THE UNIVERSITY OF TECHNOLOGY, JAMAICA
FACULTY OF SCIENCE AND SPORT
BIOLOGICAL SCIENCE DIVISION
Plant and Animal Diversity
BIO2003
http://msnucleus.org/membership/html/k
-6/lc/organ/6/images/lco6_31.gif
NAME: ____________________________ ID: _________________
INSTRUCTOR: _____________________ GROUP: _____________
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TABLEOF CONTENTS
Page
GENERAL LAB RULES………………………………………. 2
PRACTICALS
1. Evidences of Evolution…………………………... 8
2. Classification……………………………………. .14
3. The Kingdoms …………………………………….25
4. Kingdom Animalia, Phyla Porifera and Cnidaria…29
5. Kingdom Animalia, Phylum Mollusca…………….37
6. Kingdom Animalia, Phylum Annelida………….....42
7. Kingdom Animalia, Phylum Arthropoda…………..47
8. Kingdom Animalia, Phyla Echinodermata and
Chordata……………………………49
9. Kingdom Plantae (Mosses & Ferns)………………. 53
Kingdom Plantae (Conifers)
Kingdom Plantae (Angiosperms)
10.
Phylum Plantae ……………………................ 58
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General Lab Rules
1. Conduct yourself in a responsible manner at all times in the laboratory.
2. When first entering a lab room, do not touch any equipment, chemicals, or other
materials in the laboratory area until you are instructed to do so.
3. Read all instructions carefully and plan your work. Understand the experiment and if in
doubt, ask.
4. Follow the written lab procedure - laboratory activity at this level is not meant to be
creative. Improper combinations or amounts of chemicals can be very dangerous. No
unauthorized experiments are to be performed. If you are curious about trying a
procedure not covered in the experimental procedure, consult with your laboratory
instructor.
5. Lab tables should be as uncluttered as possible to allow work space and avoid accidents.
Also, keep the aisles clear to prevent tripping over your gear, and so that other people can
pass unhampered. Place book bags, pocketbooks, etc. under the lab tables. In some labs,
seats or stools are not to be used during labs - students need to be mobile to avoid
possible spills and are not to place themselves under the edge of the lab bench where
chemicals may spill.
6. Lab activities require your undivided attention. No music allowed in student labs. Radios
(including Walkman type) and other entertainment devices are not permitted. No cellular
phone use.
7. Treat chemicals with respect and understand the chemicals you are using. Material Safety
Data Sheets (MSDSs) are available in the red binders in each room. Do not remove the
MSDSs from the binders. Bring the binder to the Biology office (Room SC308) to
request a copy.
8. Learn where the safety and first-aid equipment is located. This includes fire
extinguishers, fire blankets, and eyewash stations.
9. Notify the instructor immediately in case of an accident, no matter how small it seems.
10. Students are never permitted in the Biology and Physics storage rooms or preparation
areas unless given specific permission by their instructor.
11. Handle all living organisms used in a laboratory activity in a humane manner. Preserved
biological materials are to be treated with respect and disposed of properly.
12. Leave the lab area clean. Put equipment and chemicals away and wipe off the bench top.
13. If you are not actually scheduled to be in the lab, then you should not be there.
Socialising, meeting people or having your lunch on a rainy day in the labs makes for a
very unpleasant environment for those who are there to work, so please be considerate
and leave.
14. When you are working in the laboratories, please talk quietly. If you need to discuss
something with someone who is not next to you, move closer before you have your
conversation. That way you are doing your bit to keep lab volumes down, and you can
have a well-deserved stretch at the same time!
15. Please do not bring food into the laboratories. Apart from encouraging lingering odours
and unwanted insects in the laboratories, you are also putting the equipment at risk.
HOW TO USE THE MICROSCOPE
Step 1. Carry the microscope with two hands. Keep one hand underneath the microscope and the
other on the arm. The biggest reason microscopes break is not because they wear out, but
because they are dropped.
Step 2.Never touch any lens with your fingers. This leaves oil which is hard to clean and
particles which may damage the lens. If a lens needs cleaning, use lens tissue, a lens cloth or a
lens pen and be gentle. Do not use your shirt or a towel.
Step 3.Learn the parts of your microscope. See the manual or a good website.
Step 4. Prepare a slide. If you are using prepared slides, skip this step for now, but come back
later. You will need to learn how to prepare a slide.
We will keep things simple for your first prepared slide. Find some newsprint from a magazine
or newspaper, the smaller the print the better. Cut out one letter "e". Place the "e" on a clear glass
slide and wet the "e" with a single drop of water. Careful, not too much! We just want to moisten
our specimen (the letter "e"), not drown it. Next, place a cover slip (small square of plastic) over
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the letter "e". The cover slip secures the specimen (letter "e") and it also keeps the objective lens
clean in case it accidentally touches the slide. Don't drop the cover slip straight down on the slide
or you will end up with bubbles trapped under the cover slip. Bubbles appear interesting under a
microscope, but you didn't get a microscope to look at bubbles! To keep things bubble free, place
one edge of the cover slip on the slide first, then tilt the cover slip down and over.
Congratulations. You have now prepared what is called a wet mount and it is the basic mount
used for nearly all types of specimens. Use it later to see pond water organisms and many other
interesting things.
Step 5.Place the slide on the stage of the microscope, and secure with the stage clips. Beginners
make the mistake of ignoring the stage clips. Wrong! At high magnification, when moving the
slide, the stage clips keep the slide in place when you take your finger off the slide. Even the tiny
bit of stickiness in your finger from oil on your skin will move the slide enough to lose the
specimen when you let go of the slide. This is especially true at high power. Use the stage clips.
Step 6.Rotate the objectives on the nosepiece of the microscope until the shortest objective is
over the slide and make sure the objective clicks into place. The shortest objective is LOW
power. ALWAYS START WITH THE LOW POWER OBJECTIVE! Memorize this. Low
power lens gives the widest field of view and makes it easier to find the specimen when you look
through the microscope. Finding the specimen at high power, without first centering it in the
field of view at low power, is nearly impossible.
Step 7.Set the light control. Open the iris if your microscope has an iris or rotate the diaphragm
(circular plate under the stage with different size holes) until one of the large holes is centered
under the slide. This is your light control. Start with plenty of light, but once you have focused
and found your specimen in the field of view, start reducing light until you see the most amount
of detail. The brightest setting is typically not the best for contrast and detail. In fact, when you
start hunting for pond water organisms, you'll find that many of them avoid light. Use only as
much light as you need.
Step 8.Focus slowly. It is easy to focus right past the correct focus point if you are going too fast.
If your microscope has two controls, use the coarse adjustment for low and medium power and
fine tine with the fine focus knob as needed. If you have the "e" or other specimen under the
objective properly, it should now be visible. If it is not, gently move the slide around. This may
take several tries.
Compare the position of the "e" or other specimen under the microscope with its position on the
slide without the microscope. That's right! The microscope turns everything upside down and it
reverses everything right to left as well. Memorize this rule. MOVE THE SLIDE IN THE
OPPOSITE DIRECTION YOU WANT YOUR SPECIMEN TO GO. When you want the
specimen to move to the right, move the slide to the left. When you want the specimen to move
up, move the slide down. This seems strange at first, but with practice you won't even notice it.
Step 9.Now for more magnification (power). Center the letter "e" or other specimen in the
middle of the field of view as closely to the middle as you can. Rotate the objective that has the
medium length over the slide and be sure it clicks into place. Refocus, but slowly. You will only
be seeing a part of the letter "e" or other specimen, now. Move the slide slowly back and forth if
you cannot see anything. If you get lost and lose the letter "e" or other specimen, go back to low
power, center the slide and try again. It may take several tries to find a specimen, but this is
normal. Don't give up.
Step 10.If you managed medium power and have the specimen focused and in the field of view,
you can try high power. Once again, center a part of the "e" or other specimen in the field of
view and slowly and carefully rotate the longest tube objective (high power) until it clicks into
place. It will barely clear the slide, so be careful. The next rule is very important. DO NOT USE
COARSE FOCUS ON HIGH POWER! If your microscope has both fine and coarse focus, use
only fine focus at high power. Why? The objective is very close to the slide, now. If you use
coarse focus, you can , on many microscopes jam the objective down onto the slide and break the
slide. Worse, yet, you may soil and even damage the objective.
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Rules for Writing up Labs
Your practical write-ups must be neat, clearly set out and presented in a timely manner. LATE
LABS WILLNOT BE ACCEPTED without a medical certificate from your doctor/UTECH
Health Centre!
Presentation of Biological Drawings
One important function of laboratory classes in biology is to provide opportunities for you to
learn first-hand about form, function and relationships among organisms. To do this you must be
able to make and record accurate observations. This is achieved by practice. Throughout your
studies in biology, you will be expected to record, in original drawings, the details of organisms
or materials you observe in the laboratory.
Study the material carefully before beginning to draw and frequently while making the drawing.
Do not copy from books nor from the work of other students, as copying (or plagiarism)
defeats the purpose of the laboratory course - actual observation by you. Reference books
should be used only as guides for what to look for. Draw only what you see. Previous drawings
may be inaccurate, but the specimen is always right! As you draw and label each part, try to
know what it is, an what its functions are.
Drawing Magnification
D.M. = drawing length
actual length
e.g., You measure your drawing with a ruler and find that it is 640 mm in length. You are
viewing the specimen under medium power, and have calculated the field of view to be 1.6 mm.
You then estimate that about 5 of the specimens could fit across the field of view. The drawing
magnification would be:
D.M. = __640__ = 2000 x note: the drawing magnification is written with an 'x' after it
1.6
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Sketch
External view usually done with the low power objective lens or with a dissecting microscope. A
sketch shows no cellular details but is accurate in scale and proportion.
Diagram
When a specimen is viewed using the low or medium power objective lens, a diagram can be
drawn. No cellular details are shown. The purpose of the diagram is to show the general
arrangement of structures and their relationship to one another. The diagram is accurate in scale
and proportion.
