Laboratory 7: Ecological Niche (15 points)
Lab Instructor: _______________________
Last 4 digits of your CUNYFirst Empl ID #: _____________
on the link in the Lab 7 simulation to get to the lab.
2) Read the
web page to help you understand the material in this lab before starting the
3) Utilize the
links on the bottom of the web page to conduct experiments to determine the
optimum temperature and pH for the four microbes below that match the last 4 numbers
of your CUNYFirst ID number.
You must study
fourdifferentmicrobes. If you have duplicate numbers, or 0 or 9 in
your ID number, pick one or more additional microbes randomly.
THE LIST OF
2. Falitius rebrantus
3. Scribio euglensis
4. Pseudomonas retii
5. Neisseria atol
6. Sulfolobus litia
7. Leuconostoc botolus
8. Escherichia coli
Use the links at
the bottom of the web page to begin growing cells to determine the optimum
conditions for each microbe.
the results in the Tables of Results (Temperature, pH) provided on the
following pages. Read the instructions
on the top of each table carefully.
Part I: Definitions and Background information
1. Define the term niche. (0.4 pts)
2. Name three
resources for which organisms might compete. (0.6 pts)
3. Define evolution.
How might evolution be affected by competition? (1pt)
Part II:Results Generated from the Ecological Niche
Table 1: Effects of Temperature on Microbial Growth
In the top row place the names of the 4 microbe that you will be
studying (matching your ID number).For
each temperatureenter the LOG VALUE of
GENERATIONS per HOUR (do not use generations per minute).Negative numbers should be recorded as 0. (1 pt)
Effects of pH on Microbial Growth
In the top row, place the 4 microbe names that match your student ID
number. For each pH, enter the LOG VALUE of GENERATIONS per HOUR (do not use
generations per minute). Negative numbers should be recorded as 0. (1 pt)
Fill in Table 3
with the optimal pH and temperature for each of your four microbes using your
data from tables 1 and 2.
Note: the highest log
value equals the optimum pH or temperature. (2 pts)
Table 3: Optimal Temperature
and pH for each microbe
Fill in table 4 with the highest and lowest temperatures
and pHs showing growth for each microbe using your data from tables 1 and 2.(2 pts)
Table 4: Fundamental
Lowest temp showing growth
Highest Temp showing growth
Lowest pH showing growth
Highest pH showing growth
Construct a graph demonstrating (a) the fundamental
niche (the temperature and pH range in which the
cells can grow) and (b)the optimum
niche for each microbe with respect to temperature and pH.
Thefundamental nichewill be shown as a
box on your graph – the height of box covers the whole pH range of the
microbe’s growth, and the width covers the whole temperature range.
graph will have four boxes, one for each microbe.
Theoptimum niche for each microbe will be
a point on the graph. (4 points)
1. How can you use your graph to determine which organisms
will be in competition? Using this
information, determine which of the organisms you have studied are in competition. List the organisms in competition and
indicated the ranges in which they compete? (1 point)
2. What is the significance of the optimal temperature and pH for each microbe?
3. What would happen if all of your microbes were put into a test tube at 28
degrees at a pH of 7.5? Would there be competition? Which microbe or microbes would survive? (1 point)