CHAPTER 1: BIODIVERSITY

CHAPTER 1: BIODIVERSITY SES SEMESTER II:DB024

CHAPTER 1: BIODIVERSITY

1.1 INTRODUCTION TO BIODIVERSITY AND TAXONOMY

(A) DEFINE BIODIVERSITY
Biodiversity refers to the total number of species, the variability of their genes, and the communities in
which they live.

Genetic diversity Types of biodiversity Ecosystem diversity
The genetic variation within a Varieties of community and
species. Due to different kind of Species diversity ecosystems in a given area/
genetic makeup of a species. The variety of species within a found on earth
community.

(B) BIOLOGICAL CLASSIFICATION AND NOMENCLATURE BASED ON LINNAEAN SYSTEM
● Taxonomy is the science of naming, describing and classifying organisms according to their

established natural relationship.
● Carolus Linnaeus (father of taxonomy) developed the hierarchical classification system and the system

of binomial nomenclature.
● Hierarchical classification = A method to group and categorize organisms by biological characteristic

into taxonomic groups (taxon) of organism at any given level.
● Taxon is a formal grouping of organisms at any given level. There are eight (8) taxon groups:

Do REMEMBER!
King
Peter
Came
Over
For
Good
Spaghetti

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Taxon CHAPTER 1: BIODIVERSITY SES SEMESTER II:DB024
Domain
Kingdom Example 1: Human Example 2: Mango tree
Phylum Eukarya Eukarya
Animalia Plantae
Class Chordata
Order Mammalia Angiospermae
Family Primates Dicotyledonae
Genus
Species Hominidae Sapindales
Homo Anacardiaceae

Homo sapiens Mangifera
Mangifera indica

BINOMIAL SYSTEM OF NOMENCLATURE

● Each type of organism is given a two-part Latin name.
● The first word is the genus name and begins with a CAPITAL letter.
● The second word is the species name and begins with a lowercase letter.
● The name is printed in Italics or underlined when handwritten.

The scientific name based on Writing: Homo sapiens Writing: Mangifera indica
binomial system: Typing: Homo sapiens Typing: Mangifera indica

Genus + species

Example: Leopard = Panthera pardus belongs to genus Panthera
African lion = Panthera leo
Tiger = Panthera tigris
Jaguar = Panthera onca

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CHAPTER 1: BIODIVERSITY SES SEMESTER II:DB024
(C ) CLASSIFICATION SYSTEM

By Carl Woese (1977)

i. FIVE - KINGDOM SYSTEM

● Proposed by Robert Whittaker/ R.H. Whittaker (1969).
● Classification is based on common physical characteristics (structural / morphological

differences).

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Kingdom Kingdom Kingdom Kingdom Kingdom
MONERA PROTISTA FUNGI PLANTAE ANIMALIA

Classified based on

Level of cell Level of organism Types of nutrition

organization

Prokaryotes Eukaryotes Unicellular Multicellular Saprophytic Photosynthe Holozoic

tic

Organisms Organisms Organism Organism that Organism Organism Organism

that lack that have which is consists of that secrete that convert that ingest

true true nucleus made up of many cells. enzyme for light energy organic

nucleus and and just one cell. extracellular into matter,

membrane membrane digestion and chemical digest

bound bound absorbs energy. internally.

organelles. organelles. nutrients. Also called

autotroph.

*Autotroph = photosynthetic (producer) *Heterotroph = holozoic and saprophytic

(consumer)

ii. THREE DOMAINS SYSTEM

● Proposed by Carl Woese (1977).
● Based on new information (molecular data based on analyses of small subunit 16S rRNA genes

sequences), classification now follows the three-domain system.
● There are big differences between Domain Bacteria and Archaea although these 2 domains are

categorized together under Kingdom Monera, which are prokaryotes.

