7 3. classification of Living Organism

Classification

of Living

Organisms

• To simplify our study, biologists have created a system used to classify living organisms.

• Living organisms are classified based on their similarities and differences.

• Living organisms with more similarities are classified into one category.

Created by Alfi Msk_a biology teacher of GIS JH


A. Diversity of Living Organisms• Living organisms have different characteristics,

some are large in size and some are small.• Living organisms may also have different

shapes and colors.• Their habitats may be in the water, or on/in the

land• These show that there is a diversity of living

organisms on Earth.• The diversity of living organisms is called the

biodiversity.


1. Similarities and differences between living organisms

Organ Corn (Monocot) Peanut (Dicot)

Root Fibrous root Tap root

Stem Clear and visible segmentation

No segmentation

Leaf Long and ribbon-like with parallel veins

Almost round with pinnately netted veins

Table The differences between a corn plant and a peanut plant





2. Species Diversity• Are cats able to breed with dogs and produce

offspring?• The answer is definitely “NO”, because they are

classified into different species.

• However, if a cat breeds with another cat which are similar in species, then they are able to produce fertile offspring.

• It can be concluded that living organisms which are classified into the same species, are able to breed with each other and produce fertile offspring.


3. Diversity of a species (variety)

• If we observe two living organisms from the same species, we will find several differences.

• For example, in cats we find differences in the color of their fur, body heights or sizes.

• Differences in diversity of living organisms within the same species is called variety.

• Another example of variety is in roses, rose flowers can be red, yellow, or white.

• Can you mention the variety in humans?



B. The Classification of Living Organisms

• The purpose in classifying living organisms is to make it easier for us in knowing and studying living organisms.

• we will learn 3 kinds of classification ;1. simple classification2. classification according to Carolus

Linnaeus3. classification according to Robert H.

Whittaker


1. Simple Classification• Simple classification is done based on similarities

of habitat, food types, or function.

• The classification of living organisms based on their habitat, for example ;

a. xerophytes are plants which are able to survive in an environment with little availability of water or moisture.

b. hydrophytes are plants which have adapted to living in or on an aquatic environment.

c. hygrophytes are plants which grow in a moist habitat.



• The classification of living organisms based on their food types, for example ;a. Herbivores ; feed on plants onlyb. Carnivores ; feed on animals onlyc. Omnivores ; feed on both animals and

plants


• Plants classification based on their function, for example ;

a. Plants use for clothingb. Plants for food c. Plants for medicined. Plants for furniture


2. Classification according to Carolus Linnaeus

• A subdivision of biology which is related to the science of classifying living organisms is called taxonomy.

• The person who first developed the basics of taxonomy was Carolus Linnaeus. That is why he is called the father of taxonomy.

• Carolus Linnaeus classified living organisms based on the similarities and the differences of the body structures of living organisms.


Carolus Linnaeus, the father of

taxonomy


• According to Carolus Linnaeus, living organisms can be divided into two main groups ; the kingdom of plants and the kingdom of animals.

• Carolus Linnaeus created a classification system which is internationally acknowledged and continuously used until now.

• The international classification system has been sequenced into a hierarchical method, starting from the highest level to the lowest.

• Every level in this classification system is called a taxon.


• A taxon is composed starting from the group with the most common characteristics (the highest taxon) to the group with the most specific characteristics (the lowest taxon).

• The taxonomic rank for plants and animals from the highest to the lowest level can be seen in diagram below

Kingdom of Plantae taxon

Division Class Order Family Genus

Species

Kingdom of Animalia taxon

PhylumClass Order Family Genus

Species




• So, the higher group means more different in characteristics and it has more members.

• The lower group means more similar in characteristics and it has less member.


Naming Organisms

1. The name of a species consist of a two-part name in Latin.

2. The first part is the genus and must be written with uppercase, the second part is an indication of species and must be written with lowercase.

3. The species name is written in italics or non-italics but underlined.


4. If the name more than 2 words, so between the second and the third word must give a connection.

• For example ;a. Mangifera indica

Uppercase Lowercase

b. Zae maysc. Hibiscus rosa-sinensis


• Living organisms may be grouped into five

kingdoms, they are ;

1. Kingdom of Monera The word monera comes from the Greek,

moneres, which means one and only. The members of the kingdom of Monera are

organisms which have only one cell. Its members are Bacteria and Cyanobacteria.

