Diversity: Chapter 1 & 2 Test PDF

Diversity: Chapter 1 & 2 Test Section 1.1: Identifying, Naming, and Classifying Species Characteristics of Living Things: 1. Growth: all living things grow from the inside out 2. Reproduction: limited life span, need to reproduce to replace themselves 3. Adaptation: adapt to enviro...

Diversity: Chapter 1 & 2 Test Section 1.1: Identifying, Naming, and Classifying Species Characteristics of Living Things: 1. Growth: all living things grow from the inside out 2. Reproduction: limited life span, need to reproduce to replace themselves 3. Adaptation: adapt to environment in ways favourable to them 4. Metabolism: use food to provide energy and carry out bodily functions 5. Movement: migration 6. Irritability: response to stimulus 7. Cells: with proteins, lipids, water genetics, + waste Species: a group of organisms that can interbreed in nature and produce fertile offspring - 2 million identified species on Earth (just a fraction actually on earth) - Important to farmers, doctors, aboriginals, everyone, etc. Species Concepts: various definitions of species as scientists have been unable to agree on a single definition of what a species is. 1. Morphological: body shape, size, other structural features - Measurements, descriptions of similar organisms, taking into account change over time Advantages: - Simplicity, widely used, particularly for plants Disadvantages: - Trying to decide how much difference between individuals is enough to separate them to classify 2. Biological: ability to interbreed and produce viable fertile offspring in nature Advantages: - Widely used by scientists Disadvantages: - Cannot be applied in all cases. E.g. when 2 populations physically separated, don’t have opportunity to inbreed and requirement for fertile offspring can't be tested. Not applied to asexually reproducing systems or fossils  3. Phylogenetic: evolutionary relationship among organisms - E.g. prehistoric species branch into 2 different species over time, 2 phylogenetic species Advantages: - Applied to extinct species, considers info about relationships among organism from DNA (used more and more) e.g. classification of pink iguana Disadvantages: - Evolutionary histories are not known for all species Linnaean System: Developed by Carolus Linnaeus: Father of Taxonomy - Credited for Binomial Nomenclature Taxonomy: identifies, names, classifies species based on morphology/natural features Binomial Nomenclature: 2 word Latin name for each species (species name/scientific name) First: Genus (always capitalized, italicized, sometimes abbreviated) Second: Species (always lowercase, italicized) E.g. humans = Homo sapiens (underline for handwritten) Classification: grouping organisms based on set criteria that helps organize and indicate evolutionary relationships Hierarchical Classification: classifying organisms in which species are arranged from most general to most specific Unnested Classification: No higher or lower levels of classification, all groupings are equal (e.g. fruits) Taxonomic Categories Used to Classify Organisms: Rank: level in classification scheme (e.g. phylum or order) Taxon or Taxa: named group of organisms (e.g. phylum Chordata or order Rodentia) *In order from most broad to least* (# of species) *are other sub ranks within e.g. subspecies, infraclasses* Dear: DOMAIN King: KINGDOM Phillip: PHYLUM Came: CLASS Over: ORDER For: FAMILY Good: GENUS Soup: SPECIES Section 1.2: Determining How Species Are Related Ancestor: organism from which other groups of organisms are descended - If two species share much of the same evolutionary history = fairly recent common ancestor - E.g. coyotes, jackals, foxes (Canidae family) can’t retract, pull closer unlike other family of cats. Evidence of Relationships Among Species Giant pandas have characteristics of both bears and racoons, both physiological and DNA evidence placed them closer to bears. Anatomical Evidence of Relationships: Anatomy: structure and form of organisms, including internal systems. E.g. modern birds and dinosaurs (before was thought modern reptiles were closer than birds) However: - Bones with large hollow spaces (reptiles dense bones) - Arrangement of dinosaur bones in hip leg wrist (more similar that reptiles) - Some dinosaur fossils have feathers Another Example: Living Species E.g. bones in whale, bat, horse, human - Look different from outside, similar bone structures on inside, modified for different purposes - Overall arrangement and similarities indicate shared evolutionary history Physiological Evidence of Relationships: Physiology: physical and chemical functions of organisms, including internal processes (like proteins they make) - Proteins determined by organisms genes (coded