6.1 exchange between organisms & their environment

Question 1

give examples of passive transport.

Answer 1

simple diffusion, osmosis

Question 2

give examples of active transport.

Answer 2

active transport, facilitated diffusion

Question 3

what is the relationship between surface area: volume and rate of exhange?

Answer 3

as SA:V ratio increases, rate of exchange increases

Question 4

what features does larger organisms develop for faster exchange?

Answer 4

1- flattened surface - short diffusion distance
2- specialised exchange surface - large areas to increase SA:V ratio

Question 5

what are some examples that have to be interchanged?

Answer 5

• respiratory gases
• nutrients
• excretory products
• heat

Question 6

list 5 features of specialised exchange surfaces and what do they do.

Answer 6

1- transport system - ensure movement of internal medium and maintains diffusion gradient
2- thin - short diffusion distance so materials cross rapidly
3- large surface area - increases rate of exchange
4- selectively permeable - allow selected materials to pass
5- movement of environmental medium - maintain diffusion gradient

Question 7

explain where specialised exchange surfaces are located.

Answer 7

inside an organism since easily damaged and dehydrated