biology student’s companion resources sb 025 chapter 1.0

Biology Student’s Companion Resources SB 025

1 | KMPk

CHAPTER 1.0: BIODIVERSITY

SUBTOPIC : 1.1 Biodiversity and classification

LEARNING OUTCOMES: a) State the types of biodiversity (genetic, species and ecosystem).

b) State hierarchical classification

c) Explain briefly the classification systems: -

i. Five-kingdom system (Robert Harding Whittaker, 1969) based on level of cell

organization, types of organism and modes of nutrition.

ii. Three-domain system (Carl Woese, 1977) - Bacteria, Archaea and Eukarya

based on rRNA base sequence.

MAIN IDEAS

/KEY POINT EXPLANATION NOTES

Definition of

Biodiversity

• Short for biological diversity

• Greek “bios” means life, “logos” means study so the general

meaning of biology is the study of living things.

• Diversity means the state of being diverse or a range of

different things.

• Biodiversity refers to the variation of life forms within a

given area.

• Malaysia have not less than:

15,000 plants species 140 snake’s species

150 frog’s species 80 lizard’s species

600 bird’s species 150 frog’s species

210 mammal’s species 140 snake’s species

80 lizard’s species

Why is biodiversity high in

Malaysia?

a) Types of

biodiversity

(genetic, species

and ecosystem)

• Biodiversity also refers to the interrelatedness of genes,

species, and ecosystems and their interactions with the

environment.

• Three types of biodiversity:

Ecosystem diversity

- Variety of ecosystem or throughout the entire

biosphere

Species diversity

- Diversity among species in an ecosystem

Genetic diversity

- Diversity of genes within a species.


2 | KMPk

b) The

hierarchical

classification.

(Linnaean

System)

In order to naming species of an organism, Linnaeus grouped

them into a hierarchy of increasing inclusive category.The

named taxonomic unit at any level of the hierarchy is called a

taxon (plural, taxa). In the panther example, Panthera is a

taxon at the genus level, and Mammalia is a taxon at the class

level that includes all the many orders of mammals.

Classification according to Carolus Linnaeus

* In the Linnaean system,

taxa broader than the genus

are not italicized, though they

are Capitalized.*

c) The

classification

systems

i. The Five-

kingdom system

(Robert Harding

Whittaker, 1969)

based on level of

cell

organization,

types of

organism and

modes of

nutrition.

In 1969, R.H Whittaker proposed a Five-kingdom system.

Living organisms are subdivided into 5 major kingdoms,

including the Monera (prokaryotes), the Protista (Protoctista),

the Fungi, the Plantae, and the Animalia.

The Five-kingdom system

Each kingdom is further

subdivided into

separate phyla or divisions.

Generally "animals" are

subdivided into phyla, while

"plants" are subdivided into

divisions.


3 | KMPk

The classification system is based on :

1) Level of cell organization

- Prokaryote

- Eukaryote

2) Types of organisms

- Unicellular

- Multicellular

3) Modes of nutrition

- Saprophytic

- Photosynthetic

- Holozoic

ii. Three-domain

system (Carl

Woese, 1977) -

Bacteria,

Archaea and

Eukarya) based

on rRNA base

sequence.

The Three-domain system, developed by Carl Woese, is a

system for classifying biological organisms. This classification

system model was based on principles developed by Carolus

Linnaeus, whose hierarchical system groups organisms based

on common physical characteristics. The Three-domain

system, groups organisms primarily based on differences in

rRNA structure.

Under this system, organisms are classified into three domains

and six kingdoms. The domains are Archaea, Bacteria,

and Eukarya. The kingdoms are Archaebacteria (ancient

bacteria), Eubacteria (true bacteria), Protista, Fungi, Plantae,

and Animalia.

https://www.thoughtco.com/about-carolus-linnaeus-1224834

https://www.thoughtco.com/about-carolus-linnaeus-1224834

https://www.thoughtco.com/six-kingdoms-of-life-373414


4 | KMPk

SUBTOPIC : 1.2 Domain Bacteria and Archaea

LEARNING OUTCOMES: a) State the two domain of prokaryotes, Bacteria (E.coli) and Archaea

(Sulfolobus sp.)

b) Differentiate between the two domain of prokaryotes, Bacteria (E.coli) and

Archaea (Sulfolobus sp.) based on :-

i. Cell wall structure

ii. Association of histon to DNA

iii. Structure of membrane lipids.

c) Describe the diversity of bacteria (based on cell shapes and Gram-stain)

d) State the importance of bacteria:

i. Recycling of chemicals elements in ecosystem (nitrogen fixation, as

decomposer).

ii. Symbiotic (enterobacteria e.g E coli in human intestine)

iii. Pathogenic e.g. Salmonella spp.)

iv. In research and technology (bacterial plasmid).

MAIN IDEAS


a) The two

domain of

prokaryotes

The prokaryotes contain two domains, Domain Archaea and Domain

Bacteria.

Domain Archaea

Examples of archaea is Sulfolobus sp.

➢ It’s a prokaryotic cells of various shapes.

➢ Adaptations to extreme environments. They can live in aquatic

environments that lack of oxygen or are too salty, too hot or too

acidic for most other organisms.

➢ Absorb or chemosynthesize food

➢ Unique cell wall and membranes chemical characteristics.

Domain Bacteria

➢ Diverse prokaryotes widely distributed in various environments.

➢ An example of bacteria is E.coli

➢ Has various shape

➢ Adaptations to all environments

➢ Absorb, photosynthesize, or chemosynthesize food


5 | KMPk

b) The

differences

between

Bacteria and

Archaea

Sulfolobus sp.

E. coli

sp.


6 | KMPk

c) Diversity of

Bacteria Based

on cell shapes

and gram

staining

1. Cell shapes

Individual bacteria can assume one of three basic shapes: spherical

(coccus), rod-like (bacillus), or curved (vibrio, spirillum, or spirochete).

Bacteria that do not separate from one another after cell division, form

characteristic clusters that are helpful in their identification. For

example, some cocci are found mainly in pairs like Streptococcus

pneumoniae.

Sphere

(coccus; plural cocci)

Rod-like

(bacillus; plural bacilli)

Curved

(vibrio, spirillum, or spirochete).