instructions to make proteins) - Comparing proteins, cells, tissues, among different species determine similarity or difference E.g. Guinea pig and mice - once considered closely related and classified in the same order Rodentia. - Analyzing and comparing several proteins showed significant differences, leading to the reclassification of guinea pigs into a different suborder E.g. horseshoe crab blood proteins more similar related to modern spiders than crabs E.g. DNA: animals and fungi more closely related than plants and fungi E.g. Turkey vulture appears similar to Asian/African vultures, DNA: more closely related to storks DNA Evidence: meant prior classification based on morphological, physiological, and other evidence has to be dramatically restructured, and indicates unexpected relationships. Phylogenetic Trees: branching diagram used to show evolutionary relationships among species. E.g. giant panda bear racoon one - roots/base represent oldest ancestral species - Upper ends of branches represent present day species related to ancestral - Forks in each branch represent points in past which ancestral species split/evolved/changed to become 2 new species E.g. Order Artiodactyla (hooved mammals) Figure 1.12 pg 21 - Artiodactyla typically have an even number of hooved toes on each foot, specialized teeth and digestive system adapted to eat plants. - About 150 members of this order worldwide (e.g. goats, deer, cattle, pigs, oryx, antelope) E.g. Family Bovidae (cows and antelopes have anatomical feature of horns) E.g. Family Cervidae (deer have anatomical features of antlers) Importance of Classification to Tech, Society, Environment - Sources of pharmaceutical drugs/hormones: can narrow search to species closely related to organisms already producing valuable proteins/chemicals. - Tracing transmission of disease through species that share certain genetic characteristics - E.g. Creutzfeldt-Jakob disease can transmission from cows to people - Increasing crop yield and disease resistance in plants by having a knowledge of different taxa and their characteristics - Finding a new species or reclassifying an organism as a separate species environmental implications - E.g. Some African forest elephants were reclassified, and before were protected as they were the same species as bush elephants, worried that other species were no longer protected. *cladograms vid* Section 1.3: Kingdoms and Domains Structural Diversity: biological diversity exhibited in the variety of structural forms in living things from internal cell structure to body morphology - Examining life diversity at species level is impractical, scientists look for higher taxonomic rank The Six Kingdoms: Until 1800’s: only plants and animals 1860’s: + protists 1930’s: + bacteria 1960’s: + fungi 1990’s” + archaea - 2 main cell types significant for classification - Study of cell types and genes led scientists to add domain Two Major Cell Types Prokaryotic: smaller simple type cell that does not have membrane bound nucleus - Most ancient type, still abundant - “Before nucleus” Archaea, Bacteria Eukaryotic: larger complex type cell that has membrane bound nucleus - 1000x larger, more complex - “True nucleus” Protista, Fungi, Plantae, Animalia The Three Domains Scientists found differences between Bacteria and Archaea at genetic/cellular level so great, so elevated to rank higher than kingdom: domain - Remaining kingdoms: Eukarya - Other 4 kingdoms represent Dichotomous Keys: identification tool of a series of two part choices that lead the user to a correct identification. Main Characteristics of Kingdoms: Autotroph: captures energy from sunlight (or non living substances) to convert its own energy yielding food Heterotroph: cannot make own food and gets nutrients and energy from consuming other organisms *Asexual in all kingdoms, sexual only in eukarya* Section 1.4: Classifying Types of Biodiversity Species Diversity: variety and abundance of species in a given area - E.g. within ecosystems like an alpine meadow Genetic Diversity: variety of heritable characteristics (genes) in a population of interbreeding individuals - E.g. patterns on tails of humpback whales Ecosystem Diversity: variety of ecosystems in the biosphere - E.g. variety of ecosystem in Algonquin Park Genetic Diversity E.g. Lack of genetic diversity in populations is key factor in impact of disease - Tasmanian Devils contagious cancer spread, population reduced extensively Gene Pool: genetic diversity within population - Sum of all versions of all the genes in a population - Diversity within species greater than within population because gene pools of separate populations exposed to different environmental conditions, usually contain different combos of