Chapter 1 Biodiversity_part1

MY SMART STUDY GUIDE PST SEMESTER 2: SB025
CHAPTER 1: BIODIVERSITY

1.1 BIODIVERSITY AND CLASSIFICATION

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

(B) HIERARCHICAL CLASSIFICATION

1. Taxonomy is the science of naming, describing and classifying organisms

2. Carolus Linnaeus (father of taxonomy) developed the hierarchical classification system and the

system of Binomial nomenclature

3. Hierarchical classification = A method to group and categorize organisms, by biological

characteristic, into taxonomic groups (taxon). There are 8 taxon groups.

Taxon Example 1: Human Example 2: Mango REMEMBER!
Domain Eukarya Eukarya !!
Kingdom Animalia Plantae

Phylum Chordata Angiospermae King
Class Mammalia Dicotyledonae Peter
Order Primates Came
Family Hominidae Sapindales Over
Genus Anacardiaceae For
Species Homo Good
Homo sapiens Mangifera Spaghetti
Mangifera indica

(C) CLASSIFICATION SYSYTEM

(i) FIVE- KINGDOM SYSTEM

▪ Proposed by Robert Harding Whittaker/ R.H. Whittaker (1969)
▪ Classification is based on level of cell organization, types of organism and modes of nutrition.

Kingdom Monera Kingdom Protista Kingdom Fungi Kingdom Plantae Kingdom

Animalia

Classified based on

Level of cell Types of organism Modes of nutrition

organization

Prokaryotes Eukaryotes Unicellular Multicellular Saprophytic Photosynthetic Holozoic

Organisms Organisms Organism Organism that Organism Organism that Organism

that lack true that have true which is consists of that secrete convert light that
nucleus and nucleus and made up of many cells enzyme for energy into ingesting

membrane membrane just one cell extracellular chemical energy. organic
bound bound digestion and Also call matter and
organelles organelles. absorbs autotroph. digest
nutrients internally.

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

1|Page

MY SMART STUDY GUIDE PST SEMESTER 2: SB025

(ii) THREE- DOMAINS SYSTEM

▪ Proposed by Carl Woese (1977)
▪ Based on new information (molecular data of based on analyses of small subunit 16S, rRNA base

sequences), it classifies organisms into three- domain system.
▪ There are differences between Domain Bacteria and Archaea although both are prokaryotes.

Domain Bacteria Domain Archaea Domain Eukarya
- True bacteria Bacteria lives in extreme Kingdom Protista, Fungi,
- Bacteria surrounding us/ major group environment Plantae and Animalia
Eg: Sulfolobus sp.
of bacteria
- Eg: E. coli, cyanobacteria

Prokaryotes Eukaryotes

2|Page

MY SMART STUDY GUIDE PST SEMESTER 2: SB025
1.2 DOMAIN BACTERIA AND ARCHAEA

a) TWO DOMAIN OF PROKARYOTES:

Domain Bacteria : E.coli Domain Archaea : Sulfolobus sp.

b) DIFFERENCES BETWEEN DOMAIN BACTERIA AND DOMAIN ARCHAEA

I. Domain Bacteria Characteristics Ii. Domain Archaea

Cell wall made up of peptidoglycan Cell wall structure Cell wall lack of peptidoglycan

Membrane lipid contain straight-chain Structure of membrane lipids Membrane lipid contain branched-

fatty acids bonded to glycerol by ester chain hydrocarbons link to glycerol

linkage. by ether linkages.

DNA is not associated with histone Association of histone to DNA is associated with histone

proteins DNA proteins

Eg: E. coli , cyanobacteria Eg: Sulfolobus sp.

