1. SNC2D Animal Cells and Tissues

2. 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

3. 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

4. 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)

5. 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 

6. Chick Development
6 Days
10 Days
16 Days

7. 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!

8. Structural Organization of Multicellular Organisms
atoms ↓
molecules
organelles
cells
tissues
organ
organ system
↓ organism

9. 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

10. Levels of Structural Organization
Atoms
Molecule
Organelle
Cell
Tissue
Organ
Organ System
Organism

11. 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

12. Cells that have the same Function form Tissues
Despite there being millions of different organisms, there are only a few different types of tissues!

13. 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)