Diffusion Flashcards
(14 cards)
What is diffusion?
The movement of molecules from an area of high concentration to an area of low concentration.
What is a concentration gradient?
A difference in concentration of molecules across a space or membrane.
What is the surface area to volume ratio (SA:V)?
A comparison of the surface area of an object to its volume.
Calculate the surface area and volume of a cube with a side length of 1 cm.
Surface area = 6 cm², Volume = 1 cm³
What is the SA:V ratio for a cube with a side length of 1 cm?
6:1
How does the side length of an organism affect its SA:V ratio?
The larger the side length, the smaller the SA:V ratio.
Why do small organisms like bacteria have a high SA:V ratio?
It allows substances to easily diffuse in and out of the cell quickly and efficiently.
What is a challenge for larger multicellular organisms regarding diffusion?
They have a smaller surface area compared to their volume, making diffusion too slow and inefficient.
What are specialized exchange surfaces in multicellular organisms?
Adaptations such as lungs in humans, gills in fish, and root hairs in plants that maximize the rate of exchange.
List three features of specialized exchange surfaces.
- A large surface area
- A thin barrier (short diffusion distance)
- A good blood supply or ventilation
What transport systems do multicellular organisms have?
- The circulatory system in animals (to carry oxygen, nutrients, and remove waste)
- The xylem and phloem in plants (to transport water, minerals, and sugars)
True or False: Diffusion is sufficient for transporting substances in large multicellular organisms.
False
Fill in the blank: The circulatory system in animals is responsible for transporting _______.
[oxygen, nutrients, and removing waste]
Fill in the blank: The xylem and phloem in plants are responsible for transporting _______.
[water, minerals, and sugars]