EXTRA INFO:

▪ Archaea is less widespread as compared to Bacteria

▪ They are extremophiles (live in extreme/ harsh environments). 3 groups of Archaea:

✓ Methanogens survive only in oxygen-free environment like marshy areas or guts of

✓ Halophiles ruminant animals
✓ Thermoacidophiles live in high salinity (salty) environments
live in high temperature and high acid concentration environments like

hot springs

3|Page

MY SMART STUDY GUIDE PST SEMESTER 2: SB025
c) 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

ii. Based on GRAM STAIN (due to difference in composition of their CELL WALL)

Gram - ▪ Stains blue or violet

Positive ▪ Simple cell walls with thick layer of peptidoglycan

bacteria ▪ Purple or blue stain is trapped in cell wall

▪ Less threatening pathogens

▪ Eg : Bacillus sp., Clostridium sp., Staphylococcus sp. and

Gram - Streptococcus sp.
Negative
bacteria ▪ Stain pink
▪ Cell walls with thin layer of peptidoglycan
▪ Purple or blue stain is decolorized by alcohol, so it exhibits

the color of pink safranin
▪ More pathogenic than gram-positive bacteria,

lipopolysaccharides in the outer membrane often toxic. Outer

membrane is also impermeable to antibiotic penicillin
▪ Eg: Salmonella spp., E. coli and Azotobacter sp.

THE IMPORTANCE OF BACTERIA

No. Importance Example
i. Recycling of - Nitrogen fixation. Rhizobium sp. helps in fixing of nitrogen from atmosphere

chemical elements through nodule on the root of legumes. Eg: beans, pea, clover.
in ecosystem. - Decomposer. Bacteria also decompose the organic molecules of dead
(nitrogen fixation,
as decomposer) organism and release CO2 to atmosphere

ii. Symbiotic - Enterobacteria, E. coli in human intestine helps to digest lactose and supply
vitamin K & B complex.

- Bacteria inhabit cows and other ruminant’s digestive tract. Ruminants lack
enzymes for digesting cellulose. They provide the bacteria with a nutrient-

rich home, and the bacteria digest the cellulose for them

iii. Pathogenic - Tetanus by Clostridium tetani, cholera by Vibrio cholera, syphilis by
Treponema pallidum, food poisoning by Salmonella spp.

iv. In research and - In biotechnology, E. coli used in gene cloning (as host and plasmid as vector)
technology - In food production. e.g. cheeses, yoghurt and vinegar
- Medical research, easily cultured for making antibiotics
- Use in sewage treatment and overcome oil spill

4|Page

MY SMART STUDY GUIDE PST SEMESTER 2: SB025
1.4 KINGDOM PROTISTA

Unique characteristics of Protista
▪ Eukaryote
▪ Most are unicellular, some are colonial (lives in colonies) or simple multicellular
▪ Include protozoa (animal-like protists) & algae (plant-like protists)
▪ Feeding mode: Photoautotroph (photosynthetic) for algae

Heterotroph (saprophytic or holozoic) for protozoa
▪ Reproduction: Asexual reproduction (by binary fission or spore formation) or sexual reproduction

(fusion of gametes)
▪ Most are motile (flagella or cilia)
▪ Protists are either phytoplankton (e.g. common marine algae) or zooplankton (e.g. protozoan)

(A) ALGAE

Unique characteristics of Algae (plant-like protists)

1. Both are aquatic and many species make up phytoplankton.

2. Can manufacture their own food by photosynthesis

3. They are not considered plants because they lack many plant structures

4. Algae lack cuticle

i. Phylum Chlorophyta (green algae) ii. Phylum Phaeophyta (brown algae)

Example: unicellular (Chlamydomonas sp.) and Example: Multicellular seaweeds (Fucus sp. -

multicellular (Spirogyra sp.) rockweed)

Eg: Chlamydomonas sp. Eg: Fucus sp.

▪ Oval shape with pointed anterior ▪ Appear brown due to brown pigments
▪ Has central nucleus ▪ The body is called thallus: plant-like algal body
▪ Two flagella project from the anterior end to
that lacks true roots, stems, and leaves.
propel the cell toward light ▪ Slimy material in the cell walls retards drying
▪ Has a single, large, cup-shaped chloroplast with ▪ Specialized structure:

a pyrenoid for starch synthesis Structure Function
▪ Photosynthetic pigments: chlorophyll a and b Blades/ Leaf-like structure, provide
▪ Has red pigmented eyespot (stigma) as lamina photosynthetic surface. Blade
associated with air bladders.
photoreceptor to detect changes in light intensity Stipes Stem-like structure that hold the
blades
for photosynthesis Holdfast Root-like; provide attachment to the
▪ Reproduce asexually by binary fission or sexually rock surface.
Air gas-filled structure for buoyancy
in unfavorable condition bladder (helps in floatation)
▪ Mostly freshwater. Have 2 contractile vacuoles to

eliminate excess water (osmoregulation)

