Plant Systematic - Lecture Notes PDF

Plant systematic Faculty of Women for Arts, E12BOT112 Science and Education Ain Shams University The Bachelor of Science and Education Program...

Plant systematic Faculty of Women for Arts, E12BOT112 Science and Education Ain Shams University The Bachelor of Science and Education Program Biological Science PowerPoint Lecture Presentations 1st Level / 1st Semester prepared by 2022-2023 Dr. Rabab Abd Elhai Dr. Fafy Abd El-Rahman Bacteria Archaea Vascular Botany Department Plants Systematic Supervision and revised by: Nonvascular Fungi Professor Mona Hussein Plants Professor Abeer A. Rushdy Algae 1  Two kingdoms Introduction system Three kingdoms system Systematic Four kingdoms system The Kingdoms of Life Five kingdoms system Three Domain The major divisions of life system ‫بدائيات النواه‬ ‫حقيقيات النواه‬ Prokaryotes Eukaryotes Eubacteria Protista Archaea Fungi Plant Animal 2 I- Introduction 3  Living And Non-Living Things We can find many things around us, from mountains and oceans to plants and animals. The earth in which we live is made up of several things. These “things” can be categorized into two different types: Living Things. Non-living Things. All living things breathe, eat, grow, move, reproduce, Non-living things do not eat, grow, and have senses. Living things have “life,” and though breathe, move, and reproduce. They do some might not show its evident signs as trees, it does not have senses. Things like soil, sun, not make them non-living. water, and air. The word biology comes from Greek bios means ‘life’ logos means ‘the study of’ (‘knowledge’). Some are not composed of cells The study of living things (organisms) is called biology called Acellular Infectious Particles The person who studies biology is called a biologist. as viruses, prions, viroid. 4  The cell The cell is as fundamental to biology as the atom is to chemistry Cells provide structure and function for all living things, from microorganisms to humans. Scientists consider them the smallest form of life. A compound found mainly in living things is known as an organic compound. Organic compounds make up the cells and other structures of organisms and carry out life processes. Carbon is the main element in organic compounds, so carbon is essential to life on Earth. Without carbon, life as we know it could not exist. Cells house the biological machinery that makes the proteins, chemicals, and signals responsible for everything that happens inside our bodies. Cells are the basic structural and functional Atoms are basically one of the smallest unit of living organisms. structural units of matter http://www.oum.ox.ac.uk/thezone/animals/life/respire1.htm 5 https://www.quora.com/What-is-the-difference-between-an-atom-a-cell-and-a-molecule  The cell A cell is defined as the smallest, basic unit of life that is responsible for all of life’s processes. ▪ In 1665, Robert Hook discovered a cell. ▪ All living things consist of one or more cells ▪ The cell is the simplest collection of living matter that can live. ▪ Cells are also known as 'a small room'. It is the structural, functional, and biological unit of all living beings. ▪ It is a small united area where all kinds of actions and reactions collectively take place. ▪ Everything an organism does occurs fundamentally at the Cellular Level ▪ A cell can replicate itself independently. Hence, they are known as the building blocks of life. ▪ Each cell contains a fluid called the cytoplasm, which is enclosed by a membrane. Also present in the cytoplasm are several biomolecules like proteins, nucleic acids, and lipids. Moreover, cellular structures called cell organelles are suspended in the cytoplasm. 6  How do we know is something is ‘living’? All living things are characterized as being able to do seven things These are usually remembered by the mnemonic MRS NERG The 7 characteristics of Living Things Movement – Animals move to find food and keep away from predators; plants move to face the light. Reproduction – The ability to produce offspring to keep the species in existence. Sensitivity – Responding and reacting to the environment. Nutrition – Animals need food for respiration, plants need minerals from the soil. Excretion – Getting rid of waste. Respiration – Turning food into energy. Growth – Growing larger and stronger → becoming adult size. 7  Branches of Biology Biology has a wide array of branches or divisions. Sometimes referred to as biological sciences or life sciences, each division or branches deals specifically with living things and its vital processes. Below are some of the branches or divisions of biology: Biophysics ‫الفيزياء الحيوية‬ Physiology ‫علم وظائف االعضاء‬ Biogeography ‫الجغرافيا الحيوية‬ Taxonomy ‫علم التصنيف‬ Biomathematics ‫الرياضيات الحيوية‬ Microbiology ‫علم األحياء الدقيقة‬ Bioengineering ‫الهندسة الحيوية‬ Cytology ‫علم الخلية‬ Molecular Biology ‫البيولوجيا الجزيئية‬ Genetics ‫علم الوراثة‬ Biochemistry ‫الكيمياء الحيوية‬ Ecology ‫علم البيئة‬ https://nu.kz.libguides.com/biologyresources/branches_biology 8 https://mawdoo3.com/%D9%85%D8%B9%D9%86%D9%89_%D9%83%D9%84%D9%85%D8%A9_%D8%A8%D9%8A%D9%88%D9%84%D9%88%D8%AC%D9%8A II- Systematics 9  The word systematics is derived from the Latin word ‘systema ’ which means systematic arrangement of organisms. Systematics is the scientific study of the kinds and diversity of organisms and the relationship between them through time. Systematics is the study of relationships of organisms, characters, distribution, evolution, classification…. Systematics consists of both taxonomy and evolution. Systematics takes into account both the past and present of the organism and deals with their evolutionary studies. Systematics is the scientific study of biological diversity and its evolutionary history 10  The term systematics sometimes is referred synonymously with taxonomy. ‫علم التقسيم‬ Systematic The term is derived from the Greek taxis (“arrangement”) and nomos (“law”) Taxonomy includes identification, classification, and nomenclature but systematic ‫التصنيف‬ Taxonomy includes both taxonomy and evolution (the evolutionary history of organisms ‫والتطور‬ through time). Evolution In simple terms, there are two parts of systematic. ‫علم التصنيف‬ ▪ The first part, taxonomy, is concerned with describing and naming the different Taxonomy kinds of organisms, whether exist or extinct. ‫التعريف‬ ▪ The second part, evolution, is concerned with understanding just how all these Identification kinds of animals arose in the first place and what processes are at work today to maintain or change them. ‫التبويب‬ Classification Systematics uses taxonomy as a means to understand organisms. ‫التسمية‬ Nomenclature Living organisms are classified according to many characteristics, such as: the anatomy of the organism – characteristics of cells and their structure – similarity in Today’s systematics generally makes morphology – structure, and shape of reproductive organs extensive use of molecular biology and - methods of nutrition - genetic characteristics computer Programs to study organisms.  Taxonomy's first father was the philosopher Aristotle (384-322 BC), sometimes called the "father of science." Aristotle was the first scientist who attempted to classify organisms, who first introduced the two key concepts of taxonomy as we practice it today: classification of organisms by type and binomial definition. He grouped the types of creatures according to their similarities: The problem with Aristotle's system was that it wasn't accurate enough. Carolus Linnaeus (1750s) : The Father of Modern Taxonomy After 2,000 years the Swedish botanist Carolus Linnaeus (1707-1778) managed to systematically classify all three individual nature systems: o Plants (Regnum vegetabile) o Animals (Regnum animale) o Minerals (Regnum lapideum). Carl Linnaeus is regarded as the founder of the current system of taxonomy (Linnaeus developed his classification system in 1735). He developed a system known as Linnaean taxonomy for categorizing organisms (grouped organisms by characteristics into taxa) and binomial nomenclature for naming organisms. He introduced the standard hierarchy of class, order, genus, and species, making it possible to identify plants and animals. 