1 surface area to volume ratio

what do exchange surfaces in organisms have?

many similar adaptations to make transport across the surface more efficient

the larger an object, the __ the surface area to volume ratio

smaller

what does it mean for small organisms if they have a large surface area compared to volume?

there’s a big surface for exchange of substances, but there’s a smaller distance from the outside of the organism to the middle of it. as a result, very small organisms can simply exchange substances across their surface

do large organisms have large or small sa:vol?

small. they have less surface area available for the exchange of substances compared to their total volume

what does smaller organisms having a large sa:vol allow for?

efficient exchange directly across the body surface, so often don’t require specialised exchange or transport systems

what do smaller mammals having a large sa:vol mean?

they lose heat rapidly

how do smaller mammals replace heat loss?

higher rates of metabolism and respiration which provides energy needed to provide more heat and maintain a stable body temperature

as larger animals lose heat more slowly due to their lower sa:vol, what does this mean for their metabolism?

can have a lower metabolic rate

what are some adaptations to increase sa:vol in larger organisms?

• villi and microvilli: absorption of digested food

• alveoli and bronchioles: gas exchange

• spiricles and tracheoles: gas exchange

• gill filaments and lamelle: gas exchange

• thin wide leaves: gas exchange

• many capillaries: capillary network