Biodiversity and the Interconnectedness of Life
Unit 3 QCAA Biology
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Biodiversity and the Interconnectedness of Life - Details
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| 🇬🇧 | 🇬🇧 |
| Biodiversity | Variety of living things within a given area, ecosystem or habitat |
| Ecosystem | A community of living things and their physical environment (abiotic and biotic factors) |
| Genetic Diversity | Variation in genetics witihin one species |
| Diversity in Ecosystems | Geographic areas may also be described in terms of biodiversity [i.e., many ecosystems = more diverse] |
| Ecosystem | Biological community of interacting organisms and their physical environment through which energy flows and matter is recycled |
| Biome | A large region of Earth that has a certain climate and certain types of living things: described by dominant vegetation, often containing multiple ecosystems |
| 6 Types of Biomes | Marine Desert Forest Grassland/Savannah Freshwater Tundra |
| Community | All living things in one area |
| Species Richness | Number of species counted in a sampling process |
| Strengths and Limitations of species richness | Strengths: - Total no. of species; large no. indicates higher biodiversity Limitations: - No indication of how common a single species is - Does not consider the evenness of species |
| Relative species abundance/evenness | Number of each species counted in proportion to other species sampled: one species in relation to the total population |
| Strengths and Limitations of species evenness | Strengths: - Dominance of a species can be identified (how common a species is) Limitations: - Does not account for size of individuals (hard to distinguish different species when they're very small) - No indication of the distribution of a species over the area |
| Percentage Cover | Used to determine the percentage of each quadrat a species occupies. Useful for small organisms, plants and canopy covers. |
| Percentage Frequency | Percentage of quadrats in which a species is found. This is useful since it considers both evenness of a species' distribution, as well as abundance |
| Random Sampling | Process of unbias quadrat throwing |
| Simpson's Diversity Index | Index for calculating biodiversity in an ecosystem - combines all techniques |
| 3 Types of Spatial Orientation | Uniform Distribution: Regular spread of the same species Clumped Distribution: Very common Random Distribution: Uncommon |
| Temporal variation over a day | Nocturnal/Diurnal [Night/Day] Intertidal Zones experience temporal changes in a day |
| Temporal variation over a year | Migratory seasons, change of abiotic factors, seasonal plants, hibernation |
| Abiotic factors | Non-Living conditions - change over space and time [Temperature, rainfall, soil type pH, availability of sunlight could change vertically or throughout a year] |
| Limiting factors / Tolerance levels | Abiotic or biotic factors which limit the population growth of species [Abiotic: available nutrients, food, temp, shelter, pH] [Biotic: Predators, availability of mates, disease] |
| Taxa | Kingdom Phylum Class Order Family Genus Species [Katy Perry Comes Over For Great Sex] |
| Binomial Nomenclature | Generic Epithet: First in name - name of genus [always capitalised] Specific Epithet: Second name - name of species [always lowercase] |
| Dichotomous Key | A series of paired statements or clues about features or characteristics, providing a stepwise guide toward identifying each entity |
| Reproduction Classification | Egg-Laying: Oviparous [Chickens, Platypus] Egg inside mother: Oviviparous [Sharks, Fish] Live Birth: Viviparous [Humans, Elephants] |
| R/K Selection Theory | R-selected species: Produce a lot of young, have little parental care, reach sexual maturity early and have short gestation. [r for Rabbit or Rat] K-selected species: Produce few young, lots of parental investment/care, sexual maturity developed over longer duration [K for Kayan or Kangaroo] |
| Molecular Classification | Gene sequences used to classify organisms. Similar genetic sequences indicate the organisms are more closely related. |
| Specht's Ecosystem Classification | Measurement of the percent cover of the tallest stratum, using this and the type/height of the tallest stratum |
| Clade | Phylogenetic group including all the descendents from a common descendent |
| Assumptions of Cladistics | - Any group of living things are related by a common ancestor - Lineages only bifurcate - Changes occur in every lineage over time |
| Monophyletic Group | Clade including all common descendents of an ancestor |
