Parkland 20122013 Unicellular VS Multicellular Multicellular organisms can live in a wide variety of environments grow very large obtain their energy from a wide variety of foods ID: 398307
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Slide1
Organisms Can Be Single-Celled or Multicellular
Parkland 2012-2013Slide2
Unicellular VS Multi-cellular
Multi-cellular organisms can:
live
in a wide variety of environments grow very large obtain their energy from a wide variety of foods have complex bodies specialize functions and work in harmony with other cells Slide3
Common Unicellular Organisms
–
Amoeba
Amoebas are common unicellular organisms that live in water. They move around using foot-like projections called pseudopods (false feet). They extend a pseudopod and the cytoplasm fills it. The also use their pseudopods to capture food by surrounding it between two pseudopods and absorbing it. Slide4
Paramecium
Paramecium
move swiftly through the fresh water where they live.
They are covered in hair-like structures called cilia, which move back and forth like little oars, moving it through the water. Cilia also help gather food, by channeling the food to an oral groove, which is also lined with cilia, sweeping the food into the cytoplasm forming a food vacuole. Slide5
How Substances Move Into and Out of Cells
Parkland 2012-2013Slide6
The Cell Membrane
A cell membrane allows some substances to enter or leave the cell, while stopping other substances.
It
is a selectively permeable membrane. (A permeable membrane allows all materials through, while an impermeable membrane does not allow anything through) Slide7
Activity 14Slide8
High and Low Concentration
Ask
a group of students to stand close together in one corner
of the classroom and have the remaining students spread throughout the room. Have students identify which part of the room has the highest concentration of students. (The corner with the group of students has the highest concentration.) Show students the following diagram and have them decide which portion of the oval has a higher concentration
of squares.(Part A has the higher concentration.)Slide9
Part A
Part B
High and Low ConcentrationSlide10
Diffusion
The structure of the cell membrane controls what moves in or out of a cell. Particles - moving in all directions, bumping into each other, eventually spreading out evenly throughout the cell (
diffusion
). Diffusion plays a part in moving substances into and out of a cell. Concentration determines the direction that a substance takes through the cell membrane.Particles move from higher concentration areas to lower concentration areas (equal concentration allows the movement of particles in and out equally – whereas, a higher concentration of particles on the inside of the cell will move to an area of lower concentration on the outside (so movement will only occur from inside to outside) Until
there is a balance. Slide11
Osmosis
The diffusion of water through a selectively permeable membrane is called
Osmosis
. Water helps to dissolve many of the substances involved in cell processes. When water is lost (moves out of the cell) it leaves behind a high concentration of the dissolved substances .when water moves back into the cell, the substances become more diluted and can be used by the cell for it’s life functions. Slide12
The Effect of Osmosis on Cells Slide13
Your Task …This mark will be your design process mark.
Independent Practice
:
Students will: 1. Design an experiment proving membranes can be selectively permeable.2. Explain the process of diffusion.3. Describe how osmosis occurs.4. Compare and contrast diffusion and osmosis.The procedure must be carefully organized in clear step by step procedures as well as written up. You are responsible for all the supplies you will need. Be sure to practice your experiment at home before presenting it to the
class.Students perform their experiment and complete a written lab report. Slide14
Two focus on a diffusion experiment and two focus on an osmosis experiment :
Group #1
JACOB T
LAURA DGAVIN SSUMMER M
Group #2MARK WSTEPHANIE KKRISTA RKEVIN D
Group #3
THOMAS M
MACKENZIE F
JUSTIN P
JAMES D
Group #4
TABATHA W
George B
RAHEL M
TIM D
Group #5
STEFFEN K
MITCHELL H
LIAM E
NICOLE S
Group #6
TERRY W
ILIANA D
MARKUS S
DANIEL J
Group #7
MACKENZIE K
GABE H
KIERRA D
KIRSTEN P
Group #8
ANNIKA R
SHERRY PJEN HCAITLYN HSlide15
Two focus on a diffusion experiment and two focus on an osmosis experiment :
Group #1
FRANK P
JESSICAKADEJESSE
Group #2TRISTANGRIFFINELMANUPETER
Group #3
KEREN
ALEX
KATIE
BRAILEEN
Group #4
JUDITH
RACHEL
TAYLOR
BOBBY
Group #5
ISABEL
ESTHER
CALI
JADEN
Group #6
FRANK K
NATHAN
TEIGAN
EMILY
Group #7
MADI
NOEMI
Issac
CARTER
Group #8
BRITTNIRENEE
WILLOWSlide16
Big Ideas:
1. Molecules move into and out of cells along a concentration gradient
2. Cells have semi-permeable boundaries
3. Molecules are constantly in motion4. The concentration of cells change with their changing environmentEssential Questions:1. Why do cells transport molecules in and out of their membranes?2. How do cells adapt to their environments?What students will need to know and be able to do(knowledge and skills):1. Design an experiment proving membranes can be selectively permeable.
2. Explain the process of diffusion.3. Describe how osmosis occurs.4. Compare and contrast diffusion and osmosis.5. Identify a concentration gradient and its relationship to transport.