1. Population Growth in Lemna minor

2. Pre-Lab: Important Notes & Homework
Safety: goggles, aprons, gloves
Data collection: EVERY DAY for 1st week
HW:
Become familiar with background info & procedures (S-1 – S-3 & S-5 – S-9). If anything is unclear, write it down for discussion on 10/28.
Copy Data tables, pre-lab questions (S-4) and post lab questions (S-10) into your notebook
Draw proper measuring technique for pipette, beaker, graduated cylinder

3. Pre-Lab: Class work Lecture / discussion
Each person will complete the following tasks in their own notebook. Feel free to discuss with group mates.
Answer the Pre-lab questions found on S-4 (you should have already copied the questions.)
Draw pictures of the three sets of test tubes you are establishing. Make sure to label contents of each set.
Draw figure 3

4. Lecture / Discussion Several Objectives
How L. minor population growth rate reacts in differing environments (pollution issues)
Determining r and K (biotic potential and its relationship to population growth )
Practice with designing / running an experiment (practice for Paper 3)

5. Lecture / Discussion Why need a control? Why have replicates?
What is carrying capacity?
What part of the curve shows carrying capacity?
Is that in a logistic growth curve or exponential growth curve?
What is biotic potential?

6. Determining Population Size
Where,
d means change
N means Number of individuals
Nt is N at any given time (t)
N0 is N at time = zero
r is a constant: population’s intrinsic rate of increase
rm = biotic potential
K is carrying capacity
e is Euler’s constant (number) = 2.72

7. Exponential population growth equation:
dN/dt=rN
Nt = N0ert
Logistic population growth equation:
dN/dt = rN [(K-N)/K]
Allows us to determine intrinsic rate. Or if given r, can predict N at future time.

8. Drawings Test tubes Beaker, graduated cylinder, pipette the water?
L. minor?
Any treatments:pH buffer, solutions, screens & rubberbands?
Plastic wrap with holes & rubberbands?
Beaker, graduated cylinder, pipette
The meniscus?
Pipette at 90° angle to tabletop?

9. Data Tables Three different tests x three replicates = 9 test tubes
Need a data table / each test tube