3-A: Exchange And Transport Systems Flashcards
(9 cards)
1
Q
Do smaller animals have a smaller or larger SA:Vol ratio?
A
Larger
2
Q
Why do organisms need transport to all of their cells?
A
- to supply them with substances like oxygen and glucose
- to remove waste products like CO2 (else cell damage)
3
Q
How do single celled organisms exchange substances?
How fast is this?
A
- Direct diffusion in/out of cell across the cell-surface membrane
- very fast, short diffusion distance
4
Q
How do multicellular organisms exchange substances?
A
- large distance between (most) cells and environment
- low SA:Vol
- exchange organs/mass transport
5
Q
What is used for mass transport in animals?
What is used for mass transport in plants?
A
- circulatory system
- Xylem and phloem
6
Q
What is carried by the circulatory system (within the blood)?
A
- hormones
- antibodies
- waste
7
Q
Do small organisms have a high or low metabolic rate?
Why?
A
- high
- large SA:Vol, heat lost more easily, increase metabolic rate to stay warm
8
Q
What minimises SA:Vol for a given organism?
What is this good for?
A
- Being as compact as possible
- reduced heat loss
9
Q
What maximises SA:Vol for a given organism?
What is this good for?
A
- less compact shape
- increased heat loss