Detailed Drawing
A detailed drawing is prepared when a specimen is viewed under the high power objective lens.
Accurate cellular details are shown and individual cells or groups of cells can be drawn. The
detailed drawing is accurate in scale and proportion.
Rules for Biological Diagramming
1. Biological drawings are done on plain, white, unlined paper with a sharp HB pencil.
2. Either one or two drawings can be done on a single page, but never more than two. If
only one drawing is to appear on the page, it is to be centered in the upper two thirds of
the page. The drawing must be large enough to allow for small details to be clearly
shown and labeled.
3. The drawing title is placed at the bottom of the page and the drawing magnification
calculation is shown aligned on the right margin and halfway between the bottom of the
drawing and the drawing title.
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4. If two drawings are to appear on a single page, the page can be divided in half so that the
drawings will be one above the other. The placement of the drawing title and drawing
magnification should be the same. Take a look at the examples to see how drawings can
be arranged on the page.
2. All structures which you are illustrating should be clearly and accurately labeled. Use a
ruler to draw horizontal lines from the structures to the right of the drawing to label
(print). No crossing lines!
1. Lines should be parallel and justified on their right ends such that labels appear neat and
tidy. Do not use arrowheads.
3. Label lines should never cross one another. If it is necessary for a label line to bend it
should be at an angle of 90o. Take a look at the examples to see how label lines should be
done.
4. Print your name at the top right hand corner. (Use a ruler.)
5. Title your drawing
6. Draw the outline of your subject with clear and unbroken lines. Your drawing should be
about half the page. When possible, your drawing should be vertical.
7. Use lines to show the out of visible structures. Do not shade or colour your drawings in
any way. Keep the objects in proportion to one another.
8. Measure (in cm or mm) your diagram at its longest point; show measure on the left side
of the diagram.
9. At the bottom right corner, print the subject drawn, the magnification of the drawing, and
the scale.
A Typical page of work expected
______________________________________________________________________________
Classification
Kingdom
Phylum
Class
Order
Family
Genus
Species
Name:
Date:
Cross section of the stem of a plant (Mag. x200)
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Hints
1. Be sure to draw only what you see. Don't give in to the temptation to draw what you
"think" you should have seen. It may seem like it would be easy to look in your text or
some other source to see a picture of the specimen and then to draw that, but your teacher
will probably recognize what you have done. Your teacher has much more experience
using a microscope and will know what can and cannot be seen with the specimens you
are viewing. If you add structures to your diagram which you would not be able to see
using your microscope, your teacher will catch on pretty quickly.
2. If you can't locate some of the structures you have been asked to find, ask for help from a
friend or your teacher. If you still can't find one or more structures, make a note at the
bottom of your drawing. For example, "Could not locate nucleolus or vacuole." This way,
your teacher will know that you at least tried to find everything you were asked to find.
Don't use this as an excuse to not look for the structures you have been asked to find,
though.
3. If your specimen is larger than the field of view at the magnification you want to use, just
draw what fits in the field. DO NOT draw a circle to represent the edge of the field of
view. DO NOT draw a line across the drawing to show where the field of view ended.
4. Shading may be used if it adds to the interpretation. Don't attempt to "color" or "shade "
your entire drawing.
5. Granular structures may be indicated using stippling (many small dots made with a sharp
pencil).
6. If a large structure has a uniform appearance throughout, the detail can be indicated in a
small part of the drawing. Simply note that the rest of the specimen, or area, looked
similar.
7. It is not necessary to draw all the cells in a given section of tissue or organism. Indicate
the boundaries of each different tissue using lines only. It is acceptable to draw a few
cells representative of those found in the tissue.
8. Don't rush. Take your time and produce a good drawing. You do not have to be an artist,
but you will not get full marks for sloppy work or drawings that appear to have been done
in a hurry.
How to Estimate Size Under a Microscope
By Mara Pesacreta, eHow Contributor
updated: May 6, 2010
A microscope magnifies objects.
The process of estimating the size of an object under a microscope involves forming
a relationship between its apparent and actual size. The microscope is useful because it magnifies
an image to a significant extent. Therefore, the object appears much larger than it actually is.
This enables you to see the image in greater detail, but it does not always provide you with an
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accurate idea of the true size of the object. That requires using the proper calculations and
measurements.
Instructions
Things you’ll need:
 Microscope slide
 Microscope
 Ruler
 Graph paper
 Calculator
 Paper
 Pencil
1. Put the slide on the stage of the microscope and put it into focus under low power. Low
power is the easiest magnification by which to place the object in focus. If the object
appears blurry, use the coarse-adjustment knob to bring the stage of the microscope
closer to the low-power objective lens. You can then make further adjustments by
rotating the fine-adjustment knob. The fine-adjustment knob is smaller than the coarseadjustment knob. It is necessary to have the object in focus before accurately estimating
the size under the microscope.
2. Use a ruler to measure the diameter of the field of view. Look through the eyepiece while
measuring the diameter. Place one end of the ruler at the end of the field of view.
Millimeters are a convenient unit of measurement. The diameter of the field of view is
also often measured in micrometers. To make the calculations easier, you can convert the
units to micrometers after.
3. Estimate how many times the object appears over the field of view of the microscope. To
do this, place a piece of graph paper under the object. Look through the eyepiece while
performing this estimation, otherwise you will not obtain accurate results. Use the graph
paper to determine how many squares of graph paper the object occupies. Then count the
total number of squares across the field of view. For example, if the field of view
contains a total of six graph paper squares, and the object covers a length of about two
graph paper squares, then the object fits across the field of view at least three times.
4. Divide the diameter of the field of view by the total number of times the object under the
microscope fits across the field of view. For example, if you measured the diameter of the
field of view to be 18 millimeters, and the object appeared to fit across the field of view
three times, then you would divide 18 millimeters by three. The resulting answer would
be six millimeters. Therefore, the size of the object under the microscope would be
approximately six millimeters. To convert your answer to micrometers, multiply it by
1,000 because there are 1,000 micrometers in one millimeter. Therefore, if you received
an answer of six millimeters, your answer in micrometers would be 6,000.
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Practical #1: Evidences of Evolution
INTRODUCTION
The theory of organic evolution in animals is based on evidence derived from several fields of
zoology, importantly from comparative morphology (adult structure), embryology (development
of the new individual), and paleontology (the fossil record). These studies endeavour to trace
structural features as to their beginnings and their relative degree and form of expression in
different groups of animals. In some cases it is relatively easy to follow the history of a character
in successive groups of animals but in other instances it is difficult because the evidence is scant,
absent or conflicting. Some data on evolution is also derived from comparative physiology,
biochemistry, genetics, and zoogeography, but these are omitted here because they are less easy
to demonstrate.
This exercise provides opportunity to examine some of the plainest of evolutionary evidence.
According to the materials available, in any particular laboratory, the subject may be studied in
class specimens, museum exhibits, models, or illustrations.
1. Analogy and homology. When dealing with structural evidence it is essential to
distinguish between cases of analogy (similarity of function but not of origin) and
homology (similarity of origin and basic structural similarity, even when the parts are
adaptively modified to serve for different purposes). Homology indicates common
ancestry – evolutionary relationship; analogy does not.
A. Compare the wings of some insects with the wings of birds and bats (skeleton and entire
spread wing).
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Questions
i.
In what ways are the three types of wings alike?
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________
ii.
In what ways do the skeletal frameworks of the bird and bat wings resemble
one another?
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________
iii.
Was the insect wing developed in the same way?
_______________________________________________________________
iv.
Which are homologous and which are analogous?
_______________________________________________________________
_______________________________________________________________
B. Compare the skeleton of the hind limb in a series of land vertebrates – amphibians to
mammals.
Questions
i.
Is there an underlying structural pattern?
____________________________________________________________
____________________________________________________________
ii.
Can you diagram the basic elements of this pattern in the space below?
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Limbs of land vertebrates
iii.
Does this suggest similarity of derivation for the limbs of all land vertebrates?
_______________________________________________________________
_______________________________________________________________
iv.
Are all these limbs used for the same purpose? Explain.
_____________________________________________________________
_____________________________________________________________
_____________________________________________________________
2. Comparative morphology.
The structure of organ systems and organs in adults of animals belonging to different
groups may be studied comparatively to show evidences of evolution.
A. Vertebrates. Examine in end view individual trunk vertebrae from members of 2 or more
vertebrate classes – fishes to mammals if possible (disregard detailed differences in form,
length of processes, etc.).
Questions
i.
What is the basic structural plan?
_____________________________________________________________
_____________________________________________________________
_____________________________________________________________
ii.
Does any evidence of the notochord persist?
______________________________________________________________
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Study a series of skulls from several vertebrate classes. Give attention to the position of the brain
box, the places for the sense organs (of smell, sight and hearing), and location of the foramen
magnum (through which the brain and nerve cord connect).
Questions
iii.
Disregarding details. Can you see a common structural pattern?
_____________________________________________________________
_____________________________________________________________
_____________________________________________________________
iv.
What are 5 or more structural features of mankind indicating relationships
with the mammals?
______________________________________________________________
______________________________________________________________
______________________________________________________________
______________________________________________________________
______________________________________________________________
v.
What are some characteristics that mankind shares with animals in general?
(Give three features).
_____________________________________________________________
_____________________________________________________________
_____________________________________________________________
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B. Arthropods. Compare representatives of several different arthropod classes including
crustaceans, insects, millipedes, centipedes, spiders and others that may be available.
Spider
Crayfish
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Questions
Body Covering
i.
Is there a common type of body covering material?
_______________________________________________________________
ii.
Of what is it composed?
_______________________________________________________________
iii.
In what ways is this covering well suited for life out of water?
_______________________________________________________________
iv.
Why would a soft moist epithelium or limy shell be disadvantageous for
mobility on land or in air?
