علم التصنيف: الكلاسيكية والحديثة

• Taxonomy is the science of studying living organisms, classifying them into groups for easy identification.

Classical vs. Modern Taxonomy

• Classical taxonomy mainly studies external and anatomical characteristics, relying on herbaria.
• Modern taxonomy relies on field studies and gathers information from various aspects like morphology, anatomy, environment, cells, pollen, etc.
• Modern taxonomy formulates information to reflect evolutionary relationships.

Goals of Taxonomy

• Identification is identifying plants and assigning them to groups like species, genus, order, or family.

Means of Identification

• Comparison with known specimens.

Herbarium

• A collection of dried specimens on paper containing collector name, location, and collection date.
• These specimens are stored in special cabinets.

Library

• Libraries provide references, including plant encyclopedias, indexes, monographs, and botanical dictionaries.

Botanical Garden

• A garden of living plants

Taxonomic Keys

• Requires knowledge of taxonomic terms and a complete plant specimen.

Personal Contact

• Contacting specialists familiar with the taxonomic unit

Nomenclature

• Giving a new scientific name according to the International Code of Botanical Nomenclature (ICBN).
• Taxon is the defined taxonomic category.

Taxonomic Ranks

• Kingdom
• Division
• Class
• Order
• Family
• Tribe
• Genus
• Section
• Series
• Species
• Variety
• Form
• These ranks can be further divided into sub-ranks such as subfamily or subspecies.

Categories

• Arranging plants into groups based on relationships, placing similar plants into a single species, closely related species into a larger genus, and related genera into a family.

History of Taxonomy

• Theophrastus wrote about plant classification and established its principles in De Historia Plantarum.
• Theophrastus differentiated between flowering and non-flowering plants, further dividing plants into trees, shrubs, and herbs. He is considered the "Father of Botany.”
• Important physicians arose after the Greek period.

Turner and Bock

• During the Renaissance, Turner and Bock became known for their books on medicinal herbs.
• The books focused on plants as food and medicine.
• Arab scholars like Jabir ibn Hayyan and Ibn Sina wrote about plant history and properties.
• Ibn al-Bitar described approximately 1400 plants.

Caesalpino

• Caesalpino was the first to categorize plants based on their growth nature, fruit structure, and seeds.

G. Bauhin.

• G Bauhin was the first to distinguish between genus and species.
• Although he created a binomial naming system, he did not consistently apply it like Linnaeus.

John Ray

• John Ray was the one who initially introduced the words "dicotyledons".

Carl Linnaeus

• Carl Linnaeus set the stage for the existing binomial nomenclature system and was named "Father of Taxonomy".
• He wrote essential books on the natural plant systems, "Genera Plantarum" and "Species Plantarum."

De Candole

• He first coined the term "Taxonomy" and categorized vascular and non-vascular plants, whereas Bentham and Hooker only classified seed plants .

Plant Classification Systems

• Because taxonomists approached plant categorization in different ways, various systems emerged.

Mechanical or Artificial System

• It relies solely on observable characteristics.
• One example is plants classified as either trees or bushes.
• Linnaeus' categorization is the most notable.
• It is based on the reproductive organs.

Natural Classification System

• It relies on all plant relationships based on all physical traits.
• Adanson, Hooker, and Bentham are well- known scientists that embraced the system.

Evolutionary Classification System

• It utilizes a wide range of traits and features to depict the degree of relationship among plant groups.
• Eichler and Engler are among the prominent scientists who have adopted this system.

Algae

• They are the foundation of the food chain in marine and ocean environments.
• They nourish a wide array of tiny fish, plankton, and other creatures.
• They possess chlorophyll and other pigments and as a result are autotrophic
• The algae also carry out a major function in producing oxygen within such aquatic habitats.
• Along with their primary function of delivering oxygen, they produce a beneficial effect to water.

Objectives of Studying Algae

• To define species and monitor their morphological changes.
• To research life cycles due to its importance in the field of taxonomy.
• To examine algal physiology to establish growth needs.
• To find out more about the useful species to use like a food for example.
• For some types, the water must be analyzed to determine the degree of purity.

Algae Classification

• Whittaker classified it as divided on
• Plant Kingdom
• Animal Kingdom.
• Fungi Kingdom.
• Protista Kingdom. Contains real algae.
• Monera Kingdom. Includes primitive algae and bacteria.

This classification relied on such aspects as:

• Type of dyeing
• Stored nutrition and feeding practices.
• Methods of multiplication,
• External and internal cell structure
• Cell wall structure.
• Types of movement

Algal Divisions

• Kingdom: Monera, Division: Cyanophyta (Blue-green algae)
• Kingdom: Protista
• Division: Euglenophyta (Euglenoids)
• Division: Chlorophyta (Green algae)
• Division: Bacillariophyta (Diatoms)
• Division: Xanthophyta (Yellow algae)
• Division: Chrysophyta (Golden algae)
• Division: Charophyta (Stoneworts)
• Division: Phaeophyta (Brown algae)
• Division: Rhodophyta (Red algae)
• Division: Pyrrophyta (Dinoflagellates)

General characteristics of algae

• They are non-vascular organisms (Thalloid)
• Do not have roots, stems, or leaves
• Real or primitive nucleus, made of a motile or non-motile single cell or in colonies or divided or undivided branching threads.
• They are common in all populations, particularly in marine environments, with some suspended in the water (botanical suspensions) and some fixed at the bottom near the beaches: marine herbs.
• Algae cells are enclosed by a dense wall mainly formed of cellulose with certain materials like pectin, cellan, and calcium carbonate.
• Autotrophic nutrition contains chlorophyll, which is responsible for the photosynthesis that makes it possible to produce more than 50% of the organic substances and supply the earth with oxygen.