12 https://www.dkfindout.com/uk/science/famous-scientists/carl-linnaeus/  Scientific Nomenclature The Scientific Name ▪ By the 18th century, scientists realized that naming organisms with common names was confusing. ▪ Scientists during this time agreed to use a single name for each species. ▪ Common names vary with languages and geography (Common names are misleading) ▪ Nomenclature: assigning a name to organisms in agreement with international rules. ▪ To avoid confusion, every type of organism must be referred to in a consistent way. ▪ A Scientific name has several advantages and constitutes the specific identity of the specific organism. ▪ It is used worldwide and understood all over the world How organisms are named Every organism has a scientific name beside the name by which it is known in a particular language. For example, mango is its name in English, Aam in Hindi and Mangifera indica, its scientific name. 13  Binomial Nomenclature (Binominal system) Living organisms are named according to the binomial system introduced by the Swedish naturalist of the 18th century, Carolus Linnaeus The term binomial nomenclature pertains to the two word naming system (binomial = two names; nomenclature = naming) Binomial nomenclature is used worldwide to consistently and accurately name organisms Called binomial because each organism is given two Latin names ✓ The First name is genus, beginning with a capital letter. ✓ The Second name is species, beginning with a lower case letter (no capital). These names are used by scientists all over the world so that they can share information about the same organism without confusion. 14  Rules for naming organisms: Every type of organism is referred by its genus name (noun) followed by its species name (adjective) - (Binominal system) Used Latin and Greek languages for scientific names Italics are used when the name is Both names are italicized or underlined printed. The name is underlined if it is The genus is capitalized, species lowercase handwritten. Can also be abbreviated 15  Classification Why do Scientists Classify? Imagine a grocery store… How are they organized? What would happen if they were not organized? How is your life organized? 16  Classification Why do Scientists Classify? To study the diversity of life → Biologists have identified and named over 15 million species so far. They estimate that about 100 million species have yet to be identified To organize and name organisms → Need to keep organized! (Easier to study!) How is classification useful for us? It is impossible to study every living organism from an individual level. Classification is used to organize the diversity of life: ▪ Illustrate the relationships among living things ▪ Categorizing organisms not yet studied in detail ▪ Provides a common frame of reference when organisms are discussed ▪ Identify specific species to provide scientific names to organisms ▪ Facilitate the easy study of organisms Classification makes it easy to understand and study things around us. 17  Hierarchical classification Taxonomical classification Biological classification uses taxonomic ranks, taxonomic level, or Taxonomic Hierarchy Hierarchical A series of subdivisions developed by Linnaeus to classify organisms according to Classification their complexity (into successive levels) Taxonomic ranks 8 successive taxa are used to classify each species The current taxonomic system now has eight levels in its hierarchy, from lowest to Domain highest, they are: species, genus, family, order, class, phylum, kingdom, domain. Kingdom Thus, species are grouped within genera, genera are grouped within families, families Phylum are grouped within orders, and so on.. Class Remember the first letter of this sentence: Order Family Dr. King Philip Came Over For Good Spaghetti. Genus Species In Linnaeus's system, there are three kingdoms which are divided into classes, and them into orders, families, genera, and species. Both domain and phylum https://www.shmoop.com/study- were later added to complete the system of binomial nomenclature. guides/biology/taxonomy/taxonomy-history 18 https://www.shutterstock.com/search/taxonomic-order  Hierarchical classification https://www.savemyexams.co.uk/a-level/biology/cie/19/revision-notes/18-biodiversity-classification--conservation/18-2-classification/18-2-1-taxonomic-hierarchy/ 19 https://www.shutterstock.com/search/taxonomic-order  Hierarchical classification Domain Domain is the highest level of classification (The term domain wasn’t used until 1990). Essentially, domains are superkingdoms Systematists now use a level of classification above the kingdom, called domain, based on fundamental molecular differences among the Eubacteria, Archaebacteria, and Eukaryotes. Kingdom The kingdom is a major category of living organisms below the domain level. Kingdom and domain are two types of categories to classify living organisms. Phylum (or Division) This is the next level of classification and is more specific than the kingdom. The phylum is a classification level of animals whereas division is a classification level of plants and fungi and Protista. The main difference between phylum and division is the type of organism classified. 20  Hierarchical classification Class Class was the most general rank in the taxonomic hierarchy until phyla were not introduced. Order Order is a more specific rank than class. The order constitutes one or more than one similar family. Family This category of taxonomic hierarchy includes various genera that share a few similarities. In general, the family name is named after the type genus of the family. e.g. The family Pseudomonadaceae is named after the type genus Pseudomonas. Genus A group of similar species forms a genus. Some genera have only one species and are known as monotypic, whereas, some have more than one species and are known as polytypic. Species It is the lowest level of the taxonomic hierarchy. There are about 8.7 million different species on earth. It refers to a group of organisms that are similar in shape, form, and reproductive features. Species can be further divided into sub-species. 21 The taxonomic hierarchy 22 https://slideplayer.com/slide/4899478/ III- The Kingdoms of Life 23  A Brief History of the Kingdoms of Life A Concept Map Illustrating the Development of Classification for Living Organisms (over some 140 years) https://web2.mendelu.cz/af_291_projekty2/vseo/print.php?page=4515&typ=html 24 http://thebiologyprimer.com/taxonomy-and-classification  Two kingdoms system In the 18th century, Carolus Linnaeus began identifying living organisms according to similarities in form and placing organisms in one of two kingdoms ▪ Animalia for animals Animals move but cannot make their own food ▪ Vegetabilia for plants Plants make their own food but cannot move https://www.researchgate.net/publication/319525117_Phylogenetics/ 25 figures?lo=1&utm_source=google&utm_medium=organic  Three kingdoms system Ernest Hackle introduced the Three kingdom classification system in 1866, and produced the 3rd kingdom Protista, following the discovery of unicellular microscopic organisms In kingdom Protista, all the organism which create problem in the two kingdom classification is included in the kingdom Protista. The Protista included all “simple” forms of life such as bacteria, many algae, protozoa, and multicellular fungi. Haeckel’s original term, Protista, is still used in taxonomic schemes today He classifies all living organisms into three kingdoms. ▪ Animalia ▪ Plantae ▪ Protista https://www.vedantu.com/question-answer/which-are-the-three-kingdoms-put-forth-by-ernst-class-9-biology-cbse- 26 5f6d7ef8d053ee34aea8ef2f https://www.nature.com/articles/nmicrobiol2016114 Changes came as the tools to study bacteria were developed. First, light microscopy and staining techniques were used to describe the basic structure of cells. Second, electron microscopy was used to study the ultrastructure of cells. Third, biochemical techniques were used to study the chemical composition and chemical reactions in cells. One of the most important discoveries from these various studies was that DNA looked and behaved differently during cell division in bacteria than in cells whose DNA is organized into chromosomes within a nucleus. 27  Prokaryote and Eukaryote A fundamental taxonomic groups Two fundamental groups of organisms were recognized in 1937: Prokaryotes Life form in which DNA is not organized within a cell nucleus. Eukaryotes Organisms possess an organized nucleus enclosed by a double nuclear membrane. This grouping was first proposed by Édouard Chatton (1883 – 1947) as two Empires: Prokaryota and Eukaryota In 1925, Édouard Chatton argued that organisms with the presence of a nucleus should all be placed in a large group (collectively known as Super kingdom Eukaryota), whether they are unicellular or multicellular. He suggested that all other microorganisms that lack a nucleus were in a separate kingdom. 