_______________________________________________________________
_______________________________________________________________
______________________________________________________________
Body divisions and somites
v.
What is a somite?
_____________________________________________________________
vi.
Is there evidence of somites in all of the classes represented?
______________________________________________________________
______________________________________________________________
vii.
Can you find evidence of fusion of any somites?
_____________________________________________________________
viii.
What body divisions are seen in the specimens available?
_____________________________________________________________
_____________________________________________________________
_____________________________________________________________
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Antennae
ix.
Do all classes of arthropods have antennae?
_____________________________________________________________
x.
How many are present in each of the classes exhibited?
______________________________________________________________
______________________________________________________________
xi.
Of what service are antennae?________________________________
Legs. Compare the manner of jointing in the legs of 2 or more arthropod classes.
xii.
Is there a correspondence between the segments of the legs in different
classes?
_______________________________________________________________
_______________________________________________________________
xiii. Are the legs alike or different on a single individual?
______________________________________________________________
xiv.
In what respects do the legs of arthropods differ from those of vertebrates?
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________
xv.
Do any animal groups besides the Arthropoda and the Vertebrata have legs?
_______________________________________________________________
_______________________________________________________________
C. Cleavage. Compare the stages in segmentation in such vertebrates as are available.
Likewise examine these stages in the starfish and other invertebrates.
Questions
xvi.
Are there common patterns of cleavage?
_____________________________________________________________
_____________________________________________________________
_____________________________________________________________
xvii. What is the sequence of cleavage planes?
_____________________________________________________________
_____________________________________________________________
____________________________________________________________
_____________________________________________________________
xviii. How does cleavage differ between an amphibian and bird? Why?
_____________________________________________________________
_____________________________________________________________
______________________________________________________________
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PATTERNS OF CLEAVAGE
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Practical #2: Classification
Part A
INTRODUCTION
More than one million kinds of living animals are known already, and others are being
discovered and described. It is the purpose of zoological classification (taxonomy or systematic
zoology) to group and arrange these many animals for study. Classification serves (1) to
indentify individual specimens, (2) to provide means to comprehend the number and variety of
animals, (3) to guide the arrangement of specimens in scientific collections of animals, and most
importantly (4) to express the relationships between the various kinds and larger groups as a
means of understanding their probable manner of origin.
Classification is based upon the characteristics or inherent peculiarities of the animals as to
structure, mode of development, and other features. The animal kingdom is divided first into
major groups or phyla. All animals in each phylum have certain common characteristics. Then
each phylum is divided successively into smaller and smaller groups: classes, orders, families,
genera, and species. The basic unit in classification is the species.
1. Using the numbered series of representative specimens, study each in turn; determine its more
general characteristics by which it may be classified as belonging to a particular phylum. Then
place each in its appropriate class (and order where possible). List your determinations on table 1
Consult the key which follows below when making your determinations.
2. Summarize the key characteristics of the principal phyla in table 2.
No.
Table 1 - List of Representative Animals Classified
Phylum
Class
Order
Common Name
1
2
3
4
5
6
7
8
9
10
15
CLASSIFICATION EXERCISE 1
Specimen 1
Specimen 2
Specimen 5
Specimen 3
Specimen 6
Specimen 8
Specimen 4
Specimen 7
Specimen 9
Specimen 10
Table 2 – Key Characteristics of the Principal Phyla
Phylum
(and
example)
Cells
(1, or
many
m)
Symmetry
(radial,
bilateral,
or none)
Segmentation
(present,
+; or
none, -)
External
skeleton
(if present,
name
+
Chitin
Appendages
(jointed,
flap-like, or
none)
Digestive
tract
(complete,
Body
cavity
(+ or -)
Other
distinctive
features
+
Body divided
into head,
thorax, and
abdomen
incomplete,
or none)
composition)
Porifera
Cnidaria
Platyhelminthes
Mollusca
Annelida
Arthropoda
m
(grasshopper)
Bilat.
Jointed
Complete
Echinodermata
Chordata
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Part B: Using Keys
Introduction
A key is a device, which when properly constructed and used, enables a user to identify an
organism. There are two types of keys that we will discuss; (a) dichotomous and (b) polyclave
(also called multiple access or synoptic).
Dichotomous Keys - A dichotomous key is a tool that allows the user to determine the identity
of items in the natural world, such as trees, wildflowers, mammals, reptiles, rocks, and fish. Keys
consist of a series of choices that lead the user to the correct name of a given item.
"Dichotomous" (di - two; chotomy - forked) means "divided into two parts". Therefore,
dichotomous keys always give two choices in each step. They consist of a series of paired
statements, termed couplets that describe some feature of the organism. The statements, or leads,
are in direct contrast (i.e., mutually exclusive). To use the key, begin with the first couplet and
select the statement that best fits your specimen. This will direct you to another couplet and
ultimately provide the identity of your specimen.
A. Types.
There are two types of dichotomous keys. They differ in the method by which the couplets are
organized and how the user is directed to successive choices.
1. Indented Keys (also called yoked) - indents the choices (leads) of the couplet an equal
distance from the left margin. The two choices of the couplet are usually labeled 1 and 1'
or 1a and 1b. It is not necessary that the choices are numbered, but it helps. The user goes
to the next indented couplet following the lead that was selected. For an example, check
out Figure 1.
Figure 1: Bracketed Key to Some Characters from the "Alice" stories by
Lewis Carroll
1a.
1b.
Wings present ..................................2
Wings absent ...................................3
2a (1)
2b.
Body covered only with feathers............Flamingo
Body covered with feathers and fur........Gryphon
3a. (1) Fur absent, animal usually crying...........Mock Turtle
Fur present, animal rarely crys.............4
3b.
4a. (3) Able to disappear, usually with a grin......Cheshire Cat
Unable to disappear, usually asleep........Dormouse
4b.
2. Bracketed keys - provides both choices side-by-side. The choices of the couplet must be
numbered (or lettered). It is very helpful if the previous couplet is given. Note: in some bracketed
keys alternate couplets are indented; in others, all couplets begin at the left margin. The user
proceeds to the couplet that is indicated by the lead selected. For an example, Figure 2.
Figure 2: Indented Key to Some Characters from the "Alice" stories by
Lewis Carroll
1a.
1b.
Wings present
2a. Body covered only with features........Flamingo
2b. Body covered with feathers and fur...Gryphon
Wings absent
3a.
Fur absent, animal usually crying........Mock Turtle
3b.
Fur present, animal rarely crys
4a. Able to disappear, with a grin.......Cheshire Cat
4b. Unable to disappear, usually asleep...Dormouse
B. Using a dichotomous key.
Tips for using a key:
1. don't guess - be sure that you understand the meaning of any terms that are used in the key;
2. read both choices;
3. measure;
4. watch for abnormal specimens and remember the natural variability in all organisms;
5. when in doubt, try both choices;
6. check your answer with a description or photo or herbarium specimen.
17
1. a. wings covered by an exoskeleton ………go to step 2
b. wings not covered by an exoskeleton ……….go to step 3
2. a. body has a round shape ……….ladybug
b. body has an elongated shape ……….grasshopper
3. a. wings point out from the side of the body ……….dragonfly
b. wings point to the posterior of the body ……….housefly
Notice that there were four organisms to be identified and it only took three steps. There
should be one less step than the total number of organisms to be identified in your dichotomous
key.
3. Construct a key, similar to the insect key given above, to identify the plants A– D.
In constructing keys, keep the following in mind:
i. Use constant characteristics rather than variable ones.
ii. Use measurements rather than terms like "large" and "small".
iii. Use characteristics that are generally available to the user of the key rather
than seasonal characteristics or those seen only in the field.
iv. Make the choice a positive one - something "is" instead of "is not".
v. If possible, start both choices of a pair with the same word.
vi. If possible, start different pairs of choices with different words.
vii. Precede the descriptive terms with the name of the part to which they apply.
4. After reading the descriptions below, use the dichotomous key to determine the identity
of the organisms.
Specimen 1: A large insect with two pairs of wide, clear, functional wings. Body
length is about 1.5 cm with a long slender abdomen possessing very short filaments.
Forewings are about the same length as hindwings, and with approximately the same
area. Head is almost round (not prolonged ventrally) and possesses large eyes and
short, bristle-like antenna.
Specimen 2: A chewing insect with hardened, leathery forewings covering
hindwings. Forewings have no veins, and meet in a straight line down the back.
Abdomen lacks cerci.
1.
With functional wings………………………2
Without functional wings, or with forewings thickened and concealing
membranous hindwings……………………15
2.
Wings covered with minute scales; mouthparts usually a coiled tube (butterflies,
moths)…The specimen is Lepidoptera
Wings usually clear, not covered with scales; mouthparts not a coiled
tube……..3
3.
With one pair of wings (true flies)……….The specimen is Diptera
18
With two pairs of wings………4
4.
Wings long, narrow, fringed with long hairs, body length 5 mm or less
(thrips)……The specimen is Thysanoptera
Wings not narrow and fringed, body usually longer than 5 mm…….5
5.
Abdomen with two or three threadlike "tails"; hindwings small (mayflies)….The
specimen is Ephemeroptera
Abdomen with only short filaments or none; hindwings larger………6
6.
Forewings clearly longer and with greater area than hindwings………7
Forewings not longer, or slightly longer than hindwings, and with same or less
area than hindwings……………….9
7.
Forewings noticeably hairy; antennae as long or longer than body (caddis
flies)…….The specimen is Trichoptera
Wings transparent or translucent, not hairy; antennae shorter than body………..8
8.
Tarsi 2-segmented or 3-segmented; body not wasplike or beelike…….14
Tarsi 5-segmented; usually wasplike or beelike (sawflies, ichneumons, winged
ants, wasps, bees)………..The specimen is Hymenoptera
9.
Head prolonged ventrally into a beaklike structure
(scopionflies)…………………..The specimen is Mecoptera
Head not prolonged ventrally…………………….10
10.
