systems

Organs work together to perform activities that help the organism function as a whole. Plants typically have two systems (root system and shoot ?stems and leaves ? system). A reproductive system (flowers, fruits and seeds) is often produced at certain times as well.

Topic 5 Review p. 144

WRAP-UP  p. 145
 >>>>  A good review of Topics 4 ? 5  in this Unit  <<<<