7-4 The Diversity of Cellular Life
(Biosphere)
You should be able to list
the hierarchy of biological
organization from
biosphere to molecule (or
visa versa). Practice!
specific)
specific)
7-4 The Diversity of Cellular Life
Levels of Organization
Levels of Organization in Multicellular Organisms
Muscle cell
Level & Definition
Cellular: A collection
of mollecules and
organelles that function
together to carry out
the metabolic
processes necessary
for life.
Smooth muscle tissue
Stomach
Level & Definition
Tissue: A collection of
cells specialized to
function together in
performing a specific
function within an
organ.
Types
Level & Definition
Organ: A collection of
tissues specialized to
function together in
performing a specific
function within an
organism..
1. Epithelial (coverings & linings)
2. Nervous (regulation)
3. Muscle (contractile)
4. Connective (bone, tendons, ligaments)
Digestive system
Level & Definition
Organ System: A
collection of organs
specialized to function
together in performing
a specific function
within an organism..
7-4 The Diversity of Cellular Life
7-4 The Diversity of Cellular
Life
The differences among living things arise from the ways in
which cells are specialized to perform certain tasks and the
ways in which cells associate with one another to form
multicellular organisms.
Unicellular
organisms are
made up of only
one cell.
Unicellular
organisms
dominate life on
Earth.
A spirilla bacterium.
7-4 The Diversity of Cellular Life
Multicellular Organisms
Organisms that are
made up of many
cells are called
Multicellular
Organisms. There is
great variety among
multicellular
organisms.
A 2-cell Embryo
(Multicellular organisms start
out unicellular.)
A tree of multicellular life.
(A unucellular common ancestor.)
7-4 The Diversity of Cellular Life
Multicellular Organisms
Cell Specialization: Cells throughout an organism can
develop in different ways to perform different tasks.
Specialized Animal Cells
Red blood cells transport oxygen.
Muscle cells allow movement.
Cells in the pancreas produce proteins
(digestive enzymes and insulin)
7-4 The Diversity of Cellular Life
Multicellular Organisms
Specialized Plant
Cells
Plants exchange
carbon dioxide,
oxygen, water
vapor, and other
gases through tiny
openings called
stomata on the
undersides of
leaves.
Highly specialized
cells, known as
guard cells,
regulate this
exchange.
Guard cells forming a stomate in the
epidermis of a leaf. (opening for gas
exchange)
7-4 The Diversity of Cellular Life
7-4
Cell specialization is characteristic of
a. bacteria.
b. all unicellular organisms.
c. yeasts.
d. multicellular organisms.
7-4 The Diversity of Cellular Life
7-4
Which of the following cells is specialized for
contraction?
●
muscle cell
●
red blood cell
●
pancreatic cell
●
nerve cell
7-4 The Diversity of Cellular Life
7-4
The stomach is an example of a(an)
a. tissue.
b. organ.
c. organ system.
d. organism.
7-4 The Diversity of Cellular Life
7-4
Which of the following shows the levels of
organization in an organism from the simplest to
the most complex?
●
organ system, organ, cell, tissue
●
tissue, cell, organ, organ system
●
cell, tissue, organ, organ system
●
cell, organ, tissue, organ system
7-4 The Diversity of Cellular Life
7-4
Which of the following would probably contain
the greatest variety of specialized cells?
a. an organ system
b. a tissue
c. an organ
d. a multicellular organism