TERMS Flashcards
Scientific control
- Experiment/observation designed to minimise effect of variable other than independent variable
- Increases reliability of results, often through comparison between control measurements + other measurement
Replicate
Repetition of a test or complete experiment
Cell wall
- Structural layer surrounding some type of cells, just outside cell membrane
- Can be tough, flexible + rigid
- Provides cell with structural support + protection
- Acts as filtering mechanism
Cell membrane
Semipermeable membrane surrounding cytoplasm of cell
Nucleus
- Organelle found in eukaryotic cells
- Enclosed in nuclear membrane
- Contains majority of cell’s genetic materials
- Material is organised as DNA molecules, with proteins to form chromosomes
Chromosome
- Threadlike structure of nucleic acids + proteins in nucleus of most living cells
- Carrying genetic info -> genes
Ribosomes
- Minute particle made up of RNA + proteins found in nucleus of most living cells
- Bind mRNA + tRNA to synthesise polypeptides + proteins
Golgi
- Membrane-bound organelle found in eukaryotic cell
- Made up of series flattened stacked pouches -> cisternae
- Found in cytoplasm next to ER + nucleus
Complex
- Protein or multiprotein complex group of 2 or more polypeptide chains
- Protein complexes form quaternary structure
Lysosomes
- Organelle in cytoplasm of eukaryotic cells
- Containing degradative enzymes enclosed in membrane
Mitochondria
- Rod-shaped organelles power generator of cell
- Converts O2 + nutrients into ATP
- ATP powers cell’s metabolic activities
Vacuoles
- Storages bubbles in cells
- Found in animal + plant cells
Centrioles
- Each pair of minute cylindrical organelles near nucleus in animals cells
- Involved development of spindle fibres -> cell division
Cilia
- Found in eukaryotic cells
- Slender protuberances project from much larger cell body
- 2 types: motile + non-motile
Flagella
Lash-like appendage protrudes from cell body of certain bacteria + eukaryotic cells
Chloroplast
- Organelle found in plant cells + eukaryotic cells conduct photosynthesis
- Absorb sunlight + use it in conjunction w/ water + CO2 gas to produce food for plant
Mitosis
- Type of cell division results in 2 daughter cells
- Each having same number + kind of chrom. as parent nucleus
- Somatic cells
Meiosis
- Cell division reduces chrom. number by 1/2 => 4 haploid cells
- Each genetically distinct from parent cells that gave rise to them
- Process occurs in all sexually reproducing single-celled + multicellular eukaryotes
- Germ line cells (gametes)
Diffusion
Movement of a substance from an area of high concentration to an area of low concentration
Osmosis
- Spontaneous net movement of solvent molecules through selectively permeable membrane into region of higher solute concen.
- In direction tends to equalise solute concen. on 2 sides
Photosynthesis
- Takes in CO2 produced by all breathing organisms + reintroduce O2 into atmosphere
- Process used by plants, algae + bacteria to harness energy from sunlight + turn into chemical energy
Respiration
- Movement of O2 from outside enviro. to cells w/in tissues
- Transport of CO2 in opposite directions
Natural selection
- Differential survival + reproduction of Indivs. due to differences in phenotype
- Key mechanism of evolution
- Change in heritable traits characteristics of pop. over generations
- Variation exists w/in all pops. of organisms
Artificial selection
- Intentional reproduction of indivs. in pops. that have desirable traits.
- In organisms that reproduce sexually, 2 adults that possess a desired traits are bred together
Mutation
- Change that occurs in our DNA sequence
- Due to mistake when DNA is copied or as result of enviro. factors
Stabilising selection
- Type of natural selection
- Pop. mean stabilises on a particular non-extreme trait value
Disruptive selection
- Describe changes in pop. genetics extreme values are favoured over intermediate values
- Variance of trait increases + pop. is divided into 2 distinct. groups
Directional selection
- Pop. genetics mode of natural selection that extreme phenotype is favoured over other phenotypes
- Causing allele frequency to shift over time in direction of that phenotype
Allopatric speciation
Mode of speciation that occurs when biological pops. of same species before isolated
Sympatric speciation
Evolution of new species from a surviving ancestral species while both
Phylogeny
Study of evolutionary history + relationship among indivs. or groups of organisms
Taxonomy
Science of defining + naming groups of biological organisms on basis of shared characteristics
Cladistics
- Method of hypothesising relationships among organisms
- Method of reconstructing evolutionary trees
- Basis cladistic analysis data on character, or traits, of organism that we are interested in
Hierarchal classification
- System of grouping things according to a hierarchy, or levels + orders
- Can be seen in positions of authority + power that things are ranked in unwavering order
Systematics
- Study of diversification of living forms - past + present
- Relationship among living things through time
- Relationships visualised as evolutionary trees
Kingdom Monera
- Contains unicellular organism w/ prokaryotic cell organisation eg bacteria
- Single-celled organisms w/ no true nuclear membrane
Prokaryote
Unicellular organism that lack membrane-bound nucleus, mitochondria + any other membrane-bound organelles
Heterotrophic
- Organism that cannot manufacture its own food + instead obtain food + energy by taking in organic substances
- Usually plant/animal matter
- eg. animals, protozoans, fungi, most bacteria
Autotrophic
- Organism capable of synthesising its own food from inorganic substances using light to chemical energy
- eg. green plants, algae, certain bacteria
Bacteria
- Large domain prokaryotic microorganism
- Number of shapes, ranging from spheres to rods + spirals
- Among first life forms to appear on earth + present in most of its habitats
Archaes
- Domain of single-celled microorganisms
- Prokaryotes => no cell nucleus
Virus
- Biological agent that reproduces inside of cells of living host
- When infected by virus, host cell forced to produce thousands of identical copies of original virus at extraordinary rate.