28  The endosymbiotic hypothesis How did cells change, make the transition from prokaryotic (NO nucleus) to eukaryotic (TRUE nucleus) cells? Endosymbiotic Theory Endosymbiotic theory suggests that eukaryotes arose from a symbiotic relationship between various prokaryotes. Heterotrophic bacteria became mitochondria. Cyanobacteria (autotrophic bacteria) became chloroplasts. Host cell was a larger prokaryotic cell. Evidence for this theory is that mitochondria, centrioles and chloroplasts have their OWN DNA 29 https://slideplayer.com/slide/15350831/  A Comparison of Prokaryotic and Eukaryotic Cells. Prokaryotes are unicellular Eukaryotes are organisms organisms that lack whose cells have a nucleus membrane-bound structures, and other organelles the most noteworthy of which enclosed by a plasma is the nucleus. membrane. A bacterial cell is an example of a A protozoan cell as a typical eukaryotic prokaryotic cell. Relatively few visual cell. Note the variety of cellular compartments are present. compartments 30 https://www.drghaly.com/articles/display/12512  A Comparison of Prokaryotic and Eukaryotic Cells. Similarities Cell contents bounded by a plasma membrane Genetic information encoded on DNA Ribosomes act as site of protein synthesis Prokaryote Eukaryote Cell structure Unicellular Mostly multicellular; some unicellular Cell size Smaller (0.1-5 μm) Larger (10-100 μm) Complexity Simpler More complex Cell wall Usually based on peptidoglycan When present, based on cellulose od chitin Nucleus Absent Present Pili May be present Absent Membrane-bound Several membrane-bound organelles present, including Absent organelles mitochondria, endoplasmic reticulum,.. Ribosomal Smaller (70S), free in cytoplasm Larger (80S), free in cytoplasm or attached to membranes Respiratory enzymes Bound to plasma membrane Located in mitochondria Genetic material Free in cytoplasm Contained within a membrane-bound nucleus Single Circular chromosome Multiple chromosome, generally in pairs DNA complexed DNA Form Histones absent with histone proteins Examples Bacteria, archaea Animals, plants, fungi, protists 31  Four kingdoms system Studies of the structure and function of cells also led to the recognition of two general patterns of cellular organization, prokaryotic and eukaryotic. Various taxonomists working in the late 1950s, placed bacteria in a separate kingdom of anucleate (lacking a cell nucleus) organisms rather than with organisms that have true nuclei. In 1956, Herbert Copland suggested bacteria be placed in a fourth kingdom, the Monera. (This grouping was first proposed by Édouard Chatton (1883 – 1947)) - The kingdom Monera Consists of unicellular organisms. - The protists, plants, and animals are eukaryotic organisms. - The fungi were placed in the group of plants which was considered as the drawback of the four-kingdom classification. http://inutoneko.info/kingdom-classification-system https://sites.google.com/site/plantevolutionarydiversity/introduction 32 https://biology4isc.weebly.com/a-biological-classification.html  Four kingdoms system A scheme of classifying prokaryotes and eukaryotes by the following 4-kingdom system of classification: Prokaryotes ✓ 1. Monera: all prokaryotes, including true bacteria and blue- green algae. Copeland's classification of two empires and four Euokaryotes kingdoms ✓ 2. Protoctista (Protista): all eukaryotic algae, protozoa, and fungi. ✓ 3. Plantae: all green plants. ✓ 4. Animalia: all animals derived from a zygote, a cell formed by the union of an egg and a sperm. 33 https://earthlingnature.wordpress.com/2011/12/05/a-brief-history-of-the-kingdoms-of-life/  The Five Kingdom System The most favored scheme was proposed by Robert H. Whittaker in 1969. Since Haeckel, the position of fungi was not well established, oscillating between kingdoms Protista and Plantae. The fungi are the only eukaryotic group that must externally digest their food prior to absorption, fungi could not find a suitable place in the earlier system of classification For this and other reasons, Whittaker refined the four-kingdom system into five kingdoms, identifying the kingdom Fungi as a separate, multicellular, eukaryotic kingdom distinguished by an absorptive mode of nutrition All organisms are classified based on several characteristics such as mode of nutrition, thallus organization, cell structure, phylogenetic relationships, and reproduction. 34  The Five Kingdom System It places all prokaryotes, microorganisms that lack a cell nucleus, in the kingdom Monera. It places most unicellular eukaryotes, organisms whose cells contain a distinct nucleus, in the kingdom Protista. The kingdom Monera is also called the kingdom Prokaryotes Prokaryotae. It consists of all prokaryotic organisms, including the eubacteria (“true Kingdom Monera: Bacteria bacteria”), the cyanobacteria, and the archaea. Eukaryotes Kingdom Protista: Amoeba, slim mold Kingdom Fungi: Mushrooms, Yeast, Molds Kingdom Plantae: Flowering plants, Mosses, Ferns, Cone-bearing plants Kingdom Animalia: Mammals, Birds, Insects, Fishes, Worms. 35 The Five Kingdom System https://www.knowledgeuniverseonline.com/ntse/Biology/Two-Kingdom-Classification.php 36 https://biology4isc.weebly.com/a-biological-classification.html  The Five Kingdom System Monera Protista Fungi Plantae Animalia Cell Type Prokaryotic cell Eukaryotic cell Present in some, Cell Wall Present in most Present Present Absent absent in other Cellular(Unicellular Cellular (Unicellular Unicellular or Multicellular Cell Multicellular Occasionally Occasionally multicellular (Tissue / organ / organization (Tissue / organ) grouped) multicellular) (loose tissue) organ system) Autotrophic (chemosynthetic & Heterotrophic Autotrophic Autotrophic Mode of photosynthetic) (saprophytic & (photosynthetic) (photosynthetic) Heterotrophic Nutrition Heterotrophic parasitic) Heterotrophic (saprophytic & parasitic) both sexual and Mostly Asexual. Asexual, usually by Asexual both sexual and Reproduction Occasionally both Primarily sexual binary fission (often complex Asexual sexual and Asexual life cycle) 37 https://biology4isc.weebly.com/a-biological-classification.html  No single classification system is completely accepted by all biologists. One of the most widely accepted is the 5-kingdom system The five kingdom system rested safely for about 15 years. In the late 1970s, Carl Woese, an evolutionary biologist, began a molecular analysis of living organisms based on comparisons of nucleotide sequences of genes coding for the small subunit ribosomal RNA (rRNA) found in all organisms. These analyses revealed yet another dichotomy, this time among the prokaryotes. These two groups were as different from each other as they were different from the eukaryotes. By 1990, it was clear that the kingdom Monera contained two fundamentally unrelated groups, what Woese called the Bacteria and Archaebacteria. 38  The Three Domain system With the dawn of molecular studies around 1970, significant differences were found inside the Prokaryotes, regarded, for example, to the cell membrane structure. Applying newer methods and techniques (from molecular biology and the study of genes) for determining phylogeny has led to the development of a differently shaped tree. Molecular biological methods have demonstrated that certain types of molecules in cells, called small ribosomal ribonucleic acid (rRNA), provide a “living record” of the evolutionary history of an organism. Analysis of this molecule in prokaryotic and eukaryotic cells indicates that certain unusual cells called archaea* (originally archaebacteria) are so different from the other two groups that they should be included in a separate superkingdom. Under the microscope they resemble bacteria, but molecular biology has revealed that the cells of archaea, though prokaryotic in nature, are actually more closely related to eukaryotic cells than to bacterial cells. 