B1- Exchange Surfaces Flashcards
What is diffusion in the context of organisms?
Diffusion is the process by which organisms take in substances and expel waste products.
What waste product is mentioned that is produced from the breakdown of proteins in humans?
Urea
How does carbon dioxide move in the human body?
Carbon dioxide diffuses from cells into the blood plasma for removal by the kidneys.
What does the surface area to volume ratio (SA:V) indicate about an organism?
It indicates how easily an organism can exchange substances with its environment.
How is surface area to volume ratio calculated?
By comparing the surface area to the volume of an organism.
What are the dimensions of the hippo block used in the example?
2 cm x 4 cm x 4 cm
Calculate the surface area of the hippo block.
64 cm²
Calculate the volume of the hippo block.
32 cm³
What is the surface area to volume ratio of the hippo?
2:1
What are the dimensions of the mouse block used in the example?
1 cm x 1 cm x 1 cm
Calculate the surface area of the mouse block.
6 cm²
Calculate the volume of the mouse block.
1 cm³
What is the surface area to volume ratio of the mouse?
6:1
Why do multicellular organisms need exchange surfaces?
Because they have a smaller surface area compared to their volume, making diffusion insufficient.
What adaptations do exchange surfaces have to maximize effectiveness?
They have a thin membrane, a large surface area, and many blood vessels.
