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 UpIndependent 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

ExplainSardines, Stingrays, African Cichlids and Rare Freshwater Seals!

Objective: Students will conduct independent research in order to describe the affect of salt water on aquatic organisms.

Extend & Evaluate What You Have Learned! Salt Water to Fresh WaterAquatic 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 UpPre 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 statementA 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 ResearchElodea

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 anatomy-

CHLOROPLAST- Absorb sunlight to make sugar for the plant.

Plant Cell Wall-Tough Rigid outermost structure on plant cell.

Cell MEMBRANE- Flimsy/soft layer that controls movement in and out of cell.

Video On OsmosisHow 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 EvaluatePre Lab Design

• Read the “back ground” information• Ask questions!• Next, together, we will start planning out your– Variables– Hypothesis

is used to design an experiment.

IVCDVIVCDVThe chart

REMEMBER!

Be Ready to Start the Lab Tomorrow!

Experiment Day

• We will start by identifying the variables for this investigation.

iviv dvdvconstantsconstants

saltsalt The variable (factor) that you will change is the independent variable.

These are the salt amounts varied by the experimenter.

No saltNo salt

5% salt solution5% salt solution

10% Salt Solution10% Salt Solution

iviv dvdvconstantsconstants

Cell Size (looking under microscope)Cell Size (looking under microscope)

saltsalt

No saltNo salt

5% Salt Solution5% Salt Solution

10% Salt Solution 10% Salt Solution

The variable (factor) resulting from the independent variable is the dependent variable.

iviv dvdvconstantsconstants

plant growthplant growthfertilizerfertilizer amt. of wateramt. of water

Scientist measuring waterScientist measuring water

type of planttype of plant

Source of lightSource of light

locationlocation

0 drops0 drops

2 drops2 drops

4 drops4 drops

6 drops6 drops

These are the factors that must NOT change during experimentation. They

must remain constant.

These are the factors that must NOT change during experimentation. They

must remain constant.

Size of plantSize of plant

Warm UpElodea Plasmolysis/Osmosis Lab Day!

1. What are we investigating today?2. What was your hypothesis from yesterday?3. Name 3 ways that you will be safe today in the lab.4. 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