You can read FutureLearn's Cookie policy here. This was the first course that I have done with Future Learn, have signed up to do a second! I have recently begun working as a school science technician so I think that the course content, although aimed at teachers, did cover a lot of things connected to preparing the practicals.
It was good for me, as although my role is to provide the required apparatus etc. The course provided lots of new approaches for using plants in biology lessons. As a technician I try to encourage practical work in lessons, but there is resistance from teachers especially as plant practicals can be unreliable and tricky for students to set up.
This course has given me the confidence to set up some of these experiments and encou Excellent course rage staff to try them. Category: FutureLearn Local , Learning. Category: Current Issues , General.
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Build your knowledge with top universities and organisations. Learn more about how FutureLearn is transforming access to education. Learn more about this course. What is osmosis? If there is more solute in one area, then there is less water; if there is less solute in one area, then there must be more water.
To illustrate this, imagine two full glasses of water. One has a single teaspoon of sugar in it, whereas the second one contains one-quarter cup of sugar. If the total volume of the solutions in both cups is the same, which cup contains more water? Because the large amount of sugar in the second cup takes up much more space than the teaspoon of sugar in the first cup, the first cup has more water in it.
Returning to the beaker example, recall that it has a mixture of solutes on either side of the membrane. A principle of diffusion is that the molecules move around and will spread evenly throughout the medium if they can.
However, only the material capable of passing through the membrane will diffuse through it. In this example, the solute cannot diffuse through the membrane, but the water can. Water has a concentration gradient in this system. In pure water, the cell contents the cytoplasm and vacuole push against the cell wall and the cell becomes turgid. Fully turgid cells support the stems of non-woody plants.
In a more concentrated solution, the cell contents lose water by osmosis. They shrink and pull away from the cell wall.
The cell becomes flaccid. It is becoming plasmolysed. In a very concentrated solution, the cell undergoes full plasmolysis as the cells lose more water. Plants would be exposed to higher concentrations of solutes if there was less water in the soil - for instance, if plants were not watered, or plants in drought conditions. Plant cells would then lose water by osmosis. Aquatic , freshwater plants placed in the sea, or a seaweed in a rock pool where the water evaporated in the Sun, would also lose water by osmosis.
Animal cells also take in and lose water by osmosis. They do not have a cell wall, so will change size and shape when put into solutions that are at a different concentration to the cell contents.
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