39  The Three Domain system This type of analysis has resulted in a new taxonomic category — Empires or Domains = a category above kingdom. To reflect these relationships, Carl Woese and George Fox have proposed a system that assigns all organisms to one of three domains, each described by a different type of cell. The prokaryotic cell types are placed in the Domains Archaea and Bacteria. Eukaryotes are all placed in the Domain Eukarya. The three domains, which are larger than the kingdoms are the following: Eukarya – including four kingdoms: Protists, Fungi, Plantae and Animalia Bacteria – which corresponds to the kingdom Eubacteria. Archaea – which corresponds to the kingdom Archaebacteria 40 https://www.wikiwand.com/en/Domain_%28biology%29  Three Domain Classification system Whittaker five-kingdom classification The 5-kingdom system has since been replaced by a 3-domain system in which the Monera was split into 2 parts: the Domains Bacteria and Archaea. However, the Kingdoms still are used to describe many organisms, and so we will need to be familiar with them. 41 https://www.researchgate.net/publication/274708754_Archaea_Morphology_Physiology_Biochemistry_and_Applications/figures?lo=1  Domain Bacteria Archaea Eukarya Kingdom Eubacteria Archaebacteria Protista Fungi Plantae Animalia Cell Type Prokaryotic cell Eukaryotic cell Some have Cell walls Cell wall made Cell walls cell wall of Distinguishin without Cell wall made of cellulose No Cell wall or contain cellulose, and g features peptidoglycan of chitin and contain chloroplast peptidoglycan some have chloroplast chloroplast Most Multicellular Unicellular/ Unicellular, Unicellular Unicellular and some Multicellular Multicellular Multicellular some Unicellular Multicellular Autotroph or Autotroph or Autotroph or Nutrition Heterotroph Autotroph Heterotroph Heterotroph Heterotroph Heterotroph 42 http://www.dynamicscience.com.au/tester/solutions1/biology/classification/domains.html  The classification of organisms has presented challenges in biological systematics. British zoologist Thomas Cavalier-Smith (born 21 October 1942) presented yet another classification scheme His classifications have been a major influence in modern taxonomy, particularly of protists He created Chromista (new kingdom) for a separate kingdom of some protists. Most chromists are photosynthetic In plants, the chloroplasts are located in the cytosol while in chromists the chloroplasts are located in the lumen of their rough endoplasmic reticulum. By 1981, He found the best one for general scientific use is a system of seven kingdoms which includes: Eubacteria, Archaebacteria, Protozoa, Chromista, Fungi, Plantae, and Animalia. In 1983, he adapted the term Archezoa as a kingdom, for protists that lack mitochondria (Eight kingdoms) Many of his claims have been controversial and have not gained widespread acceptance in the scientific community to date. 43 IV- The major divisions of life 44  Life ‫الخلويه‬ ‫الالخلوية‬ The major divisions ‫ فيروسات‬- Viruses Domain: Bacteria ‫ فيرويد‬- Viroid of life Domain: Archaea ‫ البريونات‬- Prions Domain: Eukarya Kingdom Protista Kingdom Fungi Kingdom Plantae Kingdom Animalia 45  Acellular Organisms (Infectious particles) Not a part of any domain or life kingdoms Not included in any of the classification or evolutionary schemes, because they are not cells and their position cannot be given. Acellular microorganisms are the smallest microorganism that cannot be seen through a light microscope No typical cell structure & no enzymatic energy-production system. They do not have membrane-bound organelles, no cell nucleus, no ribosomes, no cytoplasm, and no source of energy production of their own. They consist merely of a nucleic acid genome (DNA/RNA) and/or a protein. They can only multiply (reproduce) inside the living cells of another organism (host cell). They are called obligate intracellular parasites Examples include viruses, viroid, and prions. 46  Viruses What Are Viruses? Virus is the Latin word for Poison Acellular infectious agent They are much smaller (cannot be seen through a light microscope) and have a simple structure. Most viruses range in size from 10 to 300 nm in diameter. Scientists were not able to see viruses until electron microscopes were invented in the 1930s. Viruses are macromolecular units composed of DNA or RNA (not both at the same time) surrounded by an outer protein coat. They contain nucleic acids such as DNA or RNA and must therefore be considered as being on the border between living and nonliving. Viral nucleic acid can be single-stranded (ss) or double-stranded (ds), and linear, circular, or segmented. 47  Viruses What Are Viruses? Viruses are obligate intracellular parasites (pathogens), they infect bacteria, algae, protozoa, fungi, plants, animals, and humans. Viruses are unable to replicate on their own as their replication is directed by the viral nucleic acid once it has entered the host cell. Viruses depend on the ribosomes, enzymes, and metabolites of their host cell for protein and nucleic acid production. Viruses lack the gens and enzymes needed for energy production. Unlike cells, viruses do not divide by binary fission, mitosis, or meiosis. Viruses are distinguished from living cells in these properties 48 Components of Viruses Typical viral components are: Nucleic acid (DNA or RNA) core and a surrounding protein coat called a capsid which is composed of small protein units called capsomeres. Some viruses have a surrounding lipid and polysaccharides in a bilayer membrane called an envelope, viruses are called enveloped viruses that surround the capsid A complete virus particle, including its envelope, if it has one, is called a virion. Bacterial viruses may also have a tail, sheath, and tail fibers called bacteriophages (or phages). 49 https://study.com/learn/lesson/viroids-overview-examples.html  Plant Animal Bacterial viruses viruses viruses Different forms of viruses https://minhaji.net/printlesson/7320 Classification of Viruses Before they knew much about the structure or chemical properties of viruses, virologists classified viruses by the type of host infected or by the type of host structures infected. Thus, viruses have been classified as bacterial viruses (bacteriophages), plant viruses, or animal viruses. And animal viruses are grouped by the tissues they attack As more was learned about the structure of viruses at the biochemical and molecular levels, the classification of viruses came to be based on: Morphology as size and shape, structure of capsid – presence or absence of envelope Chemical composition Genome composition– DNA / RNA – ds/ss DNA and ds/ss RNA Methods of replication. Type of host Chemical and physical characteristics Helical morphology is seen in nucleocapsids of viruses. There is now found a single, universal taxonomic scheme for viruses led to the establishment in 1966 of the International Committee on Taxonomy of Viruses (ICTV). This committee, which meets every 4 years, establishes the rules for classifying viruses (Today, over 40,000 strains of viruses exist in collections worldwide) 51 Viral Replication In general, viruses go through the following five steps in their replication cycles to produce more virions: 1) Adsorption, the attachment of viruses to host cells. 2) Penetration, entry of virions (or their genome) into host cells. 3) Synthesis, the synthesis of new nucleic acid molecules, capsid proteins, and other viral components within host cells while using the metabolic machinery of those cells. 4) Maturation, the assembly of newly synthesized viral components into complete virions. 5) Release, the departure of new virions from host cells. Release generally, but not always, kills (lyses) host cells. https://en.wikipedia.org/wiki/Viral_replication 52  Bacteriophages Viruses that infect bacteria are called bacteriophages. As all viruses, they are obligate intracellular pathogens, in that they must enter a bacterial cell to replicate. Phages do not enter the bacterial cell they only inject their nucleic acid into the cell. Bacteriophages can be categorized into virulent phages and temperate phages according to the events that occur after the invasion of the bacterial cell. ▪ Virulent phages kill bacteria during every infection cycle since they replicate only via the lytic cycle (which ends with the destruction of the bacterial cell) ▪ Temperate phages do not kill bacteria immediately after the infection since they replicate (When infect bacteria, they are able to integrate viral DNA into bacterial chromosomes and remain in the prophage stage for several bacterial generations). 53  Economic Importance of Virus Useful roles 1. In preparing antidotes/ vaccine: Pox, mumps, polio 2. Some animals and insects which are harmful for humans can be controlled by some special virus 3. Control of disease: T2 bacteriophage virus saves humans from dysentery by spoiling some harmful bacteria, like, E-coli. 4. Phages are used as scavengers to eradicate the bacteria present in the polluted water. 5. Virus is used in lab, as the simplest living model (important in genetic engineering). 