5|Page

MY SMART STUDY GUIDE PST SEMESTER 2: SB025

(B) PROTOZOA

Unique characteristics of Protozoa (animal-like protists)

1. All are aquatic (make up zooplankton) and unicellular eukaryotic organisms.

2. Do not have cell wall.

3. Able to move independently (motile)

4. Have contractile vacuole to expel excess water for osmoregulation

5. Lives primarily by ingesting food (heterotrophic)

i. Phylum Euglenophyta ii. Phylum Rhizopoda iii. Phylum Ciliophora

Euglena sp. Amoeba sp. Paramecium sp.

Move by using flagella. Move by using pseudopodium. Move by using cilia which cover all

Special features: Special features: over the body.
✓ Mixotrophs (able to undergo ✓ Have irregular, indefinite
Special features:
photosynthesis and shape ✓ Slipper-like shape, definite shape
heterotrophic nutrition) ✓ Also use pseudopodium for
✓ Eyespot/stigma at the base of covered by pellicle.
long flagellum to detect light. feeding by phagocytosis ✓ Cilia also used for feeding
✓ Pellicle (flexible cover) to (engulfing their prey) ✓ Have 2 types of nuclei:
provide strength & flexibility
− macronucleus
iv. Phylum Apicomplexa
Plasmodium sp. − micronucleus

- A malarial parasite.
- Unicellular, non-motile and spore forming parasites.
- Spores transmitted from host to host
- They are called ‘apicomplexa’ because they have complex of

organelles specialized to penetrate host cells.

- Complex life cycle involving asexual and sexual reproduction and

need 2 host:
(i) Mammalian host (human) – protozoan live in blood stream

(ii) Invertebrate host that is female mosquito (Anopheles sp.)

(C) THE IMPORTANCE OF PROTISTA

No. Importance Example

i. Roles in CO2 fixation Can fix CO2 from atmosphere for photosynthesis

ii. Food source (Chlorella sp.) As dietary supplement. High in proteins and packed with fats and

vitamins to promote growth and tissue repair

iii. Eutrophication (algal bloom) Explosive growth of algae due to excess nutrients (P and N) in the

water. Followed by increased activity by decomposers (bacteria).

Reduce O2 content in water and cause death aquatic organism.

iv. Red tide (red algae that causes Pollution due to dinoflagellates. Release toxin when dinoflagellates

harmful algal blooms) consume by shell or fish. Can cause illness to consumer.

v. Human health Plasmodium sp. causes malaria

vi. Sewage treatment

6|Page

MY SMART STUDY GUIDE PST SEMESTER 2: SB025

1.5 KINGDOM FUNGI

(A) THE UNIQUE CHARACTERISTICS OF FUNGI AND ITS CLASSIFICATION

Unique characteristics of Fungi

1. Fungi are heterotroph by saprophytic. They secrete enzymes externally to decompose organic materials,

and then absorb the nutrients.

2. Some fungi are parasites and symbionts.

3. Most are multicellular except yeast (unicellular).

4. Cell wall made up of chitin and store food as glycogen.

5. 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 cross Hyphae has no septa,
walls (septa with pores) thus multinucleated

6. 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.

7. Fungi are classified base on the types of SEXUAL spore-bearing structures.

Phylum Phylum Zygomycota Phylum Ascomycota Phylum Basidiomycota

Type of Aseptate/ coenocytic hyphae Septate hyphae Septate hyphae
hyphae Spores form in sporangium.
Asexual Conidia that pinch off from Rare/ none
reproduction conidiophores.

Sexual Zygospores are formed in Ascospores form Basidiospores form
reproduction zygosporangium (thick wall internally inside the sacs externally outside the
resistant structure). called ascus. basidia.
Zygosporangium came from the
fusion of hyphae.

