1. Diversity of Life – Activities 1, 4 & 8 Molecules & Processes – Activity 3
Week of September 24rd 2018
Version 1.6.
9/28/ :13:55 AM

2. Field Trip – Huntley Meadows Park Saturday October 6th 9 a.m.
3701 Lockheed Blvd Alexandria VA

3. Diversity of Life - Activity 1 – Establishing a Quadrat

4. A quadrat is a measured and marked quadrilateral used in ecology to isolate a sample.
It is usually not feasible to count all the organisms in an area when studying populations.
Instead, a small, representative group of organisms is counted.
The ideal size of the quadrat depends on the types of organisms being studied, e.g.:
Mosses and lichens: 0.1 square meter.
Herbs (including grasses) and tree seedlings: 1 square meter.
Shrubs and saplings up 10 feet: 10 – 20 square meters.
Trees: 100 square meters.

5. Mark each corner of your quadrat with wire flag.
Go to forested area.
Write (w/ permanent marker) your lab section # & group # on each wire flag.
Use measuring tape to mark off a 7 x 14 m (23 x 46 ft) rectangular quadrat.
Mark each corner of your quadrat with wire flag.
Run string from flag to flag, tying loosely to each.
14 m (46 ft)  
7m (or 23 ft)
 

6. Sketch a map of your quadrat.
Include:
Boundaries relative to the forest boundaries and the campus.
Dimensions.
Main physical features.
Figure 1.1. Map of quadrat relative to surroundings, including sampling locations.

7. Make sure all materials (and trash) are returned to lab!!
Measuring tape.
Large weigh boats (2).
Permanent marker.
Nails (8).
Wire flags (4).
Ruler.
String (roll).
Funnel cups (2).
Scissors.
Shovel.
Bag (gallon size).
Cups (2).
Make sure all materials (and trash) are returned to lab!!

8. Diversity of Life – Activity 4 – Leaf Litter Organisms – Set Up

9. Collect leaf litter sample as follows:
Use ruler to measure a square on the forest floor approximately 20 cm on each side.
In this square, collect all leaf litter and top layer of soil-like material (down to approximately 1 cm, to the extent that you can remove it with your fingers).
Place all material into plastic collection bag.
Mark the location of square on your map from activity 1.

10. Assemble Berlese funnel apparatus
Goose-neck lamp
Place tape on collecting container portion. Use permanent marker to label tape w/ lab section number and group number.
Use graduated cylinder to add isopropyl alcohol to the bottom of the collecting container until it reaches a depth of approximately 1 cm.
Place funnel on top of collecting container (Fig 4.1.)
Make sure that the narrow end of the funnel is covered with screen.
Empty contents of the plastic collecting bag into funnel. Funnel should be as full as possible.
Leaf litter
Funnel
Funnel support/collection container
Screen cover
~1 cm isopropyl alcohol
Figure 4.1. Berlese funnel apparatus. Large funnel w/ leaf litter supported in collection container w/ ~1 cm isopropyl alcohol.

11. Diversity of Life – Activity 8 – Pitfall Traps – Set Up

12. Why use pitfall traps?
Pitfall traps enable the capture of arthropods larger than those that will be collected using the Berlese funnel.

13. Dig a hole large enough to insert the large cup so that its top is LEVEL with the ground (Fig 8.1.)
Write group #, section #, and the trap # inside the funnel that goes in the cup.
Place labeled flag to mark trap locations.
Mark the location of each pitfall trap on the sketch of your quadrat.
Place two pitfall traps in your quadrat.

14. Molecules & Process of Life – Activity 3 – DNA Extraction and Damage by a Pollutant

15. What is DNA?
Why is it important?
Where is it located in the cell?
Do all organisms have it?

16. 4. DNA is spooled onto a wooden stirrer.
1. DNA is in the nucleus of the cell (in eukaryotes).
2. The cell membrane is disrupted with a detergent.
DNA
3. Alcohol is added to the tube to separate DNA from other cell components and DNA migrates upward into alcohol layer.
4. DNA is spooled onto a wooden stirrer.
Alcohol
Protein and RNA
DNA

17. Soak strawberry in simulated pollutant.
Mash strawberry in plastic bag and mix with DNA extraction buffer.
Wait 5 minutes
Filter mashed mixture into tube.
Add enzymes (contact lens solution.)
Wait 2 minutes
Add cold alcohol.
It will form a layer at the top and DNA will rise.
DNA can be observed and spooled onto a wooden stirrer (do not stir – just twist).
Cheesecloth
Filter

18. Strawberry exposed to pollutant
Figure 3.1. Sketch of test tube and contents at end of DNA extraction procedure.
Normal strawberry
Strawberry exposed to pollutant
DNA
Alcohol
Water
Sketch appearance of both test tubes (normal and pollutant-exposed) containing filtered strawberry mash, alcohol and DNA.

19. Table 3.1. Qualitative description of extracted DNA of strawberries, as viewed with unaided eye
Characteristic
Normal Strawberry
Strawberry Exposed to Pollutant
Color
Whitish
Purplish
Size
Really small, tough to see
Humungous
Quantity
A lot, huge amount
Very small amount, hard to find
Structure
Long strands
Record qualitative observations of the DNA (normal strawberry and exposed to pollutant).

20. Strawberry exposed to pollutant
Figure Sketch of extracted strawberry DNA stained with methylene blue and viewed with a compound light microscope at 400X.
Normal strawberry
Strawberry exposed to pollutant
Sketch of DNA (normal strawberry and exposed to pollutant) as viewed through a microscope at 400X.

21. Weekly Data Sheet pages
What’s Due
Weekly Data Sheet pages
Weekly Write-Up pages
Activity 1
127
131
Activity 3 83
87-88
Activity 4
147
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