3.3.1 Surface Area to Volume Ratio Flashcards
What is the relationship between size and SA:Vol
The organisms SA:Vol plays a significant role in the types of adaptation an organism will achieve
What is the SA:Vol of a small organism?
Large SA:Vol (12:1)
Large surface for exchange of substances with a small distance from the outside to the middle
What is the SA:Vol of a large organism?
Small SA:Vol (1:1)
Larger diffusion distance from outside to the middle
How does organism size affect metabolic rate and transport efficiency?
Larger organisms have a higher metabolic rate, requiring more efficient transport of waste out of cells and reactants into cells
What are the 5 adaptations of large organisms?
- Villi and Microvilli
- Alveoli and Bronchioles
- Spiracles and Tracheoles
- Gill filaments and Lamellae
- Thin wide leaves
Why does staying at the right temperature depend on size and shape?
Because metabolic activity generates heat, and heat exchange is influenced by an organism’s surface area to volume ratio (SA:VOL).
How does body size affect heat loss?
Small SA:Vol means harder heat loss (large organism)
Large SA:Vol means easier heat loss (small organism)
Why do small organims have a faster metabolic rate?
Because they lose heast more easily and need to generate more heat energy to maintain body temperature
How does shape affect heat loss?
Compact shape → Large SA:VOL → Minimises heat loss.
Less compact shape → Small SA:VOL → Increases heat loss.
What are 4 behaviral and Physological adaptations?
- Organisms with a high SA:Vol lose water quickly due to evaportation therefore have kidney nefron adaptations to produce less urine
2.Eating large amounts of high energy food suppport high metabolism - Smaller mammals may have thich layers in extremely cold climate
- In hot climate when mamalas want to lose energy (Elemphants have big ear, Hippos stay in the water)
How to calculate the SA of a sphere?
4 X pi X r^2
How to calculate the Vol of a sphere?
4/3 X pi X r^3