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

7|Page

MY SMART STUDY GUIDE PST SEMESTER 2: SB025
(B) THE IMPORTANCE OF FUNGI

No. Importance Example
i. Decomposer ▪ Saprophytic fungi will decompose (by secrete enzyme for extracellular digestion)

and absorb nutrient from organic wastes and dead organisms. They able to

degrade cellulose and lignin of plant cell wall.

ii. 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

iii. Pathogens Mycorrhizae are mutualistic associations of plant roots and fungi.
✓ Fungus helps plant roots absorb water and minerals in the soil - à act as root

extensions
✓ Plant provides organic nutrients to fungus

▪ (Parasitic) fungi that attack food crops produce compounds that are harmful to
humans

▪ Fungal infection such as ringworm and athlete’s foot
▪ Candidiasis, a yeast infection of mucus membranes of the mouth, throat or vagina

iv. Commercial Fermented food by alcohol fermentation

importance in ✓ Saccharomyces cerevisiae (yeast) is used in making bread and alcohol (beer)

food production ✓ Involve in the production of “tempe” and “tapai”

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

infection)
▪ Example: Formation of antibiotics penicillin from Penicillium sp.

8|Page

MY SMART STUDY GUIDE PST SEMESTER 2: SB025
1.6 KINGDOM PLANTAE

Unique characteristics of 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.

6. Four groups of plant that are bryophytes, pteridophytes, gymnosperms and angiosperms

Primitive Advance

9|Page

MY SMART STUDY GUIDE PST SEMESTER 2: SB025
1.6.1 BRYOPHYTES

Unique characteristics of Bryophytes

1. Non-vascular plant. No vascular tissues for the transport of water and organic and inorganic nutrients.

2. Tend to be small in size and normally live in damp, shady terrestrial environments.

3. Seedless. It produces haploid spores (homosporous spores).

4. The body is called thallus, do not have true roots, stem and leaves

5. Terrestrial adaptation (more advanced than algae of protista):
✓ has epidermis with no cuticle.
✓ has stomata for gaseous exchange.
✓ has capsule to protect spores.
✓ has rhizoid (root-like for attachment and absorption of water)

6. Alternation of generation in which:

Gametophyte (n) Sporophyte (2n) Polytrichum sp.
Dominant generation. Smaller and short live.
It is larger and longer living.
Gametophyte are able to Sporophyte depends on
carry out photosynthesis gametophyte for water and
nutrients.
Gametophyte produces Can be found on female
gametes in their gametangium gametophyte. Consist of:
that are: ✓ Foot
- Archegonium: produces ✓ Seta, an elongated stalk
✓ Capsule (sporangium) that
oosphere (egg)
- Antheridium: produces producing spore
(homosporous)
flagellated sperms
(antherozoids)

7. Classification of bryophytes into three divisions/ phyla:

i. Phylum Bryophyta ii. Phylum Hepatophyta iii. Phylum Anthocerophyta
(hornworts)
(mosses) (liverworts)
Eg: Anthoceros sp.
Eg: Polytrichum sp. Eg: Marchantia sp.

Dioecious (sexes are separated) Dioecious (sexes are separated) Mostly monoecious

All dependent on water for fertilization (motile/ flagellated sperms need to swim towards egg)

10 | P a g e

MY SMART STUDY GUIDE PST SEMESTER 2: SB025
1.6.2 PTERIDOPHYTES

Unique characteristics of Pteridophytes

1. Have simple vascular tissue (simple xylem and phloem)

2. Have true root, stem and leaves. The leaves are called sporophyll (spore-bearing leaves)

* small leaves are called microphylls as in Selaginella sp. while large is called macrophylls as in ferns

3. Alternation of generation in which:
✓ Sporophyte generation is dominant in the life cycle; larger and longer lifespan
✓ Gametophyte is smaller and shorter lifespan
✓ But, the gametophyte and sporophyte are independent to each other because both of them can

undergo photosynthesis.

4. Dependent on water for fertilization (motile/ flagellated sperms need to swim towards egg)

5. Seedless plant.

6. The sporophytes bear sporangia with leaf-like appendages called sporophyll. In some cases, sporophyll

may form distinct compact structures called strobili or cones.