6. Virus plays a vital role to acquire knowledge about the trend of evolution and the process of formation of living organisms because virus contains both living and non-living characteristics Harmful roles 1. The virus destroys plenty of bacteria useful for humans 2. Causes different diseases like common Cold, Influenza, Mumps, Pox, Polio, Yellow fever, Aids, etc. 3. Virus does not produce symptoms directly in animals (humans). But it indirectly affects the host. The envelope of the virus is toxic to the body of the host. It causes allergic reactions. Virus DNA is incorporated into the DNA of the host. It stimulates the genes of host cells. Thus, host cells start dividing and produce tumors (cancer). Viruses destroy the immune system of the host like AIDS. 54 For more information https://www.academia.edu/35269671/Economic_Importance_of_Bacteria_and_Viruses_1_Economic_Importance_of_Bacteria  Viroids Viroids are plant infecting particles smaller than a virus containing nucleic acids without a protein coat. Viroids genomes are naked small single-stranded circles of RNA. They cause plant diseases such as potato spindle tuber ( produce small, cracked spindle-shaped potatoes). They do not cause animal diseases. Potatoes spindle tuber viroid (PSTV) Prions The word prion is derived from the term "proteinaceous infectious particle" A prion is a protein that changes its three-dimensional shape, which can cause disease Prions are small infectious proteins found in the brain and are resistant to proteases. that cause fatal neurological diseases in animals as mad cow disease https://study.com/academy/lesson/viroid-definition- structure.html and fatal insomnia in humans. https://www.news-medical.net/life-sciences/What- 55 are-Prions.aspx  Prokaryotes Prokaryotes are organisms made up of cells that lack a cell nucleus or any membrane-encased organelles. The DNA in prokaryotes is contained in a central area of the cell called the nucleoid, which is not surrounded by a nuclear membrane. Many prokaryotes also carry small, circular DNA molecules called plasmids, which are distinct from the chromosomal DNA and can provide genetic advantages in specific environments. DNA is a single loop. Most prokaryotes are made up of just a single cell (unicellular) but there are a few that are made of collections of cells (multicellular). Scientists have divided the prokaryotes into two groups, the Bacteria, and the Archaea. 56  Bacteria Bacteria have been around for a very long time. In fact, they are the oldest known forms of life on Earth The earliest fossils are of prokaryotes. These fossils date back to over 3.5 billion years ago They have also adapted to a range of different environments. They can live inside the human body, at the North Pole, and even at the bottom of the ocean (and live almost everywhere). ▪ Called Bacteria or Eubacteria (means “true bacteria”) ▪ Cell Type → Prokaryote ▪ Number of Cells → Unicellular ▪ Organells → Lack organelles such as a nucleus, mitochondria, or chloroplasts ▪ Nutrition → Autotroph or Heterotroph ▪ Cell wall → Rigid cell wall containing contain Peptidoglycan ▪ Reproduction → Mainly by Binary fission. Examples: Streptococcus, Escherichia coli (E. coli), Salmonella 57  Bacteria Size of Bacteria ▪ Bacteria are single-celled organisms (each bacterium is made up of only one cell). ▪ Bacterial cells can measure from about 1to10μm long. (1 μm, is 1000 times smaller than a millimeter). Bacterial shapes ▪ Bacteria have characteristic shapes Spherical (cocci), rod-shaped (bacilli) and spirals, and others ▪ Occur in characteristic aggregates (pairs, chains, tetrads, clusters, etc.). ▪ These traits are usually typical for a genus and useful in identification. 58 https://www.tropicalhainan.com/viruses-discovery-size-structure-and-how-they-infect-people/  Bacterial Structure The common structures that most bacteria have include: 1. Cell Wall -a rigid wall that gives the cell its structure and is responsible for the characteristic shape of the cell and provides the cell with mechanical protection and is made up of a special protein called peptidoglycan 2. Plasma membrane -also termed a Cell Membrane or Cytoplasmic Membrane. The plasma membrane is flexible, composed of a lipid bilayer and proteins, that surround the cytoplasm of the cell and that control the movement of nutrients in and out of the cell. It is a selectively permeable membrane of the cells. 3. Capsule -a third layer that helps prevent the bacteria from drying out or being engulfed by larger microorganisms (only present in some types of bacteria) 4. Cytoplasm or protoplasm -a gel-like substance composed mainly of water that also contains enzymes, salts, nutrients, wastes, gases, ions, various organic molecules, and cell components such as ribosomes and genetic material. Bacterial Structure The common structures that most bacteria have include: 5. Flagellum - complex filamentous cytoplasmic structures that protrude through a cell wall, that help the bacteria move around and sense their environment 6. Pili -hair-like structures that help bacteria attach to surfaces and other bacteria 7. Endospores - dormant structures produced by some bacteria, they form inside cells when they are under stress (under starvation conditions when not enough nutrients are available). They do not need nutrients and are resistant to extreme conditions. The endospores become active when the conditions are favorable again. 8. Nucleoid Region - the region of prokaryotic cells that contains their genomic DNA 9. Plasmids - a small, circular, double-stranded DNA molecule that is distinct from a cell's chromosomal DNA. 10.Ribosomes - are cell structures responsible for protein production. A prokaryotic cell lacks certain organelles like mitochondria, endoplasmic reticulum, and Golgi bodies.  Reproduction in bacteria Bacteria reproduce primarily by binary fission, an asexual process whereby a single cell divides into two. Recall that the DNA of a prokaryote usually exists as a single, circular chromosome. Prokaryotes do not undergo mitosis. Under ideal conditions some bacterial species may divide every 10–15 minutes—a doubling of the population at these time intervals. The steps involved in the binary fission in bacteria are: ▪ DNA replication ▪ Cell elongation ▪ Segregation of DNA ▪ Formation of division septum ▪ Cell separation 61 https://socratic.org/questions/why-is-binary-fission-so-effective-for-bacteria  Nutrition in bacteria Bacteria need nutrients to complete various activities like growth, reproduction, and metabolism. Bacteria can be classified nutritionally based on their Carbon, Energy, and Electron requirements and on their ability to synthesize essential metabolites. Sources of Carbon, Energy, and Electrons Carbon Sources Autotrophs → Carbon source from CO2 sole (inorganic form) Heterotrophs → Carbon source from organic molecules Energy Sources Phototrophs → Energy source from light Chemotrophs → Energy source from oxidation of organic or inorganic compounds Electron Sources Lithotrophs → Electron source from inorganic molecules Organotrophs → Electon source from organic molecules 62 https://biologyreader.com/nutrition-in-bacteria.html  Economic Importance of Bacteria A. Beneficial Activities of Bacteria: There are many kinds of bacteria without which we could not live. They are absolutely essential to the presence of life on earth. In Agriculture In our bodies Decay and decomposition Help degrade the food we eat Soil fertility (fix free nitrogen into nitrogenous Help make nutrients available to us and neutralize compounds) toxins. Biological Control of Insect (Biopesticide). Play an essential role in the defense against infections by protecting colonized surfaces from In Industries invading pathogens Dairy industry (butter, yogurt, and cheese) Found as microbiomes that are essential for human The process of tanning hides in leather making and animal lives and functions. The production of linen The preparation of coffee and cocoa In Medicine Excrete waste products of great commercial Source of Antibiotics importance as Lactic acid, Citric acid, Butyl Preparation of Serums and Vaccines alcohol, and Acetone. Production of vitamins. 