Cell Specialization and
Multicellular organisms are made up of many cells.
These cells have different appearances and
perform different functions (or jobs) they are
specialized for certain tasks.
Muscles cells, which affect movement by
shortening, are typically elongated and tapered
at either end.
Epithelial cells (those that form the lining of
the lung) are thin and flat, because they easily
allow substances to pass through them easily.
Nerve cells have a cell body with an elongated
axon or fibre that is surrounded by insulating
cells. Its form is related to its function of
carrying electrical signals long distances within
the body to communicate information.
Bone cells secrete a matrix mineral in which
they live to provide the body with a bony
Red blood cells are thin and disk-like, and
extrude their nucleus which helps to maximize
their capacity for carrying oxygen.
Structure is related to function!
Read page 138-139. Can you identify the cells on page
Advantages of being Multicellular (Read page 139)
Cells become specialized at performing one or
two jobs. As a result the cell becomes very
efficient at doing those jobs.
o Red blood cells become efficient at
picking up oxygen and carrying it to other
The specialized cells all contribute to the
overall functioning of the organism
the organism can live in a variety of
environments (land, water)
the organism can grow to a large size
the organism can obtain energy from a variety
of food sources
Recall the levels of organization in living things.
(C T O S)
Read page 140
Tissues (2 level of organization)
A tissue is a group of cells having a similar set of
Muscle tissue – moves body parts
Nerve tissue – carries signal between the brain
and other parts of the body to co-ordinate
Connective tissue (bone) – provides physical
protection and support for the body.
Epithelial tissue – is a very thin tissue that
lines the intestine and the lungs.
Plant tissue consists of xylem tissue, phloem tissue
and epidermal tissue.
Activity on page 142 – Looking at animal tissues
Hand in #1 & 2 under “What did you find out”
Organs (3 level of organization)
- are structures that consist of at least two
- Each organ performs a specific function for
the body that no other organ can perform
o Heart – pumps blood throughout the body
o Kidneys – filters the blood
o Lungs – oxygen and breathing
- Plant organs include the root, stem, and
Draw figure 2.24 into notes!
You may use different colours!
In your lab groups work on the investigation on
Plants have 2 main systems:
1) the root system
a. below the ground
b. function is to obtain water and minerals
from the soil and to anchor the plant to
2)the shoot system
a. above the ground
b. function is to make food for the plant
Page 144 #1-5
Pager 145 #1-5, 7, 8, 11, 13, 14