7. Spores are produced inside the sporangia.

*Strobilus (plu: strobili) is the reproductive structure that formed from sporophylls and sporangia that

grouped together at the tips of the stem.

8. The spores may be homosporous or heterosporous:

Homosporous Heterosporous

Plants that produce only one type of spore Plant that produce two different types of spores;
✓ smaller microspores develop into male

gametophytes
✓ larger megaspores develop into female

gametophytes

The spore develops into a bisexual The spore develops into a unisexual gametophytes

gametophytes (with both archegonia & (separate male and female gametophytes)

antheridia)

Strobilus of homosporous plant Strobilus of heterosporous plant
e.g: Lycopodium sp. and Dryopteris sp. e.g. Selaginella sp.

9. The spores germinate to produce a haploid gametophyte, called prothallus. (either bisexual or
unisexual gametophytes)

10. In gametophytes, male organs (archegonia) produce sperms/ antherozoids while female organs
(antheridia) produce egg cell.

11. Fertilization needs external water for movement of sperms/ antherozoids.
12. The diploid zygote formed is retained in the archegonia where it develops into a young sporophyte.
13. Classification of pteridophytes into two divisions/ phyla:

11 | P a g e

MY SMART STUDY GUIDE PST SEMESTER 2: SB025
i. Phylum Lycopodiophyta/ Lycophyta ii. Phylum Pterophyta

Lycopodium sp. Selaginella sp.

(homosporous) (heterosporous) Eg: Dryopteris sp. (homosporous)
- Reproductive structure:
- Sporophyte consists of stems, rhizomes, leaves

Strobilus at the tip of the stem = consist of (fronds)and roots
sporangia (containing spores) found on the fertile - Circinnates (fiddleheads) is coiled young fronds
- Reproductive structure:
leaves called sporophylls

Underneath mature fronds are sori (clusters/ a

group of sporangia that produces spores)

Development of gametophyte and sporophyte in Dryopteris sp.

Rhizoid

Group of sporangia The spore will germinate and develop a The diploid zygote formed and
underneath mature bisexual gametophytes (prothallus). develops into a young sporophyte.
fronds (sori) produces Water is need for fertilization. Independent gametophyte and
spores that are sporophyte (both can undergo
homosporous. photosynthesis). But, the sporophyte
generation is dominant.

REMEMBER!
!!

SEEDLESS plants is the LOWER plants SEED plants is the HIGHER plants
• Bryophytes • Gymnosperms
• Pteridophytes • Angiosperms
✓ Reproduce by SPORE ✓ Reproduce by SEED

12 | P a g e

MY SMART STUDY GUIDE PST SEMESTER 2: SB025
1.6.4 GYMNOSPERMS

Unique characteristics of Gymnosperms

1. Gymnosperms are non-flowering plants (do not produce flowers or fruits)

2. Seed plants. The seed is naked (exposed/ unprotected because the seed is not enclosed in fruit). For

example, seeds borne on scales of cone or naked on branches.

3. Complete vascular tissue. The xylem consists only tracheid (without vessel elements) and phloem

consists only sieve tube (without companion cells).

4. Alternation of generation in which:

5. Sporophyte is dominant in the life cycle

6. Gametophyte is very much reduced and dependent on sporophyte

7. Reproductive structures are called cones or strobilus and they are heterosporous.

8. Female cones have megasporangium containing megaspores. Megaspore develops into female

gametophyte and retained/ kept in the ovule.

9. Male cones have microsporangium containing microspores. Microspore develops into male gametophyte

(pollen grain)

10. After fertilization, the ovule develops into naked seed (due to lack ovaries/ flower)

11. Do not need external water for fertilization, but need wind as the pollinating agent.

12. Classification of gymnosperms into four divisions/ phyla:

i. Phylum ii. Phylum iii. Phylum Ginkgophyta iv. Phylum Gnetophyta

Pinophyta/ Cycadophyta

Coniferophyta

Pinus sp. Cycas sp. Ginkgo sp. Gnetum sp.