63  B. Harmful Activities of Bacteria: Some bacteria are harmful to human affairs in different ways Food Poisoning Spoilage of food Causes Diseases Destruction of domestic articles (destroying textiles, wooden articles, and canvas) Reduction of Soil fertility (convert soil nitrates and ammonia into free nitrogen) Water pollution Biological Warfare. For more information https://www.academia.edu/35269671/Economic_Importance_of_Bacteria_and_Viruses_1_Economic_Importance_of_Bacteria 64  Cyanobacteria (Cyanophyta) The cyanobacteria, formerly known as blue-green algae, are of special importance in the balance of nature. Cyanobacteria were key players in the evolution of life, as they were the first oxygenic phototrophs to evolve on Earth The cyanobacteria are phylogenetic relatives of gram-positive bacteria Cyanobacteria contain chlorophyll and various accessory pigments as carotenoids, and phycobilin,. Cyanobacteria may be unicellular, colonial, or filamentous. Each filament consists of a sheath of mucilage and one or more cellular strands called trichomes. Some filamentous cyanobacteria contain special structures called heterocysts that carry out nitrogen fixation. https://www.epa.gov/national-aquatic-resource-surveys/indicators-cyanobacteria 65 https://www.facebook.com/Cyanobacteria.BlueGreenAlgae/  Actinobacteria (Actinomycetes) Actinobacteria are Gram-positive bacteria with high G+C DNA content that constitute one of the largest bacterial phyla Actinomycetes are facultative anaerobic bacteria that are distinctive because most have filamentous cells called hyphae that differentiate to produce asexual spores. Its filamentous structure resembles the fungal mycelium, which consists of a highly dense and filamentous network (termed as thread or ray bacteria) All are chemoorganoheterotrophs, Actinomycetes has adapted to a wide range of ecological environments (present in soils, fresh and salt water, and the air) they are more abundant in soils than other media. Some of the form the normal flora of the mouth and female genital tract. Actinomycetes were considered transitional forms between fungi and bacteria. Indeed, like filamentous fungi, many Actinobacteria produce a mycelium, and many of these https://media.sciencephoto.com/f0/20/13/04/f0201304-800px-wm.jpg mycelial actinomycetes reproduce by sporulation. https://www.slideshare.net/SalmanAli83/actinomycetes-58131399 66 https://www.intechopen.com/chapters/49285  Actinobacteria (Actinomycetes) In soil, actinobacteria are saprophytic, and they have the important function of degrading plant or animal resides. Many Actinomyces species are pathogens of humans, mammals and plants (parasitic) Actinobacteria are of great importance in the field of biotechnology, as producers of bioactive secondary metabolites with extensive industrial, medical, and agricultural applications Produce about two-thirds of all naturally derived antibiotics in current clinical use, as well as many anticancer, anthelmintic, and antifungal. The presence of these actinomycetes contributes to an important form of specific disease resistance that can be used to suppress certain pathogenic soil fungi and thus of great importance to soil health 67  Archaebacteria Archebacteria are ‘older’ and more primitive. Microbiologists who study bacteria determined that the DNA of these (Archaebacteria) is much different from other, true bacteria. Archaebacteria differ from other bacteria in structure, composition, and physiology. Cell Type → Prokaryote Number of Cells → Unicellular Nutrition → Autotroph or Heterotroph Cell Wall → Composed of protein, glycoprotein, or pseudomurein; peptidoglycan is absent Location → Live in extreme environments (Volcanoes, Deep Sea Vents, Hot Springs) by unusual metabolism, but others live in mild ones. They do not require oxygen and can live in extremely salty environments as well as extremely hot environments. Examples: Methanogens Thermophiles – Thermoacidophiles 68  Archaebacteria Archaebacteria are obligate or facultative anaerobes Archaeal cells, like bacterial cells, exhibit a variety of shapes. Cocci and rods are common, curved rods, and spiral-shaped archaea have also been observed. Both usually exist singly, but some cocci form clusters, and some rods form chains. The rigid cell wall provides shape and support to the Archaebacteria. It also protects the cell from bursting under hypotonic conditions. Archaeal plasma membranes contain phospholipids different from the phospholipids of bacteria and eukaryotes. (Example: the glycerol component of archaea phospholipids is an isomer of glycerol in bacteria and eukaryotes.) These do not possess membrane-bound organelles such as nuclei, endoplasmic reticulum, mitochondria, lysosomes, or chloroplast. The mode of reproduction is asexual, known as binary fission. 69  Eukaryotes Organisms are made up of cells that possess a membrane-bound nucleus (true nucleus) and membrane-bound organelles They do not have peptidoglycan in the cell wall. Cells divide by mitosis. Eukaryotes that include four of the original kingdoms: ▪ Protista: a catchall kingdom for a variety of organisms; autotrophic and heterotrophic. ▪ Fungi: chemoheterotrophic; unicellular or multicellular; cell walls of chitin; develop from spores or hyphal fragments ▪ Plantae: multicellular; cellulose cell walls; undergo photosynthesis ▪ Animalia: multicellular; no cell walls; chemoheterotrophic. Kingdom Protista Junk drawer” kingdom ‫درج النفايات‬ https://www.ck12.org/book/ck-12-biology-advanced-concepts/section/12.2/ https://www.embibe.com/exams/kingdom-protista/  Protista Kingdom Protista is known as the “junk drawer” kingdom. ▪ Protists are so different from one another and because they don’t fit into another kingdom scientists group them in the protist kingdom. ▪ They are not animals, plants, or fungi but some are animal-like, plant-like, and fungus-like organisms. ▪ Due to the fact protists share few common characteristics the best word to describe the protist kingdom is very diverse. These organisms are so different from each other that sometimes Protista is known as junk drawer kingdom, because just like a junk drawer which contains items that don’t fit any other category this kingdom contains the eukaryote which cannot be put into any other kingdom. 72  Protista Cell Type → Eukaryote (true nucleus) Number of Cells → Most Unicellular, some multicellular Nutrition → Autotroph or Heterotroph or mixotrophs (combine photosynthesis and heterotrophic nutrition) Location → Live in moist environments Cell wall → May not have a cell wall Moving → Some move and some don’t Reproduction → are highly varied, some asexually and others can also reproduce sexually. This kingdom includes the widest variety of organisms Protists are organized into three categories Plant-Like Protists - called Algae (Autotrophic) Animal-Like Protists - also called Protozoans (heterotrophic) Fungus-Like Protists –also called Molds (decomposers). 73  Protista Protists can be economically beneficial or detrimental Photosynthesis and oxygen production from some species Certain protists have shells (tests), of calcium carbonate. Carbonate shells deposited in great numbers by such protists that lived in ancient oceans formed (the limestone used in building the pyramids of Egypt). Because different test-forming protists gained prominence during different geological eras, helps determine the age of the rocks. Occur in rock layers near petroleum deposits, so geologists looking for oil are pleased to find them. Food sources (brown, red, green algae) as animal feed, fertilizers, algae sheets are used in some Japanese dishes. Some autotrophic protists produce toxins that do not harm the oysters that eat the protists, but the accumulated toxins can cause disease or even death in people who subsequently eat the oysters (great economic losses to oyster harvesters). Other autotrophic protists multiply very rapidly in abundant inorganic nutrients and form a https://en.wikipedia.org/wiki/Protist_shell “bloom,” a thick layer of organisms over a body of water. This process, called eutrophication, https://lapatiala.com/the-ultimate-oyster- guide-order-shuck-eat-store-oysters/ blocks sunlight, killing plants beneath the bloom and causing fish to starve. https://mlabscience.weebly.com/habitatnich Can cause disease,Avian & human malaria, Amoebic Dysentery. e.html 74  Protista Animal-like protists ▪ Animal-like protists are called Protozoans which means “little animals”. ▪ Animal protists are heterotrophs which get their food from ingestion. Some prey on other, smaller microorganisms, which they engulf and digest in a process known as phagocytosis. Others may feed on non- living, organic matter ▪ Most can move from one place to another. ▪ Unlike animals, Protozoans are unicellular. ▪ No cell walls or chlorophyll so they are consumers ▪ Scientists distinguish between types of Protozoans based on the way the organisms move and live. 75 https://www.sciencefacts.net/protists.html  Protista Plant-like protists ▪ Plant-like protists are called algae (singular, alga). ▪ Eukaryotes ▪ They are a large and diverse group. ▪ Most unicellular (as diatoms), but some multicellular (as seaweed) ▪ Range in size from microscopic to hundreds of feet in length ▪ Photoautotrophs (photosynthetic organisms, that have chlorophyll with different accessory pigments) ▪ Found in a moist environment (water and moist soil habitats) ▪ Most have flagella ▪ Classified Based on Color (chlorophylls and different accessory pigments) https://beautyfromhashes.wordpress.com/2011/12/30/plant-like-protists/ ▪ Reproduce asexually or sexually. https://bio.libretexts.org/Bookshelves/Introductory_and_General_Biology/Book%3A_I ntroductory_Biology_(CK- 12)/08%3A_Protists_and_Fungi/8.05%3A_Algae#:~:text=Plant%2Dlike%20protists%20a 76 re%20called%20algae.,algae%2C%20euglenids%2C%20and%20dinoflagellates.  