Kingdom Protista
- Eukaryotic organisms
- Large multi-cellular protist that provide food, shelter + O2 for numerous underwater ecosystems
- eg. kelp/seaweed
Eukaryote
Organism whose cell has a nucleus enclosed within membrane
Saprophytic
- Organism that gets its energy from dead + decaying organic matter
- Heterotrophs
- Consumers in food chain
Sexual reproduction
Life of life cycle where generations. alternate cells with single set of chrom. + cells w/ double
Asexual reproduction
- Offspring arise from single organism
- Inherit genes of that parent only
- Does not involve fusion of gametes
- Never changes # of chrom.
Lichen
- Composite organism arise from algae or cyanobacteria living among filaments of multiple fungi species in mutualistic relationship
- Combined linen properties different from those of its component organisms
Fungi
- Member of group of eukaryotic organisms like yeasts, molds, mushrooms
- Kingdom fungi
Gamete
- A mature haploid male or female germ cell
- Able to unite w/ another of opposite sex in sexual reproduction
- To form a zygote
Spore
- Unit of sexual or asexual reproduction that may be adapted for dispersal + for survival
- Often for extended periods of time in unfavourable conditions
- Spores form part of life cycles of many plants, algae, fungi + protozoa
Mycelium
- Vegetative part of a fungus or fungus-like bacterial colony
- Consisting of mass of branching, thread-like hyphae
- Fungal colonies composed of mycelium are found in and on soil + many other substrates
Mycorrhizae
- Symbiotic association between a fungus and a plant
- Role of the fungus in the plant’s rhizosphere - its root system
- Role in plant nutrition, soil biology + soil chemistry
Kingdom Plantae
- Taxonomic kingdom of all living or extinct plants
- 1 of 5 highest taxonomic group into organisms are grouped
- Monera, Protoctista, Plantae, Fungi or Animalia
Alternation of Generations
- Type of life cycle found in terrestrial plants + some algae
- Subsequent generations of individuals alternate between haploid + diploid organisms
Gymnosperm
Group of seed-producing plants
- Includes conifers, cycads, Ginkgo + gnetophytes
Angiosperm
- Plant of large group w/ flowers + produce seeds
- Enclosed w/in carpel, including herbaceous plants, shrubs, grasses + most trees
Xylem
Transport water from roots to stems and leaves + transports nutrients
Phloem
- Tissue in plants conduct foods made in leaves to all other parts of plant
- Composed of various specialized cells called sieve tubes, companion cells, phloem fibres, and phloem parenchyma cells
Vascular Bundle
A strand of conducting vessels in the stem or leaves of a plant, typically with phloem on the outside and xylem on the inside.
Guard Cell
- Cells surrounding each stoma
- Help to regulate rate of transpiration by opening + closing stomata
Stomate
- A pore found in epidermis of leaves, stems, and other organs
- Facilitates gas exchange
- Pore is bordered by pair of specialized parenchyma - guard cells
- Responsible for regulating size of stomatal opening.
