2. Transport in Organisms
Don’t worry, urine good hands

3. What is transport?
Transport – refers to all processes that move materials into and out of cells
Materials must enter and exit cells via the plasma membrane
Diffusion – material moving from high to low concentration, no energy required
Osmosis – diffusion of water, no energy required
Active transport – moves materials from low to high concentration, takes energy
Water is very important to transport
makes up most of cytoplasm in a cell
Dissolves most materials to be transported
Cells must have enough water but not too much
Maintains homeostasis – internal balance of cells

4. How does transport in unicellular organisms work?
What is a unicellular organism?
Most of these organisms use diffusion
Material moves through plasma membrane based on concentrations

5. How does transport work in multicellular organisms?
All animals are multicellular
Hydras and flatworms only have a few layers of cells (hydras only have 2 layers)
None of their cells are far from the exterior environment
These animals live in water where materials are mostly exchanged by diffusion
Oxygen and carbon dioxide

6. What about larger multicellular organisms?
Since most larger organisms cells are not in direct contact with the environment they have circulatory systems
network of tubes or spaces that transport materials dissolved in a fluid to or away from the cells of an organism
Purpose is to connect interior cells with exterior environment
2 types
Closed circulatory system
Open circulatory system

7. What does the circulatory system need?
This system needs 3 things:
Fluid for transporting material
System of tubes and spaces for material to travel through
Force that moves fluid through the body

8. What are closed circulatory systems?
Closed circulatory systems – the fluids that transport materials never leave their network of tubes
Most animals have blood as the fluid
Blood transports glucose and oxygen while removing carbon dioxide
Blood travels through hollow tubes called blood vessels
Heart provides force to move blood in humans and most vertebrates
3 types of blood vessels
Artery – carries blood away from heart
Vein – carries blood to heart
Capillaries – tiny vessels that allow gas exchange between cells and blood

9. Can invertebrates have closed circulatory systems?
Earthworms, squid and octopi have closed circulatory systems
heart animation

10. Assignment! Virtual Earthworm dissection
Read the earthworm guide and use it to label the organism
Call me over once you have labeled it and I’ll check you off
Answer the journal questions on your own paper and turn it in
ndex.html

11. What are open circulatory systems?
Open circulatory systems are not made of closed vessels
Body cavity contains fluid that surrounds cells, tissues, and organs with nutrients and oxygen
Fluid can’t be diverted to specific organs at specific times
Common to mollusks (snails, oysters, clams) and arthropods (insects, spiders, crustaceans)

12. How do plants transport materials?
Plants do not have circulatory systems or tubes but they do have tissues
2 types of plants
Vascular plants (tracheophytes)
Use vascular tissue to transport water and nutrients
Includes some seedless plants like ferns, flowering and nonflowering plants
Nonvascular plants (bryophytes)
Do not have specialized tissue for transport
3 types
Mosses
Liverworts
Hornworts
Live in shady places to prevent drying out
Usually small

13. How do organisms get rid of waste?
Waste is generated through life processes and must be removed from the organism
Simple organisms rid themselves of waste by diffusion
Some cells store wastes in vacuoles until they can be removed
Circulatory systems transport wastes to places they can be removed
Urinary system – filters cellular wastes, toxins, and excess water from the body
aka. Excretory system

14. How does the urinary system work?
Kidneys are main organ of urinary system
Blood enters kidney through renal (think kidney when you see renal) artery
Blood is filtered to remove waste and excess water
Clean blood returns to circulatory system through renal vein
Waste leaves kidney as urine

15. Where does urine go once it leaves the kidney?
Urine travels down the ureter to a saclike structure called urinary bladder
Urine is stored in the urinary bladder until it leaves the body through the urethra
excretory system

17. Does waste leave the body in other ways?
Aside from the urinary and digestive systems, waste also leaves through skin and lungs
Skin excretes water and salt as sweat or perspiration
Maintains homeostasis (what is this again?) by cooling the body
Lungs release carbon dioxide and water from cellular respiration

18. Assignment! Complete the excretory system worksheet packet
All you need is the worksheet and something to write with