Plant-like protists ▪ They resemble plant Contain chloroplasts and produce food & oxygen (Autotrophs) through photosynthesis (Producers) The algal groups that form a clade with the land plants include the glaucophytes, the red algae, and the green algae. All members of the clade share a primary plastid. It was from a common ancestor of these protists that the land plants evolved (the closest relatives of land plants). Green algae contain the same carotenoids and chlorophyll a and b as land plants, whereas other algae have different accessory pigments and types of chlorophyll molecules in addition to chlorophyll a. Both green algae and land plants also store carbohydrates as starch. ▪ They are quite different from plant Although not plants They lack many other structures of true plants. For example, algae do not themselves, algae were probably the ancestors of have roots, stems, or leaves. Some algae also differ from plants in being plants motile (move with pseudopods or flagella). https://slideplayer.com/slide/12735498/ 77 https://www.digitalatlasofancientlife.org/learn/embryophytes/overview_plant_relationships/ https://bio.libretexts.org/Courses/Lumen_Learning/Fundamentals_of_Biology_I_(Lumen)/07%3A_Module_4-_Protists/7.08%3A_Groups_of_Protists  Structure of Cell Wall Phylum Pigments Food Storage Nutritions Example Thallus composition Unicellular Chlorella Chlorophyta Chlorophyll a & b Mainly Filamentous Carotenoids Starch Photoautotrophs Spirogyra (Green Algae) Cellulose Multicellular Ulva Chlorophyll a & c Phaeophyta Cellulose- Multicellular Carotenoids Fucoxanthin Laminarin Photoautotrophs Sargassum (Brown Algae) Peridinin Algin Rhodophyta Chlorophyll a & d Cellulose Multicellular Floridian Starch Photoautotrophs Corallina (Red Algae) Phycobilins Carotenoid CaCO3 Jania Bacillariophyta Unicellular Some Chlorophyll a & c Oil & Chrysolaminarin Pectin Diatoms Carotenoids Xanthophyll (a polymer of glucose) Photoautotrophs (Diatoms) Colonial SiO2 Chrysophyta Unicellular Some Chlorophyll a & c Oil & Chrysolaminarin Chrysamoeba Xanthophyll Carotenoids (a polymer of glucose) Cellulose (Golden Algae) Colonial Photoautotrophs Xanthophyta Chrysolaminarin or unicellular Chlorophyll a & c Leucosin (oil, lipids, Cellulose Vaucheria yellow-green algae multicellular Xanthophyll Carotenoids and glucose polymer) Photoautotrophs Pyrrophyta Chlorophyll a & c Starch ½ Autotrophs and ½ Unicellular Cellulose Peridium (Dinoflagellates) Carotenoids and fat Heterotrophs Autotrophs, but can be Euglenophyta Chlorophyll a & b No Cell Wall Unicellular Paramylon Heterotrophs (if sun is Euglena (Euglenoids) Carotenoids Xanthophyll but Pellicle not available) Different kind & shapes of Algae  Chlorophyta / green algae Chlorophyta is a taxonomic group (a phylum) comprised of green algae that live in marine habitats. It is a large grouping of algae, some of them are found in freshwater and on land. Some species have even become adapted to thriving in extreme environments, such as deserts, arctic regions, and hypersaline habitats. They are eukaryotic photosynthetic organisms that possess chloroplasts and photosynthetic pigments such as chlorophyll a and b, carotene, and xanthophylls Their carbohydrate food reserves are in the form of starch. Members are unicellular, multicellular, colonial, and flagellates Green algae reproduce both asexually, by fragmentation or dispersal of spores, or sexually, by producing gametes that fuse during fertilization The Ancestors of Land Plants… Were most likely some type of Green Algae Green algae split into two groups, the chlorophytes and the charophytes. The charophytes are the nearest living algal relative to plants (It is likely that plants and charophytes share a common ancestor). ✓ The chlorophytes include Chlorella, Chlamydomonas, Ulva, and Volvox. ✓ The charophytes include Chara 80  Rhodophyta / Red Algae The red algae are almost exclusively marine. Some are unicellular but most are multicellular, Multicellular forms can be filamentous, leafy, sheet-like, coralloid, or even crust-like. They have true chloroplasts containing chlorophyll a. Like the cyanobacteria. Red pigment (phycoerthine) allows the red algae to photosynthesize at deeper depths than the green. Unlike green algae and plants, red algae store carbohydrates as Floridean starch. The life cycle is one of the most complex life cycles in nature, a haplodiplontic (alternation of generations) life cycle Ex: Polysiphonia, Coralline 81  Economic importance of algae The source of more than half of the world's oxygen through photosynthesis i) Food source 1.Healthy source of carbohydrates, fats, proteins, and vitamins A, B, C, and E. 2.Used as food supplements. 3.Used as fodder to feed livestock such as cattle and chickens 4.The larger algae provide a habitat for fish and other invertebrate animals. ii) Medicines Algae like Coralline is used to treat infections caused by worms. iii) Biological indicator Algae help in checking water pollution. iv) Pisciculture In fish farming, algae help in the production process (Fish used plankton as food). V) Ecology 1. Algae are at the base of the food chain and used by other organisms in the food web 2. Algae are rich in minerals and vitamins. So they are used as fertilizer which helps in the repairing level of nitrogen present in the soil. 82  Protista Fungus-like protists ▪ Molds (Moulds) Fungus-like protists are. ▪ Most use pseudopods, (“false feet”) to move around. ▪ Live in damp watery places ▪ They resemble fungi ✓ Absorb their food from dead organic matter (feeders on decaying organic matter), Heterotrophs – decomposers (nutrition) ✓ They reproduce with spores as fungi do. ▪ They are quite different from fungi ✓ They have cell walls made of cellulose, (fungi have cell walls made of chitin). ✓ Like other protists, they have complicated life cycles with both asexual and sexual reproduction. https://www.nps.gov/articles/000/slime-molds.htm ✓ They are motile during some stages of their life cycle. https://taylorsciencegeeks.weebly.com/blog/fungus-like-p Two major types of fungus-like protists are slime molds and water molds. 83  Slime Moulds The name ‘slime’ comes from the gelatinous appearance of macroscopic slime moulds. ▪ Many of them live as unicellular and small multicellular eukaryotic organisms. ▪ Slime mold name was given to several kinds of unrelated eukaryotic organisms with a life cycle that includes a free-living single-celled stage and the formation of spores. Part of their life they resemble amoebas and at times form mold-like clumps that release spores like fungi. The Plasmodial stage resembles protozoa and Fruiting bodies form spores resembling fungi ▪ They are saprophytic decompose dead organic matter Play key roles in the recycling of organic material ▪ Some are parasitic and found in the roots of some plants. There are two types of slime: Cellular and Acellular slime molds. Acellular slime molds Cellular slime molds Enormous single cells with thousands of Spend most of life as free-living uninucleate nuclei forming a multinucleate plasmodium cell that resembles an amoeba. 84  Water Moulds Many types of microbial growth in water and on moist, humid surfaces are referred to as “water mold.” Growth and buildup in swimming pools, ponds, and pipes. ▪ Water Molds Belong to phylum Oomycota, most of them are small single-celled organisms. ▪ Live in fresh or brackish water or wet soils. ▪ Oomycota" means "egg fungi," and refers to the large round oogonia, or structures containing the female gametes ▪ The water molds resemble other fungi: They have branched filaments and form spores. They are heterotophic, either saprophytic or parasitic - The majority of species are saprotrophic which live on dead or decaying organic matter in water - Parasitic species have caused significant human suffering by destroying crops and fish. ▪ In contrast to fungi: The vegetative state of Oomycetes is diploid, whereas true fungi are haploid The cell wall of oomycetes is made up of a combination of cellulosic compounds, while fungi have chitin. Oomycetes produce hyphae that are nonseptate (coenocytic), i.e. lacking in cross walls. 