Antennae very short and bristlelike; eyes large; abdomen long and slender
(dragonflies, damselflies)………..The specimen is Odonata
Antennae not short and bristlelike; eyes moderate to small………………11
11.
Hindwings broader than forewings; cerci present(stoneflies)…………..The
specimen is Plecoptera
Hindwings little if any broader than forewings; cerci absent……………..12
12.
Mothlike; wings noticeably hairy and opaque; antennae as long or longer than
body (caddis flies)…………………..The specimen is Trichoptera
Not mothlike; wings not noticeably hairy, usually clear; antennae shorter than
body…………13
13.
Wings with few cross veins; tarsi 4-segmented; length to 8 mm
(termites)………..The specimen is Isoptera
Wings with numerous cross veins; tarsi 5-segmented; length to 75 mm (fishflies,
dobsonflies, lacewings, ant lions)…………………The specimen is Neuroptera
14.
Mouthparts sucking, beak arising from rear of head (cicadas, hoppers,
aphids)………..The specimen is Homoptera
Mouthparts chewing, beak absent; body length less than 7 mm (book lice, bar
lice)……….The specimen is Pscoptera
15.
Wings entirely absent………….16
Wings modified, forewings hard and leathery and covering
hindwings…………..27
16.
Narrow-waisted, antlike (ants, wingless wasps)…………The specimen is
Hymenoptera
Not narrow-waisted or antlike………………17
17.
Body rarely flattened laterally; usually do not jump……………18
Body flattened laterally; small jumping insects (fleas)………The specimen is
Siphonaptera
18.
Parasites of birds and mammals; body nearly always flattened
dorsoventrally………19
Never parasitic; body usually not flattened…………20
19
19.
Head as wide or wider than thorax (chewing lice)………………The specimen
is Mallophaga
Head narrower than thorax (sucking lice)……………………The specimen is
Anoplura
20.
Abdomen with stylelike appendages or threadlike tails (silverfish,
bristletails)…………….The specimen is Thysanura
Abdomen with neither styles nor tails………..21
21.
Abdomen with a forked tail-like jumping mechanism (springtails)………The
specimen is Collembola
Abdomen lacking a jumping mechanism……….22
22.
Abdomen usually with two short tubes; small, plump, soft-bodied (aphids,
others)………….The specimen is Homoptera
Abdomen without tubes; usually not plump and soft-bodied………………23
23.
Lacking pigment, whitish; soft-bodied………24
Distinctly pigmented; usually hard-bodied…………25
24.
Antennae long, hairlike; tarsi 2-segmented or 3-segmented (psocids)……….The
specimen is Psocoptera
Antennae short, breadlike; tarsi 4-segmented (termites)…….The specimen is
Isoptera
25.
Body shape variable; length over 5 mm………….26
Body narrow; length less than 5 mm (thrips)……………The specimen is
Thysanoptera
26.
Antennae 4-segmented or 5-segmented; mouthparts sucking (wingless
bugs)……..The specimen is Hemiptera
Antennae many-segmented; mouthparts chewing (some cockroaches,
walkingsticks)…………The specimen is Orthoptera
27.
Abdomen with forcepslike cerci (earwings)…………The specimen is
Dermaptera
Abdomen lacks forcepslike cerci……….28
28.
Mouthparts sucking; beak usually elongate……………29
Mouthparts chewing…………………30
29.
Forewings nearly always thickened at base, membranous at tip; beak rises from
front or bottom of head (true bugs)……………..The specimen is Hemiptera
Forewings of uniform texture throughout; beak arises from hind part of head
(hoppers)……..The specimen is Homoptera
30.
Forewings with veins, at rest held rooflike over abdomen or overlapping
(grasshoppers, crickets, cockroaches, mantids)……..The specimen is Orthoptera
Forewings without veins, meeting in a straight line down back
(beetles)………….The specimen is Coleoptera
5. Use the Key to the Animal Kingdom to determine the sub-kingdoms, phyla, and
class of the specimen provided. Note the number of the steps used to identify each
specimen.
For example the steps used to identify specimen A are: 10 – Subkingdom Metazoa, 16,
25, 82 – Phylum Chordata, 88 - Vertebrates, 90 – Subphylum Gnathostomata, 94 – Land
Vertebrates, 96, 97 – Class Reptilia.
20
21
22
23
24
Glossary
Annuli - a ring; a ringlike part, band, or space
Antenna - one of the jointed, movable, sensory appendages occurring in pairs on the heads of
insects and most other arthropods
Biramous - consisting of or divided into two branches
Bristles - a short stiff coarse hair or filament
Calyx - a cuplike animal structure (as the body wall of a crinoid)
Chitin – a complex polysaccharide found in the exoskeleton of some invertebrates
Ctenoid - having rough-edged scales
Cycloid - (of the scale of a fish) smooth-edged, more or less circular in form, and having
concentric striations
Exoskeleton - an external covering or integument, esp. when hard, as the shells of crustaceans
Hemispherical – having the form of a sphere, that is, a half of a sphere bounded by a great circle
Hypostome – a mound or cone that bears the mouth of hydropolyps
Meridional – along a meridian, that is from north to south
Monoecious – having male and female sex organs in the same individual
Operculum – a. the gill cover of fishes and amphibians; b. (in many gastropods) a horny plate
that closes the opening of the shell when the animal is retracted
Ossicle – an internal skeletal piece, commonly calcareous as in echinoderms
Peduncle – muscular, flexible stalk of barnacles that attaches to the substratum at one end and
bears the major part of the body at the other
Placoid - platelike, as the scales or dermal investments of sharks
Proboscis - any of various elongated or extensible tubular processes (as the sucking organ of a
butterfly) of the oral region of an invertebrate
Scute - A horny, chitinous, or bony external plate or scale, as on the shell of a turtle or the
underside of a snake
Setae - a stiff hair, bristle, or bristlelike process or part on an organism
Somite - any of the longitudinal series of segments or parts into which the body of certain
animals is divided; a metamere
Tube feet - the small flexible tubular processes of most echinoderms that are extensions of the
water-vascular system and are used especially in locomotion and grasping
Valve - one of the two or more separable pieces composing certain shells
Velum – shelf formed by the margin of the umbrella projected inward which is characteristic of
most hydromedusae; or one of the ciliated flaps with which a veliger larva swims and feeds.
Ventral - of or pertaining to the venter or belly; abdominal
25
Practical # 3 – Kingdoms Eubacteria, Protista
and Fungi
Procedure
A. You are provided with the following specimen:
Kingdom Eubacteria
Bacillus
Spirillum
Streptococcus
Kingdom Protista
Entamoeba or Amoeba
Paramecium
Plasmodium vivax
Euglena
Kingdom Fungi
Penicillium
Aspergillus
Mushrooms
1. Draw each specimen on plain paper.
2. Classify each specimen to class. This must be written in the top left hand corner of the
page.
For example: Lumbricus sp.
Kingdom: Animalia
Phylum: Annelida
Class: Oligochaeta
3. State two identifiable characteristic features of the phyla of each specimen.
B. Examination of fresh samople for plant-like and animal-like protists
1. Use the dropper in the water culture to get a drop out of the container, and place it on a
microscope slide. Place a cover slip on top of the drop.
2. Find protists under low power and observe them. Shift to high power, and get a closer
look.
3. Carefully draw a few plant-like and animal-like protists
Conclusion/Analysis:
1. Would you expect all students to observe exactly the same shape when observing a live
protist under the microscope? Explain.
2. What is a pseudopod?
3. What two functions do the cilia provide for the paramecium?
4. Unlike the higher plants, plantlike protists do not have roots, stems, or leaves. Explain
why they do not require these structures.
5. Why do protists live in aqueous environments?
6. What three groups make up the kingdom Protista?
7. What characteristics distinguish plant-like protists from animal-like protists?
26
27
28
Rhizopus
Aspergillus
Fungi as a kingdom are separated into roughly four major phyla based on how they
sexually reproduce.

Basidiomycetes are fungi that produce spores on tiny little “stools”
called basidia. Most common mushrooms with gills (like in your salads and on
your pizzas) arebasidiomycetes.

Actinomycetes make up the next phylum, and they produce spores mostly in
chambers (though some mushrooms, like the super expensive morel mushroom,
areactinomycetes).

The third phylum is Zygomycota. They reproduce by forming zygospores, which
are large spores formed when two zygomycetes are close together...they look
kind of like a giant ball being held by two strings. The spore and surrounding cells
are called a sporangium.

The last phylum is where scientists put fungi when they just don’t know how they
mate. This phylum is called Deuteromycota. There is some debate as to
whether this phylum should exist or not. Scientists enjoy debate.
The genera Aspergillus and Penicillium belong to Actinomycota. Rhizopus is
a Zygomycete. On a microscopic level Aspergillus have long stalks with a fuzzy ball at
the end. The fuzzy ball is where the spores are. Rhizopus species just look like tangles
of hyphae (fungal cells) with big balls interspersed between them (these are
the zygospores). All fungi release enzymes into their surroundings that digest large
macromolecules (like the starch in bread, for instance) and then absorb the smaller
molecules to use for energy. Starch can be easily converted into glucose by these
enzymes, and glucose is a great source of carbon and energy. The most important
factor for fungi to grow is moisture – they require a lot of moisture. That’s why you don’t
often see fungus on dried bread crumbs.
29
Practical # 4 – Kingdoms Animalia
Phyla Porifera and Cnidaria
INTRODUCTION - Phylum Porifera (10,000+ spp.)
Sponges are the lowest of multicellular animals; the ‘body’ has many pores and consists of a
simple loose tissue structure supported by a framework of minute or microscopic rods or
spicules. The spicules may be calcareous, siliceous or of protein fibres. There are three forms
which the sponge body form may take asconoid, syconoid and leuconoid.
