Ppt

CLASSIFICATION

CLASSIFICATION

•Definition of classification•Importance of classification•Hierarchy of classification•Evolution of classification•General plant classification

What is Classification?

Classification is the process of arranging organisms into groups based on similarities.

It is the arrangement of entities in a hierarchical series of nested classes, in which similar or related classes at one hierarchical level are combined comprehensively into more inclusive classes at the next higher level.

IMPORTANCE OF CLASSIFICATION OF ORGANISMS

IMPORTANCE OF CLASSIFICATION OF ORGANISMS

1. It makes the study of such a wide variety of organisms easy.

IMPORTANCE OF CLASSIFICATION OF ORGANISMS

2. It projects before us a good picture of all life forms at a glance.

IMPORTANCE OF CLASSIFICATION OF ORGANISMS

3. It helps us understand the interrelationship among different groups of organisms.

IMPORTANCE OF CLASSIFICATION OF ORGANISMS

4. It serves as a base for the development of other biological sciences such as biogeography etc.

IMPORTANCE OF CLASSIFICATION OF ORGANISMS

5. Various fields of applied biology such as agriculture, public health and environmental biology depend on classification of pests, disease vectors, pathogens and components of an ecosystem.

HIERARCHY OF CLASSIFICATION

HIERARCHY OF CLASSIFICATIONDOMAIN

KINGDOM

CLASS

DIVISION

TRIBE

GENUS

ORDER

FAMILY

SUBCLASS

SUPER ORDER SUBFAMILY

SUBTRIBE

VARIETY

FORM

CULTIVAR

SPECIES

Domain

It is the highest taxonomic rank of organisms, higher than a kingdom. According to the three-domain system of Carl Woese, introduced in 1990, the Tree of Life consists of three domains: Archaea, Bacteria and Eukarya.

The arrangement of taxa reflects the fundamental differences in the genomes.

Kingdom

It is a taxonomic rank, which is either the highest rank or in the more recent three-domain system, the rank below domain.

Division

It is a term used for animals while its synonym division is used for plants. It is collection of similar classes.

Class

One or more than one order makes a class. It can be:

Angiospermae (Angiosperms) - Plants which produce flowers.

Gymnospermae (Gymnosperms) - Plants which don't produce flowers

Subclass

Subclass is either:Dicotyledonae (Dicotyledons, Dicots) - Plants with

two seed leaves

Monocotyledonae (Monocotyledons, Monocots) - Plants with one seed leaf

SUPERORDER

A group of related Plant Families, classified in the order in which they are thought to have developed their differences from a common ancestor.

The names of the Superorders end in -idae

ORDER

Each Superorder is further divided into several Orders.

The names of the Orders end in -ales

FAMILY

Is a group of closely related genera.Modern botanical classification assigns a type

plant to each Family, which has the particular characteristics which separate this group of plants from others, and names the Family after this plant.

The names of the Families end in -aceae

SUBFAMILY

The Family may be further divided into a number of sub-families, which group together plants within the Family that have some significant botanical differences.

The names of the Subfamilies end in -oideae

TRIBE

A further division of plants within a Family, based on smaller botanical differences, but still usually comprising many different plants.

The names of the Tribes end in -eae

SUBTRIBE

A further division, based on even smaller botanical differences, often only recognizable to botanists.

The names of the Sub tribes end in -inae

GENUS

It is a collection of closely related species.

the usual major subdivision of a family or subfamily in the classification of organisms, usually consisting of more than one species.

The name of the Genus should be written with a capital letter.

SPECIES

This is the level that defines an individual plant. Often, the name will describe some aspect of the plant - the colour of the flowers, size or shape of the leaves, or it may be named after the place where it was found.

The name of the species should be written after the Genus name, in small letters, with no capital letter.

VARIETY

A Variety is a plant that is only slightly different from the species plant, but the differences are not as insignificant as the differences in a form. The Latin is varietas, which is usually abbreviated to var.