Woody tree Palms-like Woody tree Trees, vines and shrubs

Needle-like leaves Compound leaves with Fan-shaped leaves that turn gold Broad leaves with reticulate

palm-like tree before fall off venation

Evergreen or Evergreen Deciduous (autumn) Evergreen

deciduous (winter)

Reproductive Reproductive structure: Reproductive structure: Strobilus Reproductive structure: Flower-

structure: Cones Large strobilus/ cone like strobili

Xylem is only tracheid without vessel elements Xylem with tracheid and vessel

elements

Phloem consist of sieve tube only Phloem consist of sieve tube

and companion cell

Monoecious : ♂ & ♀ Dioecious: separate ♂ & Dioecious: ♀ plants have naked Mostly dioecious: ♂ & ♀
cones in the same
♀ trees seed. Outer seed coat is fleshy but strobilus (flower-like form) in

plants release unpleasant odor. different plants.

Naked seed for Gymnosperms and seed enclosed in fruit for Angiosperms

13 | P a g e

MY SMART STUDY GUIDE PST SEMESTER 2: SB025
1.6.5 ANGIOSPERMS

Unique characteristics of Angiosperms

1. Angiosperms are flowering plants (produce flowers and fruits)

2. Have complete vascular tissue, xylem consist of tracheid and vessel element while phloem consists of

sieve tube and companion cells)

3. Seed producing plant. The seed is enclosed in fruit (protected seed)

4. Alternation of generation in which:
✓ Sporophyte generation is dominant/ longer living.
✓ Gametophytes generation reduced in size and depends on sporophyte for nutrition.

5. Angiosperms reproductive structures are flowers. There are also heterosporous (produce two different

types of spore) with double fertilization:

(a) Microspores will produce pollen grain (male gametophyte)

(b) Megaspores will produce embryo sac (female gametophyte)

6. Not need of external water for fertilization, but need pollinating agent like insects and wind.

7. After double fertilization:
- Ovary develops into fruit.
- Ovule develops into seed.
✓ Seed contain diploid embryo and triploid endosperm (cotyledon).
✓ Seed is enclosed by seed coat (derive from integuments of ovule)

Angiosperms (Division/ Phylum Anthophyta)

i. Class Monocotyledonae ii. Class Dicotyledonae

One cotyledon in seed Two cotyledons in seed

Veins in leaf usually parallel pattern Vein in leaf usually net-like pattern

Vascular bundles usually shows complex arrangement/ Vascular bundles usually arranged in ring

scattered in the stem (phloem outside/ xylem inside)

Fibrous root system Taproot usually present

Floral parts usually in three or multiple of three Floral parts usually in multiple of four or five

Example: Zea mays (maize) Example: Mangifera indica (mango)

IMPORTANT CONCEPT:

Differences of Angiosperm and Gymnosperms in terms of reproduction

ANGIOSPERMS GYMNOSPERMS

- Reproductive organ is flower - Reproductive organ is cone/ strobilus

- Undergoes double fertilization - Does not undergoes double fertilization

- The seed possess endosperm - The seed does not possess endosperm

- The seed are protected by fruit/ovules enclosed by - The seed are not protected by fruit/ovules not

ovaries enclosed by ovaries/ naked seed

- Several pollinating agents like wind, animal/ insect - Pollinating agent is wind

14 | P a g e

MY SMART STUDY GUIDE PST SEMESTER 2: SB025
1.6.6 EVOLUTIONARY RELATIONSHIP IN PLANT KINGDOM

Characteristics Bryophytes Pteridophytes Gymnosperm Angiosperm
i. Size
Small sporophyte, Large sporophyte, Large sporophyte, Large sporophyte,
ii. Dominance to large gametophyte small gametophyte reduced reduced gametophyte
gametophytes and
sporophytes Gametophyte (n) gametophyte
iii. Dependence to
gametophytes and Sporophyte (2n)
sporophytes
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 for
v. Presence and Need water for fertilization)
complexity of Fully depend on fertilization
vascular tissues Complete vascular tissue
vi. Embryo water for Simple vascular
protection tissue
fertilization
Seed production No-vascular tissue

Present of true Within archegonia Some protection Within seed coat Within seed coat
root, stem and
leaves (gametophyte) within archegonia enclosed in fruit

(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)

15 | P a g e