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Prokaryotes Eukaryotes

Domain Bacteria Domain Archaea Domain Eukarya

- True bacteria. Bacteria which live in extreme Kingdom Protista
- Bacteria surrounding us / a environments. Kingdom Fungi
Kingdom Plantae
major group of bacteria. E.g.: Sulfolobus sp. Kingdom Animalia

- E.g.: Escherichia. coli (E.
coli), cyanobacteria (blue-
green algae)

THREE DOMAINS SYSTEM

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1.2 DOMAIN BACTERIA AND DOMAIN ARCHAEA

(A) TWO DOMAINS OF PROKARYOTES:
Domain Bacteria. Eg: E.coli
Domain Archaea. Eg: Sulfolobus sp.

Unique characteristics of prokaryotes:
● Have no distinct nucleus
● No membrane bound organelles
● Unicellular
● Some have plasmid
● Have cell wall made up of peptidoglycan
● Contain 70S ribosomes
● Reproduction by binary fission or
endospore formation if condition is not
suitable

(B) DIVERSITY OF BACTERIA

i. Based on cell shape

Coccus (plu: cocci) Spherical shape;

Streptococci (chain), Diplococci (pair),

Staphylococci (cluster)

Bacillus (plu: bacilli) Rod shape

Spirillum (plu: spirilla) Spiral shape

Vibrio Comma shape

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(C) THE IMPORTANCE OF BACTERIA

Importance Example
Recycling of chemical ● Nitrogen fixation. Rhizobium sp. helps in fixing nitrogen from the atmosphere
elements in ecosystem
through root nodules.
Symbiotic ● As a decomposer. Bacteria also decompose the organic molecules of dead

Pathogenic organisms and release CO2 to the atmosphere.
In research and Enterobacteria
technology e.g.: E. coli in the human intestine helps to digest lactose and supply vitamin K &
B complex. In herbivores, bacteria used to digest cellulose.
Salmonella sp. cause food poisoning
In biotechnology, E. coli (its plasmid) is used in gene cloning as vector.

1.3 DOMAIN EUKARYA: KINGDOM PROTISTA

(A) UNIQUE CHARACTERISTICS OF PROTISTA

Unique characteristics of Protista
▪ Eukaryotes - Have true nucleus and membrane-enclosed organelles
▪ Mostly unicellular and some simple multicellular.
▪ Feeding mode: Autotrophic (photosynthetic) for algae

Heterotrophic (saprophytic or holozoic) for protozoa
▪ Most are motile (using flagella or cilia).
▪ Mostly are free-living (An organism that is not directly dependent on another organism for survival).
▪ Reproduction: Asexual reproduction (by binary fission or spore formation) or sexual reproduction

(fusion of gametes)
▪ Habitat - in water or very damp surfaces

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CHAPTER 1: BIODIVERSITY SES SEMESTER II:DB024
(B) CLASSIFICATION OF PROTISTA

Classification of Protista

Protista has 2 groups of organisms:

(a) Algae (plant-like) Eg: Chlamydomonas sp.

(b) Protozoa (animal-like) Eg: Amoeba sp.

Algae: Chlamydomonas sp. Protozoa: Amoeba sp.

Algae Protozoa
• Unicellular to simple multicellular • Unicellular

• Photoautotroph • Most heterotroph except Euglena sp.

• Live in water or on damp surfaces • Live in aquatic or moist terrestrial
environments

(C) IMPORTANCE OF PROTISTA

Importance Example
Human food source (Chlorella sp.) As a dietary supplement. High in proteins and packed with fats and
Sewage treatment // wastewater vitamins to promote growth and tissue repair
treatment Sewage treatment is the process of removing contaminants from
wastewater, containing mainly household sewage plus some industrial
Human health wastewater. The importance of protozoa in wastewater treatment is to
maintain a slime layer within trickling filter systems. They play a
predatory role in removing bacteria, other protozoa and several small
particles.
Plasmodium sp. causes malaria

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CHAPTER 1: BIODIVERSITY SES SEMESTER II:DB024
1.4 DOMAIN EUKARYA: KINGDOM FUNGI