7 | KMPk

2. Gram-staining

Cell wall with a less peptidoglycan

Cell wall with a large amount of

peptidoglycan

Do not retain crystal violet stain Retain crystal violet stain

More pathogenic Less threatening pathogens

Example: E. coli

Example :Bacillus, Staphylococcus

and Streptococcus

d) The

Importance of

bacteria

Bacteria are microscopic, single-celled organisms that thrive in diverse

environments. These organisms can live in soil, the ocean and inside the

human gut. Humans' relationship with bacteria is complex. Sometimes

bacteria lend us a helping hand, such as by curdling milk into yogurt or

helping with our digestion. In other cases, bacteria are destructive, causing

diseases like pneumonia and diarrhoea. These are several importance of

bacteria to human and ecosystem:

Recycling of

chemical

elements in

ecosystem

(nitrogen

fixation as

decomposer)

When plants and animals die, they become food for

decomposers like bacteria. Decomposers recycle dead

plants and animals into chemical nutrients like

nitrogen that are released back into the soil, air and

water. Nitrogen fixing bacteria such as cyanobacteria,

incorporate nitrogen from the environment into

amino acids and other cellular material. Some

nitrogen fixers form symbiotic relationships with

plants, providing them with nitrogen.

Symbiotic

relationships

with other

organisms

Act as enterobacteria in human intestines. The human

gut is a comfortable setting for bacteria, with plenty

of nutrients available for their sustenance. For

example: E. coli and Streptococcus sp. aid in digestion,

prevent colonization by harmful pathogens, and help

to develop the immune system. Other examples, to

supplies vitamin K and vitamin B complex and

breaking cellulose in herbivores such as in ruminants.


8 | KMPk

Pathogenic Although vast majority of bacteria are harmless or

beneficial to one's body, a few pathogenic bacteria

can cause infectious diseases. The most common

bacterial disease is tuberculosis, caused by the

bacterium Mycobacterium tuberculosis. Pathogenic

bacteria contribute to other globally important

diseases, such as pneumonia, which can be caused by

bacteria such as Streptococcus sp.and Pseudomonas

sp., and foodborne illnesses, which can be caused by

bacteria such as E.coli and Salmonella sp.

In research

and

technology

(bacteria

plasmid)

In the genetic engineering, the genes of an organism is

manipulated. This manipulation is also called

recombinant DNA technology. The genes are inserted

into a plasmid of a bacteria. This recombinant plasmid

or DNA is replicated in a host cell and passed on to

daughter cells along with the rest of its DNA. The

bacterial cells are used in production of commercially

important products. Examples include production of

human insulin (used to treat diabetes).


9 | KMPk

SUBTOPIC : 1.4 Domain Eukarya: Kingdom Protista

LEARNING OUTCOMES: a) State the unique characteristics of Protista

b) State the classification of Protista based on the unique feature:

i. Two major phyla of algae (photosynthetic pigment): • Chlorophyta (Chlamydomonas sp.) • Phaeophyta (Fucus sp.)

ii. Four major phyla of Protozoa (locomotioa): • Euglenophyta (Euglena sp.) • Rhizopoda (Amoeba sp.) • Ciliophora (Paramecium sp.) • Apicomplexa (Plasmodium sp.)

a) Explain the importance of Protista:

i. Roles in CO2 fixation

ii. Food source (Chlorella sp.)

iii. Eutrophication (algal bloom)

iv. Red tide (dinoflagellates)

v. Human health (Plasmodium sp. – malaria)

vi. Sewage treatment

MAIN IDEAS


a) State the

Unique

characteristics

of Protista

• Eukaryotes • Most are unicellular and some multicellular • Most are microscopic, but some are large • Heterotrophic or autotrophic • Reproduce asexually or sexually

b) State

classification

of Protista

based on the

unique

feature:

(i) 2 major

phyla of algae (photosynthetic

pigment):

Phylum Chlorophyta

Use green colour to

highlight the

photosynthetic part of

the organism.

Chlamydomonas sp.


10 | KMPk

Phylum Phaeophyta

Unique characteristics of Algae

1. Photosynthetic

• Chlorophyll a + other photosynthetic pigments

2. Not differentiated into stem, leaves or root

• Thallus : an undifferentiated vegetative tissues

3. Habitat

• Water or on damp surfaces

4. Great diversity in structure

• Unicellular

• Simple filamentous

• Colonials

• Huge seaweeds

5. Types of reproduction:

i. Asexual reproduction

a) Zoospores

The zoospores are formed from certain older cells of the

filaments. The cytoplasm divides to form zoospores

which are escaped from the mother cell and developed

into new plant. They are always formed in favourable

conditions. The zoospores are always motile. Motile

flagellate spores produced by many algae. Eg:

Chlamydomonas.

Fucus sp.

Chlamydomonas.


11 | KMPk

b) Binary fission

The mother cell divides into two equal halves and the

daughter cells are produced, which become new

plants.

Diatom

ii. Sexual reproduction

Conditions for sexual reproduction:

(a) The sexual reproduction takes place after considerable

accumulation of food material and the climax of

vegetative activity is over.

(b) The bright light is the major factor for the production

of the gametes.

(c) A suitable pH value is required.

(d) The optimum temperature is necessary.

Types of sexual reproduction:

a) Isogamy: Fusion of two identical in shape

and size gametes

• Spirogyra, Chlamydomonas

b) Anisogamy: The motile gametes taking part in

fusion may either differ in size

(morphological anisogamy) or

physiological behavior. One

gamete is less motile and larger

than the other


12 | KMPk

c) Oogamy: The male antherozoid fuses with the

female egg. One gamete is large

and stationary. One gamete is small

and motile. Known as male and

female gametes respectively

iii. Vegetative reproduction

Fragmentation: The plant body breaks into several parts or

fragments and each such fragment

develops into an individual. This type of

vegetative reproduction is commonly met

within filamentous forms. Eg: Spirogyra

(ii) 4 major

phyla of

Protozoa

(locomotion):

1. Phylum Euglenophyta (Euglena sp.)

2. Phylum Rhizopoda (Amoeba sp.)

male female

Spirogyra


13 | KMPk

3. Phylum Ciliophora (Paramecium sp.)

4. Phylum Apicomplexa (Plasmodium sp.)

Unique

characteristics

of Protozoa

a. Animal-like: Protozoa represent the most primitive group of

animal organisms.