| Paraphyletic Group | Group including some but not all descendents from a common ancestor |
| Polyphyletic Group | Group of similar organisms which do not share a directly common ancestor |
| Phylogenetic Tree | Diagram representing the evolutionary steps of a species |
| Difference between Phylogram and Cladogram | Phylogenetic tree represents the relation of different organisms relative to evolutionary time along with the amount of variations occurring within that time. Cladogram only represents the common ancestral relationships between organisms |
| Protein Relatedness | Comparison of amino acid sequences in proteins to identify similarity, even across distantly related species. [Fewer differences between organism's protein amino acid sequences then there are between nucleotide sequences since DNA changes do not always result in amino acid mutation] |
| DNA Hybridisation | Single-stranded DNA absorbs UV light, double-stranded doesn't since DNA separates at 87°C [every 1°C difference under 87°C and separation is a 1% difference] |
| Biological Definition of Species | Group of organisms which can mate with each other and produce viable offspring [Hybrids are NOT species as they are infertile (Male donkey + Female Horse = Mule, Zebra + Donkey = Zonkey, Lion + Tiger = Liger)] |
| Flaws in the Biological Definition of Species | Asexual Reproduction: No mating occurs, however, bacteria are still considered as species Extinct Organisms: Mating between some species is unknown |
| Morphological Definition of Species | Characteristics of physical form such as shape, size, the presence/absence of physical features |
| Phylogenetic Definition of Species | Trace and comparison of DNA |
| Interspecific Competition | Both species are harmed: Species competing/fighting for limited resources |
| Predation | A species benefits whilst the other is harmed: Predator kills and eats another organism |
| Micro-predation | A species benefits whilst the other is harmed: Predator kills and eats part of another organism |
| Symbiosis | An ecological relationship in which two species live together in close association with eachother |
| Parasition | Symbiotic relationship in which a parasite benefits at the expense of the host - parasite does not aim to kill the host [Ticks, Diseases] |
| Mutualism | Species association wherein both parties benefit [Clownfish with sea anemone] |
| Commensalism | Symbiotic relationship in which one species benefits and the other is not benefited nor harmed [Bird's nest in a tree] |
| Amensalism | Symbiotic relationship wherein one species benefits and the other neither benefits nor is harmed |
| Ecosystem | Community of living organisms together in an environment |
| Habitat | Natural home of an organism: includes all the organism's requirements |
| Macrohabitat | Large scale place in which a species lives, providing needs such as food, water and conditions for reproduction [City/Town] |
| Microhabitat | Immediate, small scale place in which a species lives [Suburb/Street] |
| Management Requirements | Classification of ecosystems allows ecologists to plan and manage other ecosystems based on what has been learned in other ecosystems of the same type |
| Climax Communities | Take many years to grow, must be managed meticulously |
| Soils | Become less productive if not managed appropriately. Damaged easily, plants are sensitive to changes in the soil |
| Old growth forests | Climax communities which take many years to establish. Managed for tourism and preservation of the system |
| Coral Reefs | Balance conservation with tourism. Ecosystem can be damaged by certain practices [pollution, sunscreen damages coral] |
| Stratified Sampling | Sampling technique wherein an ecosystem is divided into strata/zones, each stratum is randomly selected |
| Minimising Sampling Bias | - Large number of samples - Random placement of quadrats across a strata using a number generator - Specific rules set before sampling [i.e., if an organism only half in the quadrat counts] - Use of calibrated instruments |
| Autotrophs | Able to convert inorganic compounds via photosynthesis and chemosynthesis, producing glucose and water using sunlight's energy |
| Photosynthesis | Process by which plants use sunlight, water, and carbon dioxide to create oxygen and energy in the form of sugar. [6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂] |
| Biomass | The dry-weight of all organic molecules in an organsim [expressed as g/m²] |
| Primary Productivity | Biomass produced by an autotroph |