(A) UNIQUE CHARACTERISTICS OF FUNGI

Unique characteristics of Fungi
1. Multicellular eukaryotes
2. Fungi are heterotroph by saprophytic. They secrete enzymes externally to decompose organic materials,

and then absorb the nutrients.
3. Some fungi are parasites and symbionts.
4. Most are multicellular except yeast (unicellular).
5. Cell wall made up of chitin and store food as glycogen.
6. They have body which consists of long, branched

threadlike filaments called hyphae. Mass of hyphae
called mycelium. Types of hyphae:

Septate Aseptate / Coenocytic

Hyphae are divided by Hyphae has no septa, thus
cross walls (septa with multinucleated.
pores)

7. Fungi reproduce by using spores (sexual or asexual). Spores are produced on specialized aerial hyphae
or in specialized spore-forming (fruiting) structures called sporangium. Spores germinate to form new
hyphae.

(B) CLASSIFICATION OF FUNGI BASED ON SPORE BEARING STRUCTURE

Phylum Phylum Zygomycota Phylum Ascomycota Phylum Basidiomycota
Aseptate / coenocytic hyphae (Sac Fungi) (Club Fungi)
Type of Spores form in sporangium.
hyphae Septate hyphae Septate hyphae
Asexual
reproduction Conidia that pinch off from Rare / none
conidiophores.

Rhizopus sp. Penicillium sp.

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Sexual Via formation of Via formation of ascospores Via formation of
reproduction zygospores Zygosporangium within ascus. basidiospores, outside of
came from the fusion of basidia.
hyphae. Ascocarp
Basidiocarp

Example The asci are arranged in The basidia are arranged in
fruiting bodies called fruiting bodies called
ascocarps. basidiocarps.
Agaricus sp.
Black bread mold, Rhizopus Yeast and Penicillium sp.
sp.

(C) IMPORTANCE OF FUNGI

Importance Example
Decomposers Saprophytic fungi will decompose (by secrete enzymes for extracellular
digestion) and absorb nutrients from organic wastes and dead organisms. They
are able to degrade cellulose and lignin of plant cell wall.

Symbionts Lichens are a symbiotic association between algae and fungi.
✔ Algae provides fungus with food / produce carbohydrate through

photosynthesis
✔ Fungus provides moisture, shelter, minerals and anchorage

Lichen ▪ (Parasitic) fungi that attack food crops produce compounds that are harmful
Pathogens
to humans
▪ Fungal infection such as ringworm and athlete’s foot
▪ Candidiasis, a yeast infection of mucous membranes of the mouth, throat

or vagina.

Candidiasis

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Commercial importance in Fermented food by alcohol fermentation.
food production
✔ Saccharomyces cerevisiae (yeast) is used in making bread and alcohol
(beer).

✔ Involve in the production of “tempe” and “tapai”.

Pharmaceutical ▪ Some fungi produce antibiotics that are antibacterial (used to treat bacterial
infection).

▪ Example: Formation of antibiotics penicillin from Penicillium sp.

1.2 DOMAIN EUKARYA: KINGDOM PLANTAE

(A) UNIQUE CHARACTERISTICS OF PLANTAE

Unique characteristics of Kingdom Plantae
1. Multicellular eukaryotes.
2. Autotrophic - Synthesis its own organic food through photosynthesis.
3. Non-motile - Anchored to surfaces by root or rhizoid (root-like structure).
4. Cell wall made of cellulose and food storage in the form of starch.
5. Life cycle with alternation of generation which alternation of haploid gametophyte phase (n) and diploid

sporophyte phase (2n).
✔ Sporophyte produces haploid spores by the process of meiosis.
✔ Gametophyte will give rise to haploid gametes by mitosis.