A. Asconoid; B & C. Syconoid; D. Leuconoid
Sponges are aquatic and live attached to submerged rocks, weeds, wood, and animal shells; all
live in salt water, except for a few gelatinous-bodied species inhabiting fresh waters.
There are four classes of poriferans:
Class Calcarea
Contain calcium carbonate spicules. All three grades of structure represented, eg.
Leucosolenia (asconoid), Sycon (syconoid).
Class Hexactinellida
Otherwise known as glass sponges. Spicules of silicon. eg Euplectella Most are
syconoid in structure with the epidermis composed of interconnecting
pseudopodia
of amoebocytes.
Class Demospongiae
Spicules of calcium carbonate or spongin. All are leuconoid. Most species belong
to this class. e.g. Cliona
Class Sclerospongiae
Consists of a small group of leuconoid sponges. They possess an internal skeleton of
silicon spicules anf sponging fibres and an external covering of
calcium carbonate. e.g.
Ceratoporella
1. External features. Examine an entire fresh or preserved specimen of a sponge provided.
Identify the following structures:
- Body
- Base
- Osculum
- Spicules
- Ostia or pores
- Bud (if present)
30
2. Internal structure. Label the internal structures of the sponge.
- Spongocoel
- Incurrent canals
- Osculum
- Radial canals
- Ostia
- Spicules
Figure 1 External structure of a sponge
Figure 2 Internal structures a typical sponge
Questions
i.
What is the main function of the spicules found in sponges?
_______________________________________________________________
ii.
Trace the path of water currents through the body of a sponge.
_______________________________________________________________
_______________________________________________________________
iii.
What creates the water currents?
_______________________________________________________________
iv.
How is food obtained and digested by a sponge?
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________
31
v.
What advance does a sponge show over a colonial protozoan?
_______________________________________________________________
_______________________________________________________________
vi.
What are two relations between living sponges and other animals?
_______________________________________________________________
_______________________________________________________________
vii.
What is a ‘bath’ sponge?
_______________________________________________________________
INTRODUCTION Phylum Cnidaria (10,000 spp)
The cnidarias are the lowest multicellular animals with distinctive layers of cells organized as
tissues and with a definite digestive cavity. The individual cnidarian is either an attached
cylindrical polyp, single or in colonies, or else a free-floating bell-like medusa; both types appear
in the life cycle of many species. All cnidarians are aquatic, and all but a few are marine.
Classes of Cnidarians include:
- Hydrozoa – solitary or colonial; possess medusa and polyp forms eg Hydra,
Obelia, Physalia, Stylaster
- Scyphozoa – solitary, medusa form prominent. Think mesogloea with wandering
amoeboid cells eg. Aurelia
-
Cubozoa – solitary, medusa prominent. eg. Carybdea
-
Anthozoa – solitary or colonial; polyp form prominent. Many supported by
skeletons. This group includes sea anemones, hard corals, sea fans, sea pens and
sea pansies
1. General Structure. Study a living hydra in a watch glass under low magnification.
Identify and label the following structures in figure 3:
- Body column
- Enteron (cavity of body and tentacles)
- Basal disc (for attachment)
- Number of tentacles
- Hypostome (at top of column)
- Mouth (in hypostome)
- Bud (if present)
- Nematocysts (stinging cells; minute, in groups on tentacles)
- Cell layers (2; in body and tentacles)
32
Figure 3
Question
i. What type of symmetry is present?
______________________________________________________________________
2. Behaviour Observe the normal movements of the column and tentacles.
Tap the dish lightly and observe the reaction of the hydra. Twirl the dish slowly.
ii. How does the animal respond?
_____________________________________________________________________
_____________________________________________________________________
Wash a dissecting needle carefully, and then use it to touch the body and tentacles very
gently at different points; allow the hydra a brief rest between tests.
iii. What parts are most sensitive?
_____________________________________________________________________
iv. Is the response proportional to the stimulus?
_____________________________________________________________________
v. Are contractions of the body and tentacles independent or coordinated?
____________________________________________________________________
vi. How does the enteron of hydra differ from the central cavity of a sponge and from the
digestive tract of a frog?
________________________________________________________________________
________________________________________________________________________
________________________________________________________________________
vii. What is the function of the mesogloea in cnidarians?
_______________________________________________________________________
_______________________________________________________________________
33
viii. How are respiration and excretion performed by cnidarians?
_______________________________________________________________________
______________________________________________________________________
______________________________________________________________________
_______________________________________________________________________
3. Many members of the class hydrozoa grow as colonies of minute polyps, others as
medusae of some size, and most of the species include both polyp and medusa stages in
their life cycles.
Label the following structures in figure 4 f the Life cycle of Obelia:
-
Hydranth or feeding polyp
Gonangium
Perisarc
Coenosarc
Enteron
Stolon
Mouth
Tentacles
Epidermis
Gastrodermis
Medusa bud
manubrium
radial canal
Figure 4
Questions
i.
What is meant by division of labour between the two types of polyps in a hydroid
colony?
____________________________________________________________________
ii.
What two types of reproduction are shown in a colonial hydroid?
____________________________________________________________________
iii.
What is meant by alternation of generations in hydrozoans?
___________________________________________________________________
34
iv.
Outline the life cycle of Obelia.
____________________________________________________________________
____________________________________________________________________
___________________________________________________________________
___________________________________________________________________
4. Examine the jellyfish specimen and label the following structures in figure 5
-
Aboral surface or exumbrella
Oral surface or subumbrella
Manubrium (central stalk on oral surface)
Mouth
Tentacles
Gastric cavity
Mesogloea
Rhopalium
Circular canal
Oral arms
Epidermis
Gastrodermis
Radial canal
Gonads
Figure 5
35
Questions
How does a jellyfish swim?
____________________________________________________________________
How does a jellyfish capture and digest food?
____________________________________________________________________
____________________________________________________________________
____________________________________________________________________
How is food distributed through the jellyfish body?
____________________________________________________________________
____________________________________________________________________
____________________________________________________________________
Outline the life cycle of Aurelia.
____________________________________________________________________
____________________________________________________________________
____________________________________________________________________
When and where does a sexual reproduction occur?
____________________________________________________________________
How does the life cycle of Aurelia differ from that of a colonial hydroid?
____________________________________________________________________
____________________________________________________________________
5.
-
Examine the sea anemone provided. Identify and label the following structures in figure 6
Body column
- septal filaments (thick, convoluted, on edges of septa)
Pedal disc
- acontia (slender ends of filaments)
Oral disc
- gonads (bead-like, on edges of septa)
Mouth
- muscles (in body wall and on septa)
Tentacles
- ostia (openings in septa below oral disc)
Gullet
Enteron
Septa (radial, dividing enteron)
Figure 6
36
Questions
Of what special service are the septa?
_____________________________________________________________________
_____________________________________________________________________
On what type of food does the sea anemone feed?
___________________________________________________________________
How does the sea anemone capture its food?
___________________________________________________________________
___________________________________________________________________
How does the sea anemone reproduce?
__________________________________________________________________
__________________________________________________________________
Is the sea anemone monoecious or dioecious?
__________________________________________________________________
Is there a medusa stage in the life cycle of the anemone?
__________________________________________________________________
In what ways are hydras, the colonial hydroid, the jellyfish, and the anemone alike? How do
they differ?
____________________________________________________________________
____________________________________________________________________
____________________________________________________________________
____________________________________________________________________
____________________________________________________________________
_____________________________________________________________________
_____________________________________________________________________
What is a coral? What is a coral reef?
____________________________________________________________________
____________________________________________________________________
How are coral reefs formed?
_____________________________________________________________________
_____________________________________________________________________
_____________________________________________________________________
37
Practical # 5 - Mollusca
INTRODUCTION
Most mollusks of the Class Gastropoda have a fleshy head, a ventral muscular foot and a
dorsal visceral mass, the last covered by a membranous mantle and enclosed in a limy shell of
one piece. The shell is coiled in a high spiral on most snails, the spiral is a flattened oval on
abalones, and the conical shell of limpets shows no sign of coiling in the adults. Slugs have
either a small flat shell within the body or none. In most snails the small body may be withdrawn
completely into the shell, and some have a disc like operculum to close the shell aperture.
Gastropods live variously in the sea, in fresh waters or on the land; most terrestrial species
inhabit moist environments.
1. The Shell (Figure 1)
A. The single shell or valve of a snail resembles a narrowly conical tube wound in a close spiral.
Examine an entire shell and also cut along its axis; identify:
- Apex (pointed closed end; oldest part of shell)
- Aperture or opening (with outer and inner lips)
- Whorls (complete turns; number?)
- Suture (line of contact between adjacent whorls)
- Lines of growth (on whorls, parallel to the edge of aperture)
- Columella (central axis between whorls; see in cut shell)
When the whorls, as viewed from the apex, turn clockwise from apex to aperature, a shell is
termed dextral or right-handed; if counterclockwise, it is sinistral or left-handed. An alternative
method is to hold the apex upward and the aperature toward the observer; the aperature is at the
right in dextral shells and at the left in sinistral shells.
B. If available examine other shells of the same species and different species.
(1) Are they all exactly alike in any one species?
(2) How do shells of young and old individuals of a species differ as to size, shape and
number of whorls?
(3) As between different species, what are some of the characters or differences in the
shells?
(4) Does any shell exhibited have an operculum?
(5) Does any have a narrow siphonal canal (grooved prolongation of shell) extending
ventrally from the aperture?
