SCHOOL OF BIOSCIENCES

MOLECULES FROM
NATURE: BIODIVERSITY
AND NATURAL PRODUCTS
BIO62704
(August Semester 2023)

STUDENT NAME : __________________________

Arienne Lee

STUDENT ID : __________________________
0361310

PRACTICAL SESSION: __________________________

Class 01 Sec O2

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 PRACTICAL 2

Collection and Identification of Samples

Around Campus

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Aim
1. Collect and identify Protists from a water sample from Taylor’s Lake.
2. Collect and identify samples around Taylor’s Lakeside Campus.

Introduction
The protistans are a diverse assemblage of organisms, both green (photoautotrophic) and non-
green (heterotrophic). They are so diverse that different protistans have previously been
classified as fungi (eg. slime molds, oomycetes), animals (eg. protozoans) and plants (e.g. algae).
The majority of Protists are single-celled organisms. These organisms range from ciliates,
flagellates, algae, seaweed, and water molds.

Approximately 475 million years ago, plants originated from an aquatic green algal ancestor.
Early diversification gave rise to liverworts, hornworts and mosses, plants that are informally
called Bryophytes. Bryophytes resemble other plants in having apical meristems and embryos
that are retained on the parent plant. However, bryophytes lack lignified vascular tissue, are
therefore called ‘nonvascular plants’ although water-conducting tubes appear to be present in
some mosses. None of these plants is taller than 20 cm. Bryophytes play a major role in
maintaining the ecosystem’s humidity level, by their ability to absorb and retain water.

Bryophytes are restricted to moist habitats. Their flagellated sperm must swim through water to
reach the egg. Mosses are the most abundant plants in both the Arctic and the Antarctic. Asexual
reproduction in bryophytes is accomplished by fragmentation or by tiny vegetative "sprouts"
called gemmae, which form in special little structures called gemmae cups. The leafy green plant
of the moss or a liverwort is called gametophyte, which is the dominant stage in all bryophytes.
The sporophytes of bryophytes do not have a free-living existence. They grow directly out of the
fertilized egg in the archegonia and remain dependent on the parent gametophyte for their
nutrition. Primitive bryophytes like mosses and liverworts can rely on diffusion to move water in
and out of the plant. The vascular tissues in the more advanced ferns and "fern allies" are made
up of xylem and phloem (vascular tissue), which conduct water, nutrients, and food throughout
the plant body. Ferns and fern allies possess true vascular tissues, they can grow to be much
larger and thicker than the bryophytes.

Flowering plants (Angiosperms) are more numerous and widespread than fruitless plants
(Gymnosperms). The Gymnosperms produce seeds, but do not produce flowers. They consist of
four plant Divisions. Their seeds lack the external layer (fruity part) that surrounds the seeds of
flowering plants. Gymnosperms have advanced vascular tissues: xylem for transporting water
and nutrients and phloem for transporting photosynthetic products. The cones are reproductive

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structures. In most gymnosperms, male cones produce microspores that later develop into
pollen grains. The pollen grain is transported to a female cone where fertilization occurs; female
cones produce megaspores (female gamete). As in gymnosperms, the xylem tissue of
angiosperms is composed of tracheids, but also contains large- diameter, open-ended vessels.
Angiosperm vascular tissues provide more efficient transport than that of in Gymnosperms.
Angiosperms are the most successful plants and they have become the dominant plant form on
earth, especially the terrestrial habitats. Thus, they become an important food source for most
of the living beings on earth. In addition, they also serve as a source of pharmaceuticals, fibre
products, timber, ornamentals, and other commercial products.

Materials and Apparatus

• Compound microscope
• Stereomicroscope
• Water samples from Taylor’s Lake.
• Samples around campus.
• Microscope slides and coverslips

Procedures
A: Investigation of water samples from Taylor’s Lake
1. Prepare a wet mount of a water sample (the best sample usually is from the bottom of the
bottle).
2. Use the microscope to focus on the slide (try different objectives, some may be better than
others for viewing the slide).
3. Draw and label THREE (3) microorganisms from the water sample.

A: Investigation of samples around Campus

1. Use the microscope to focus on the structure of samples collected around campus.
2. Draw and label FIVE (5) samples collected around campus.

Results
Note: Drawing Specimens
1. Use pencil - you can erase and shade areas.
2. All drawings should include clear and proper labels (and be large enough to view details).
Drawings should be labeled with the specimen’s name and magnification.

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LABORATORY WORKSHEET 2 (16 marks)
Name : Arienne Lee
Student ID : 0361310

Part 1: Lake Water Samples (3 X 2 marks)

Ulothrix Navicula

⑧
*
41)
*

B
g O

f
↑

⑨
culoroplast 1.
⑯
⑧

⑨
1:1:
~

⑲
-
⑧ ⑧
-
8

B
⑲

⑧ 1
⑧

chloroplasts ->
⑧
⑧
⑦
·

call
-
.. .
⑨
I Nucleus
-

.
-
8 nucleus

Drawing of microorganism 1 from water Drawing of microorganism 2 from water

sample ( 400 X). sample ( 400 X).

Englena

mag.
im8. Nucleus
wucle.o
0

Drawing of microorganism 3 from water

sample ( 100 X).

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Part 2: Samples Around Campus (5 X 2 marks)

t ere se
HibiscuiSette" a

Drawing of sample 1 collected around Drawing of sample 2 collected around

campus ( 40 X). campus ( 40 X).

e
Drawing of sample 3 collected around
e

Drawing of sample 4 collected around

campus ( 40 X). campus ( 40 X).

e
phajj
Drawing of sample 5 collected around
campus ( 4 X).

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