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CHAPTER 1: BIODIVERSITY SES SEMESTER II:DB024
(B) CLASSIFICATION OF PLANTAE INTO FOUR GROUPS:

I. UNIQUE CHARACTERISTICS OF BRYOPHYTES (e.g.: Polytrichum sp.)

Unique characteristics of Bryophytes Polytrichum sp.
1. No vascular tissue for transporting water, sugar and essential minerals.
2. Seedless.
3. Do not have true roots, stem and leaves. The body is called thallus
4. Gametophyte generation is dominant than the sporophyte generation
5. Sporophyte depends on gametophyte for water and nutrients
6. Dependent on water for fertilization
7. Small in size and normally live-in damp, shady terrestrial environments
8. It produces haploid spores (homosporous spores: plants that produce

only one type of spore).
9. Water movement is via diffusion from cell to cell
10. Absorption of water and mineral is via rhizoid (root like for attachment

and absorption of water)
11. Its terrestrial adaptation (more advanced than algae of Protista):

✔ has epidermis (with no cuticle)

✔ has stomata (for gaseous exchange)

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✔ has capsule (to protect spores)
✔ has rhizoid
12. Female gametophyte produces oosphere (gametes) in
archegonium.
13. Male gametophyte produces antherozoids (flagellated
sperms) in antheridium.
14. Sporophyte can be found on female gametophyte.
Consist of:
✔ Foot
✔ Seta, an elongated stalk
✔ Capsule (sporangium) that producing spore

(homosporous)

II. UNIQUE CHARACTERISTICS OF PTERIDOPHYTES (e.g.: Dryopteris sp.)

Unique characteristics of Pteridophytes
1. Have simple vascular tissue
2. Seedless plant.
3. Have true root, stem and leaves.
4. Sporophyte generation is dominant than gametophyte generation
5. Sporophyte is independent from gametophyte
6. Dependent on water for fertilization (*motile / flagellated sperms need to swim towards egg*)
7. Presence of cuticle and stomata.
8. The spores may be homosporous (plants that produce only one type of spore) or heterosporous (plants

that produce two types of spores – microspores (develop into male gametophytes) and megaspores
(develop into female gametophyte)

Heterosporous - Selaginella sp. Homosporous - Dryopteris sp.

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Dryopteris sp.

III. UNIQUE CHARACTERISTICS OF GYMNOSPERMS (e.g.: Pinus sp.)

Unique characteristics of Gymnosperms
1. Gymnosperms are non-flowering plants (*do not produce flowers or fruits*)
2. Has naked seeds. The seeds are exposed on the surface of spore-producing structures, sporophylls // the

seeds are not protected by fruits.
3. The seed does not possess endosperm.
4. Have complete vascular tissue. Xylem consists only of tracheid (without vessel elements) and phloem

consists only of sieve tube (without companion cells).
5. Sporophyte generation is dominant than gametophyte generation.
6. Gametophyte depends on sporophyte.
7. Reproductive structures are called cones or strobilus and they are heterosporous.
8. Do not need water for fertilization, but need wind as pollinating agent.
9. No double fertilization and no endosperm formation.

Pinus sp. Strobili / cones

IV. UNIQUE CHARACTERISTICS OF ANGIOSPERMS (e.g.: Hibiscus rosa-sinensis)

Unique characteristics of Angiosperms
1. Angiosperms are flowering plants (produce flowers and fruits). Reproductive structures are flowers.
2. Have enclosed seed where the seed is protected by fruit
3. The seed possesses endosperm
4. Have complete vascular tissue. Xylem consist of tracheid and vessel elements while phloem consists of

sieve tube and companion cells.
5. Sporophyte generation is dominant than gametophyte generation.

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6. Gametophyte depends on sporophyte.
7. There are also heterosporous (produce two different types of spores - microspores and megaspores) with

double fertilization:
(a) Microspores will produce pollen grain (male gametophyte).
(b) Megaspores will produce embryo sac (female gametophyte).

8. Do not need water for fertilization, need various pollinating agents such as insects and wind.
9. After double fertilization:

- Ovary develops into fruit.
- Ovule develops into seed.

