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Based on the method by which they get food_ organisms are classified as autotrophs or heterotrophs. Which organism listed below is correctly paired with its metabolism.ppt

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Based on the method by which they get food_ organisms are classified as autotrophs or heterotrophs. Which organism listed below is correctly paired with its metabolism.ppt Powered By Docstoc
					Based on the method by which they
get food, organisms are classified as
autotrophs or heterotrophs. Which
organism listed below is correctly


           CPS
paired with its metabolism?

A.   Mushroom-autotroph
B.   Human-heterotroph 
C.   Grass-heterotroph
D.   Fish-autotroph
  Orchids were studied to determine if
  the amount of humidity affected the
  flowering of these plants. Which of
  these was the independent variable

            CPS
  in this study?

A The percentage of humidity 
B The amount watered
C The length of time required for flowering
D The number of flowers on each plant
An experiment was designed to determine the 
effects of cool temperatures on the germination 
of piñon pine seeds. Which of these variables 
was LEAST important to control in this 


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experiment? 
A The brand name of the refrigerator used to 
 produce the cool temperatures
B The number of seeds used in each group
C The amount of time that the seeds were 
 exposed to cool temperatures
D The temperature range used to define cool 
 temperatures
PROPERTIES OF WATER
http://www.youtube.com/watch?v=
 wOOY1szbcX4&feature=related
                WATER
The most abundant compound in living things.

Universal solvent

Expands as it freezes.

Ice is less dense than liquid water so it floats in 
water. Think about importance- polar bears
  Other Useful Info on Water
The 2 to 1 ratio of hydrogen to water 
remains the same, no matter what
Polar nature of water allows it to be the 
“universal” solvent
The low density of water in its solid state 
(ice) allows for organisms to survive cold 
water environments.
What characteristic of water remains the
same no matter what is dissolved in it?


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A. The ratio of hydrogen to oxygen
B. The ability to refract light
C. The hydroxide ion concentration
D The freezing temperature
Fish survive through severe winters because of the
property of water that allows water to —




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A. form chemical bonds as it freezes, raising the
water temperature below the ice
B. increase in density while it freezes, dissolving
more oxygen from the air
C. expand when it freezes, creating a floating and
insulating layer of ice
D. precipitate vital nutrients when it freezes,
increasing the food supply
If the properties of water were to change so that the
solid form was denser than the liquid form, organisms
living in a cold pond environment would be less likely
to survive because water would no longer —


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A. dissolve enough oxygen from the air
B. produce solutions containing vital nutrients
C. remain neutral, instead becoming highly acidic
D. produce a floating insulating layer of ice
       WATER MOLECULE
Polar Molecule – A covalently bonded 
molecule where the e- are shared unequally 
causing the two ends to be oppositely charged.
   **Opposites attract


                  H+        H+

                       O-
 HYDROGEN ATTRACTIONS
  Weak attractions between polar ends of 
  different water molecules (H+ and O-)
***Think of each water molecule being a tiny
 magnet that attracts other water molecules
 and/or other different molecules

 Causes cohesion and adhesion.

 NOT A “BOND”
COHESION vs. ADHESION
       Cohesion – attraction 
       between one molecule of 
       water to other molecules of 
       water.
       n   i.e.  water droplets – “beads up”

       Adhesion – attraction between 
       molecules of different 
       substances.
       n   i.e.  capillary action – H2O 
           attracted to glass or tissue 
           (meniscus and plants)
       n   Water droplets sticking to the side 
           of a car window
Cohesion, Adhesion or Both?
Examining the pictures, explain which 
water property or properties is occurring. 
Be Specific!!!
The unique properties of water
enable life to exist on Earth. Which
of these is a property of pure water?


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A. Its solid form is more dense than its 
   liquid.
B. It has a low heat absorption capacity.
C. It is slightly more acidic than air.
D. It dissolves many substances. 
Which factor makes water an effective
solvent?

          CPS
A. The presence of molecular oxygen
B. Its lack of covalent bonds
C. The polar nature of its molecules
D. Its abundance on Earth’s surface
                MIXTURES
Two or more elements or compounds that 
are physically mixed
NOT chemically mixed!!!!!
n   i.e.  salt/pepper, iced tea


Water can form 2 types of mixtures:
n   Solutions
n   Suspensions
                  SOLUTION
A mixture in which molecules are evenly 
distributed
n   Solute – substance being dissolved
n   Solvent – substance doing the dissolving.


          -
                            Cl-
     Cl                Na
                       +
                                            Na+

                       Water
Water
                SUSPENSION
A mixture in which materials are NOT dissolved 
in water and separate or settle out.
n   i.e. blood, salad dressing, snow globe
Two clear solutions are placed in 
separate beakers.  The first solution has 
a pH of 4, and the pH of the second 


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solution is unknown.  If the two solutions 
are mixed and the resulting pH is 5, the 
second solution must have – 

 A   Fewer suspended solids
 B   A lower temperature
 C   More dissolved salt (NaCl) particles
 D   A higher concentration of OH- ions

				
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posted:2/17/2014
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Lingjuan Ma Lingjuan Ma
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