Download SNC2D Animal Cells and Tissues

SNC2D Animal Cells and Tissues
What factors influence cell specialization
in Animals?
• Take a look on p85 and
take a couple of minutes to
read the page
• The contents of the cell’s
cytoplasm
• Environmental conditions
(like temperature)
• The influence of
neighbouring cells
The Effect of Cytoplasm on Cell
Specialization
• After cytokinesis, the contents of the cytoplasm may
differ in each daughter cell
• This helps determine what type of cell it will become
The Effect of Environmental Conditions
on Cell Specialization
• For example, in siamese
cats, only cells that develop
at cool temperatures
produce dark hair colour
(this usually occurs at the
tips of cat’s feet, tail, ears,
and nose)
The Effect of Neighbouring Cells on Cell
Specialization
• When cells are close to each
other, substances can diffuse
through the cell membrane
• These substances change
which genes in DNA gets
expressed
• For example, in the embryo of
a chick, neighbouring cells
influence eye development in a
specific location in the embryo
• 16 days embryo 
Chick Development
6 Days
10 Days
16 Days
Abnormal Development
• Chemicals (contaminants
like heavy metals) in the
environment can affect an
animal’s development
• In humans, 90% of
developmental issues can
be traced to environmental
factors!
Structural Organization of Multicellular Organisms
atoms
↓
molecules
↓
organelles
↓
cells
↓
tissues
↓
organ
↓
organ system
↓
organism
Review
Chemical – atoms combine to form molecules
Cellular – molecules interact to make up cells
Tissue – cells are grouped into tissue
Organ – tissues compose organs
Organ system – organs function together to form
organ systems
Organism (individual) – made up of the organ
systems
Levels of Structural Organization
Atoms
Molecule
Organelle
Cell
Tissue
Organ
Organ System
Organism
Necessary Life Functions
• Ideas?
• Maintaining boundaries
– Cellular level – accomplished
by plasma membranes
– Organism level –
accomplished by the skin)
• Movement
• Responsiveness
• Digestion
• Metabolism
• Excretion
• Reproduction
• Growth
Cells that have the same Function form
Tissues
• Despite there
being millions
of different
organisms,
there are only
a few different
types of
tissues!
What are the different tissues?
• Find out for yourself! Fill in your chart of Animal Tissues
using the hand out
• For homework, answer questions p76 #2-5 (on the
Nelson Textbook Handout)