C. In a cut or broken specimen, identify the three layers of the shell:
Periostracum (outermost; coloured)
Prismatic (middle; thickest)
Nacre (innermost; glistening)
2. External features. (Figure 2)
In an extended snail, preserved or living, identify:
 Foot (ventral; long, broad, flat and muscular)
 Head (anterior; not distinct from foot)
 Visceral mass (dorsal; behind head and above foot; enclosed in shell)
 Tentacles (2 pairs; on head; slender, often retracted [involuted] in preserved
snails)
 Eyes (2; on ends of posterior tentacles)
 Collar or mantle margin (soft thick roll at end of shell aperture)
 Mouth (ventral on head, below first pair of tentacles)
 Pedal mucous gland (opens ventral and posterior to mouth)
 Respiratory pore (on collar, above or medial to anus)
 Anus (on right side of collar)
 Genital pore (minute; on right side of head below tentacles)
3. Internal Structure. (Figure 3)
Gently turn the shell in a counterclockwise direction to remove it from the soft visceral mass
within. If this is not possible, use forceps to pick away the shell in small pieces, beginning at
the edge of the aperture; use care not to damage delicate membranes or structures inside.
38
The visceral mass is covered by a thin membrane, the mantle; this is the body wall of the
visceral mass, and it secretes the shell. The mantle fold, a distinctive characteristic of
mollusks, extends as a fold of the body wall to roof the mantle cavity within; the latter cavity
extends posteriorly and makes a half turn to end on right side of the visceral mass.
A. Insert the point of small scissors through the respiratory pore and cut the mantle fold
(pigmented membrane) along the dorsal border of the collar; continue the cut to the posterior
end of the mantle cavity and then dorsally; turn up the mantle fold to expose the mantle
cavity. Identify:
 Pulmonary veins (on inner surface of mantle, converging to auricle;
mantle and veins serve in respiration as lung)
 Heart (posterior in mantle fold; delicate) consists of:
 Auricle (1; dorsal; receives veins)
 Ventricle (1; ventral; pear-shaped; connects to 2 aortas, anterior and
posterior)
 Pericardial cavity (space around heart; connects by reno-pericardial pore
to kidney)
 Kidney (brownish or yellowish; extends dorsoventrally in narrowed part
of mantle cavity behind heart; wall thin, with irregular internal folds; duct
from kidney extends along left border of rectum)
 Rectum or posterior intestine (tubular, along ventral posterior wall of
mantle cavity at base of visceral spiral; connects to anus)
 Digestive gland or ‘liver’ (large, grayish brown; occupies upper part of
visceral spiral)
A. Lift the membranous body wall flooring the mantle cavity and slit it in mid-line, both
anteriorly and posteriorly; then pin out or cut out the sides of the body. Pick away the thin
connective tissue to expose the organs. From each posterior tentacle there extends a
(blackish) retractor muscles, and similar muscles (or tendons) from several other organs
extend to the columella muscle which is centered in the visceral spiral.
Question
(6) What is the function of these retractor muscles?
________________________________________________________
(7) How are the organs to which they are attached protruded?
________________________________________________________
The organs lie within the large perivisceral or body cavity, which is a hemocoel
containing blood. In mollusks the coelom is represented only by the cavities within the
pericardium and kidney(s).
4. Reproductive System
Identify the following structures:
 Genital atrium (short, rounded; joined to both penis sac (medial) and vagina (at
right)
 Penis sac (slender, oval; contains short penis)
 Flagellum (long, slender folded appendage of penis sac)
 Sperm duct (branches off flagellum to run parallel to oviduct)
 Vagina (short; walls thick and muscular)
 Mucous glands (1 or 2; joined to vagina; each of several finger-like lobes)
 Oviduct (slender, wavy; extends from vagina; parallels sperm duct)
5. Digestive System
Cut across the genital atrium and gently turn the reproductive organs back over the
visceral mass to expose the digestive system. Beginning anteriorly, identify:
 Buccal mass (muscular; around mouth and between anterior tentacles)
 Oesophagous or pharynx (slender; from mouth posteriorly to crop)
 Crop (large, thin-walled, in left side of body space)
 Salivary glands (thin, yellowish, on outer surface of crop; each with duct to
buccal cavity)
 Stomach (small, roundish, embedded in liver)
 Liver
 Intestine (slender. tubular, loops in visceral spiral and then returns to right side)
39


Rectum (continuation of intestine)
Anus
6. Nervous System.
Dorsal to the pharynx, find the pair of white cerebral ganglia and trace their connections to
the ventral pedal ganglia close beneath; the visceral ganglia are located some distance
prosteriorly.
Figure 1 – Snail Shell
Figure 2 - Snail External And Internal Structures
Figure 3 – Dissected snail
Description: "Dissection of snail. T., Short horn; TT., long horn with eye; N., cerebral ganglia; S.G., salivary glands
on the crop; F., foot; M., columellar muscle; V.C., visceral coil; O.T., ovotestis; V., ventricle of heart; R. rectum; U.,
ureter; B.V., blood vessels returning to the auricle from the mantle; A., pulmonary aperture; MA., edge of the
mantle." -Thomson, 1916
Source: Thomson, J. Arthur Outlines of Zoology (New York: D. Appleton & Company, 1916) 389
40
B. PHYLUM GASTROPDA – CLASS BIVALVIA
Animals of the Phylum Mollusca have soft bodies which, in many species, are enclosed in a
limy shell of one or more parts. The clams, mussels and other bivalves (2-shelled) are mostly
marine species, but certain kinds inhabit fresh waters. Some move freely, others are attached to
solid submerged objects, and still others burrow. Unlike other mollusks, the bivalves have no
head region and no means for rasping or cutting large food; they subsist upon microscopic
floating organisms (plankton) and organic debris which are drawn with water between the valves
and passed to the mouth.
1. External features.
Identify:
 Valves right and left
 Margins; anterior, posterior, dorsal and ventral
 Umbo (dorsal swollen part of each valve)
 Lines of growth (concentric)
Questions
(1) What is the oldest part of a valve?
______________________________________________________
(2) If the heavier line of growth indicate age in years, how old is the specimen?
_______________________________________________________
2. The Shell.
A. Place a clam in water, raise the left valve slightly and insert a scalpel close beneath. Move
the blade back and fourth to free the sheet-like mantle adhering to the inner surface and also
to cut the muscle attached to the valve. Press the ventral margins of the muscles together and
then release them.
B. Remove the left valve completely and find:
 Margin of mantle (fleshy band just within edges of valves)
 Foot (fleshy, can be protruded through anteroventral margin of mantle)
 Hinge ligament (elastic; dark; on dorsal margin)
 Hinge teeth (near dorsal margin; none in Anodonta)
 Pallial line (on inner surface, where margin of mantle attaches)
C. Examine the broken edge or a thinly ground section of a valve under low magnification
and identify the layers:



Periostracum (outermost, thin, dark; organic in composition)
Prismatic layer (middle, thickest near dorsal margin0
Nacre or mother of pearl layer (innermost, smooth, glistening)
(3) What produces each of these layers?
D. Place a small fragment of shell in hydrochloric acid and another in sodium hydroxide
solution. Watch the results.
(4) Of what is the shell composed?
(5) Where are the materials obtained for shell formation?
3. Internal structure.
A. Place the right valve containing the soft body in water and locate the following parts:
 Muscles (5; scars seen on shell; note direction of fibers in each)
 Mantle (thin fleshy sheet, of left and right lobes; internal organs enclosed
in mantle cavity between lobes)
 Siphons (formed of thickened posterior edges of mantle margin)
41


Incurrent siphons (ventral, with short sensory papillae inside margin)
Excurrent siphon (close above proceeding; exit for water)
B. Lift the left lobe of the mantle and cut it off, beginning at the incurrent siphon; avoid
damaging the soft parts beneath. Find:
 Gills (2 pairs right and left; thin sheets with vertical ribs; cut off left pair along their
dorsal margin)
 Visceral mass (large, soft; behind anterior adductor muscle)
 Foot (ventral; firm muscular projection from visceral muscles)
 Labial Palps (2; thin soft lobes below anterior adductor muscles)
Strip epidermis off the foot to see the muscles beneath.
4. Digestive tract.
Shave away the muscles on the left side, then gentle pick away the soft visceral mass to see
parts of the digestive tract medially and two branched gonads laterally; locate:
 Mouth (small opening between labial palps)
 Esophagus (short tube behind mouth)
 Stomach (rounded; dorsal in visceral mass)
 Digestive glands or ‘liver’ (2; one on either side of stomach0
 Intestines (coiled, in visceral mass; often contains a soft gelatinous rod, the crystalline
style, providing digestive enzyme)
 Rectum (from intestine, posteriorly through heart and then dorsal to posterior adductor
muscles)
 Anus (enters excurrent siphon behind posterior adductor muscle)
5. Circulatory system.
Dorsally, behind the visceral mass, find the slender thin walled pericardial sac
enclosing the heart.
At either side of the pericardial sac, posteroventrally is a blackish soft hollow kidney.
42
Practical # 6 – Phylum Annelida
INTRODUCTION
Members of the phylum Annelida are all worms, most of which have the body divided into a
series of similar segments and have a definite body cavity or coelom lined by peritoneum.
Segmentation is externally as well as internally obvious. The internal structure which separates
the coelom into segments or metameres is called a septum. Where the external surface of the
body is divided but the divisions do not extend internally they are called annuli (singular
annulus). Annelids also have few to many fine hard spines or setae projecting from the sides of
the body wall that assist in locomotion.
The phylum includes many marine species that variously swim, burrow or live in tubes; the
earthworms that inhabit the soil and related forms in fresh waters; the leeches that live in water
or on damp soil; and some other types. Annelid ecological associations are broad. They exist as
free living, predacious and parasitic forms. In terms of size they range from the microscopic
parasitic bronchiobdellids to eleven foot oligochaetes. Brilliant colours are found in some,
especially the polychaetes, and some can exhibit bioluminescence.
Classification
Phylum:
Annelida 15,000 spp.
Class: Polychaeta
Presence of lateral appendages called parapodia;
No clitellum
Class: Oligochaeta
earthworms, no lateral appendages
but few setae (chaetae) present; clitellum present
Class: Hirudinea
leeches, usually no parapodia or setae
Class Oligochaeta (Earthworms)
Earthworms live in moist loamy soil and burrow extensively. At night they come to or onto the
ground surface to feed, mainly on decaying vegetation.