b. Locomotion by pseudopodia, flagella, cilia, and direct cell

movements; some sessile

c. Unicellular:

i. Some colonial

ii. Some with multicellular stages in the life cycle

d. Modes of nutrition (heterotrophic, autotrophic, parasites).

i. They are symbiotic or commensal organisms, living in

association with other organisms. Protozoa form an

important link in the food chain of aquatic

environments, both fresh water and marine. Many of

them feed on other microorganisms, and they

themselves are devoured by larger organisms.

e. Some are parasitic and pathogenic.

i. Cause serious human diseases

ii. Examples: Plasmodium – malaria, Trypanosoma –

sleeping sickness

f. Live in many different environments: Aquatic or terrestrial

habitat

g. Free-living or symbiotic mode of life h. Reproduction

i. Asexual:

• Binary fission: The nucleus divides mitotically to

produce a large number of nuclei before the cell

divides. Each nucleus, with the surrounding


14 | KMPk

cytoplasm, forms a daughter cell. The daughter

cells then separate. Multiple fission is best known

in the malarial parasite, Plasmodium and amoeba.

• Budding: daughter nuclei produced by mitotic

division migrate into a cytoplasmic protrusion

(bud) which is ultimately separated from the

mother cell by fission.

• Cysts are stages with a protective membrane or

thickened wall. Protozoan cysts that must survive

outside the host usually have more resistant walls

than cysts that form in tissues. Some protozoa form

cysts that contain one or more infective forms.

Multiplication occurs in the cysts of some species

so that excystation releases more than one

organism. For example, when the trophozoite

of Entamoeba histolytica first forms a cyst, it has a

single nucleus. As the cyst matures nuclear division

produces four nuclei and during excystation four

uninucleate metacystic amebas appear.

ii. Sexual:

• Conjugation of ciliates: an elaborate process in

which two individuals unite with each other by

fusion of their pellicles and nuclei are exchanged.

Apparently, the nuclei act as gametes. The ciliates

possess two different types of nuclei, — the

micronucleus and the macronucleus. Only

micronuclei take part in conjugation.

• Syngamy: the complete and permanent union or

fusion of two specialised protozoan individuals or

gametes resulting in the formation of a fertilized cell

or zygote or oospore. The nuclei of the gametes fuse

to form the zygote nucleus. The zygotes develop into

adult.

c) The

importance of

Protista

i. Roles in CO2 fixation Photosynthetic protista (most of algae and some of protozoa) Examples:

a. Protozoa: Euglena sp.

b. Algae: Fucus sp., Chlamydomonas sp.

ii. Food source (Chlorella sp.) Chlorella served as a potential source of food and energy

because its photosynthetic efficiency (8% comparable with

other highly efficient crops such as sugar cane)

iii. Eutrophication (algal bloom) • Ecosystem response to the addition of artificial or natural

substances, such as nitrates and phosphates, through

fertilizers or sewage, to an aquatic system

• growth of algae


15 | KMPk

• Caused the depletion of oxygen in the water which

induces reductions in specific fish and other animal

populations iv. Red tide (dinoflagellates)

• Common name for a phenomenon known as an algal bloom

(large concentrations of aquatic microorganisms). • Caused by a few species of dinoflagellates and the bloom

takes on a red or brown color • Some red tides are associated with the production of natural

toxins, depletion of dissolved oxygen or other harmful

effects v. Human health (Plasmodium sp. – malaria)

Infected female Anopheles transmits Plasmodium sporozoites

into human blood

vi. Sewage treatment

• Protozoan play important role in waste water treatment

process

• Protozoa feeds on bacteria, and improve sewage treatment

resulting in a lower organic load in the output water of the

treated wastes.

• As biosensors they could provide valuable information

regarding adverse effects of environmental chemicals for

the effective operation of biological waste-water treatment

processes.


16 | KMPk

SUBTOPIC : 1.5 Domain Eukarya: Kingdom Fungi

LEARNING OUTCOMES: a) State the unique characteristics of Fungi

b) State the classification of Fungi phyla based on the spore-bearing structure:

• Zygomycota (Rhizopus sp.),

• Ascomycota (Penicillium sp.),

• Basidiomycota (Agaricus sp.)

c) State the importance of Fungi:

i. Decomposer

ii. Symbionts

iii. Pathogens

iv. Commercial importance in food production (fermented food)

v. Pharmaceutical (penicillin)

MAIN IDEAS


a) The unique

characteristics

of Fungi

• Eukaryotic

• Do not contain chlorophyll

• Non-photosynthetic

• Absorptive heterotrophs (extracellular digestion)

➢ Release digestive enzymes to break down organic material

of their host

➢ Digest food first & then absorb it into their bodies

• Store food energy as glycogen

• Most are saprophytic – live on other dead organisms

• Heterotrophic

- Parasitic

- Saprophytic

- Mutualist

• Important decomposers & recyclers of nutrients in the environment

• Most are multicellular, but some unicellular like yeast

• The major constituents of the fungal cell wall are chitin, glucans,

and glycoproteins.

Chitin is a

structurally

important

component of

the fungal cell

wall located

closest to the

plasma membrane.


17 | KMPk

Structural organization

• Basic building units called hyphae

• Form interwoven mat called mycelium

• Not divided into true cells

• Cross-walls or septa (singular septum): divide into

compartments - Septate

• Hyphae without septa - Non-septate

Reproduction in Fungi

• Reproduce both asexually and

sexually

• Most fungi are haploid throughout

their life cycle

• Sexual reproduction occur: when

hyphae of different mating types (+

and -) meet and fuse together.


18 | KMPk

b) The

classification of

Fungi phyla

• Kingdom Fungi is divided into three phyla, namely Phylum

Zygomycota, Phylum Ascomycota,and Phylum

Basidiomycota.

• Each of the phylum is classified based on the spore-bearing

structure


19 | KMPk

Phylum Zygomycota

➢ Spore-bearing structure - zygosporangium

➢ Zygosporangium contain zygospores (formed by sexual

reproduction)

Phylum Ascomycota

➢ Fruiting body – ascocarps. The ascocarps contain the

spore-forming asci.