Mesophyte
- Terrestrial plants neither adapted to particularly dry nor particularly wet environments
- eg. rural temperate meadow, contain goldenrod, clover, oxeye daisy
Xerophyte
A xerophyte is a species of plant that has adaptations to survive in an environment with little liquid water, such as a desert or an ice- or snow-covered region in the Alps or the Arctic. Popular examples of xerophytes are cacti, pineapple and some Gymnosperm plants
Bilateral symmetry
- Balanced distribution of duplicate body parts or shapes w/ body of an organism
- In nature and biology, symmetry is always approximate
- eg. plant leaves
Radial symmetry
- Symmetry about a central axis
- eg. starfish
Transpiration
- Process by moisture is carried through plants from roots to small pores on underside of leaves
- Where it changes to vapor + released to atmosphere
- Evaporation of water from plant leaves
Hydrostatic skeleton
- A flexible skeleton supported by fluid pressure
- Common among simple invertebrate organisms
Exoskeleton
- External skeleton that supports + protects an animal’s body
- In usage, some of larger kinds of exoskeletons “shells”
Endoskeleton
- Internal support structure of an animal
- Composed of mineralized tissue
Closed circulatory system
- Blood closed at all times within vessels of different size + wall thickness
- Vertebrates + a few invertebrates have
- Blood is pumped by a heart through vessels
- Does not normally fill body cavities
Open circulatory system
- Pump blood into a hemocoel w/ blood diffusing back to circulatory system between cells
- Evolved in crustaceans, insects, molluscs + other invertebrates
- Blood pumped by heart into body cavities where tissues surrounded by blood
Metamerism
- Phenomenon of having linear series of body segments similar in structure
- Some of them perform special function
- eg. in animals, metameric segments
Exponential Growth
- Exhibited when rate of change (change per instant or unit of time) of value of a mathematical function of time is proportional to function’s current value
- Resulting in its value at any time being an exponential function of time
Logistic growth
- Common “S” shape
- Equation: where e = natural logarithm base
Fundamental niche
Entire set of conditions under an animal (population, species) can survive + reproduce itself.
Realised niche
- Set of conditions actually used by given animal (pop, species)
- After interactions w/ other species (predation + competition) taken into account
Symbiosis
Relationships between two or more organisms that live closely together
Mutualism
- Interaction between individuals of different species
- Results in positive (beneficial) effects on per capita reproduction and/or survival of interacting populations
Commensalism
Long-term biological interaction members of one species gain benefits while those of other species neither benefit nor are harmed
Parasitism
- Relationship between species, where one organism, parasite, lives on or in another organism, host, causing it some harm,
- Also adapted structurally to way of life
Predation
- Biological interaction where one organism, predator, kills + eats another organism, prey
Amensalism
- Relationship between organisms of different species
- One is inhibited or destroyed while other organism remains unaffected
Herbivore
Animal that gets its energy from eating only plants
Detritivore
Heterotrophs obtain nutrients by consuming detritus
Food chain
- Linear network of links in a food web starting from producer organisms
- Ending at apex predator species, detritivores, or decomposer species
- Shows how organisms are related w/ each other by food they eat
- Each level of a food chain represents different trophic level
Food web
A system of interlocking and interdependent food chains.
Decomposer
- Organism that decomposes, or breaks down, organic material like remains of dead organisms
- eg. bacteria + fungi
Ecosystem
- Community of living organisms with nonliving components of their environment
- Interacting as a system
- Biotic + abiotic components linked through nutrient cycles + energy flows
Supralittoral zone
- Area above spring high tide line, on coastlines + estuaries, that is regularly splashed, but not submerged by ocean water
- Seawater penetrates these elevated areas only during storms w/ high tides
Littoral zone
- Part of a sea, lake or river is close to shore
- In coastal environments, extends from high water mark to shoreline areas that are permanently submerged
Sublittoral zone
- Neritic zone relatively shallow part of ocean
- Above the drop-off of continental shelf
- Approx. 200 meters in depth
Phytoplankton
- Autotrophic components of plankton community
- Key part of oceans, seas + freshwater basin ecosystems
Zooplankton
- Heterotrophic plankton
- Plankton are organisms drifting in oceans, seas, + bodies of fresh water
Mangrove
- Shrub or small tree that grows in coastal saline or brackish water
- Also topical coastal vegetation consisting of such species
Counter-current
- Mechanism occurring in nature
- Crossover of some property, heat or some chemical
- Between two flowing bodies flowing in opposite directions to each other
Trophogenic zone
- Photic zone
- Upper portion of lake where photosynthesis occurs.
Tropholytic zone
- Deeper part of a lake
- Dissimilation of organic matter tends to predominate
River continuum concept
- Model for classifying + describing flowing water
- Classification of individual sections of waters after occurrence of indicator organisms
Biome
A large naturally occurring community of flora + fauna occupying a major habitat, e.g. forest or tundr
Keystone species
Species that has a disproportionately large effect on its natural environment relative to its abundance
Biodiversity
- Variety + variability of life on Earth
- Measures variation at genetic, species + ecosystem level
- Terrestrial biodiversity is usually greater near equator, result of the warm climate + high primary productivity
Conservation biology
- Management of nature + of Earth’s biodiversity w/ the aim of protecting species, their habitats, + ecosystems
- From excessive rates of extinction + erosion of biotic interactions
Extinction
- Termination of an organism or of a group of organisms (taxon), usually a species
- Moment of extinction death of last individual of species
