Posts Tagged ‘osmosis’

Oceans topic performance task

Wednesday, March 30th, 2011

Flooding from tsunami near Sendai, Japan by NASA Goddard Photo and Video on flickr

No one can have failed to be shocked by the recent earthquake and tsunami in northern Japan. 

The final perfomance task for this unit requires you to take what you have learned about water, solubility, osmosis, and use it to answer this problem:-

Read this document for details of the performance task.  oceans performance task

Here are the rubrics that will be used to grade your work. Rubric for performance task – oceans  FINALRubric DCP

Saltwater vs freshwater ecosystems

Wednesday, March 30th, 2011

mangrove reflections by Claire `a Taiwan

Plants and animals that live in saltwater and freshwater must have special adaptations to cope with their particular environments.  They need to ensure that they can access water and oxygen at all times.  This can be difficult in circumstances where a plant’s root are surrounded by sea water, as this can affect osmosis. 

Your task is to select one freshwater animal and one saltwater animal and compare their adaptations in the form of a table.  You should then do the same for one freshwater plant and one saltwater plant.  The focus of this exercise is for you to identify the specializations of each species and how it is adapted for it’s environment.  Think about how it accesses water and oxygen.  Think about how it excretes waste.  Here are a few links to get you started, but you should extend your research beyond this.

How plants cope in the mangroves.  Mangrove trees.  How do plants survive in salt water?   Freshwater plant adaptations

Freshwater vs saltwater fish.    Animal adaptations.   Bullsharks.    Why do saltwater fish die when put in freshwater?

Transport in plants

Thursday, March 17th, 2011

Cactus series by PVCG on flickr

Here is Mr Taylor’s presentation on this topic.  Transport in angiospermophytes

  • How do water and mineral ions enter a plant?
  • How does water move upwards, against gravity, in a plant stem?
  • What is transpiration and what are the factors that affect it?
  • How are plants adapted for particularly dry or wet environments?

We will also set up a lab to investigate which surface of a leaf transpires the most, and learn what a potometer is and how to use it.

What happened to my French fries?

Monday, March 7th, 2011

Once you have grasped the theory, you are going to demonstrate your understanding by tackling the following challenge:

You are a trainee chef working in the ISM kitchens.  You have had a hard day at work, and are just about to leave for home, when your boss informs you that you will be in charge of making French fries the next day.  You are excited about the responsibility being placed on you, so you decide to get a head start and peel and slice the potatoes that afternoon.  You place the cut potato pieces into water and leave them there overnight.  When you arrive the next day, you drain the water and are surprised to find that the potato pieces are all ‘pumped up and hard’ (like Sylvester Stallone in Rocky 4).  Your boss tells you that they cannot be used to make French fries, and suggests that you should have put some salt in the water.  He gives you the task of finding out what the ideal concentration of salt in water would be for leaving the potato pieces overnight without them becoming too hard or too soft.

You must design and carry out an experiment that allows you to answer the problem above.  Use the rubrics to guide you, but you must include the following headings in your report: FINAL Rubric design  FINALRubric DCP  FINAL Rubric CE

Research Question, Hypothesis, Variables, Apparatus, Diagram, Method, Results, Graph, Conclusion, Evaluation

Diffusion and osmosis

Wednesday, March 2nd, 2011

[youtube][/youtube]Ever wondered how substances move into cells, or why, when you open the front door, you can smell your favourite food cooking in the kitchen, several rooms away?  The answer is diffusion.  We’ll talk about concentration gradients to explain how smells (the nice and the not so nice!) travel through the air.  Here is a useful animation to help you understand the process.

Osmosis is a form of diffusion that deals specifically with water.  Here is a good animation to explain what is going on.  This site goes into some detail about how osmosis affects living organisms and introduces some new vocabulary – hypotonic, hypertonic and isotonic.  Make sure you know what these terms mean.  Can you explain the science behind what is happening in the video above?

Membrane structure

Friday, September 3rd, 2010

Lipid bilayer of the cell membrane - model by wellcome images

We’ll use this presentation in class.  You’ll need to be able to:

  • Draw and label a diagram to show the fluid mosaic model of membrane structure.
  • Explain the terms hydrophobic and hydrophilic, and how these properties help to maintain membrane structure.
  • List the many functions of membrane proteins.

And for a good idea of where this is taking us, here’s a short video.

The kidney

Monday, January 11th, 2010
kidney by kidneynotes on flickr

kidney by kidneynotes on flickr

OK – this is the last section of the syllabus before we begin our options.  Here are some of the key points we’ll learn:

  • What is excretion? (And what isn’t)
  • How to draw and label a diagram of the kidney.  We’ll dissect one too.
  • What a nephron is, how to annotate a diagram of one to help explain the processes of ultrafiltration and reabsorption.
  • What is osmoregulation, and what role do hormones play in it?
  • What are the differences between concentrations of various components in blood and urine, and the reasons for those differences.

We’ll again use this wonderful presentation from Mr S Taylor as well as our textbooks.  In addition, once we’ve completed this topic, you could watch this video.  It’s a little complicated, so I wouldn’t recommend watching it at the start, but after we’ve covered some of the theory.

Another useful review powerpoint from Mr Hobbins: 11.3 The Kidney