➢ Spore-bearing structure – asci (singular, ascus).

➢ Ascus contain ascospores.

➢ is an important genus of phylum ascomycota, found in

the natural environment

For Penicillium sp., they

reproduce asexually by

producing enormous numbers

of asexual spores called

conidia. Conidia are produced

externally at the tips of

specialized hyphae called

conidiophores.

Phylum Basidiomycota

➢ is a large and diverse phylum of fungi and most advance

fungi. Example: Agaricus sp.(mushrooms) ➢ filamentous fungi composed of hyphae. ➢ Most species reproduce sexually with a club-shaped

spore-bearing organ (basidium) that usually produces

four sexual spores (basidiospores). ➢ Basidia are borne on fruiting bodies (basidiocarps),

which are large and conspicuous

Rhizopus sp.

https://www.sciencedirect.com/topics/immunology-and-microbiology/phylum

https://www.sciencedirect.com/topics/immunology-and-microbiology/ascomycetes

https://www.merriam-webster.com/dictionary/diverse

https://www.britannica.com/science/mushroom

https://www.britannica.com/science/basidium

https://www.britannica.com/science/spore-biology

https://www.merriam-webster.com/dictionary/conspicuous


20 | KMPk

c) The

importance of

Fungi

i. Decomposers • Saprophytic fungi • Feed on dead and decaying organisms (example:

Penicillium sp.) • Help to recycle nutrients (phosphates, ammonia,

sulphates) ii. Symbionts (example: Lichens (Fungi + algae)

• Algae photosynthesize and provides organic food

• Fungus receives food in exchange for housing, water,

and minerals

• Commonly encrusted on rocks and tree trunks

iii. Pathogen

• Some of fungal species are parasites mostly of plants • Cause huge economic effects

iv. Commercial importance in food production (fermented food) • Example: Yeasts (Produce alcoholic beverages & Rise

up bread dough) v. Pharmaceutical (Penicillin) • Used as antibiotics (Penicillin).

• Processed from Penicillium sp. that kills or stops the growth

of certain kinds of bacteria inside the body.


21 | KMPk

SUBTOPIC : 1.6 Domain Eukarya: Kingdom Plantae

LEARNING OUTCOMES: (a) Describe alternation of generation as the unique characteristics of Plantae.

(b) State the classification of Plantae into four groups :-

i. Bryophytes iii. Gymnosperms

ii. Pteridophytes iv. Angiosperms

MAIN

IDEAS /KEY

POINT

EXPLANATION NOTES

a) The

alternation of

generation as

the unique

characteristics

of Plantae

Alternation of generations

• Alternation of generations is a type of life cycle found in

terrestrial plants and some algae in which subsequent generations

of individuals alternate between haploid and diploid organisms.

• In general, the generations alternate between the

➢ sporophytes capable of creating spores

➢ gametophytes, capable of creating gametes.

➢ Sporophyte :

o To form a sporophyte, two haploid gametes come together to

form a diploid zygote (2n).

o When the sporophyte reaches maturity, a key point in the

alternation of generations takes place.

o The sporophyte develops organs, known as sporangia to

produce haploid spores. These spores will be released into

the air or water and carried away.

o When they reach a suitable environment, they will begin the

process of developing into the gametophyte.

➢ Gametophyte

o This represents the next generation in the alternation of

generations, as the haploid spore is created.

o This spore will undergo successive rounds of mitosis to form

a new multicellular individual, the gametophyte.

o Where the sporophyte generation creates spores, the

gametophyte generation creates gametes that produced

by gametangia.

o These gametes are then broadcast into the environment, or

transferred between plants.

https://biologydictionary.net/sporophyte/

https://biologydictionary.net/zygote/

https://biologydictionary.net/gametophyte/


22 | KMPk

o When they find an opposite gamete, they begin the process

of fusing to form another zygote. This zygote will and

eventually become a sporophyte and the alternation of

generations will keep turning. reproductive cycles to define

the species.

b) The

classification

of Plantae

into four

groups

Kingdom Plantae can be divided into 2 groups :-

i) Non-vascular

• Lack vascular tissue • Leafy or thalloid appearance • No true roots, stems and leaves

ii) Vascular

• Have vascular tissue that transports water and nutrients - xylem transports water - phloem transport dissolved substances

FOUR major groups of plants :-

i. Bryophytes ii. Pteridophytes iii. Gymnosperm iv. Angiosperm

https://biologydictionary.net/gamete/


23 | KMPk

SUBTOPIC : 1.6.1 Bryophytes

LEARNING OUTCOMES: (a) Describe the unique characteristics of bryophytes.

(b) State the classification of Bryophytes into 3 divisions/ phyla :-

i. Phylum Hepatophyta (Marchantia sp.)

ii. Phylum Bryophyta (Polytrichum sp.)

iii. Phylum Anthocerophyta (Anthoceros sp.)

(c) State the terrestrial adaptation for bryophytes

MAIN

IDEAS /KEY

POINT

EXPLANATION NOTES

a) The unique

characteristics

of bryophytes

• Simplest group of land plants • Live in damp, shady places • Restricted in size

- Very small (1-2 cm in height) → To make sure all cells could

obtain enough nutrients • Non-vascular plants

- Lack specialized vascular tissues

➢ Rely on diffusion and osmosis

➢ Whole surface of the plant can absorb needed nutrients • Seedless plants : Produce haploid spores • No true roots, stems and leaves

➢ Anchored by rhizoids: Tiny,

root hair-like structures

➢ Not composed of tissues

➢ Lack specialized

conducting cells

➢ Do not play a primary role

in water and mineral

absorption

➢ Have flat, broad tissues

that function like leaves

➢ contain chloroplast for

photosynthesis

• Alternation of generations - Gametophyte : Dominant

➢ Male gametophyte : antheridia (singular antheridium)

➢ Female gametophyte : archegonia (singular archegonium)

- Sporophyte

➢ Attached and dependent upon the gametophyte for

nutrition

➢ Smaller and shorter-lived

➢ The smallest and simplest sporophytes


24 | KMPk

b) The

classification

of Bryophytes

The bryophytes are grouped into three divisions/ phyla:

i. Phylum Hepatophyta (Marchantia sp.)

• Common name – Liverworts, refer to the liver-shaped

gametophytes.