| Gross Productivity | Overall rate of energy capture or the energy that goes into an organism before any is used |
| Net Productivity | Energy/Biomass left over after metabolic activity [Muscle gain/growth of a tree: ways to store excess after metabolic survival] |
| Heterotrophs | An organism which cannot manufacture its own food instead it obtains energy/food from consuming other organic substances [plants/animals] |
| Trophic Levels | Grouping of organisms within an ecosystem whose food is the same number of steps removed from producers Tertiary Consumer: Secondary Predator [Least Biomass] Secondary Consumer: Primary Predator Primary Consumer: Herbivore Producer [Most Biomass] Sun |
| Photosynthetic Efficiency | Fraction of the light from the sun reaches the plant which converts it to chemical energy via photosynthesis [50% of sunlight falls within the light range which chloroplasts can use; 50% of sunlight used for biomass] ~90% of energy is lost as heat at each consumer trophic level → ~10% of the energy entering a trophic level is available for the next trophic level [Reason for limited trophic levels: only ~0.1% of the energy in an ecosystem is converted to biomass at the top trophic level] |
| Food Chain | Diagram showing flow of energy through an ecosystem - arrow shows energy flow from one to another |
| Food Web | Many interconnected food chains |
| Energy Pyramid | Shows percentage of energy flowing onto the next trophic level, decomposers and heat/respiration |
| Biomass Pyramid | Total biomass of organisms at each trophic level |
| Hydrologic Cycle Steps | Precipitation Evaporation Transpiration Condensation Runoff [People Eat Trays Containing Rice] |
| Precipitation | Rain/Hail/Snow: Water falling onto the ground |
| Evaporation | Water evaporating back into the atmosphere |
| Sublimation | Evaporation of snow into the atmosphere |
| Transpiration | Release of water from plants into the atmosphere |
| Condensation | Formation of aqueous water in the atmosphere |
| Infiltration | Process by which water moves down into soil |
| Percolation | Process by which water enters the water table/aquifiers |
| Runoff | Precipitation which doesn't soak, instead moves toward streams |
| Carbon Cycle | Biogeochemical cycle by which carbon is exchanged among the biosphere, pedosphere, geosphere, hydrosphere and atmosphere Photosynthesis Respiration Decomposition Burning [Playful Raccoons Digest Burritos] |
| Photosynthesis | Formation of organic molecules by turning CO₂ into glucose |
| Respiration | Conversion of ATP/energy releasing CO₂ into the atmosphere and respiration of microbes |
| Decomposition | The break down of organic matter → soil carbon formed, fossil fuels made. |
| Burning | Burning fossil fuels → releasing CO₂ into the atmosphere |
| Nitrogen Cycle | Fixation Ammonification Nitrification Assimilation Denitrification [Fruity African Negros Ate Dominos] |
| Fixation | Builiding NH₃ from gaseous N₂ via bacteria in the nodules of certain plants or lighting |
| Ammonification | Conversion of organic nitrogen compounds (like proteins and nucleic acids) into ammonia (NH₃) and ammonium ions ([NH₄]⁺) by decomposer microorganisms |
| Nitrification | Biological conversion of ammonia (NH₃) to nitrite (NO₂⁻) and then to nitrate (NO₃⁻) by specific bacteria |
| Assimilation | Inorganic NH₃ is built into organic compounds [amino acids] |
| Denitrification | Bacteria convert NO⁻ ₃ into N₂ |
| Fundamental Niche | Full range of environmental conditions that a species can occupy with no limiting factors to constrain their populations |
| Realised Niche | The actual range of environmental conditions occupied by the species |
| Competitive Exclusion | When 2 species occupy the same niche, 1species (A) will out-compete the other (B)→ forcing B to die out [The complete removal of one species from its habitat] |
| Resource Partitioning | When 2 species occupy the same fundamental niche, they will have evolved to take advantage of different "slices" [Temporal, area or technique] of that niche [allows for co-existence] |
| Niche | The ecological role a species plays in a community |
| Keystone Species | A plant or animal which plays a unique and crucial role in the function of an ecosystem [a species that has a disproportionately large effect on its natural environment relative to its abundance] [Southern Cassowary travels lengthy distances spreading seeds which form the rainforest. Beavers dam rivers to make pools and wetlands that become habitats for a wide diversity of species.] |
| Carrying Capacity | The maximum number of individuals of a species which the ecosystem can support: mediated by limiting factors |