Biology II Presentation

7/29/2019 Biology II Presentation

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BIOLOGY II


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SCIENCE NEWS Water issues have become an

extremely pressing global threat.

With climate change come

unprecedented environmental

impacts: torrential

flooding

insome areas, droughts i

n others,

rising and falling sea levels. Add

to that the threat of

overpopulation

--

and the demandand pollution a

swelling

population

brings

--

and

water becomes one of the

paramount environmental issues to

watch for in the next generation.

Water treatment plants and

systems are now adapting reverse

osmosis to address some of these

concerns. In Perth, Australia

(notably dry and arid, yet

surrounded by sea), nearly 17

percent of the area's drinking

water is desalinated sea water

that comes from a reverse

osmosis plant [source:

TheEconomist

]. Worldwide, there arenow over 1

3,000 desalination

plants in the world, according to

the International Desalination

Association.
http://science.howstuffworks.com/nature/natural-disasters/flood.htmhttp://science.howstuffworks.com/nature/natural-disasters/flood.htmhttp://people.howstuffworks.com/population.htmhttp://people.howstuffworks.com/population.htmhttp://www.economist.com/node/11484059http://www.economist.com/node/11484059http://www.economist.com/node/11484059http://www.economist.com/node/11484059http://www.economist.com/node/11484059http://www.economist.com/node/11484059http://people.howstuffworks.com/population.htmhttp://science.howstuffworks.com/nature/natural-disasters/flood.htm


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CELLS

Are the basic building blocks of all

living things.

They provide structure for the body,

take in nutrients from food, convert

those nutrients into energy, and

carry out specialized functions.

Cells have many parts.


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DIFFUSION

is the movement of

particles

(atoms, ions or

molecules

) from a region in which

they are in higher concentration

to regions of lower

concentration.


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Here the molecules move out of the

liquid and into the air by diffusion.


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OSMOSIS

Is the passage of water from aregion of high water concentrationthrough a semi-permeable membraneto a region of lower concentration


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SEMI-PERMEABLE

MEMBRANE Are very thin layers of material

which allow some things to passthrough them but prevent otherthings from passing through.


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Condition Cell Solution EnvironmentalSolution

Movement ofWater as Solvent

1. Solute

concentration in theenvironment is lower

than in the cell;

solvent is higher in

the environment.

2. Solute

concentration in the

environment is higher

than in the cell;

solvent is lower in

the environment.

3. Soluteconcentration in theenvironment is equalto that in the cell.


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ASSIGNMENT/ HOMEWORK

Do try this at home:

EGG OSMOSIS -you need eggs, vinegar, scales toweigh egg if possible.

1. Weigh the uncooked eggs and carefully place themin large glass of vinegar.

2. Cover and leave for 2 days. It might look a bitlike beer but please dont drink the liquid.

3. Remove the eggs and rinse gently under the tapwater. All of the shell should be gone by now.

4. Weigh the egg again. Record all your observationsand be ready for class discussion.

Biology II Presentation

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