• The gametophyte is flattened shape (thalloid).

• Gametangia elevated on gametophore.

• Sporophytes have a short seta (stalk) with an oval capsule.

Anteridia and archaegonia of Marchantia sp.


25 | KMPk

ii. Phylum Bryophyta (Polytrichum sp.)

• Consists of mainly gametophytes

• The sporophytes are elongated and visible. The cells of

the sporophytes contain plastids that are usually green

and photosynthetic when the they are young (green) and

turn tan when ready to release spores. • A sporophyte consists of a foot, a seta and a sporangium.

• The foot (embedded in the archegonuim) absorbs nutrient

from the gametophyte.

• The capsule produces spores by meiosis.

capsule

seta sporophyte

gametophyte

rhizoid

Polytrichum sp.

Structure of a mature sporophyte in

Marchantia sp.


26 | KMPk

iii. Phylum Anthocerophyta (Anthoceros sp.)

• Refer to the long, tapered shape of sporophyte. The sporophyte is

lack of seta and consists only a porangium. The sporangium

releases mature spores by splitting open, starting at th etip of the

horn.

• Usually the first species to colonize open areas with moist soils;

a symbiotic relationship with nitrogen-fixing cyanobacteria.

c) The

terrestrial

adaptations

of bryophytes

● Drying out: A sterile jacket developed around antheridia and

archegonia which prevent them from drying out.

● Reproduction : Delicate sex cells must be protected by gametangium.

● Gaseous exchange: Presence of stomata facilitate the movement of

gasses such as CO2 and O2 in and out through the cuticle

sporophyte

Gametophyte

Anthoceros sp.


27 | KMPk

SUBTOPIC : 1.6.2 Pteridophytes

LEARNING OUTCOMES: (a) Describe the unique characteristics of pteridophytes

(b) State the classification of pteridophytes into two divisions/ phyla :-

i. Phylum Lycopodiophyta/ Lycophyta (Lycopodium sp., Selaginella sp.)

ii. Phylum Pteridophyta (Dryopteris sp.)

MAIN

IDEAS /KEY

POINT

EXPLANATION NOTES

a) The unique

characteristics

of

pteridophytes

• Vascular plants ➢ Has true roots, stems and leaves ➢ Has lignified vascular tissues, and the xylem has

tracheids and sieve tube only for transport and support

system • Seedless

➢ Produce spores • Non-flowering plants • Photosynthetic – can make

their own food • The sporophyte is dominant

and easily visible • Gametophyte is reduced to a

small and simple structure.

• The alternation of

generation:

(a) Mature sporophyte (2n) undergoes meiosis and produces

spores (n).

(b) Spore grows into gametophyte. Each gametophyte

develops sperm-producing organs called antheridia and

egg-producing organs called archegonia.

(c) The sperm use flagella to swim to eggs in the archegonia

and fertilize.

(d) A zygote develops into a new sporophyte, and the young

plant grows out from an archegonium of its parents, the

gametophyte.


28 | KMPk

The alternation of generation in Dryopteris sp.

Reproductive organs in a gametophyte of Dryopteris sp.

• Type of spores.

- There are two types of spores in pteridophytes.

1. Homosporous ▪ Plants producing one type of spores

▪ The spores are equal in size

▪ The spores are produced from the same sporangia.

▪ The spores developed one kind of gametophyte.

▪ Spores germinates in soil and produce independent

gametophyte.

▪ Example: Lycopodium sp.

a)

b)

c)

d)


29 | KMPk

2. Heterosporous

▪ Plants producing 2 types of spores

▪ Megaspores (large spores) ----- female gametophyte

▪ Microspores (small spores) ----- male gametophyte

▪ The microspores are produces from the microsporangia

and megaspores are produced from the megasporangia.

▪ The microspores develop into male gametophyte

whereas the megaspore develops into female

gametophyte.

▪ Spores germinate within sporangia and produce

dependent gametophyte.

▪ Example: Selaginella sp.

b) The

classification

of

pteridophytes

into two

divisions/

phyla

i. Lycoppdiophyta/ Lycohyta

Lycopodium sp.

Selaginella sp.

sp.


30 | KMPk

ii. Pteridophyta

Dryopteris sp.


31 | KMPk

SUBTOPIC : 1.6.4: Gymnosperm

LEARNING OUTCOME: (a) Describe the unique characteristics of gymnosperms.

(b) State the classification of gymnosperms into four divisions:-

i. Cycadophyta (Cycas sp.)

ii. Pinophyta/ Coniferophyta (Pinus sp.)

iii. Ginkgophyta (Ginkgo sp.)

iv. Gnetophyta (Gnetum sp.)

MAIN IDEAS


a) The unique

characteristics

of

gymnosperms

• Non-flowering plants • Have true roots, leaves and stems. Therefore, have vascular tissues

- Xylem with tracheid only - Phloem with no companion cells - Vascular cambium leads to secondary growth (wood)

• Naked seed - Seeds are exposed on the surface of spore producing structures

called sporophylls • Heterosporous

- Microspores (smaller structure that produce male gametes) - Megaspores (bigger structure that produce female gametes)

• Reproductive organs are usually bear in cones. - sporophylls are spirally arranged - no double fertilization

• Ovules (modified megasporangium) - Contain the female gametophyte

Alternation of generations

- Sporophyte dominant - Gametophyte very much reduced

➢ Depends entirely on the sporophyte ➢ No free-living gametophyte

b) The

classification

of

gymnosperms

i. Cycadophyta (Cycas sp.)

i.

Female cone

of Cycas sp.

Male cone

of Cycas sp.


32 | KMPk

Pinophyta/ Coniferophyta (Pinus sp.)

Ginkgophyta (Ginkgo sp.)

Gnetophyta (Gnetum sp.)

Male and female cones of Pinus sp.