(C) EVOLUTIONARY RELATIONSHIP IN PLANT KINGDOM

Characteristics Bryophytes Pteridophytes Gymnosperms Angiosperms
i. Size Small sporophyte, Large sporophyte, Large sporophyte, Large sporophyte,
large gametophyte small gametophyte
ii. Dominant reduced reduced
generation Gametophyte (n) gametophyte gametophyte
iii. Dependency Sporophyte (2n)

iv. Water Sporophyte Gametophyte and Gametophyte dependent on sporophyte
dependence in dependent on sporophyte are
fertilization gametophyte independent No (non-motile sperm doesn’t need water
v. Presence and Fully depend on Need water for for fertilization)
complexity of fertilization
vascular tissues water for Complete vascular tissue
vi. Embryo fertilization Simple vascular
protection No-vascular tissue tissue

Seed production Within archegonia Some protection Within seed coat Within seed coat

Present of true (gametophyte) within archegonia enclosed in fruit
root, stem and
leaves (gametophyte)

Absence of seed Presence of naked Present of protected

seed seed

No true root, stem Have true root, stem and leaves

and leaves (thallus

body)

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CHAPTER 1: BIODIVERSITY SES SEMESTER II:DB024

1.6 DOMAIN EUKARYA: KINGDOM ANIMALIA

(A) UNIQUE CHARACTERISTICS OF KINGDOM ANIMALIA

Unique characteristics of Kingdom Animalia
▪ Multicellular eukaryotes
▪ Feeding mode: Heterotrophic (holozoic)
▪ (Most) reproduce sexually
▪ (Most) have nervous systems and muscle systems
▪ Motile // Capable of locomotion (*during at least a part of their life cycle*)
▪ Have diverse body plans (*body plan = the basic structure and functional design of the body*)
▪ Body plan = body symmetry, tissue organization and body cavity
▪ Have a period of embryonic development

(B) CLASSIFICATION OF ANIMALIA INTO NINE PHYLA

Animal classification based on body plan which are:

(i) Body symmetry

Asymmetry Radial symmetry Bilateral symmetry
Body can be divided into two mirror-
NO pattern of symmetry. Body can be divided into mirror images, right and left halves through
only one plane.
Body cannot be divided into halves through multiple planes.

mirror halves.

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Parazoa (ii) Tissue organization
No true tissue / No germ layer Eumetazoa
E.g.: Sponges (Phylum Porifera)
Have true tissues - collections of specialized cells isolated from other
tissues by membranous layers.
(i) Diploblastic = Having two germ layers (ectoderm & endoderm)
(ii) Triploblastic = Having three germ layers

(ectoderm, mesoderm & endoderm)
(iii) Body coelom and germ layer

▪ Body cavity is a fluid-filled space separating the digestive tract from the outer body wall.
▪ Also known as coelom.
▪ Three types of body cavity:

1. Acoelom
2. Pseudocoelom
3. Coelom

Acoelom Pseudocoelom Coelom
LACK a body cavity Have a body cavity but NOT Have a fluid-filled body cavity
completely lined by mesoderm. (coelom) and COMPLETELY lined
by mesoderm.
(Develops between mesoderm and
the endoderm) (Internal organ develop & suspended
in coelom)

Segmentation

▪ Segmentation is the division of some animal body plans into a series of repetitive sections. Advanced
animals have body segments and specialization of tissue.
(a) Metamerism: segments are similar with each other
(b) Tagmatization: segments are different and may fused into groups specialized for specific function
(i) 3 segments (Head, thorax and abdomen)
(ii) 2 segments (Cephalothorax and abdomen)

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CHAPTER 1: BIODIVERSITY SES SEMESTER II:DB024
PHYLOGENETIC TREE OF KINGDOM ANIMALIA

I. PHYLUM PORIFERA
Unique characteristics of Porifera

Example: Sponges - Leucosolenia sp.
1. No true tissues (Parazoa) and no body symmetry (asymmetry).
2. They are sessile (lived permanently attached to the surface).
3. Suspension feeders (feed on food particles suspended in the water that passes through its body).
4. Sac-like body with tiny pores (ostium) on the body wall for water to enter. Water exits through the

osculum (large opening to the outside through which the current of water exits after passing through the
spongocoel).
5. Central cavity is spongocoel (the large, central cavity of sponges).
6. (Most) are hermaphrodites = the SAME individual can produce BOTH sperms and eggs.
7. They can reproduce by both asexual and sexual means.
✔ Sexual reproduction: amoeboid cells produce egg & sperm into water, they fused to form new

sponge
✔ Asexual reproduction: budding

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Choanocytes/ ▪ Flagellated cells line the inside of the sponge wall
collar cell ▪ Beating of flagella generates water current that brings food and oxygen and carries out

carbon dioxide and waste through the osculum.