Note: Throughout this exercise roman numerals are used to designate the somites,
beginning at the anterior end.
1. Carefully examine the external features of the earthworm Lumbricus terrestris.
2. Identify the following external features:
-
Anterior end
- Ventral surface (slightly flattened)
Mouth
- Somites (ring-like divisions of body)
Prostomiun
- Clitellum (smooth swelling over several
Posterior end
anterior somites)
Anus (vertical slit in posterior end)
Dorsal surface (darker, with median blackish line of dorsal vessel)
Setae (minute spines on somites)
Openings in Body (besides mouth and anus)
- Oviducts (2, small, ventral, on XIV)
- Sperm ducts (2, ventral, on XV)
- Seminal receptacles (2 pairs, small, lateral, between IX – X and
X – XI)
- Nephridiopores (2 per somite, small, lateroventral)
- Dorsal pores (minute, middorsal in furrows between somites)
43
X
XV
XX
Figure 7
3. Dissection of an earthworm (Figure 8)
a. Place the earthworm on its ventral side. (The ventral side is more
flattened than the dorsal side.) Using a scalpel, make a shallow
incision anterior to the clitellum and continue the incision toward
the mouth. Be careful not to cut too deep or you will slice into the
digestive system. Using forceps spread the incision open and pin
the body wall to the dissection pan as shown in the illustration.
You may choose to add some water to the specimen to prevent it
from drying.
b. Identify the thin walls between each segment. These are called
septa.
c. Identify the organs of the digestive system. Beginning at the
mouth, locate the thick-walled pharynx. The esophagus extends
from the pharynx. Next, 2 swollen structures can be seen, the crop
and the gizzard. The crop temporarily stores food and the gizzard
then grinds it. Leading from the gizzard is the intestine, which runs
the length of the worm to its anus. The earthworm feeds on
organic material in soil, pushing this material through its digestive
tract and absorbing nutrients.
d. Locate the dorsal blood vessel, which is found along the dorsal
surface of the digestive tract. Identify the 5 pairs of aortic arches,
or hearts, which circle the esophagus.
e. Identify the cerebral ganglia, which are found along the dorsal
surface of the pharynx. A ventral nerve cord can be seen
beginning at the cerebral ganglia and extending the length of the
worm.
f. Locate the excretory organs called nephridia. These paired organs
are found in each segment. Nephridia remove nitrogenous waste.
g. DRAW your dissection.
44
Figure 8
4. Draw the T.S. annelid slide and interpret the parts with the aid of the drawing in figure 9.
Figure 9
Questions
a. What type of symmetry is shown in the earthworm?
___________________________________________________________________
b. To what degree is anterioposterior differentiation shown?
___________________________________________________________________
45
c. On what does the earthworm feed?
________________________________________________________________
d. What organs perform the function of respiration in an earthworm?
________________________________________________________________
e. What substances are removed by the nephridia?
_________________________________________________________________
f. What organs in the frog or man perform equivalent functions?
_________________________________________________________________
g. What are the respective functions of the two muscle layers of the body wall?
__________________________________________________________________
__________________________________________________________________
h. How is food move along the intestine of the earthworm?
__________________________________________________________________
A. Phylum Annelida – Class Oligochaeta
The organisms in this group are characterized by a well developed, metamerised body
and a spacious coelom. Segmentation is externally and internally obvious.
The septum
separates the coelom into segments.
Demonstrations of transverse sections of Lumbricus terrestris (earthworm) are
provided.
Use figure 3.1 to identify the following structures in the section:
- Epidermis
- Circular muscle layer
- Longitudinal muscle layer
- Setae
- Intestinal lumen
- Dorsal vessel
- Ventral nerve cord
- Coelom
Figure 3.1 T.S. of Lumbricus terrestris
46
B. Phylum Annelida - Class Polychaeta
The annelids in this group consist of a wide variety of marine forms which
display lateral appendages called parapodia.
Fan Worms are marine segmented worms that are sessile, attached to rocks or sand by
their base. Fan Worms are usually of the families Terebellidae (Medusa Worms), Sabellidae
(Feather Dusters), or Serpulidae (Christmas Worms). While their close cousins the mobile
(Errantia) bristleworms have a body with equal segments (metameres), the sessile bristleworms
(Sedentaria) will have body segments of different sizes. Found in nearly all tropical regions of
the world, Fan Worms will produce parchment, a skin-like casing made from body secretions, as
they burrow into the substrate of choice. Christmas Worms position themselves in such a way
that their "host" coral grows completely around the worm, with only its plume (radiole) crown
visible. While the Fan Worm is a solitary animal, it is often found in large clusters of individuals.
Observe the structural features of the fan worm. Use Figure 3.2 to guide your
observation.
Figure 3.2 Structure of a polycheate
47
Practical # 7 – Phyla Arthropoda
and Echinodermata
A. Phylum Arthropoda
The arthropods are the most extensive taxon in the animal kingdom. In complexity of
morphological organization, as well as diversity in ecological adaptation, they are unequalled.
Subphylum Crustacea , Class Malacostraca, Order Decapoda
The decapods or Decapoda are an order of crustaceans within the class Malacostraca, including
many familiar groups, such as crayfish, crabs, lobsters, prawns and shrimp. Most decapods are
scavengers.
Remove and draw the different types of legs of the crab.
Figure 3.3 Crab external structure
B. Phylum Arthropoda,
Subphylum Uniramia, Class Insecta
Insects feed on a wide variety of substances, and for this reason require appropriate mouth part
adaptations to deal with their particular food type. In general, mouthparts are either adapted for
biting or sucking, although combinations of these are frequently encountered.
In this practical we will be examining the mouthparts of:
Blaberus (cockroach) – biting mouthpart
Anopheles (mosquito) – piercing, sucking mouthpart
1.
2.
3.
4.
Use the low power objective (x4) to view the mouthparts of Blaberus.
Draw, label and annotate. Use figure 3.4 as a guide.
Examine the demonstration slide of the mouthpart of Anopheles.
What are the distinguishing features of the mouthparts of Anopheles and
Blaberus?
48
Figure 3.4 Cockroach mouthparts
Figure 3.5 Mouthparts of a mosquito
49
Practical # 8 – Phyla Echinodermata and
Chordata
The echinoderms (phylum Echinodermata) are coelomate deuterostomes. All echinoderms are
marine and are much different that the phyla studied recently; as adults, they have abandoned the
evolutionary advantage of being bilaterally symmetrical. The adult echinoderms exhibit
pentaradial symmetry. This pentaradial symmetry develops secondarily as the larvae of
echinoderms are clearly bilaterally symmetrical and metamorphose into the pentaradial adults.
The pentraradial symmetry of the adults results in a reduced degree of cephalization and the
nervous system is simple and consists of a ring of nerves with radial nerves branching laterally;
there is no centralized brain. Generally speaking, echinoderms are slow moving organisms.
Echinoderms possess a supportive endoskeleton of calcareous plates, spines, and ossicles. Many
of these calcified structures protrude through the epidermis and give echinoderms a “spiny”
appearance (hence the name of the phylum, echinos = spiny).
Perhaps the most distinguishing feature of an echinoderm is the water-vascular system. The
watervascular-system is used for locomotion, foraging, gas-exchange and the removal of
metabolic wastes. The water-vascular system consists of a series of tubular ducts which can be
used to move seawater. The movements of the seawater create hydrostatic pressure differences
on the distal ends of the flexible tube feet and create suction.
Echinoderms also have the ability to regenerate lost body parts and many echinoderms can
control the physical release of body parts to avoid predation. This may be due in part to the fact
that echinoderms have mutable connective tissue. They have the unique ability to control the
hardening and softening of their connective tissues at a moments notice. The presence of this
mutable connective tissue has made echinoderms important research subjects in understanding
and possibly treating disorders like arthritis.
50
1. List the characteristics previously described for a coelomate deuterostome.
________________________________________________________________________
________________________________________________________________________
________________________________________________________________________
2. Describe the symmetry of an adult echinoderm and compare it with the symmetry of a
larval echinoderm.
________________________________________________________________________
________________________________________________________________________
________________________________________________________________________
________________________________________________________________________
________________________________________________________________________
________________________________________________________________________
3. List the functions of the water-vascular system.
________________________________________________________________________
________________________________________________________________________
________________________________________________________________________
4. What type of skeletal system do echinoderms have?
________________________________________________________________________
5. How is the body of a sand dollar adapted for burrowing in loose sediments like sand?
________________________________________________________________________
________________________________________________________________________
________________________________________________________________________
8. How may a sea cucumber defend itself from a predator.
________________________________________________________________________
________________________________________________________________________
________________________________________________________________________
51
The chordates (phylum Chordata) are coelomate deuterostomes with closed circulatory
systems, complete digestive systems with some degree of metamerism. Like the arthropods,
there is a tremendous amount of diversity within members of the phylum; from very simple
animals like the tunicates to very complex animals like humans.
All chordates possess at some point in their life cycle four main characteristics (the “big 4”).
Examples of Chordates
The urochordates – tunicates or sea squirts The tunicates are strange looking animals. At first
glance, they superficially resemble a lower animal like a cnidarian or mollusk. However, upon
closer examination their chordate heritage is evident. Only the larval stages will possess the
“Big 4” characteristics. The larvae are free swimming and use the pharyngeal clefts to filter
plankton from the water column. An eyespot is located at the anterior of the dorsal hollow nerve
cord and is used for photoreception. At the end of the larval stage, the tunicate larva attaches
itself to a suitable substrate (such as a piece of coral) using its adhesive papillae located on the
anterior end. Once attached, the tunicate will undergo metamorphosis into the adult form. The
adults have highly reduced cephalization and of the “Big 4”, only retain the pharyngeal slits.