different versions of genes Population: group of individuals of the same species in specific area at specific time Genetic Diversity Provides Resistance to Disease - If none individuals of population have ability to survive disease, entire population eliminated, could lead to extinction of species - Also allows populations and species to survive changing environmental conditions (e.g. resource availability, climate change, predator population, non-native species) Genetic Diversity Supports Conservation Biology - E.g. Florida panthers population reduced to between 30-50 individuals (lack of genetic diversity) - Recovery plan: introduced 8 female panthers from Texas panthers, population rose to 100 Ecosystem Diversity Largest Scale (smallest = genetic) - Ecosystems: biotic and abiotic factors - Biotic: interacting populations of species - Abiotic: altitude, geology, soil nutrients, climate, light levels - Because of diversity of relationships among organisms and variety of abiotic factors, Earth’s surface highly varied physically/chemically, rich ecosystem diversity - Ecosystems can range in size from small plant on other plant to tropical rainforest Ecosystem Services Benefits experienced by organisms (incl. humans) which are provided by sustainable ecosystems, so we protect them - E.g. wetlands - Storing water (avoid floods), filtering water (avoid pollutants), provide habitat - Other examples: Ecosystem Function and Species Diversity Ecosystems exhibit resilience Resilience: ability of the ecosystem to remain functional and stable in the presence of disturbances to its parts. - E.g. experiment using many growing plots each with specific # of native plant species - More species present in plot, more efficient the ecosystem - Plots with more native species produced more biomas, more trapped CO2 - Consumed more nitrate (toxic in high quantity)  -More diverse plots able to resist invasion of non native species and reduced disease Ecosystem Services and Human Actions Sometimes humans make changes to enhance the services of the ecosystem. E.g. wildlife officials stock lake with fish to provide recreation for fishing enthusiasts - Reduced population of several amphibian and variety of aquatic insect species - These species must now compete with non native trout (top predators) for food - E.g. widespread introduction of smallmouth bass in Ontario lakes increased fishing, but loss of natives like stickleback and dace. *chapter 1 review* Section 2.1: A Microscopic Look at Life’s Organization *Unicellular organisms: structural diversity exists at cellular level* Viruses: structure contains strands of DNA or RNA surrounded by a protective protein coat; can’t live independently outside of cells *do not fulfill all criteria of life, but some* - Functionally dependent on internal workings of cells - Must invade cells and use host cell machinery for survival and reproduction - Not cellular: no cytoplasm/membrane bound organelles - Cause disease, infection, food shortages, illness, used in biotech to clone genes Evidence Viruses are Non-Living: - Do not grow or carry out respiration - Only contain one kind of nucleic acid - Contain only few enzymes - No cellular organization Evidence Viruses are Living: - Contain one nucleic acid - Can replicate (requiring a living cell) - Can evolve Classifying Viruses Not part of classification system of life Size and Shape of Capsid: protein coat that surrounds genetic material (DNA or RNA) of virus - + lipid membrane in some viruses “enveloped” or “naked” surrounding protein coat - E.g. HIV = spherical, POLIO = small crystals 20 sides, tobacco mosaic = cylindrical, T4 Bacteriophage = infects bacteria, distinct head and tail region Reproduction in Viruses Do not reproduce by cell division, but replication within host cell (pro/euk) - Copies assembled by host cell inside it Lytic Cycle: replication process in viruses which viruses genetic material uses copying machinery of host cells to make new viruses Lysogenic Cycle: replication process in viruses which viral DNA enters host cell’s chromosome, may remain dormant and later activate and instruct host cell to produce more viruses *video* In the lytic cycle: - The entire replication process occurs in the cytoplasm of the host cell. - The virus’s genetic material enters the host cell, and the cell replicates the viral DNA or RNA. - The host cell makes new capsids and assembles new viral particles. The host cell lyses, or breaks open, and the new viruses leave the cell. In the lysogenic cycle: - The virus’s genetic material enters the host cell’s chromosome. In many cases, the genes are not activated until later. - Activation results in a continuation of the lytic cycle. Viruses and Disease Lyctic Cycle: newly