Amoeboid ▪ Digest food particles trapped by collar cells. Then, it transports nutrients to another
cell / cell.
amoebocytes
▪ Secrete spicules.
Spicules ▪ Secrete spongin to provides support and elasticity
▪ Produce sperm and egg / gamete
▪ Secrete by amoeboid cell
▪ Sharp pointed structures to provide support for a sponge and protection from

predators

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II. PHYLUM CNIDARIA

Unique characteristics of Cnidaria
Example: Obelia sp.
1. Has true tissues, have radial symmetry and diploblastic.
2. Has single-opening in the gastrovascular cavity that acts as mouth and anus.
3. Their unique features are tentacles with cnidocytes that discharge nematocysts (stinging structure). It is

used to trap prey and as protection / defense.

4. Some species dimorphism / polymorphism: the existence of two different body forms (polyp and

medusa) within a species.

Polyp Medusa

Sessile Free swimming / motile

Cylindrical shape body Umbrella / bell-shaped body

The mouth directed The mouth directed downward

upward (dorsal opening) (ventral opening)

▪ Polyp form:
(i) reproductive polyp (gonozoids) - no tentacles,
containing medusa buds for reproduction
(ii) feeding polyps (gastrozoids) - have tentacles to
trap pray

▪ Medusa form:
- Produce by reproductive polyps by budding
- Free swimming medusa reproduce sexually

Asexual Sexual reproduction
reproduction
Reproductive The sperm from male medusa and
polyp (gonozoid) ovum from female medusa
produces medusa combine to form a zygote.
through budding Zygote develops into planula larva
and forms a new colony of polyp.

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III. PHYLUM PLATYHELMINTHES

Unique characteristics of Platyhelminthes
Example: Taenia sp.
1. Has true tissues, bilateral symmetry, triploblastic, acoelom.
2. Show cephalization (head formation) with eyespot and sensory organ in head.
3. Flattened and thin bodies.
4. Unsegmented body (except Class Cestoda - tapeworm)
5. Most are hermaphrodite- an individual in which reproductive organs of both male and female sexes

are present.
6. Gastrovascular cavity/digestive tract has a single opening which serves a mouth (no anus) // incomplete

digestive system
7. Mostly are parasites.
8. Flame cell / protonephridia as their excretory organ / osmoregulation (fluid balance).
9. Body muscle cannot be contracted and locomotion only by swimming.
10. Live in host, aquatic animal.
11. No circulatory system and respiratory organ. Due to flattened body, circulation is carried out by

diffusion.

E.g.: Tapeworm (Taenia sp.)

▪ Adaptations possessed by Platyhelminthes as endoparasites:
i. Scolex (head) with suckers and hooks. Sucker to absorbs nutrients from host and hook for
attachment to host
ii. Proglottids
✔ Each contains a complete set of male and female reproductive organs (hermaphrodite)
✔ A mature proglottid has many eggs
iii. Has cuticle body

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IV. PHYLUM NEMATODA

Unique characteristics of Nematoda (roundworm)
Example: Ascaris sp.
1. Has true tissues, Bilateral symmetry, triploblastic, pseudocoelom.
2. Unsegmented and cylindrical shape with tapered / pointed ends.
3. Complete digestive tract with mouth and anus.
4. No circulatory system.
5. Has hydrostatic skeleton.
6. Separate sexes (dioecious) - normally female is larger than male).
7. Trashing motion because it has longitudinal muscles only.
8. Shows cephalization (head formation).
9. Mostly parasitic, living inside the host.
10. Tough and transparent cuticle forms the outer body covering for shape and protection.

Ascaris sp.