A translucent tunic, a heavy coat of tissue that surrounds the body, covers the body of the adult
tunicate Usually visible through the tunic are the numerous pharyngeal slits used for filterfeeding plankton. The tunic is folded to form the incurrent and excurrent siphons. As the tunic
contracts and relaxes, water is drawn into the body through the incurrent siphon and routed to the
mouth where the plankton is filtered. Once filtered, the water is expelled through the excurrent
siphon along with any digestive wastes eliminated from the anus.
52
Questions
1. What do tunicates feed on?
________________________________________________________________________
________________________________________________________________________
________________________________________________________________________
2. How does the larva of a tunicate differ from the adult?
________________________________________________________________________
________________________________________________________________________
________________________________________________________________________
3. Which of the four main characteristics of chordates is found in the adult form of a
tunicate?
________________________________________________________________________
________________________________________________________________________
________________________________________________________________________
4. What structures are used by the tunicate larva to attach itself to the substrate?
________________________________________________________________________
________________________________________________________________________
________________________________________________________________________
53
Practical # 9 – Phylum Plantae
Collect plant samples on the UTECH campus from the following groups:
A. Phylum Filicinophyta (ferns)
B. Phylum Coniferophyta
C. Phylum Angiospermophyta – Dicotyledonae
D. Phylum Angiospermophyta – Monocotyledonae
Draw each plant. Label and annotate your drawings.
Phylum Filicinophyta (ferns)
Ferns represent the second major step in the evolutionary sophistication of plants. While they
still reproduce by spores like mosses, the ferns add a vascular system -- i.e. specialized organs
for transporting fluids throughout the plant.
As an indication of this extra evolution, the gametophyte stage of growth is significantly
reduced. In this way, a fern can be thought of as the inverse of a moss. The moss plants we
commonly see are gametophytes: the sporophyte stage is small and often overlooked. By
contrast, the fern plants we commonly see are the sporophytes: it is the gametophyte stage that is
small and often overlooked.
The gametophyte generation of ferns is a small, heart-shaped, plant called the prothallium. They
are less than an inch (1 - 2 cm) in diameter and look very much like thalloid liverworts or
hornworts. Male and female sex organs are located on the underside of the prothallium and,
when conditions are right, the sperm swims from the male antheridium to fertilize the egg in the
archegonium. The result of this union is the fern plant we have come to know and recognize.
This plant, the sporophyte, grows to maturity and then produces spores on the undersurface of its
leaves or fronds. Fern sporophytes can grow as tall as trees. They can reproduce vegetatively
from root cuttings. They never have flowers.
54
Phylum Coniferophyta
They are cone-bearing seed plants with vascular tissue; all extant conifers are woody plants, the
great majority being trees with just a few being shrubs. Typical examples of conifers include
cedars, cypresses, douglas-firs, firs, junipers, kauris, larches, pines, redwoods, spruces, and yews.
All living conifers are woody plants, and most are trees, the majority having monopodial growth
form (a single, straight trunk with side branches) with strong apical dominance. The size of
mature conifers varies from less than one metre, to over 100 metres.
The leaves of many conifers are long, thin and needle-like, but others, including most of the
Cupressaceae and some of the Podocarpaceae, have flat, triangular scale-like leaves. Some,
notably Agathis in Araucariaceae and Nageia in Podocarpaceae, have broad, flat strap-shaped
leaves. In the majority of conifers, the leaves are arranged spirally with a few exceptions.
Leaf size varies from 2 mm in many scale-leaved species, up to 400 mm long in the needles of
some pines (e.g. Apache Pine Pinus engelmannii). The stomata are in lines or patches on the
leaves, and can be closed when it is very dry or cold. The leaves are often dark green in colour
which may help absorb a maximum of energy from weak sunshine at high latitudes or under
forest canopy shade. Conifers from hotter areas with high sunlight levels (e.g. Turkish Pine
Pinus brutia) often have yellower-green leaves, while others (e.g. Blue Spruce Picea pungens)
have a very strong glaucous wax bloom to reflect ultraviolet light. In the great majority of genera
the leaves are evergreen, usually remaining on the plant for several (2-40) years before falling,
but five genera (Larix, Pseudolarix, Glyptostrobus, Metasequoia and Taxodium) are deciduous,
shedding the leaves in autumn and leafless through the winter. The seedlings of many conifers,
including most of the Cupressaceae, and Pinus in Pinaceae, have a distinct juvenile foliage
period where the leaves are different, often markedly so, from the typical adult leaves.
Most conifers are monoecious, but some are subdioecious or dioecious; all are wind-pollinated.
Conifer seeds develop inside a protective cone called a strobilus (or, very loosely, "pine cones",
which technically occur only on pines, not other conifers!). The cones take from four months to
three years to reach maturity, and vary in size from 2 mm to 600 mm long.
Phylum Angiospermophyta – Dicotyledonae
Angiosperms add the final improvement to plant reproduction: they grow their seeds inside an
ovary (Greek: angeion = vessel) which is, itself, embedded in a flower. After it is fertilized, the
flower falls away and the ovary swells to become a fruit.
Angiosperms in the class Dicotyledoneae grow two seed-leaves (cotyledons). In addition, foliage
leaves typically have a single, branching, main vein originating at the base of the leaf blade, or
three or more main veins that diverge from the base.
55
The vast majority of plants are Dicots. Most trees, shrubs, vines, and flowers belong to this
group of around 200,000 species. Most fruits, vegetables and legumes come from this class.
Phylum Angiospermophyta – Monocotyledonae
Monocots start with one seed-leaf. The main veins of their foliage leaves are usually unbranched
and nearly parallel to each other. Around 30,000 plants are classified as monocots including
many of the prettiest members of kingdom Plantae: orchids, lilies, irises, palms and even the
Bird-of-Paradise plant. The grasses which carpet our lawns and meadows are also monocots.
Monocots provide us with our primary sources of nutrition, supplying us and the animals we eat
with grains such as wheat, oats, and corn, as well as fruits such as dates and bananas.
56
57
Parts of a Grass Spikelet
58
Practical # 10 – Phylum Plantae
When studying plants and animals it is necessary to collect, preserve and analyse them.
We have discussed some of the collection and preservation techniques in class. In this practical
you will collect and preserve a few plants and animals and you will also prepare temporary
mounts of plant and animal specimen.
Part A. – Plant Collection and Preservation
1. Collect representative parts of a plant (leaves, flowers, fruits and seeds) on the UTech
campus.
2. Make notes on the habitat and the structural features of the plant. (tree, shrub, colour of
flowers and fruits, location of plant)
3. Place the plant between sheets of newspaper. Arrange the plant so that all the parts can
be seen. The dorsal and ventral views of the leaves must be displayed.
4. If the plant has a fruit that may be too large to press whole, cut transverse sections of it
and place them between the sheets of newspaper as well.
5. Place the plant and newspaper between the sheets of board provided.
6. Check on the status of the plants during the next lab session
7. When the plants completely dry tape them to sheets of plain paper and attach the
information you had collected about the plant to the sheet.
Part B. – Collection of animals in leaf litter.
1. Collect leaf litter.
2. Set up the Berlese funnel apparatus as shown in the diagram.
3. The light bulb should be kept at least 10 cm away from the funnel.
4. Observe the contents of the beaker after about 5 days.
59
Part D. - Preparation of Temporary Mounts
Plant leaves (Rhoeo discolor)
Procedure
1. Insert a piece of leaf into a vertical slit made down the centre of a piece of moistened
carrot.
2. Hold the carrot piece in one hand, cut the sections rapidly and smoothly with a sharp
razor blade held in the other hand.
3. Place the sections in a dish of water.
4. Select one or two thin sections, including at least one that is cut through the midrib, and
mount in water on a slide.
5. Place a cover slip over the slide. Examine the slide under the microscope.
Plant stems (Coleus or Zea mais or Phaseolus)
Procedure
1. Soak a stem segment in water.
2. Cut thin transverse sections with a razor blade: hold the piece of stem in one hand and the
blade in the other, cut smoothly and rapidly, and constantly wet the blade and surface of
the stem with water.
3. Transfer the stem sections into a dish of water.
4. Select one or two thin sections for staining (e.g. using safranine) and then mount in dilute
glycerine.
5. Place a cover slip over the slide. Examine the slide under the microscope.
Leaf Epidermis (Rhoeo discolor or onion)
Procedure
1. Place a small drop of colourless nail varnish on a slide.
2. Place a leaf on the drop. Hold flat until the nail varnish dries.
3. Remove the leaf from the slide. A negative replica will be obtained on the slide.
4. Examine the replica under the microscope.
Animal Epithelial cells (Cow corneal cells)
Procedure
1. Gently touch the surface of the cornea of a fresh ox eye or of an ox eye (fresh or
refrigerated) with a clear slide.
2. Add a drop of methylene blue stain on the slide.
3. Place a cover slip over the slide. Examine the slide under the microscope.
60
LEARNING AND TEACHING APPROACHES 2012 – 2013
Teaching is through lectures, tutorials and laboratory sessions using independent
learning packages, team projects and peer tutoring.
ASSESSMENT PROCEDURES
Weightings
(%)
1.
Test 1
15
(To test students’ knowledge and understanding of
basic concepts in Units 1 - 9)
(Week 6)
2.
Practicals
10
3.
Group project
10
4.
Test 2
(Test students overall comprehension of topics covered
in units 10 - 22)
(Week 11)
5.
Final examination
6.0
BREAKDOWN OF HOURS
50
Classroom lectures
3 x 13 -> 39 hrs
Practicals
3 x 13 -> 39 hrs
Independent direct learning
-> 8 hrs
Assessment
-> 4 hrs
7.0
15
TEXTBOOKS AND REFERENCES
Biological Science 1&2
Biology
DJ Taylor, CPO Green, GW Stout
EP Solomon, LR Berg, &
Cambridge
DW Martin
ISBN 0 521 56178 7
Brooks/Cole
ISBN0 03 033503 5
61