The name follows the Genus and species name, with var. before the individual variety name.

FORM

A form is a plant within a species that has minor botanical differences, such as the colour of flower or shape of the leaves.

The name follows the Genus and species name, with form (or f.) before the individual variety name.

CULTIVAR

A Cultivar is a cultivated variety, a particular plant that has arisen either naturally or through deliberate hybridisation, and can be reproduced (vegetatively or by seed) to produce more of the same plant.

The name follows the Genus and species name. It is written in the language of the person who described it, and should not be translated. It is either written in single quotation marks or has cv. written in front of the name.

Example of Plant scientific ClassificationCategory Scientific Name Common Name

KINGDOM Plantae Plant

DIVISION Magnoliophyta Magnolia

CLASS Angiospermae Angiosperms

SUBCLASS Dicotyledonae Dicotyledons

SUPERORDER Magnoliidae Magnolia Superorder

ORDER Ranunculares Buttercup Order

FAMILY Ranunculaceae Buttercup Family

SUBFAMILY Ranunculoideae Buttercup Subfamily

TRIBE Ranunculeae Buttercup Tribe

GENUS Ranunculus Buttercup

SPECIES (Ranunculus) flammula Lesser Spearwort

SUBSPECIES (Ranunculus flammula) subsp. flammula Lesser Spearwort

VARIETY (Ranunculus flammula subsp. flammula) var. tenuifolius Narrow-leaved Lesser Spearwort

EVOLUTION OF CLASSIFICATION

1. Two kingdoms

• The classification of living things are animals and plants in ancient times.

• Aristotle (384–322 BC) classified animal species in his work The History of Animals, and his pupil Theophrastus (c. 371–c. 287 BC) wrote a parallel work on plants (Historia Plantarum (The History of Plants)).

1. Two kingdoms

Life

Regnum Vegetabile

Regnum Animale

2. Three kingdoms

Life

Kingdom Protista

Kingdom Plantae

Kingdom Animalia

3. Four Kingdoms

Life

Kingdom Monera

Kingdom Protista

Kingdom Animalia

Kingdom Plantae

3. Four Kingdoms

Life

Kingdom Animalia Kingdom Plantae Kingdom Protista

Empire Prokaryota Empire Eukaryota

Kingdom Monera

4. Five Kingdoms

Life

Empire Prokaryota Empire Eukaryota

Kingdom Monera Kingdom Protista Kingdom Plantae

Kingdom Animalia Kingdom Fungi

5. Six Kingdoms

Life

Domain Bacteria Domain Archaea

Domain Eukarya

Kingdom Protista Kingdom Plantae

Kingdom Animalia Kingdom Fungi

Kingdom Bacteria Kingdom Archaea

General Plant Classification

General Plant Classification

A. Non-vascular PlantsB. Vascular Plants

a. with seedsb. without seeds

Non-vascular Plants

the simplest of all land dwelling plants

Do not produce seeds or flowers.

Divisions in Non-Vascular Plants

1. Division Bryophyta• the first true plants, evolving from charophytes almost 500 million years ago.•Includes • mosses (Class musci), •liverworts (Class Hepaticae) •hornworts (Class Anthocerotae).

Division Bryophyta

leafy liverwort picture of a hornwort

Mosses

• 2. Division Rhodophyta/ Red Algae

•typically tropical and come in saltwater forms. •contain chlorophyll as well as other accessory pigments, such as phycoerythrin, phycocyanin, and phycobilin.

Division Rhodophyta

Ptilota filicina, Smithora naiadum, and Botryoglossum ruprechtianum

3. Division Phaeophyta / Brown Algae• 99% of this species are found in the marine

environment; they basically only exist in saltwater forms.

• The thallus or the body of the brown kelp algae is made of:–Holdfast–Stipe –Pneumatocyst –Blade

Division Phaeophyta

4. Division Chlorophyta / Green Algae•Several species of this are symbiotic and form linchens with fungi or live with corals.