33 | KMPk

SUBTOPIC 1.6.5 : Angiosperms

LEARNING OUTCOMES: (a) Describe the unique characteristics of Angiosperms (Division/ Phylum

Anthophyta)

MAIN

IDEAS /KEY

POINT

EXPLANATION NOTES

a) The unique

characteristics

of

Angiosperms

• Flowering plants

- Produce flowers and fruits

• True roots, stems, leaves and flowers. Therefore, has a complete

vascular tissue with:

- xylem

✓ consists of tracheid and vessel element

✓ Fiber cells: support

✓ Efficient water transport

- phloem

✓ consists of sieve tubes and companion cells

• Seed plants

- seed enclosed in fruit

• The most diverse and geographically widespread

- Herbaceous and woody plant

• Alternation of generations

- Sporophyte

✓ Dominant

✓ The plant body

- Gametophyte

✓ Very much reduced

✓ Male gametophyte : Pollen grains

✓ Female gametophyte : Embryo sac

• Reproduce :

- Asexually →Vegetative propagation or producing heterosporous

- Sexually →Reproduction involves double fertilization:

✓ 1(n) sperm with 2 polar nuclei (2n) and becomes endosperm

(3n),

✓ another 1 sperm (n) with 1 egg (n) and becomes zygote (2n) .

✓ Endosperm develops into a seed

✓ Zygote develops into an embryo

Hibiscus rosa-sinensis


34 | KMPk

MAIN

IDEAS /KEY

POINT

EXPLANATION NOTES

Evolutionary relationship in plant kingdom

Double fertilization in angiosperms


35 | KMPk

SUBTOPIC : 1.6.6 Evolutionary relationship in plant kingdom

LEARNING OUTCOMES: (a) Explain the evolutionary relationships among groups in the plant

kingdom (bryophytes to angiosperms) based on

i. size

ii. dominance to gametophytes and sporophytes

iii. dependence to gametophytes and sporophytes

iv. water dependence in fertilization

v. presence and complexity of vascular tissues

vi. embryo protection

Groups BRYOPHYTES PTERIDOPHYTES GYMNOSPERMS

ANGIOSPERMS

Size

Very small Medium Large Large

Dominance of

gametophytes

and

sporophytes

Gametophyte Sporophyte Sporophyte Sporophyte

Dependence of

gametophytes

and

sporophytes

Sporophyte

depends on the

gametophyte for

the rest of its life

Sporophyte depends

on the gametophyte

only at the early

development

Sporophyte is

totally independent

Sporophyte is totally

independent

Water

dependence in

fertilization

Needed - sperm

motile

Needed- sperm

motile

Not needed- sperm

non-motile

Not needed- sperm

non-motile

Presence of

vascular

tissues

Absent- lack

lignified vascular

Simple vascular

tissues - lignified

vascular

Complex vascular

tissue

- lignified vascular

Xylem - tracheids

only

Phloem - Sieve

tubes with no

companion cells

Complex vascular

tissue

- lignified vascular

Xylem - tracheids

and vessels

Phloem - Sieve tubes

and companion cells

Embryo

protection

Not protected Not protected Protected by the

seed Protected by the seed


36 | KMPk

SUBTOPIC : 1.7 Domain Eukarya: Kingdom Animalia

LEARNING OUTCOMES: (a) Describe the unique characteristics of Kingdom Animalia

(b) State the classification of Animalia into nine phyla: Porifera,

Coelentrata/Cnidaria, Platyhelminthes, Nematoda, Annelida,

Arthropoda, Mollusca, Echinodermata and Chordata.

(c) Discover the unique characteristics of the following phyla:

i. Porifera (e.g: Leucosolenia sp.)

ii. Cindaria (e.g: Obelia sp.)

iii. Platyhelminthes (e.g: Taenia sp.)

iv. Nematoda (e.g: Ascaris sp.)

v. Annelida (e.g : Pheretima sp.)

vi. Arthropoda (e.g: Valanga sp.)

vii. Mollusca (e.g: Achatina sp.)

viii. Echinodermata (e.g: Asterias sp.)

ix. Chordata (e.g: Amphioxus sp.)

(d) Explain evolutionary relationships of animals based on their:

i. Level of organization

ii. Germ layers

iii. Body symmetry

iv. Body coelom

v. Segmentation

MAIN IDEAS


a) The unique

characteristics of

Kingdom

Animalia

• Eukaryote: Organisms whose cells have a nucleus enclosed within

membranes. • Multicellular: Organisms that consist of more than one cell • Heterotrophic: Organism that cannot manufacture its own food by

carbon fixation and therefore derives its intake of

nutrition from other sources of organic carbon, mainly

plant or animal matter (types of nutrition is holozoic). • Store excess carbohydrate as glycogen: Animals store their excess

glucose or energy into

glycogen and fats. The

glycogen will be kept in the

liver and muscle, meanwhile

fats in adipose tissues. • Complex body system and have differentiated tissues for response to

stimuli and locomotion (e.g: nerve tissues, muscle tissues). • Reproduce sexually (most): Fusion of male and female gametes. • Dominant stage in the life cycle is diploid


37 | KMPk

b) State the

classification of

Animalia into

nine phyla

-Porifera

Coelentrata/

Cnidaria,

Platyhelminthes,

Nematoda,

Annelida,

Arthropoda,

Mollusca,Echino

dermata,

Chordata

Kingdom animalia consists of various multicellular eukaryotic animals.

Basically, animals are divided into two group, invertebrates (without

backbone) and vertebrates (with back bone). Below are the phyla of kingdom

animalia according to the groups.

KINGDOM ANIMALIA

PHYLUM EXAMPLE

Invertebrates

i. Porifera Leucosolenia sp.

ii Cindaria Obelia sp.

iii Platyhelminthes Taenia sp.

iv Nematoda Ascaris sp.

v Annelida Pheretima sp.

vi Arthropoda Valanga sp.

vii Mollusca Achatina sp.

viii Echinodermata Asterias sp.

Vertebrates

ix Chordata Amphioxus sp.

c) The discovery

of the unique

characteristics of

the following

phyla

i. Phylum Porifera (e.g: Leucosolenia sp.)

• Consists of all species of sponges

• No true tissues →The cells that make up a sponge are not organized into

tissues. Therefore, sponges lack true tissues and organs.

• Asymmetrical →No body symmetry

• No body cavity

• Most are sessile

➢ Sponge larvae are able to swim; however, adults are non-

motile and spend their life attached to a substratum through a

holdfast.

• Aquatic mainly marine

➢ The majority of sponges are marine, living in seas and oceans.

