C4.1 SL / HL Flashcards
Ecological hierarchy
the synergy of organisms with their environment and leads to the formation of a grouping of organisms
population
a group of individuals of the same species living and interbreeding within a given area
Transect sampling
a method used to study the distribution and abundance of organisms along a line or pathway
Random sampling
used to select a sample that is unbiased. Within each area, every part of the area must have an equal chance of being chosen. Random sampling withquadratsis used to examine differences between contrasting habitats within an habitat
sessile organisms
an organism that is anchored to a substrate and cannot move about freely
motile organisms
an organism has the capability to move under its own power
Quadrats
a frame used in ecology, geography, and biology to isolate a standard unit of area for study of the distribution of an item over a large area
Capture-mark-release-recapture
a technique used to estimate the size of a population of a particular species
Lincoln Index
a statistical measure used in several fields to estimate the population size of an animal species
carrying capacity
the maximum population size of a biological species that can be sustained by that specific environment, given the food, habitat, water, and other resources available
Limiting Factors
anything that constrains a population’s size and slows or stops it from growing
Positive feedback
output of a system amplifies the system
Negative Feedback
responds when conditions change from the ideal or set pointand returns conditions to this set point
Density-dependent factors
factors that affect the per capita growth rate of a population differently depending on how dense the population already is
Density-independent factors
limiting factors that affect the population of organisms but not restricting them to be at or within a certain number, range, or density
Lag phase
the adaptation phase for the organism where they acclimatizes themselves to the new environmental conditions provided. The growth is slow at this stage
Exponential phase
where there is a rapid increase in population growth as natality rate exceeds mortality rate
Transition phase
where the population growth slows significantly due to limiting factors
Plateau phase
Eventually the increasing mortality rate equals the natality rate and population growth becomes static. The population has reached the carrying capacity (κ) of the environment
Death Phase
population decreases as death rate is now greater than birth rate; this is usually because food supply is short
Logarithmic graphs
graphical representation that employs a logarithmic scale, diverging from the conventional linear scale used in most charts, where values are evenly spaced by creating varying intervals between values
model organisms
non-human species that scientists use in the lab to investigate and understand biological processes
Duckweed
tiny, free-floating, aquatic green plants commonly found in lentic or slowly moving water bodies, belonging to the family Lemnaceae
Community
an interacting group of various species in a common location
Intraspecific relationships
Intra-specific interactions arethose that occur between individuals of the same species, while interactions that occur between two or more species are called inter-specific interactions
Intraspecific competition
a competition between individuals from the same species (cospecifics)
herbivory
the consumption of plant material by animals, and herbivores are animals adapted to eat plants
predation
a biological interaction where one organism, the predator, kills and eats another organism, its prey
parasitism
a relationship between the two living species in which one organism is benefitted at the expense of the other
pathogenicity
the ability of an organism, a pathogen, to produce an infectious disease in another organism
mutualism
association between organisms of two different species in which each benefits
Symbiosis
any of several living arrangements between members of two different species, including mutualism, commensalism, and parasitism
self-pollinate
occurs when the pollen from the anther is deposited on the stigma of the same flower, or another flower on the same plant
nitrogen fixation
the bacterial process whereby molecular N2gas is converted to reactive, biologically available forms of nitrogen
nitrogen-fixing bacteria
prokaryotic microorganisms that are capable of transforming nitrogen gas from the atmosphere into “fixed nitrogen” compounds, such as ammonia, that are usable by plants
Fabaceae
the pea or legume family of plantsand are sometimes referred to by their old family name the Leguminosae
root nodules
the knob-like structures formed especially on and from roots of leguminous plants, as a result of symbiotic infection bynitrogen-fixingbacteria such as Rhizobium
rhizobium
nonspore-forming rod-shaped, motile, aerobic, gram-negative soil bacterium able to colonize in the rhizospheric region of leguminous plants and symbiotically fixes atmospheric nitrogen
Mycorrhiza
a mutualistic relationship between fungi and plant roots in most plants
hyphae
the feathery filaments that make up multicellular fungi. They release enzymes and absorb nutrients from a food source
coral polyps
Corals are made up of tiny individuals called polyps. Each polyp is like a fluid-filled bag with a ring of tentacles surrounding its mouth, and looks like a tiny anemone
Zooxanthellae
unicellular, golden-brown algae (dinoflagellates) that live either in the water column as plankton or symbiotically inside the tissue of other organisms
Coral bleaching
When water is too warm, corals will expel the algae (zooxanthellae) living in their tissues causing the coral to turn completely white
Endemic species
any species or other taxon whose geographic range or distribution is confined to a single given area
Invasive species
non-native species that have colonised a new area to the point of damaging the surrounding environment
cane toads
a large, warty, poisonous amphibiannative to South and Central America and considered to be one of the worst invasive species in the world
red squirrels
a small rodent with a bushy tail. It is typically a rust-red color with a white or cream-colored underside
gray squirrels
mainly grey fur, but may have red-brown patches, especially around the face and legs. The species has a long, bushy tail
Presence-Absence matrix
a one represents the presence of species j in cell i, and a zero indicates absence
chi-squared test
a statistical test commonly used to determine if there is a significant association between two variables
null hypothesis
a hypothesis that says there is no statistical significance between the two variables
Qualitative data
descriptive, expressed in terms of language rather than numerical values
critical value
cut-off values that define regions where the test statistic is unlikely to lie
Alternative hypothesis
an opposing theory to the null hypothesis. For example, if the null hypothesis predicts something to be true, the alternative hypothesis predicts it to be false
Null hypothesis
a hypothesis that says there is no statistical significance between the two variables. It is usually the hypothesis a researcher or experimenter will try to disprove or discredit
predator-prey interaction
occurs whenever a predator captures and eats an organism
Bottom-up Control
ecological concept where ecosystems are primarily regulated by the availability of nutrients, light, or water, which influenceprimary productionand subsequently impact other ecosystem functions
Top-down Control
directional regulation within an ecosystem, where species occupying higher trophic levels exert controlling influences on species at the next lower trophic level
Allelopathy
a common biological phenomenon by which one organism produces biochemicals that influence the growth, survival, development, and reproduction of other organisms
secondary metabolites
the products of metabolism not essential for normal growth, development or reproduction of an organism
sinigrin
a natural aliphatic glucosinolate present in plants of theBrassicaceae family
penicillin
bactericidal beta-lactam antibiotics that inhibit bacterial cell wall synthesis
antibiotic
medicines that fight bacterial infections in people and animals
zone of inhibition
an area of media where bacteria are unable to grow, due to presence of a drug that impedes their growth
