F based upon the steps you performed to determine the

(f.) Based upon the steps you performed to determine the size of the Paramecium specimen using
the ocular reticle and the stage micrometer, list a set of brief instructions to determine the actual
size (in SI units) of any object. Report the calibration of reticle units you determined for each
objective in the table below as well.
25.
10.
2.3
N/O

Group Members: Erin Armstrong. Nathaniel Belachew. Patrick Dunne. Diego Garcia Exercise: 2 Date:14 February 2013
LI Sanjeev Namjoshi Unique 49150 Day: Tuesday Room: PAI 1.08 Lab Start Time: 6:00 PM
Exercise 1 Page
4
of
7
N/O indicates not observed. The lab did not include oil immersion microscopy.
(3) I
NDIVIDUAL
: Paramecia (permanent dry and fresh wet mounts)
(a.) Based on your experience in this exercise, report in tabular form at least two advantages and
two disadvantages of permanent dry mounts compared with wet mounts for determining
features of specimens as observed by brightfield microscopy.
Advantages / Disadvantages Wet mounts Dry mounts
Advantage-
Wet mount’s movement
Wet mount slides allow the
observer to see the specimen’s
organelles alive and in use.
There is no internal
movement of structures
within the cell, and the
cellular movement cannot
be observed.
Advantage-
Dry mount’s lack of movement
The specimen may move out
of the field of view, so higher
magnifications are difficult to
obtain.
Specimen does not move.
Can be observed at higher
magnifications without
having to move the stage.
Advantage
Wet mount’s cell is alive
A properly prepared wet
mount Paramecia slide will
contain several live
Paramecia, so they can be
observed as if they were in the
natural habitat of water.
Since dry mount slides are
permanent and use dyes,
the Paramecia are dead
when observed.
Advantage
Dry mount’s cell has better
contrast
Since dyes often kill the
specimen, wet mount slides
often do not have their
specimens dyed, so the
contrast between cellular
structures is not very visible.
Permanent dry mount
slides include dyes that
stain cytoplasmic
structures, so they can be
more easily seen.