• In taxonomy, organisms are classified into categories called taxa (singular, taxon). • A Species is given a name consisting of a species name and a Genus (plural, genera) name. A Five-Kingdom Survey For example, the domesticated dog is categorized into the genus Canis and is given the name Canis familiaris. Closely related animals are grouped in the same genus. Thus, the wolf, Canis lupis, and the coyote, Canis latrans, share the same genus with the domesticated dog. The Five Kingdom The Five Kingdom 2 Dr. Abboud ElKichaoui 1 Dr. Abboud ElKichaoui Islamic University- Biology Department Islamic University- Biology Department Mephitis Lutra Canis Felis Canis mephitis lutra familiaris SPECIES catus lupus Genera that share related features are grouped in a Family. (striped (European (domestic (domestic (wolf) cat) skunk) otter) dog) Related families, in turn, are grouped in Orders, which are grouped successively in Classes, Phyla (singular, phylum) (or divisions for fungi and plants), and finally, kingdoms. A good way to remember the successional order of taxa is to remember the phrase “ GENUS Felis Mephitis Lutra Canis Kings Play Chess On Fine Green Sand,” in which each word gives the first letter of each taxon from kingdom to species. FAMILY Felidae Mustelidae Canidae ORDER Carnivora The Five Kingdom The Five Kingdom 4 Dr. Abboud ElKichaoui 3 Dr. Abboud ElKichaoui Islamic University- Biology Department Islamic University- Biology Department Kingdom Monera Five kingdoms are currently used to categorize all organisms. •The single, distinguishing characteristic The characteristics of each of these kingdoms, and important taxa of organisms in the kingdom Monera is within these kingdoms, are described below. that they are prokaryotes. As prokaryotes, they lack nuclei and the various organelles of eukaryotes. •Prokaryotes possess a single “naked” chromosome consisting of a single DNA molecule without the proteins found in eukaryotes. MONERA PROTISTA PLANTAE FUNGI ANIMALIA •Some prokaryotes have plasmids, small circular DNA molecules, in addition to the major chromosome. • •The cell walls of most prokaryotes contain peptidoglycans, a polysaccharide modified with polypeptides. In contrast, the cell walls of plants contain cellulose. The Five Kingdom The Five Kingdom 6 Dr. Abboud ElKichaoui 5 Dr. Abboud ElKichaoui Islamic University- Biology Department Islamic University- Biology Department 1 Currently, many prokaryotes are organized by their mode of Flagella, when present in monerans, consist of the globular protein flagellin nutrition, that is, how they metabolize resources, as follows: arranged in helical chains (not tubulin arranged in 9 + 2 microtubule arrays as in eukaryotes). ﺣرﻛﺔ اﻟﻣﻔﺗﺎح 1. Autotrophs Prokaryotes without flagella move by a corkscrew motion, while still others may exhibit a gliding motion through slimy material that they secrete. ﺣرﻛﺔ اﻧزﻻﻗﯾﺔ .Autotrophs manufacture their own organic compounds To do this, We have: Photoautotrophs use light energy (as in photosynthesis) and Chemoautotrophs use energy obtained from inorganic substances (as in chemosynthesis). Examples of inorganic substances used by chemoautotrophs are: -hydrogen sulfide (H2S), -ammonia (NH3), and -other nitrogen compounds (NO2–, NO3–). The Five Kingdom 8 Dr. Abboud ElKichaoui 7 Islamic University- Biology Department 2. Heterotrophs Another feature important in describing prokaryotes is their Heterotrophs must obtain their energy by consuming organic ability to survive in the presence or absence of oxygen. substances produced by autotrophs. – Obligate aerobes must have oxygen to live. Some heterotrophic bacteria are Parasites, obtaining their energy from the living tissues of a host. – Obligate anaerobes can survive only in the absence of oxygen. Others are Saprobes (or saprophytes), obtaining their energy from dead, decaying matter. Since saprobes contribute to the decay of organic matter, – A facultative anaerobe grows in the presence of oxygen but, when they are called Decomposers. oxygen is absent, can switch to an anaerobic metabolism. Others are Symbiotic obtaining their energy from a symbiotic relationships with their host (Plants, animals act…) The Five Kingdom The Five Kingdom 10 Dr. Abboud ElKichaoui 9 Dr. Abboud ElKichaoui Islamic University- Biology Department Islamic University- Biology Department Archaebacteria Molecular analysis has revealed two distinct groups within the Monera, Archaebacteria are distinguished by these three • The Eubacteria (“true” bacteria) and major features: • The Archaebacteria. 1. Their cell walls lack peptidoglycans. 2. Their ribosomes are more similar to ribosomes of eukaryotes than to those of eubacteria. 