V. PHYLUM ANNELIDA

Unique characteristics of Annelida
Example: Pheretima sp.
1. Has true tissues, bilateral symmetry, triploblastic, coelom.
2. Has metameric segmentation - contains the same organs in each segment except for head.
3. Digestive tracts are straight from mouth to anus.
4. Have longitudinal and circular muscle // rounded body
5. Body muscle can be contracted and various forms of locomotion.
6. Have tiny bristles called setae / chaetae help in movement.
7. Has nephridia / metanephridia as excretory organs and has a closed circulatory system.
8. Body covered by cuticle
9. Shows cephalization.
10. It may be hermaphrodite or some are dioecious.
11. Has a closed blood circulatory system.
12. Has hydrostatic skeleton.

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Earthworm (Pheretima sp.)

VI. PHYLUM ARTHROPODA

Unique characteristic of Arthropoda
Example: Valanga sp.
1. Has true tissues, bilateral symmetry, triploblastic, coelom.
2. Main body cavity is hemocoel that is filled with hemolymph in adults.
3. Show cephalization, well-developed sensory organ at the anterior end of the body.
4. Has segmented body.
5. Have complete digestive system
6. Have an open circulatory system - the blood is not contained within an enclosed circuit of vessels
7. Excretory system is the Malpighian tubules collect wastes from the blood and reabsorb water so that only

dry material is excreted.
8. Has jointed appendages (The appendages including antenna, pincers, mouthparts, walking legs, swimming

appendages are jointed).
9. Have tagmata – head, thorax and abdomen.
10. Cephalothorax - only head and thorax fused.
11. Body covered by hard exoskeleton – chitin and protein.

Valanga sp.

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VII. PHYLUM MOLLUSCA

Unique characteristics of Mollusca
Example: Achatina sp.
1. Has true tissues, bilateral symmetry, triploblastic and coelom.
2. Unsegmented: soft body covered by a shell composed mainly of calcium carbonate.
3. Metanephridia as excretory organ.
4. Has hydrostatic skeleton.
5. Body soft and fleshy.
6. Open circulatory system – except Cephalopoda.
7. Respiratory system:

i. Aquatic - gill in mantle cavity
ii. Terrestrial – mantle as a lung
8. Main body cavity is hemocoel, a space containing blood.
* Hemocoel is not a coelom
9. Mollusca using radula to scrape up food.
* Radula is not present in clams
10. Reproduction – separate sexes, some hermaphrodites.
11. Three important body structure:
a) Visceral mass: Containing most of internal organs.
b) Mantle: cover the visceral mass and contain glands that secrete calcareous shells containing calcium
carbonate.
c) Muscular foot: contain both sensory and motor organs for movement / locomotion.

Achatina sp. (garden snail)

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VIII. PHYLUM ECHINODERMATA

Unique characteristics of Echinodermata
Example: Asterias sp.
1. Has true tissues, adult is pentaradial symmetry while larva is bilateral symmetry, triploblastic and

coelom.
2. Unsegmented.
3. Complete digestive system. Mouth generally on the lower (oral) surface of the body and anus on the upper

(aboral) surface.
4. Have water vascular system - function in movement, feeding and gaseous exchange.

a. Network of fluid-filled canal and chambers
b. Branching into extensions called tube feet

i. Tube feet functions in locomotion, feeding and gas exchange
ii. Each tube feet consist of ampulla and podium
iii. Ampulla store fluid and is used to operate the tube feet
5. Calcareous endoskeleton.
6. Absence of cephalization.
7. Has spines that covered the body for protection.
8. Simple nervous system without brain.
9. No excretory organ.
10. Sexes usually separate (external fertilization).
11. All marine.

Starfish (Asterias sp.)

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IX. PHYLUM CHORDATA

Unique characteristics of Chordata
Example: Amphioxus sp.
1. Has true tissues, bilateral symmetry, triploblastic and coelom.
2. Close circulatory system: Blood and interstitial fluid does not mix. Blood never leaves the blood vessel.
3. Has myotomes: Segmented muscle blocks
4. Has notochord: A longitudinal, flexible rod located between the digestive tube and the nerve cord. Give

rise to vertebral column / endoskeleton
5. Has post anal tail: Muscular tail extending beyond the anus.
6. Has dorsal hollow nerve cord: A hollow tube above the notochord. Develops into the central nervous

system: the brain and spinal cord (CNS).
7. Presence of pharyngeal cleft: Connect the pharynx, just posterior to the mouth, to the outside of the

animal. As suspension-feeding devices in many invertebrate chordates. Modified for gas exchange called
gill in aquatic vertebrates and become a part of ear and other structure in head and neck in tetrapods
(amphibians, reptiles, birds and mammals).