• Body has an endoskeleton made up of spicules or spongin

➢ The presence and composition of spicules (made up of calcium

carbonate) and spongin are the differentiating characteristics

between the classes of sponges. Some contain either or and

some contain both compositions.


38 | KMPk

• Reproduction

➢ They are hermaphrodites, meaning that each individual

functions as both male and female in sexual reproduction by

producing sperm and eggs.

• Sponges are filter feeders:

➢ They filter out food particles suspended in the surrounding

water as they draw it through their body, which in some

species resembles a sac perforated with pores.

➢ Water is drawn through the pores into a central cavity, the

spongocoel, and then flows out of the sponge through a

larger opening called the osculum.

• Feeding mode:

➢ Water flows through the sponge allow for feeding, waste

removal and the intake of oxygen.

➢ A combination of pressure, flagella and contractile

movement pump water

• Types of cells:

i. Flagellated choanocytes, or collar cells

✓ lining the interior of the spongocoel are (named for the

finger-like projections that form a “collar” around the

flagellum).These cells engulf bacteria and other food

particles by phagocytosis.

ii. Mesohyl cell.

✓ Because both cell layers are in contact with water,

processes such as gas exchange and waste removal can

occur by diffusion across the membranes of these cells.

iii. Amoebocytes cell

✓ These cells move through the mesohyl and have many

functions. For example, they take up food from the

surrounding water and from choanocytes, digest it, and

carry nutrients to other cells.

iv. Porocytes: specialized cells for the passage of incoming

water current and are located in the body wall of

sponges

Morphology of Leucosolenia sp.


39 | KMPk

Phylum Cnidaria (Obelia sp.)

• Obelia is a genus of hydrozoans,

• Simple structure

• Mainly live in marine and some freshwater

• Dimorphism (two distinct forms) in their life cycle.

i. Medusa form (umbrella shape)

- Male and female, produce sperm and egg

- Motile

- mouth and tentacles directed downwards

ii. Polyp form

- Feeding polyp (has tentacles)

- Reproductive polyp (reproduce by budding)

- Non-motile

- mouth and tentacles directed upwards

The filter feeder and amoebocytes

Obelia sp. in a medusa form


40 | KMPk

Life cycle of Obelia sp.

1. Sexual reproduction involves the production of medusa, which

bud from the second type of polyp, called reproductive polyps.

2. They produce tiny free-swimming sexual medusae (male &

female) complete with tentacles and gonads, which release egg

cells and sperms into the water.

3. Fertilization results in a zygote which develops to form planula

larva consisting of a ball of cells with a ciliated outer layer.

4. Planula larva develop to produce new mature polyps.

Life cycle of Obelia sp.

Reproductive

polyp

Obelia sp. in a polyp form

1

2

3

4


41 | KMPk

Phylum Platyhelminthes (Taenia sp.)

• Bilaterally symmetrical body plan

A basic body plan in which the left and right sides of the organism can

be divided into approximate mirror images of each other along the

midline.

• Triploblastic → Has three germ layers

✓ ectoderm (outer most layer)

✓ mesoderm (middle layer)

✓ endoderm (inner most layer)

• Acoelomate

✓ No body cavity

• Unsegmented

head

Taenia sp.

ectoderm

mesoderm

endoderm

gut


42 | KMPk

• Shows cephalization (development of head region).

iii. Excretory system

✓ Protonephridia = 2 lateral canals with branches bearing flame

cells

• No specialized circulatory or respiratory system →Gas exchange

occur by diffusion

• Incomplete digestive system →Has mouth but no anus

• Nervous system

• Parasitic (except for Class Turbellaria (e.g Planaria sp.))

Taenia mature proglottids

Nervous system in Taenia sp.

Excretory

system

Nerve

cord


43 | KMPk

Phylum Nematoda (e.g: Ascaris sp.)

• Bilaterally_symmetry

• Triploblastic

• Unsegmented

• Pseudocoelomate

• Most are free living found in fresh water, marine, moist soil,

tissues

• Some are parasitic

• Endoparasite

➢ found in guts of humans, pig and tissues of plant

➢ Complete alimentary canal with separate mouth & anus.

Structure of Ascaris sp.


44 | KMPk

• Nervous system

➢ simple with several ganglia in the head region (but no brain)

➢ nerves extend from ganglia →control movement

• Excretory system

➢ a series of excretory tubes that end in an excretory pore

• No circulatory & respiratory systems

• Have hydrostatic skeleton

➢ move to maintain shape and allows for locomotion

➢ move by contracting muscles on alternating sides of the body,

no circular muscle

• Reproduction

➢ Dioecious - separate sexes in most species

➢ female is much bigger & longer than male

➢ Internal fertilization

➢ Parasitic nematodes often have complex life cycle (involve 2

or 3 different hosts or several organ in a host)

• Body is covered with smooth cuticle (thick flexible cuticle)

➢ provides protection

➢ reduces H2O loss

➢ withstand hydrostatic pressure of pseudocoelom

- -Brugia malayi sp. as Elephantiasis causing agent.


45 | KMPk

Phylum Annelida (e.g: Pheretima sp.)

• Bilaterally symmetry

• Triploblastic

• Segmented

• Coelomate -fluid-filled cavity between the gut and other body

organ

• Metameric segmentation

➢ Division of body into a number of segments each contains

same organ (muscles, blood vessels, nerves)

➢ Septum (membrane) between segment

• Free-living, terrestrial or aquatic form

• Complete digestive system:

➢ mouth, long tube & anus

➢ digestive tract with anterior mouth & posterior anus

➢ one-way digestive tract

• Excretory system

➢ consists of a pair of nephridium for each segment

segmented

The structure of Pheretima sp.


46 | KMPk

• Closed blood circulation system

➢ Blood travels through vessel

• Respiratory system

➢ Through skin or gills

• Nervous & sensory system are present

• Chitinous setae

➢ Each segment has setae to assist movement

➢ Have longitudinal and circular muscle for burrowing and

swimming

• Reproduction system

➢ Most reproduce sexually

➢ Dioecious or monoecious

Phylum Arthropoda (e.g: Valanga sp.)

• Bilateral symmetry

• Triploblastic → Organ-system level of organization

• Paired segmented appendages/jointed legs in pair

• Segmented bodies

➢ Segments are fused to form specialized body regions →

Tagmata

• Cephalization

➢ Head, thorax & abdomen

Leg structure of Valanga sp.