85  Water Moulds ▪ Reproduction by sexual or asexual Asexually: Oomycetes may germinate directly on the host plant by way of a germ tube Oomycetes can reproduce asexually, by forming a structure called a sporangium or zoosporangium. Inside these sporangia, zoospores are produced with flagella (motile asexual spores), Their flagellum allows the zoospores to move rapidly through the water. Zoospores are used to classify various water mould species. Sexually: Sexual reproduction involves specialized reproductive structures (gametangia) called antheridia and oogonia, where meiosis can occur, and gametes formed. Oogonia produce large cellular structures called oospheres, each containing a haploid nucleus Reproduce sexually, by direct injection of the male nuclei (sperm) into the oogonium. The fusion of gametes (sex cells-non-flagellate) from differentiated sex organs occurs in an oogonium during sexual reproduction resulting in the formation of thick- walled oospores. 86  Slime Molds Water Molds Acellular slime molds (Plasmodial) Myxomycophyta Plasmodial slime mold threads on rotting wood. Cellular Slime Molds Acrasiomycota https://protistaproject.weebly.com/acrasiomycota.html https://www.britannica.com/science/water-mold https://www.myxotropic.org/myxomycetes/ https://bio.libretexts.org/Bookshelves/Botany/A_Photographic_Atlas_for_Botany_(M 87 https://www.nps.gov/articles/000/slime-molds.htm orrow)/04%3A_Protists/4.02%3A_Water_Molds Kingdom Fungi True fungi https://www.biologyexams4u.com/2013/02/kingdom-fungi.html  Fungi The word fungus comes from the Latin word for mushroom The study of fungi is called Mycology Enormous variety of living organisms collectively referred to as Eumycota, or true fungi. Cell Type → Eukaryote Number of Cells → Some unicellular and Most multicellular Cell wall → Thick & rigid layers contain chitin (complex polysaccharides) glucan (not cellulose as in plants) Move → Can not move. Location → Thrive in environments that are moist and slightly acidic. Nutrition → Heterotrophs Parasitic- Saprophytic- Symbiotic Most Fungi are Decomposers Example Mushroom, yeast 89  Fungi Fungi are not capable of photosynthesis.They use complex organic compounds as sources of energy and carbon. Fungi can reproduce by vegetative, asexual, or sexual reproduction. Some fungal organisms multiply only asexually, whereas others undergo both asexual and sexual reproduction. In both sexual and asexual reproduction, fungi produce spores that disperse from the parent organism by either floating in the wind or hitching a ride on an animal. Most fungi produce a large number of spores that are disseminated by the wind. Because of the variety of reproductive methods, the specific structures produced by a fungal for reproduction help to classify it among fungal phyla (subgroups) Fungi often interact with other organisms, forming mutually beneficial or mutualistic associations. Participate in the cycling of nutrients by breaking down organic materials into simple molecules  The Structure Cell walls are made of chitin (complex polysaccharide) The vegetative body of a fungus is called a thallus and can be unicellular or multicellular. Grow as microscopic tubes or filaments called hyphae, hypha is characterized as a tube-like structure with a rigid, filled with cytoplasm, collection of hyphae is called mycelium. The length of the hypha varies in different fungal species The hyphae help to absorb nutrients through their very large surface area The presence of cross walls is an important feature in most of the fungi. These cross walls are called septa (singular septum) some members lack the septa in their hypha called Coenocytic hyphae. The septa of many species have pores, allowing cytoplasm to flow freely from one cell to the next. Cytoplasmic movement within the hypha provides a means to transport of materials. The hyphae help to absorb nutrients through their very large surface area. https://thebiologynotes.com/fungal-structure/ https://preparmy.com/life-science/biology/agriculture/general-characteristics-fungi/ https://www.bio.miami.edu/dana/160/160S22_18.html  Reproduction 1-Vegetative reproduction: It is the type of reproduction that involves the somatic portion of the fungal thallus. It occurs by the following methods: Fragmentation, Budding, Fission, Sclerotia, Rhizomorphs Fragmentation. ▪ Fragmentation occurs when a fungal mycelium separates into pieces, and each component grows into a separate mycelium as a new individual. Fission ▪ The nucleus divides into two daughter nuclei, the cell constricts in the center and divides into two giving rise to new individuals. Budding ▪ The budding is commonly found in Saccharomyces (Unicellular). ▪ The buds arise from the protoplasm of the parent cells and separate into a completely independent entity. https://www.inspiritvr.com/general-bio/protists-and-fungi/fungi-reproduction-study-guide  2-Asexual reproduction In fungi asexual reproduction is more common than sexual reproduction. It is usually repeated several times in a season. Different fungi form different types of spore, Sporangiospore, Conidiospore, Arthrospore, Chlamydospore, Blastospore Fungal species reproduce asexually by the production of spores. There are mainly two types of spores–Exogenous and endogenous. Endogenous spores Such spores may be produced in special sacs, known as sporangia and the spores are known as sporangiospores. Spores may also be motile and, in this case they are called zoospores. Exogenous spores The spores produced externally on the branched or unbranched conidiophores called exogenous spores or conidia. The condiophores may be septate or aseptate. https://www.uobabylon.edu.iq/eprints/publication_1_13183_803.pdf  3-Sexual Reproduction: Sexual spores are fewer in number than asexual spores. Sexual reproduction is occur in all groups of fungi except the Deuteromycetes. Sexual reproduction takes place by fusion of two nuclei originating from two individuals of opposite mating types, generally designated as male and female. Process of sexual reproduction involves three phases: Plasmogamy: fusion of protoplasm Karyogamy: fusion of nucleus (production of a diploid cell, called zygote) Meiosis: reductional nuclear division (restore the hyploid cells) Types of sexual spores, Ascospore, Basidiospore, Zygospore, Oospore. tps://slideplayer.ae/slide/17283354/  Nutrition Fungi cannot synthesize their own food. It starts absorbing the dissolved molecules from other species (from live or dead material). It is known as Heterotrophs. The Fungi get attached to the organic matter and absorb Carbohydrates. Fungi will produce extracellular digestive enzymes to break down insoluble organic matter (carbohydrates and Proteins) and the hyphal walls absorb it into their bodies. (The surface of the rotten fruits became soft. This is because of fungal enzymes). It absorbs and metabolizes various soluble Carbohydrates like Glucose, Fructose, and Sucrose. Also, Fungi have the ability to absorb and process insoluble carbohydrates like cellulose, hemicellulose, and starches along with complex hydrocarbons such as lignin. Many Fungi even absorb Proteins as a source of carbon and nitrogen. Many parasitic Fungi have some specialized features like absorptive organs. This is known as haustoria. Types of Nutrition in Fungi Nutrition Saprotrophic Fungi Fungi obtain food from dead decaying organic matter. (decompose the organic matter) Many saprotrophs have the ability to destructure and destroy giant structures like timber using the digestive enzyme. Parasitic Fungi Fungi live in or on other organisms and get their nutrients from their host. These types of fungi start extracting nutrients from the living cytoplasm. This causes disease and death to the host. Parasitism is a type of symbiotic relationship between organisms of different species in which one, the parasite, benefits from a close association with the other, the host, which is harmed. Symbiotic Fungi The Fungi grows in the other organism, and it does not cause any harmful effects for the living Organism. Both the living Organism and Fungi get mutually benefited. The symbiotic Fungi are of two types. They are mycorrhizae and lichen.  Classification of Fungi (The fungal groups) Kingdom Fungi are classified based on different modes: Mode of nutrition Spore Formation The mode of sexual reproduction Chytrids Zygomycetes Glomeromycetes Ascomycetes Basidiomycetes Deuteromycetes (Lower Fungi) Conjugated fungi (Endomycorrhizal fungi) (Sac Fungi) (Club Fungi) (Imperfect Fungi) The different types of fungal groups Chytrids (lower fungi) - Could just as well be Protists Zygomycetes (conjugated fungi) Glomeromycetes (Arbuscular mycorrhizal) Ascomycetes (sac fungi) Basidiomycetes (club fungi) Deuteromycetes (The Imperfect Fungi) 97  Kingdom Fungi are classified into the following based on the formation of spores: Zygomycetes Basidiomycetes Sexual reproduction by the formation of known as the club fungi, Mushrooms are sexual spores (zygospores) formed by the the most commonly found basidiomycetes fusion of two different cells (+ & -), while the