True or False?
Unicellular organisms require specialised exchange surfaces.
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True or False?
Unicellular organisms require specialised exchange surfaces.
False.
Unicellular organisms do not require specialised exchange surfaces due to their large surface area to volume ratio.
Define the term exchange surface.
An exchange surface is a specialised area in multicellular organisms that maximises the exchange of materials by increasing the efficiency of transport processes.
What are the three transport processes used by living organisms for exchange?
The three transport processes used by living organisms for exchange are diffusion, osmosis, and active transport.
What are alveoli?
Alveoli are exchange surfaces in animals used for gas exchange in the lungs.
Define the term villi.
Villi are exchange surfaces in animals found in the small intestines for absorption of digested food.
True or False?
Large multicellular organisms have large surface areas compared to their volumes.
False.
Large multicellular organisms have relatively small surface areas compared to their volumes.
What is the primary function of the blood and circulatory system in animals?
The primary function of the blood and circulatory system in animals is to carry necessary substances around the body.
State two properties of exchange surfaces that maximise material exchange.
Two properties of exchange surfaces that maximise material exchange are having a large surface area and a thin barrier to provide a short diffusion path.
Name two examples of exchange surfaces in plants.
Two examples of exchange surfaces in plants are leaves and roots.
Define the phrase surface area to volume ratio.
Surface area to volume ratio is the surface area of an object in relation to its volume.
What happens to the surface area to volume ratio as cell size increases?
As cell size increases the surface area to volume ratio decreases.
Define diffusion distance.
Diffusion distance is the distance molecules have to travel when they diffuse from one region to another.
What is the effect of decreasing diffusion distance on the rate of diffusion?
As diffusion distance decreases, the rate of diffusion increases.
True or False?
Increasing temperature decreases the rate of diffusion.
False.
As temperature increases, the rate of diffusion also increases. Molecules move around faster at higher temperatures, resulting in faster diffusion.
What is the effect of increasing temperature on the movement of particles?
At higher temperatures particles move around faster; this is because they have more kinetic energy.
True of False?
Increasing the concentration gradient will increase the rate of diffusion.
True.
As the concentration gradient increases, the rate of diffusion also increases.
What is Fick's law used to calculate?
Fick's law is used to calculate the rate of diffusion.
State the equation of Fick's law.
The rate of diffusion can be described using Fick's law, which is:
Rate of diffusion ∝ (surface area x concentration gradient) ÷ diffusion distance
"∝" means proportional to.