formed viruses burst from the host cell, usually killing it, new viruses in multicellular cells infect neighbouring cells causing damage. Lysogenic Cycle: effects on host may not be immediate - HIV: retrovirus Retrovirus: enzyme called reverse transcriptase: causes host cell to copy viral RNA into DNA, and enters chromosomes of host cell so it is a provirus - When host cell divides by mitosis, replicates provirus along with own DNA, so every descendant of host cell carries copy of provirus in chromosomes - Can continue for years without harm, but can separate from host chromosomes and complete damaging lytic cycle Patterns of Disease E.g. herpes simplex virus causes cold sores in humans - May appear and disappear on skin throughout lifetime - Appear when viral cycle destroys cells, disappear when virus is in provirus stage, trigger unknown E.g. HIV - Forms provirus in host cell chromosomes, also produces small # new viruses while cell functions normally - Why people may test + for HIV and still remain healthy for ages (only if infection spreads more for symptoms) - Symptoms from infections by other other micro orgs because HIV destroyed body’s immune system fighters other diseases Prions: Non Viral Disease Causing Agents Infectious particle that causes damage to nerve cells in the brain, and that appears to consist mostly or entirely of a single protein. - Only known disease causing agents that lack RNA or DNA - Diseases result when prions convert from normal form into harmful particles w. Same chemical composition but different molecular shape Viruses and Biotechnology - Viruses useful tools for genetic engineers because they direct the activity of host cell DNA - E.g. to make copy of gene, insert gene into genetic material of virus, virus enter host cell, directs cell to make multiple copies, each new virus in each new cell has added gene needed to be copied. Viruses and Human Health Destruction of host cell causes symptoms of the disease - Viruses are NOT destroyed by Antibiotics - Vaccines are inactive forms of viruses that are injected so that the body can produce antibodies. - These antibodies allow for the body to become immune to the disease. *immunization and passive immunity* Section 2.2: Comparing Bacteria and Archaea Types of Archaea: Methanogens, Halophiles, Thermophiles Methanogens: - Methane producing - Live below surfaces in swamps, bogs, marshes and sewage treatment plants - Use CO2 N2 or HS for energy, Expel CH4 as a waste product Methanogenesis: anaerobic process that occurs in environments that lack oxygen, often final stage of decomposition, methanogens live in digestive tracts of animals like cattle Halophiles: - Salt loving archaea - Live in salt pools, evaporation ponds etc. - Live in salt concentrations of 20% or greater (normal seawater is 3.5%) Thermophiles: - Extreme heat environments - Live in hot sulfur springs - Use sulfur for energy - Some live near volcanoes - Grow best at 80 C + temperatures Bacteria (Photosynthesis) - Cell walls made of peptidoglycan (Archaea lack) - Photosynthetic bacteria = cyanobacteria - Like green plants, use solar energy to convert CO2 and H2O to sugar using oxygen - These bacteria abundant in both fresh and saltwater, much of atmospheric oxygen on earth - Some archaea use energy in sunlight as metabolic energy though. Gram Staining Staining technique used to identify bacteria - Gram positive: thick peptidoglycan wall - Retain the crystal-violet gram stain - Gram negative: thin peptidoglycan wall - Crystal violet stain washes out, counterstained red/pink Comparing Morphology Most common forms in both are spheres and rods Cocci: spherical Bacilli: rod Spirilli: spiral Other: cubes, pyramids, rods with star shaped, plates, changeable shapes Prefixes: mono - single, diplo - pairs, strepto - chains, staphylo - clumps Aggregations: Cells Grouped Together Streptococcus: chains of spheres Streptobacillus: rod shaped chains *Most carry out photosynthesis, few cells convert nitrogen into environment into usable forms* Comparing Habitats Bacteria and Archaea able to occupy diverse habitats because of the way they obtain nutrients - Both archaea and bacteria occupy environments with oxygen (aerobic) and without oxygen (anaerobic) Extremophiles: Archaea’s ability to live in extreme environments (Can be mesophilic archaea) 1. Deep Sea Vents and Hot Springs (Thermophile)  2. Volcanic Crater Lakes and Mine Drainage Lakes (Acidophile) 3. Salt Lakes and Inland Seas (Halophile) Mesophiles: Bacteria occupying environments with moderate conditions (can be extremophilic bacteria) Comparing Reproduction No mitosis/meiosis as they lack nuclei, but they are prokaryotes that are contained in single chromosomes within cells. Binary Fission: asexual