1. Environmental Science
Duckweed Lab
Environmental Science

2. Warm Up
We will be starting our duckweed lab today. Over the next few weeks we will be observing it. Make a prediction about your duckweed population. (Use complete sentences)

3. Objective
Students will understand factors that affect population growth
Students will identify characteristics of population growth curves

4. Pre-lab Questions
What factors are associated with changes in a population?
What do you know about the human population?

5. Key Terms
Carrying Capacity- maximum population size of a species that and environment can hold
Expediential Growth- population grows quickly, has not reached the carrying capacity.
Closed System- nothing can go in or out of this system (nutrients, organisms)
Ex. Island (control)
Give me another example
Open System- no boundaries, things (nutrients, organisms) come and go
Ex. Yellow Stone National Park (no control)

6. What is duckweed? Lemna minor Small aquatic plant
Floats of the surface of water
Food source for some organisms
Very fast growing
Reproduces by budding

7. Duckweed Diagram Frond Bud* Frond (leaf like structure) Root
*Vegetative Budding (asexual reproduction)- reproduces itself

8. Procedures Write your name neatly on your plastic container
Measure 400 mL of water
Pour the water into your plastic container
Your instructor will give you your duckweed frond colony
Mark your water level on your cup with your marker
Count your duckweed plants
Complete Data Table 1. Observations
Write a hypothesis