(C) THE EVOLUTIONARY RELATIONSHIP OF KINGDOM ANIMALIA

Phylum Level of Germ layers Body plan Body cavity Segmentation
Porifera organization No true tissue (symmetry) - / metamerism
Asymmetry
Cell No

Cnidaria Tissue Diploblastic Radial - No

Platyhelminthes Organ Triploblastic Bilateral Acoelom No

Nematoda Organ Triploblastic Bilateral Pseudocoelom No

Annelida Organ system Triploblastic Bilateral Coelom Yes

Arthropoda Organ system Triploblastic Bilateral Coelom Yes

Mollusca Organ system Triploblastic Bilateral Coelom No

Echinodermata Organ system Triploblastic Bilateral (Larva) Coelom No
Triploblastic Radial (adult) Coelom Yes
Chordata Organ system Bilateral

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CHAPTER 1: BIODIVERSITY SES SEMESTER II:DB024

Protostomia (coelom
from cell masses)

Deuterostomia
(coelom from
digestive tube)

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CHAPTER 1: BIODIVERSITY SES SEMESTER II:DB024

TERMINOLOGIES DEFINITION
Any of the gram-negative bacilli belonging to the Family Enterobacteriaceae
TERM An organism that consists of only one cell
Enterobacteria An organism that consists of more than one cell
Unicellular A single cell organism, lack nucleus and have no membrane bound organelles
Multicellular Multicellular organism that has nucleus and membrane bound organelles
Prokaryotes An organism that is not directly dependent on another organism for survival
Eukaryotes An organism, typically a plant, obtaining energy from sunlight as its source
Free-living of energy to convert inorganic materials into organic materials.
Photoautotroph An organism that is unable to synthesize its own organic carbon-based compounds
from inorganic sources, hence it feeds on organic matter produced by, or available
Heterotroph in, other organisms.
Feeding, absorbing or growing on decaying organic matter (e.g., dead or
Saprophytic decaying animal
An organism that obtains its nourishment by the ingestion and absorption of organic
Holozoic matter as animals do.
Any of various organisms (bacteria and fungi) that return organic substances to
Decomposer ecological cycles by feeding on and breaking dead organisms (extracellular
digestion).
Detritivore An organism (earthworm or fungus) that feeds on dead and decomposing organic
matter
Bacillus Used to describe any bacterium that has a rod shape
Coccus Used to describe any bacterium that has a spherical shape
Spirillum Refers to a bacterium with a cell body that twist like a spiral
Motile Capable of movement
Sessile Fixed in one place, non-motile
Coenocytic Fungal mycelium in which hyphae lack septa
Hyphae Long, branching filamentous structures of a fungus
Pathogenic A condition that capable of producing disease
Thallus Green shoot or twig which is the undifferentiated vegetative tissue of some
organisms such as algae, fungi, some liverworts and lichen.
Rhizoid Root like structure
Heterosporous plants that produce two types of spores
Homosporous spores plants that produce only one type of spore
Non-vascular plant Plant without a vascular system (xylem and phloem) but possess simpler tissues that
are specialized for internal transport of water
Hermaphrodite An organism that has reproductive organs normally associated with both male and
female sexes.
Dioecious Separate sexes
Metameric The property of having repeated segments such as annelids
Nephridia An invertebrate organ which occurs in pairs and performs a function similar to the
vertebrate kidney
Jointed appendages Appendages with joints
Tagmata The body segments are the head, thorax, and abdomen
Cephalothorax Head and thorax fused.
Hydrostatic skeleton One that contains no rigid, hard structures or bones for support, but rather relies on
a fluid-filled cavity within the body (another form of skeletal support)

END OF TOPIC

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