Division Chlorophyta

Caulerpa taxifolia Acetablaria ryukyuensis

General Plant Classification

2. Vascular Plants - Vascular plants (also known as tracheophytes or higher plants) are those plants that have lignified tissues for conducting water, minerals, and photosynthetic products through the plant.Divided into:

a. Seedless Plantsb. Seed Plants

Divisions in Vascular Plants (seedless plants)

1. Division Pterophyta (ferns)The Pterophyta includes the ferns. Ferns

represent the second major step in the evolutionary sophistication of plants. The division Pterophyta is a group of non-seed plants with a fossil record dating back to the lower Devonian. The division consists of about 11,000 living species.

Division Pterophyta (ferns)

Divisions in Vascular Plants (seedless plants)

2. Division Lycophyta (club mosses) These plants are commonly known as the

lower ferns and possess true vascularized stems, leaves and roots. The position and microanatomy of the vascular tissue is characteristic of these forms. The most significant feature of lycophytes are microphylls.

Division Lycophyta (club mosses)

Divisions in Vascular Plants (seedless plants)

3. Division Psilophyta (whiskfern) They have been considered “primitive,”

recent developmental and molecular evidence suggests that the group may actually be reduced from fern-like ancestors. Despite the uncertainty of their relationships, psilophytes do structurally resemble certain early vascular plants, and are used as a model for understanding the ecology of these plants.

Division Psilophyta (whiskfern)

Divisions in Vascular Plants (seedless plants)

4. Division Sphenophyta (horsetails)The Order is divided into two common

groups known as the "horsetails" and "scouring rushes". The horsetails have jointed hollow and narrow stems with much reduced leaves and side branches are lacking. The scouring rushes have rough-ridges stems with side branches that are long and narrow.

Division Sphenophyta (horsetails)

Divisions in Vascular Plants (seed plants)

1. Division Anthophyta (angiosperms, flowering plants)

Division Anthophyta, the angiosperms, or flowering plants, contains 99.5% of all extant plant species, as well as 80% of all living plants. First appearing in the Cretaceous period, angiosperms contain several key adaptations that allowed them to become dominant in the plant world. First of all, angiosperms typically have broad, flat leaves, which allows for a more efficient collection of solar energy and a better rate of photosynthesis

Division Anthophyta (angiosperms, flowering plants)

Divisions in Vascular Plants (seed plants)

2. Division Coniferophyta (the gymnosperms, evergreen trees)

Conifers are generally large trees and include pines, spruce, firs, cedars, redwoods, junipers, larches, cypresses, and yews. Most conifers are evergreens and so they keep their leaves year-round. The leaves are needle-shaped and have a thick cuticle for protection and to decrease water loss. Conifers are so named because of the reproductive cones they produce. Division Coniferophyta comprises the conifers, the most abundant gymnosperms today

Division Coniferophyta (the gymnosperms, evergreen trees)

Divisions in Vascular Plants (seed plants)

3. Division CycadophytaCycads are an ancient group of seed plants

which are characterized by a large crown of compound leaves and a stout trunk. They are evergreen, gymnospermous, dioecious plants having large pinnately compound leaves and belong to the division Cycadophyta.

Division Cycadophyta

Divisions in Vascular Plants (seed plants)

4. Division GnetophytaThis group has three orders Ephedrales,

Gnetales, and Welwitschiales, each with one living genus, Ephedra, Gnetum, and Welwitschia, respectively. Although they are allied with the gymnosperms, members of these orders have very little in common with one another or with other gymnosperm groups. Plants of this division have primitive vessels in the secondary xylem.

Division Gnetophyta

Divisions in Vascular Plants (seed plants)

5. Division Ginkgophyta Division Ginkgophyta, the ginkgoes, lived

on earth millions of years ago. Its vegetative characteristics are deciduous trees bearing distinctive fan-shaped leaves. Branches with numerous spur shoots that bear the reproductive structures. Stems with extensive secondary growth producing considerable secondary xylem

Division Ginkgophyta

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