Transcript Investigating an ecological niche File
Investigating an ecological niche
AS 3.1
4 Credits Biozone book pages 14 - 52
Choosing an Organism
Location
: Kina Peninsula
Possible organisms
: - Mud crab - Tube worms - Flat worms - Sea Anemones - Catseyes - Whelks
Monday 19
th
of March
Trip one to Kina
: You will only have about an hour to check out the site. A hand out will be given for you to fill out.
Try to identify as many rocky shore organisms as possible.
Think about variables you could manipulate to investigate an ecological niche of an organism.
Background Research – Needed for your INTRODUCTION
Research possible rocky shore organisms before Monday 19 th of March, from the list in slide 2, or any ones that might interest you. BE PRACTICAL THOUGH!
Research
: Habitat, ecological niche of organism, adaptive features of organism, advantages, disadvantages, feeding, protection ….
Aim
A formal statement of the purpose of the investigation.
Example
: To investigate Periwinkle activity in different salinity concentrations.
Hypothesis
A testable statement of the expected outcome of the investigation.
Null hypothesis – not necessary (A statement of the expected outcome if the variable has no effect on the organism) Example : Periwinkles will become less active in decreasing Salinity concentrations.
This is because the tidal zone is exposed to rain which can decease the salinity concentration.
Method
An accurate description of the materials and experimental procedure used in the investigation. Written in third person. Method must be detailed enough so that an independent person could carry out the investigation with out your help.
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Periwinkle Method
Example
Collect sufficient number of similar sized periwinkles (minimum 150) Collect 1 litre of sea water from flowing sea Need 1 litre of tap water Make up 5 different concentrations of sea water (100mls each) Make sure periwinkles are out of water for at least 30mins prior to the investigation Place 10 periwinkles in each of the Petri dishes, add to each Petri dish 5ml of each of the different concentrations of seawater.
Leave for a set time (10 seconds), then count how many periwinkles in each Petri dish are active, record.
Repeat the process 1 – 7 three times.
Control – light (carry out in shade), temperature (water room temperature), amount of seawater (5ml) and number of periwinkles (10/petri dish) so that it is the same for all trials.
Periwinkle method cont….
Salinity concentrations : 20% - 20mls seawater + 80mls tap water 40% - 40mls seawater + 60mls tap water 60% - 60mls seawater + 40mls tap water 80% - 80mls seawater + 20mls tap water 100% - normal seawater (nothing done to it) How the controls might effect my investigation: If light and temperature are not controlled then the periwinkles may not be exposed to the same conditions. Therefore what they maybe responding to is not salinity concentration but light or temperature.
Active The periwinkle is visible. Front part of the animal is out of the shell (feeding apparatus).
Thursday 22
nd
March
Must get to me before trip with equipment requirements. If you see me on Thursday P3 I may not be able to help you!
Carry out your investigation. If you find you need to modify your method, make a note of That in your log book.
Record data - YAY
Recording data
Example only
Trial 1 Trial 2 Trial 3 Average
Seawater concentrations
20% 40% 60% 80% 0 0 3 9 0 0 0 0 0 0 2 0 2.5
10 10 9.7
100% 8 8 8 8
Results
This should be a summary of your findings.
Have
tables and graphs
accompanied by explanations.
You can carry out statistical analyses, however this does not have to be done but could be a good way to show validity of results!
Conclusion & Discussion
• A statement of the conclusion(s) from your findings, it should relate back to your aim and hypothesis.
• Follow the conclusion with an in-depth discussion of the biological significance of your results and how they relate to the organisms ecological niche.
• If your results do not show this you need to discuss this discrepancy.
Evaluation
This is where you get to discuss your Limitations (problems with your investigation): • Problems encountered and how they may have effected your investigation • How the effects of bias were reduced (Random selection, control of variables) • Sources of error and how they were eliminated • The validity of the conclusion (if you use stats)
References
APA – American Psychological Association format.
NO REFERENCE NO PASS!!!!
Use this website to help you: http://www.waikato.ac.nz/library/learning/g_apagui de.shtml
Otherwise look up books in library or go see Miss Gass
5
th
Aprils (Thursday)
3.1 is DUE and its Holidays, so YAY
Happy Easter
Hand in to Miss Gass
by 3:30pm
. If you can’t find Miss Gass take if to office and get them to put the time on it and the office can put it in my pigeon hole.