IB Bio HL1 C4.1

ecosystem

ecosystem

How living organisms and physical terrain work together as a unit

habitat

nonliving components of ecosystems

population

the living amount of a single species in a (SAT)

Community

Multiple species within a common location/vacinity

Carrying capacity

finite amount of organisms an ecosystem can support

Positive feedback loop

as one variable increases, the other increases

Negative feedback loop

as one variable increases, the other decreases

Density dependent factors

impact/severity of thing depends on population. (disease spreads faster with denser populations in an area)

Density independent factors

thing’s impact/severity is equal, regardless of how dense or not dense a population is

herbivory

animals eat plants

predation

animals eat animals

intraspecific competition

two species competing for the same resources

symbiosis

any relationship with two or more organisms, where they live closely together

mutualism

+/+ a type of symbiosis where both species benefit from their interactions

commensalism

+/= a type of symbiosis where one organism benefits, but the other doesn’t benefit or is harmed

parasitism

+/- a type of symbiosis where one organism benefits, but the other is harmed. Typically an organism taking nutrients from the other

pathogenicity

an organisms ability to spread disease. similar to parasitism, but pathogenicitic parasites cause diseases

disease vector

the means for transmitting disease (bats → COVID, mosquito → malaria)

random quandrat sampling

Methodology for chi-squared. Dividing an area of sessile organisms into a grid, randomly choosing boxes, then using a ratio between the boxes counted and total boxes and applying it to the results to estimate the population of the area

capture-mark-release-recapture

Methodology for the lincoln index. Capture them, mark them, release, recapture & count the
marked that appear. Also used to estimate population

Lincoln index

Statistical measure/result of capture-mark-release capture method that gives a direct estimate of the
population. (n1/n2)/n3 n1 = # initially marked, n2= # recaptured, n3= # of recaptured that are marked

chi-squared

a statisitical test to determine correlational relationship between two variables

fabaceae

family of legumes (bacteria gets carbon, legume gets nitrogen)

mycorrhizae

a fungi that typically has a symbiotic relaitonship with the roots of its host plant (m->carbon, o-> nitrogen)

orchidaceae

orchid family (m->carbon, o-> nitrogen)

zooxanthellae

photosynthetic cells within corral (z, get protection, corrals get glucose from z)

endemic

(of a plant) to express nativity

top-down control

predators limit population size

bottom-up control

resources such as water regulate population size

allelopathy

chemicals widely released to inhibit growth/survival of organisms within an area

antibiotics

antibodies released to prevent growth/survival of microorganisms