47 | KMPk

• Exoskeleton with chitin (Protective, mobile)

• Digestion

➢ Complete digestive system

➢ Modified mouth parts & anus

• Excretory

➢ Depending as much on their environment as on the

subphylum to which they belong

• Movement

➢ Segmentation & Appendage →better locomotion

• Nervous system consisting of:

➢ a double cerebral ganglion

➢ a double ventral nerve cord network of nerves

➢ Sensory organs include antennae, hairs, simple compound eye

• Hemocoel (blood cavity) instead of a coelom

➢ filled with hemolymph (blood-like fluid)

➢ Open blood circulation system with true heart

➢ Have artery but no vein

➢ Blood flow via hemocoel before return to heart

Cephalization of Valanga sp.

mouth stomach

anus

intestine esophagus

Digestive system of Valanga sp.

Nervous system of Valanga sp.


48 | KMPk

• Reproduction

➢ Generally, reproduces sexually

➢ Separate sexes

- Male (smaller size)

- female (bigger size)

• Respiration through the tracheal system

➢ Trachea, spiracles and air sacs

Phylum Mollusca (e.g: Achatina sp.)

● Asymmetry ● Triploblastic ● Unsegmented / head ● Coelomate ● Mollusks inhabit marine, freshwater, and terrestrial habitats. ● The body plan is similar and distinct from all other phyla

Circulatory system of

Valanga sp.

Respiratory structure of Valanga sp.


49 | KMPk

The Mollusca body plan includes:

● Visceral mass ➢ Contain most of the internal organs. Example: digestive

system, excretory system, heart ● Muscular foot/ head-foot

➢ located at the ventral site of the body ➢ for locomotion and attachment

● mantle ➢ formed from fold of tissue/soft skin that covers visceral

organs ➢ have gland that secretes the shell

● Complete digestive system ➢ anus open into mantle cavity ➢ Mouth has radula ➢ tongue-like organ with rows of teeth

- drill, scrape & cut food

• Excretory organs

➢ Nephridia - remove metabolic waste from the hemolymph (body

fluid) ● Circulatory system

➢ open / close blood circulation ➢ consists of dorsal heart

● Respiratory system →gills or lung in the mantle cavity ● Advanced nervous system

➢ Brain and well-developed sense organs (eyes in cephalopods) ● Reproduction

➢ monoecious and dioecious ➢ external development ➢ external & internal fertilization


50 | KMPk

Phylum Echinodermata (e.g: Asterias sp.)

• Body symmetry ➢ Larvae

- Bilateral symmetry

➢ Adult

- Radial symmetry

• Triploblastic • No body segmentation • Internal and external parts radiate from centre - five spokes. • No head • Mouth generally on lower (oral) surface of body • Anus on upper (aboral) surface.

• Tube feet

➢ locomotion ➢ feeding ➢ gas exchange

Larvae of Asterias sp.

Asterias sp.


51 | KMPk

• Water vascular system

➢ A network of hydraulic canals branching into extensions

called tube feet • Simple nervous system without brain • No circulatory, respiratory or excretory systems • Slow moving or sessile • Endoskeleton →Hard calcium carbonate plates and spines that

covered by thin epidermis • Sexual reproduction

➢ Separate male and female individuals: Release gametes into

water. ➢ Asexual reproduction: Most capable of regenerating lost parts.

Phylum Chordata (E.g: Amphioxus sp.)

Not all of these characteristics are apparent in adult organisms and may

appear only in the embryonic or larval stages.

• bilaterally symmetrical • Triploblastic

Coelom well developed • Myotomes

➢ Muscular tissues arranged in blocks ➢ Present in embryonic stage ➢ Maintained in some adults chordates

• Closed circulatory system ➢ Hepatic portal system

- blood from alimentary canal taken to liver and taken back

to the heart ➢ Heart is ventral position

- found behind and below pharynx.


52 | KMPk

The animals in the phylum Chordata share four key features: a notochord,

a dorsal hollow nerve cord, pharyngeal slits, and a post-anal tail.

• Notochord ➢ Longitudinal, flexible rod

- located between digestive tube and nerve cord - later become vertebral column / backbone

➢ Provides skeletal support. - Place for muscle attachment.

• Pharyngeal cleft (slits in the pharynx) ➢ Found in all chordate embryos

- A series of pouches separated by grooves found along the

sides of the pharynx - The perforated pharynx evolved as a filter feeding

apparatus. modified into internal gills used for

respiration. ➢ Function: Invertebrates chordates

- Suspension feeding devices (invertebrate chordates) - Modified for gaseous exchange (vertebrates) - Gill slits at sides of pharynx

• Dorsal hollow nerve cord ➢ Develops from a plate of ectoderm that rolls into a tube

located above the notochord ➢ Develops into central nervous system

- brain and spinal cord • Post anal tail

- Tail extending posterior to anus - Lost during embryonic development - Contains skeletal elements and muscles - Provides propelling force in many aquatic species

d) The

evolutionary

relationships of

animals.

i. Level of organization

Multicellular organisms are made of many parts that are needed for

survival. These parts are divided into levels of organization. There are

five levels: cells, tissue, organs, organ systems, and organisms.

Amphioxus sp.


53 | KMPk

ii. Germ layers

Any of three cellular layers, the ectoderm, endoderm, or mesoderm, into

which most animal embryos differentiate and from which the organs and

tissues of the body develop through further differentiation

iii. Body symmetry

A basic feature of animal bodies is their type of symmetry

or absence of symmetry.

• A radial animal, such as a sea anemone (phylum Cnidaria), does

not have a left side and a right side.

• A bilateral animal, such as a lobster (phylum Arthropoda), has a

left side and a right side.


54 | KMPk

iv. Body coelom

v. Segmentation

Segmentation is the serial repetition of similar organs, tissues, cell types

or body cavities along the anterior-posterior of bilaterally symmetric

animals. The concept of segmentation in biology relies upon the ability

for organisms to duplicate organs and structural elements, such as arms

and legs. Segmentation allows for a greater degree of variety among

species.

➢ Different segmentation in arthropods.


55 | KMPk

2 segments 3 segments

biology student’s companion resources sb 025 chapter 1.0

Documents