3. Their plasma membranes contain lipids that differ from those found EUBACTERIA ARCHAEA in the plasma membranes of all other organisms. Monera The Five Kingdom The Five Kingdom 12 Dr. Abboud ElKichaoui 11 Dr. Abboud ElKichaoui Islamic University- Biology Department Islamic University- Biology Department 2 Eubacteria Various features are used to categorize the Eubacteria, as follows: 1. The principal means by which the eubacteria are categorized is by their mode of nutrition, or how they metabolize resources. 3. Eubacteria are distinguished by their means of motility, whether by flagella, 2. Some eubacteria are distinguished by their ability to produce endospores, gliding, or corkscrew motion. When resistant bodies that contain the genetic material and a small amount of cytoplasm surrounded by a durable wall. flagella are present, they can be apical or posterior, or they can completely cover the cell. Endospore The Five Kingdom The Five Kingdom 14 Dr. Abboud ElKichaoui 13 Dr. Abboud ElKichaoui Islamic University- Biology Department Islamic University- Biology Department 5. The cell wall distinguishes two broad groups of bacteria. Bacteria that stain positive with the Gram stain have a thick 4. Bacteria are classified into one of three shapes: cocci (spherical), bacilli technique (rod shaped), and spirilla (spirals). peptidoglycan cell wall, while Gram-negative bacteria have a thin peptidoglycan wall Gram-positive covered with a layer of lipopolysaccharides. Gram-negative The Five Kingdom 15 Dr. Abboud ElKichaoui Islamic University- Biology Department Some of the more common groups of bacteria follow: Some cyanobacteria have specialized cells called heterocysts that produce nitrogen-fixing enzymes. 1. Cyanobacteria are photosynthetic, using chlorophyll a to capture light energy, splitting H2O, and releasing O2 as do plants. They also contain accessory pigments called phycobilins. The Five Kingdom The Five Kingdom 18 Dr. Abboud ElKichaoui 17 Dr. Abboud ElKichaoui Islamic University- Biology Department Islamic University- Biology Department 3 4. Spirochetes are coiled bacteria that move with a corkscrew motion. Their flagella are internal, positioned within the layers of the cell wall. 2. Chemosynthetic bacteria are autotrophs. Some of these are called nitrifying bacteria because they convert nitrite (NO2–) to nitrate (NO3–). 3. Nitrogen-fixing bacteria are heterotrophs that fix nitrogen. Many of these bacteria have mutualistic relationships with plants; that is, both the bacteria and the host plant benefit from an interdependent relationship. The bacteria live in nodules, specialized structures in plant roots. nodules The Five Kingdom The Five Kingdom 20 Dr. Abboud ElKichaoui 19 Dr. Abboud ElKichaoui Islamic University- Biology Department Islamic University- Biology Department Kingdom Protista A) Algaelike Organisms in this kingdom may be: algaelike, animallike, funguslike, unicellular, or multicellular. Algaelike (or plant-like) members of the Protista all obtain energy by photosynthesis. The Five Kingdom The Five Kingdom 22 Dr. Abboud ElKichaoui 21 Dr. Abboud ElKichaoui Islamic University- Biology Department Islamic University- Biology Department 2. Dinoflagellata, or dinoflagellates, have two flagella. One flagellum is posterior, while the second flagellum is transverse and rests in an encircling mid groove perpendicular to the first flagellum. Some distinguishing characteristics of the phyla follow: 1. Euglenophyta, or euglenoids, have one to three flagella at their apical (leading) end. The Five Kingdom The Five Kingdom 24 Dr. Abboud ElKichaoui 23 Dr. Abboud ElKichaoui Islamic University- Biology Department Islamic University- Biology Department 4 5. Chlorophyta, or green algae, have both chlorophyll a and b, have cellulose cell 3. Chrysophyta, or golden algae, are golden yellow and have one or two apical walls, and store their carbohydrates as starch. There is considerable variation in flagella. sexuality. Plastid 4. Bacillariophyta, or diatoms, have tests (shells) that consist of silica (SiO2). The Five Kingdom The Five Kingdom 26 25 Dr. Abboud ElKichaoui Dr. Abboud ElKichaoui Islamic University- Biology Department Islamic University- Biology Department 6. Phaeophyta, or brown algae, are multicellular and have flagellated sperm cells. Some brown algae are giant seaweeds, or kelps. Because of these various characteristics and evolutionary trends, the Chlorophyta are believed to be the ancestors of plants. The Five Kingdom The Five Kingdom 28 Dr. Abboud ElKichaoui 27 Dr. Abboud ElKichaoui Islamic University- Biology Department Islamic University- Biology Department 7. Rhodophyta, or red algae, B) The protozoa contain red accessory pigments called phycobilins. They are multicellular, and their gametes do not have flagella. The protozoa, or animal-like protists, are heterotrophs. They consume