Freshwater and Saltwater
Investigations
Agenda
• Independent Scientific Research
• Adaptations QUICK poster
– Make a poster about your favorite salt water gone freshwater organism!
• Pre lab instruction
– What is osmosis? (What effect does salt have on the movement of
water?)
– What are the basics of a plant cell’s anatomy?
– How do we set up our investigation? (Variables/Hypothesis etc)
• Plasmolysis/Osmosis Lab Investigation!
• Communicating Science Lab Poster or Power Point Presentation
– Create a presentation in order to document your lab and communicate
your findings!
Warm Up
Independent Research Day
1. What affect does salt water have on
organisms?
2. What is a dependent variable?
3. What is an independent variable?
4. What is a constant?
5. Write a hypothesis to this statement:
Sam thinks that using bigger worms will help
him to catch more fish.
Engage: Do you recognize these aquatic organisms?
The reading today will tell you why they are unique!
Sardines, Stingrays, African Cichlids and Rare
Freshwater Seals!
Explore: Independent Scientific Research!
Read About the Effects of Salt Water on Organisms
Objective: Students will conduct
independent research in order to
describe the affect of salt water on
aquatic organisms.
Explain
Sardines, Stingrays, African Cichlids and Rare Freshwater Seals!
Extend & Evaluate What You Have Learned!
Salt Water to Fresh Water
Aquatic Organisms Poster
• After conducting research (Fish formerly found in saltwater
were forced to adapt to their new habitat) you will pick your
favorite aquatic organism to make a poster.
• Your poster must include:
– Name of the organism
– What is the organism’s relationship with salt water (past and
present)
– What is the organism’s relationship with freshwater (past and
present)
– Picture of the organism
– Explain why fresh water and salt water have different effects on
organisms (ask for help!)
Plasmolysis Elodea Lab Investigation
Objective: Students will create and test a
hypothesis in order to determine the affect of
salt on freshwater plants.
Warm Up
Pre Lab Instructions Day
1. What affect does salt water have on aquatic
organisms?
2. Name 4 aquatic organisms that originated (started)
in salt water and have adapted to fresh water.
3. Use the following statement
A freshwater plant that was put in saltwater would
shrivel up.
A. Name the IV, constants and DV for this statement.
B. Write a hypothesis for this statement.
Engage: What is happening in this video?
Watch closely!
HINT: Think about the effect that salt
water has on organisms!
Explore: Independent Research
Elodea
Complete a power
paragraph in order
to describe the
elodea plant.
Explain:
“Cell Movement Notes”
Set Up Cornell Notes Under Your Power
Paragraph on Elodea
We have already gone over some of the basics…
Let’s put it in writing to make sure you know!
Osmosis- movement of water from high to low concentration.
Water always moves toward a solute (example: salt).
Basic Plant cell anatomyPlant Cell Wall-Tough
Rigid outermost structure
on plant cell.
Cell MEMBRANE- Flimsy/soft
layer that controls movement
in and out of cell.
CHLOROPLAST- Absorb
sunlight to make sugar
for the plant.
Video On Osmosis
How are these pictures different?
What type of cells are they?
These are elodea cells and YES they are
different!
You will find out why very soon!
Extend and Evaluate
Pre Lab Design
• Read the “back ground” information
• Ask questions!
• Next, together, we will start planning out your
– Variables
– Hypothesis
REMEMBER!
The
IVCDV
chart
is used to design an experiment.
Be Ready to Start the Lab Tomorrow!
Experiment Day
• We will start by identifying the variables for
this investigation.
iv
constants
dv
salt
The variable (factor) that you
will change is the independent
variable.
No salt
These are the salt amounts
varied by the experimenter.
5% salt
solution
10% Salt
Solution
iv
salt
dv
constants
Cell Size (looking under
microscope)
No salt
5% Salt
Solution
10% Salt
Solution
The variable (factor) resulting
from the independent variable
is the dependent variable.
iv
fertilizer
constants
amt. of water
dv
plant growth
Scientist
measuring
water that must NOT
These
are
the
factors
2 drops
0 drops
change
during
experimentation.
They
type
of
plant
4 drops
must
remain
constant.
6 drops
Source of light
location
Size of plant
Warm Up
Elodea Plasmolysis/Osmosis Lab Day!
1.
2.
3.
4.
What are we investigating today?
What was your hypothesis from yesterday?
Name 3 ways that you will be safe today in the lab.
What are the consequences if you do not meet
expectations in the lab today?
5. What do you do in the lab if you have a question?
RAISE YOUR HAND AND MAKE EYE CONTACT WITH THE
TEACHER. YOU WILL BE HELPED IN THE ORDER THAT
YOU ASK. CALL POLITELY IF NEEDED!
Engage: What is happening to the
Elodea cells in this video?
Explore: What do you remember from the Pre Lab
Instruction?
•What conditions would make these cells swell up?
•What are the green circles in the cell?
•What is the tough outline around the cell?
•What controls the movement of stuff in and out of the cell?
Explain: Quick Demo/reminder on
how to make a wet slide
Extend: Begin the Lab!
Evaluate: Turn in your lab reports!
Make sure your lab report has:
• Pictures for all 3 water solutions in both
magnifications
• Written observations
• All prelab materials sorted out