| |
Lab Activity 7.2
Responses to Surfaces
|
|
|
|
Directions
|
|
|
Study
the instructional material below. Be sure to click on each of the photographs
for an enlarged view in a separate window. The
larger version is necessary to complete the assignment.
It opens in a separate window which can be resized by grabbing the bottom
right corner and dragging it. It
can also be moved by
grabbing the top heading bar and dragging it.
Be sure to close the extra window by using the X in IBM, or the close box
in MAC when you are finished using them. |
|
|
Introduction
|
|
|
Studying
the behavior of aquatic organisms can be fascinating. Their basic activities
are similar to our own and include seeking favorable conditions. When we
directly observe them carrying out their daily activities we get a chance
to understand them more fully. Directional movements are examples of behavioral
responses to environmental factors. Mobile organisms can move in a way that
will allow them to enjoy favorable environmental conditions. In this lab
activity you will study the behavior of a simple aquatic crustacean. Ask
yourself if its behavioral responses increase its probability of survival. |
|
Instruction
|
|
|
Study
the information and photographs in the experiment that follows.
Be sure to complete the observations, formulate answers to the questions
you're asked, and write them in your notebook.
Be sure
to write about what you are learning in the lab section of your notebook.
You will be expected to answer questions about the lab activity during
the lab self test and lab quiz. It helps to have your text and coloring
books open beside you for support.
|
| |
| Supporting
Information |
| Refer
to the Assigned Readings Below: |
| Marine
Biology Textbook |
None |
| Marine
Biology Coloring Book |
None |
|
| |
|
Responses
to Surfaces by Amphipod Crustaceans
|
|
In this experiment
we will observe the response of a small animal to the presence of
surfaces. We will use the animal's movements to determine the nature
of its responses. Movement toward surfaces is called a positive
thigmotaxis. Movement away from surfaces is called a negative thigmotaxis.
|
 |
Experimental
Set Up:
- We obtained a
plastic petri dish and transferred an amphipod into it.
- We placed the
petri dish over a black circle. The circular mark divided the
plate into to portions of equal area. The area of dish outside
the circle was all adjacent to the dish wall; while the area of
dish inside the circle was all away from the dish wall.
- We timed the amphipod's
movements for 10 minutes watching it choose between the area adjacent
to the wall and the dish's interior.
- We created a table
reporting the results of this experiment.
|
Observe the photograph
of the experimental set up.
|
|
Observations:
- How long did
the amphipod spend near the wall outside the circle (count in
seconds)?
- How long did
the amphipod spend in the interior inside the circle (count in
seconds)?
- What percentage
of the time did the amphipod spend near the wall?
- What adaptive
value would wall seeking behavior have for amphipods in nature?
- What type of
thigmotaxis does the amphipod display (positive or negative)?
|
|
Time
spent in wall space (min)
|
Time
spent in interior space (min)
|
| 8 |
2 |
|
|
|
|
|
|
|
|
