Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Biodiversity Biodiversity ● ● ● ● Contracted form of “biological diversity” Best defined as “the variety of all living things” Qualified by physical appearance, genetic similarities, and habitats Quantified by taxonomy classifications Bacteria, Protozoans (Protists), & Fungi Bacteria ● Prokaryotic cells – ● Lack organelles surrounded by a membrane Found everywhere – Air – Water – Soil – In & on other living things Bacteria ● ● Cell Shapes – Bacillus (rod-shaped) – Coccus (sphericalshaped) – Spirillum (spiralshaped) Cell Size – Measured in micrometers Bacteria ● ● Internal Cell Structures – DNA (nucleiod region) – Ribosomes (protein factories) – Cytoplasm External Cell Structures – Cell wall (protection) – Capsule (protection/nutrient source) – Pili (reproduction) – Flagella (movement) Bacteria ● Reproduction – Asexual ● Binary fission – ● One cell divides into two cells Spore formation – “DNA” vault formed to allow the cells to survive environmental hardships Bacteria ● Reproduction – Sexual ● Conjugation – ● Transformation – ● Transfer of genes between living cells using the pili Uptake of free DNA (from dead bacterial cells) Transduction – Transfer of genes from one living bacteria to another using a virus as the “middle man” Bacteria ● ● Metabolism – Fermentation (anaerobic respiration) – Aerobic respiration – Fermentation – Photosynthesis Ecological Importance – Cycling nutrients – Decomposing – Beneficial/Harmful growth in and on other living things Protozoans (Protists) ● Eukaryotic Cells – ● ● Contain organelles surrounded by membranes Found mostly in watery environments Neither bacteria, fungi, plants, nor animals Protozoans (Protists) ● Amoebas – “The Blob” – Move by pseudopods – Nutrients acquired by phagocytosis Protozoans (Protists) ● Flagellated Protozoans – Move by flagella – Euglena ● ● Nutrients acquired by photosynthesis “Red spot” – ● Photoreceptor that guides the cell to light Reproduces by longitudinal binary fission Protozoans (Protists) ● Ciliated Protozoans – Move by cilia – Paramecium ● Pellicle – ● Chitin-like protein to stiffen the cell membrane so as to resist swelling from diffusion of water into the cell Contractile vacuole – Organelle which pumps excess water out of the cell to help preserve cell integrity Protozoans (Protists) ● Sporazoans – Lack cilia, flagella and pseudopods – Apical complex of organelles at anterior of the cell helps penetrate the host ● “Apicomplexans” – Sexual and asexual reproduction seen – Many are parasitic ● ● Cryptosporidium, Toxoplasma, and Plasmodium are noted genera Important in human diseases – – Malaria African sleeping sickness Fungi ● Eukaryotic cells – ● ● ● ● ● Cell organelles surrounded by a membrane Structurally plant-like; genetically animal-like Important decomposers Often form symbiotic relationships with other living things Important pathogens (diseaseproducing) organisms Commercially beneficial to humans General Characteristics of Fungi ● Morphology – Hyphae ● filamentous fungal cells – – – – – Mycelium ● – Septated Non-septated Cell walls contain chitin Reproductive structures develop from the hyphae to produce spores Mass of hyphae Yeast ● Single cell stage of most all fungi General Characteristics of Fungi ● Mode of Nutrition – Chemoheterotrophs ● ● – Fungi produce digestive enzymes which act extracellularly Fungi then absorb the digested foods to be utilized internally Fungi are therefore decomposers General Characteristics of Fungi ● Growth Factors – Most are aerobic – Optimum temperature ● ● ● Most normally grow best @ 25 degrees C Pathogens @ 37 degrees C Some prefer colder temperatures – Acidity requirement varies but usually encourages growth – Mutualism ● ● Benefits to fungus and its ‘partner’ Mycorrhizal fungi – – Plant symbyotes Nodules on soybean roots General Characteristics of Fungi ● Reproduction – Asexual ● Spore formation – ● Fragmentation – ● Exospores formed on special reproductive bodies outside the hyphae Parts of the hyphae break off the filament and germinate into new hyphae Budding – Occurs in yeasts General Characteristics of Fungi ● Reproduction – Sexual ● Heterokaryon formation – ● ● – Nuclei of different ‘mating types’ combine into a diploid cell (heterokaryon) Diploid cell divides by meiosis to the haploid state Spores form from the haploid cells Advantages ● Different genetic combinations allow for possible improved survivability Fungi Classification Zygomycota (Zygomycetes) ● ● ● ● ● Terrestrial fungi Decompose plants and animals Non-septated hyphae Zygospores produced by sporangia, bulbous asexual reproductive structures Rhizopus, the black bread mold Ascomycota (Ascomycetes) ● Terrestrial fungi ● Some symbiotic – ● ● ● ● Lichens (fungus and algae) Some plant pathogens Molds, mildews, and morels Conidia (ascospores) produced in the ascus (“sac”) “Sac Fungi” Basidiomycota (Basidiomycetes) ● ● ● Terrestrial fungi Mushrooms, bracket fungi, puffballs, stinkhorms, smuts, rusts – Some edible – Some very poisonous Some Pathogens – ● ● Rust and smut plant diseases Basidiospores produced on the basidia of the basidiocarp “Club Fungi” Deuteromycota (Deuteromycetes) ● ● “Imperfect fungi” – No sexual reproduction has been observed – Sexual reproduction is probable but hasn’t yet been observed Human pathogenic fungi – Candida albicans ● – Candidiasis (“thrush”) Dermatophytosis (Fungal infections of the skin) Deuteromycota (Deuteromycetes) ● Human pathogenic fungi – Dermatophytosis (Fungal infections of the skin) ● ● Tinea pedis Onychomycosis Deuteromycota (Deuteromycetes) ● ● Fungal infections in any part of the body Aspergillosis (Aspergillus sp.) – ‘Fungal ball’ of mycelium in the lungs – Otomycosis “ear fungus” – Some produce mycotoxins – Aflatoxins ● ● ● induces cancer especially in the liver. Ergot – Fungi that commonly grow on rye – Produce alkaloids which cause ergotism if ingested – Consumption results in numbness,psycosis, seizure, paralysis – Links to the Plague and Salem witch trials LSD is a derivative of ergot