3. Classification according to Robert H. whittaker


General characteristics of the kingdom of Monera are as follows ; 1. unicelluler2. they do not possess a nuclear envelope,

therefore it is called a procaryote

Bacteria are ubiquitous (live in all habitats) on Earth.

Some bacteria are advantegous, for example, to help dissolve digestive waste in the colon.

They are also harmful bacteria, for example, bacteria which cause typhoid, tuberculosis, and dysentery.


• There are 3 forms of bacteria ; coccus (spherical-shape), bacillus (straight and rod-shape), spirillum (long and helical-shape).


Coccus Bacillus

Spirillum


• Cyanobacteria live in the water as poducers, and as food for fish and shrimp.

• Cyanobacteria can be utilized to fertilize farm soil.

• For example, Anabaena azollae, Nostoc commune, Oscillatoria sp.

Anabaaena azollae Nostoc commune Oscillatoria sp.


2. Kingdom of Protista Protista has the following characteristics ;1. Unicellular, usually found in an aquatic

environment, however some of them also live in the ground or as parasites inside other organisms.

2. The nucleus is covered with a nuclear envelope, it is called eucaryote

3. Protista can reproduce by binary fission, some of them also undergo conjugation.


A protista is divided into several simple groups ; 1. Protozoa (animal-like protist)2. Algae (plant-like protist)3. Myxomycota and Oomycota (fungus-like protist)

Protozoa is classified into 4 groups ;1. Rhizopoda ; moves using pseudopodia, ex. Amoeba

sp.2. Flagellata ; moves with flagella, ex. Trypanosoma

gambiensi3. Ciliata ; moves using cilia, ex. Paramaecium

caudatum4. Sporozoa ; doesn’t have any specific moving

mechanism, ex. Plasmodium sp.


Amoeba sp.

Tripanosoma sp


Amoeba sp.


Paramaecium sp. Plasmodium sp.


Paramaecium sp.


Plasmodium sp.


Algae live in freshwater, seawater, and moist environment.

Algae is classified according to their pigmen color ;

1. Green algae (Chlorophyta) ex. Spirogyra, Chlorella.

2. Golden algae (Chrysophyta) ex. Dinobryon,Vaucheria.

3. Brown algae (Phaeophyta) ex. Sargassum, Fucus.

4. Red algae (Rhodophyta) ex. Eucheuma, Gelidium.


Chlorophyta


Chrysophyta

Dinobryon Vaucheria


Phaeophyta

Fucus


Rhodophyta

Eucheuma Gelidium


Myxomycota have a similar reproduction method to fungi through the production of spores, in the vegetative phase of a plasmodial slime mold they are able to move like an Amoeba.ex. Plasmodial slime molds

Oomycota produce spore which are called oospora. Oospora are thick-walled spores which are highly resilient to extreme environments and continue growing to be new hypha.ex. Water molds


Plasmodial slime molds

Water molds


3. Kingdom of FungusThe characteristics of fungus are ;

1. Most are multicellular in form and some are single-celled

2. Multicellular fungus consists of filaments called hyphae which are long, a mass of connected hyphae is called a mycelium.

3. Posses a nuclear envelope (eukaryote)4. Live in moist environments and reproduce with spores5. They do not have chlorophyll, therefore live as

saprophyte or as parasites on animals, plants and humans.


Based on their sexual reproduction mechanisms, fungi divided into 4 divisions, they are ;

1. Zygomycota, which sexual reproduction is characterized by zygospores. Ex. Rhizopus

2. Basidiomycota, which sexual reproduction is characterized by basidiospores. Ex. Volvariella volvacea

3. Ascomycota, which sexual reproduction is characterized by ascospores. Ex. Penicillium notatum

4. Deuteromycota, its sexual reproduction has never been observed. Ex. Monilia sitophyla


Rhizopus oryzae Rhizopus stolonifer

Volvariella volvacea


Penicillium notatum

Monilia sitophyla


4. Kingdom of PlantaeThe characteristics of kingdom plantae are ;1. Multicellular 2. The plant cells have cell wall and a nuclear

envelope (eukaryote)3. They have chlorophyll

Based on the have of vascular tissue, kingdom plantae has been classified into 2 groups ;

1. non-vascular plants ; Bryophyta2. Vascular plants ; Pterydophytes and

Spermatophyta


a. Bryophyta (Moss)

• They live in moist environments

• Consist of parts which look like roots, stems, and leaves.