Algae with Non-True Nuclei

• Called Bluegreen algae/Cyanobacteria

Properties

• Nucleus is undefined and intermingled within the cytoplasm.
• They lack mitochondria, and enzyme production centers mostly on the surface of the plasma membrane.
• There are no chloroplast organelles, and the chlorophyll spreads through the cytoplasm.
• Autotrophic organisms produce their own nutrition by way of photogenesis because of their chlorophyll pigment.
• Absence of sexual reproduction; reproduction is typically accomplished only by binary fission or segmentation (fractionation).
• Colors vary from green to olive green due to pigments such as phycocyanin (blue in color), phycoerythrin (red in color), chlorophyll (green in color), carotene (orange in color), and xanthophyll (yellow in color).
• Varying organisms include unicellular colonies or filamentous forms.
• Widespread in nature, capable of surviving in many environments, and withstand many environmental factors such as aridity, temperature and humidity.
• Their cells do not move mostly because have no flagella, but movement can be achieved by sliding over the viscous layer released from cell layers.

Shapes of Blue-Green Algae

• Unicellular, either individual (spherical, bacillus, and helicoidal), example: Chrococcus
• Cells accumulated in complex colonies example: Merismopedia

Shapes of Blue-Green Algae (Filamentous)

• Filamentous forms either branched or unbranched), Example: Unbranched: Anabaena.

Methods of Reproduction

• Vegetative reproduction

Binary Fission

• The cell divides by a wall that extends inward, leading the nucleus to divide at two nuclei.

Fragmentation

• It is caused by the separation of portions of the thallus and from an algal filament and referred to Heterocysts the section confined by the vegetative cells.
• It is a section from cells between separate capsules

Asexual Reproduction

• Akinetes is a vegetative cell transformed into a resting spore because of adverse environmental settings.
• These cells enlarge to accumulate raw materials and are confined by strong outer layer.
• They can utilize stored nutrients for subsequent germination and give rise to a newly discovered seaweed.

Classification

• The green algae are classified to five main categories:

First The chroococcascales

• Genus meruz mobidia
• Cells are sphere- formed; are positioned inside sheets with structural patches being flat.
• Live with inside the fresh with saturated mineral water.
• Multiplication by fragmentation
• The nutrient reserved for glycogen are cyanoficin and starch.
• gelatinous غمد

Secondly: The Hormogonales

• Genus Oscillatorial
• The cell are on the surface of the rocks.
• An alga is in the shape of a cylinder.
• The terminal ends of the bulb are convex.
• There is no single heterocyst
• It proliferates by

Family : Nostocaceae

• Class nostic

• Exists in alkali soils and rocks soaked in water.

• The alga is fibrous & consists of spherical cells.

• Consist of irregular vesicles that are important in the process of nitrogen stabilization.

• It is by spores ( the Kinnite ) and germination تتكاثر

Genus Anabaena

• Exists in rivers and fresh water
• The algae of fibrous that is formed of cylindrical cells.

Divisions Based on Nuclei

• Euophycophyta: Algae possess highly-developed nuclei
• Chlorophyta: green algae.

Characteristics:

• It exists among the aqueous environments, the fresh and the marine water or in the soil or installed at rocks or from trunks of the trees.
• Much as greater plants in which cells will have specific cores limited.

Includes :

• chlorophyll has the parts ( the Alpha , Beta ) in conjunction along with Xenon Phil and Karotin. ( Irregular to it ) .

the nutrients of:

• the food nutrients stored will be in the state of starch that has the shape of a cup.
• cell wall that's the structure can be varied at the way ,

It exists the types

• Single-celled or multiple cells منها (colonies متحركها are متجرك .

Multiplication

• Multiplication at that partition that's following 3 Multiplication styles :
• Green ( Vegertative
• The gender multiplication
• The gender multiplication .

1- The Class of Volvox

• That are one- celled creatures , with a moving comet fashion because of some whip.

Alamonthh

• Alplastdh that the shape of the fan.

• 3 - To get her with to Vacathan incitation in the front of .

• ( 3) 5- Exists within the stable mineral and organic materials within turbid soil and the humidity ratio.

• Multiplication styles:

• The generation by the dividing of tow

• Multiplication is not kind the route of microbes floating zoospores with with the conditions.

• Multiplication جنس which has the conditions.

With of the two ways

• Multiplication has the same parts Isogamy