form used by most prokaryotes and some eukaryotic organelle where the cell divides into 2 genetically identical cells or organelles. - When cell reaches certain size, it elongates, separating og and copy chromosome - Cell builds partition called septum and og cell splits smaller Conjugation: New Genetic Content Transfer or exchange of genetic material involving two cells - Increase genetic variation, better adaptation - One cell links to another through bridging structure and transfers all or part of its chromosomes to other - Unlike asexual, this results in new genetic content - Receiving cell undergoes binary fission then for same genetic make up Plasmids: Small Loops of DNA - Separate from the main chromosome that contains genes and different - Can split from chromosome and rejoin it and transfer - Important for genetic recombo in prokaryotes Endospores: Protecting Genetic Material A dormant bacterial cell able to survive for long periods during extreme conditions (not in archaea) - E.g. high temps, freezing, radiation, toxic chemicals - When suitable conditions, germinates back into active bacterium - Not yet seen in archaea Bacteria and Human Health 1. Clostridium Botulinum: anaerobic causes illness in humans - Found in soil, forms endospores resistant to heat, produces toxic products causing nausea or death - Not dangerous unless trapped with food for period of time 2. Streptococcus pyogenes: gram positive causing strep throat infections 3. Streptococcus mutans: gram positive causing tooth decay Trillions of bacteria live in your gut: (symbiosis) – Help the immune system, Provide vitamins, Prevent growth of pathogenic bacteria, Some prevent tumor growth Bacteria and the Environment Bacteria (decomposers): break down organic materials releasing carbon, hydrogen and others for use - Nutrient cycles depend on chemicals excreted - E.g. cyanobacteria major producers of oxygen through photosynthesis and convert atmospheric nitrogen to usable (prob first orgs on Earth to carry it out) Archaea and Biotechnology Biotech depend on enzymes for processes like DNA analysis and diagnosis for disease - Most enzymes break down and stop working in extremes, archaeon enzymes do not - E.g. PCR (polymerase chain reaction): from archaea can withstand high temperatures to produce millions of copies of DNA, now is automated Section 2.3: Eukaryotic Evolution and Diversity Endosymbiosis: theory explaining how eukaryotic cells evolved from symbiotic relationships between two or more prokaryotic cells - One cell engulfs different type of cell, engulfed cell survives and becomes an internal part of the engulfing cell - Organelles are ancestors of once free-living prokaryotes - Chloroplast: photosynthetic eukaryotes converting solar energy to sugar - Mitochondria: extracts energy stored in sugar so cell can do work *vid* Chloroplasts and Mitochondria Were once small free living prokaryotes, remained intact rather than being digested, and continued to do inside cells what they had previously done outside Endosymbiont: cell engulfed by another Host Cell: cell that engulfs another Evidence Supporting Theory: - Membranes of both are similar to living prokaryotes - Ribosomes more similar to prokaryotic than eukaryotic - Reproduce by binary fission within cell - Each contains circular chromosome - Gene sequences match living - Chloroplast match modern cyanobacteria (photosynthetic both) Multicellularity Endosymbiosis itself doesn’t account for multicellularity  - Aggregations of prokaryotes considered to be collections of individuals, not one individual (often clones tho) - Based on fossil evidence red algae on rocks in arctic Canada, think that large complex eukaryotes developed 550 mil ago and first multicellular 1.2-1.5 bill ago - First multicellular organisms arose from colonies created by dividing individual cells - Genes within these cells contained instructions for some to become specialized - E.g. some groups became specialized to absorb nutrients, other to gather info Life Cycles and Reproduction Eukaryotes more reproductive diversity as well - Some use multiple fission (multiple copies made of a cell more or less at one time) - Cell div not same as reproduction esp in multicellular individuals - E.g. humans: sexual reproduction (common among euk), but unique to eukaryotes Section 2.4: Protists: The Unicellular Eukaryotes Protists: eukaryotic, usually unicellular, not fungus, plant, animal Characteristics of Protists: - Most unicellular (don’t fit into other kingdoms) - Most aquatic, or wet environment organisms - Aerobic metabolism (use O2) - Reproduce asexually or sexually Algae? - Some plants, some protists - Red green plants, brown protists Animal Like Protists *just read slide/textbook*