• The root-like structures are called rhizoid, and its function is to adhere bryophyta to the substrate and to absorb water.

• Moss go through certain life cycles, consisting of the sporophyte phase and the gametophyte phase.

• Moss classified into 3 division ; 1. Liverworts (Hepaticophyta), 2. Hornworts (Anthocerotophyta),3. Moss (Bryophyta)


Liverworts


Hornworts


Moss


b. Pterydophyta (Fern)

• Ferns have vascular tissues, that consist of 2 types xylem and phloem.

• Ferns have roots, stems, and true leaves with chlorophyll.

• Ferns do not produce flowers.• New leaves usually curl, on the underside of

mature fertile leaves there are many blackish brown masses, each of these masses is called sorus.

• Ferns go through certain life cycles ; the sporophyte phase and the gametophyte phase.


Fern new leaf


Mature leaf with sorus


• Ferns are divided into 4 division ;1. Psylophyta, which do not have true roots and

leaves. Ex. Psilotum sp.2. Lycophyta, which have true roots and leaves.

Ex. Lycopodium sp., Selaginella sp.3. Sphenophyta, ex. Equisetum sp.4. Pterydophyta, often referred as true ferns.

Ex. Asplenium nidus (bird’s nest ferns), Cyathea australis (tree ferns), Adiantum cuneatum (maidenhair ferns)


Psilotum sp. Lycopodium sp. Selaginella sp.


Equisetum sp. Asplenium nidus Cyathea australis

Adiantum cuneatum

c. Spermatophytes (seed plants)• Spermae means “seed” and phytes means “plants”

• Another name is anthophytes ; antho means flower and phytes means plants

• Spermatophytes are included in vascular plants

• They have roots, stems, and true leaves

• Reproduce with seeds

• Based on the position of yhe seeds, they are classified into 2 groups ;1. The naked-seeded plants (Gymnospermae)2. Enclosed-seeded plants (Angiospermae)Created by Alfi Msk_a biology teacher of GIS JH

1. Gymnospermae (naked-seeded plants) • Gymnos = naked, spermae = seed

• The ovules are exposed and are not enclosed by ovary wall during pollination

• they have cone-shaped ovules as their reproductive cells

• They do not lose their leaves in the dry season

• Example ; Gnetum gnemon (melinjo), Cycas rumphii (pakis haji), Agathis alba (pine), Abies balsamea (balsam), Ginkgo biloba (ginko)



Gnetum gnemon (melinjo)

Male melinjo flowers Female melinjo flowers


Cycas rumphii (pakis haji)

Male Pakis Haji flowers Female Pakis Haji flowers


Agathis alba (pine)


Abies balsamea (balsam)


Ginkgo biloba (ginko)

2. Angiospermae enclosed-seeded plant

• Angio = enclose, spermae = seed

• Also called flowering plants

• They have flower as their reproductive organs

• Based on the number of cotyledon (embryonic seed leaf), they are classified into dicot and monocot



Dicots • Have 2 cotyledons

• The 2 cotyledons are clearly visible when the seeds are germinating

• Dicots have a taproot

• The stems are able to thicken because they have cambium

• The xylem and phloem are well-arranged in the vascular system

• The leaf venation of dicots are usually pinnately (like fins) or palmately (like fingers)

• The flowers are usually in multiples of 4 or 5Created by Alfi Msk_a biology teacher of GIS JH



Monocots• Have one cotyledon

• Have fibrous root

• The stem has internodes but are lacking branches and cambiums

• The xylem and phloem in the vascular system are scattered

• The leaves have a ribbon-like appearance with parallel veins

• The flowers are usually in multiples of 3




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7 3. classification of Living Organism