Unit 2: Ecology

Carnivore

organism that obtains energy by eating animals

Herbivore

organism that obtains energy by eating only plants

Omnivore

an animal that eats both plants and animals

Decomposer

an organism that breaks down wastes and dead organisms

Producer

an organism that makes its own food

Primary consumer

consumer that feeds directly on producers

Secondary consumer

an organism that mainly eats primary consumers

Tertiary consumer

an organism that mainly eats secondary consumers

Quaternary consumer

carnivore that mainly eats tertiary consumers

Order of trophic levels

producers, primary consumers, secondary consumers, tertiary consumers, quaternary consumers

Food web

a community of organisms where there are several interrelated food chains

Food chain

a series of steps in which organisms transfer energy by eating and being eaten

10% rule

only 10% of the total energy produced at each trophic level is available to the next level. The amount of energy passed up to the levels of the food pyramid reduces as you go up

Niche

an organism’s particular role in an ecosystem, or how it makes its living

Symbiotic relationships

mutualism, commensalism, parasitism

Mutualism

a relationship between two species in which both species benefit

Commensalism

a relationship between two organisms in which one organism benefits and the other in unaffected

Parasitism

one organism benefits and the other is harmed

Exponential growth

growth pattern in which the individuals in a population reproduce at a constant rate

Logistic growth

growth pattern in which a population’s growth rate slows or stops following a period of exponential growth

Carrying capacity

largest number of individuals of a population that an environment can support

Limiting factors

conditions in the environment that put limits on where an organism can live

Hydrogen cycle

condensation, precipitation, (river flow, surface run off, soil moisture), ground water flow-transpiration, evaporation

Carbon cycle

the organic circulation of carbon from the atmosphere into organisms and back again

Nitrogen cycle

the transfer of nitrogen from the atmosphere to the soil, to living organisms, and back to the atmosphere

Population overshoot

occurs when the population of a species exceeds the carrying capacity and starts to die off because of lack of resources

Population dieback

when the growth of a population slows down and decreased because of overshoot

Emigration

movement of individuals out of a population (EXIT)

Immigration

migration to a new location (IN)

Cell theory

every living thing is made up of cells

Levels of organization

atoms - molecules - organelles start functioning - cell tissue - organs - organ systems - organism/individual - population - community - ecosystem - biome - biosphere

Energy use

when organisms use energy to survive, grow and reproduce

Growth and development

development of the physical body of an organism over time

Reproduction and inheritance

the act of passing traits down through genetics

Evolution

how species change over time, and when they pass traits to their offspring with some changes happening naturally, leading to new species forming over another cycle

Homeostasis

tendency to maintain a stable, relatively constant and intentional state of your body (eternal like heart rate, oxygen levels, blood pressure)

Response to stimuli

if an organism reacts to an activity, meaning the organism is living

Biomagnification

when going up the trophic levels, minerals accumulate (good), but toxins can also build up, accumulating a higher and more dangerous amount (bad)

Ecological pyramid

a diagram that shows the relative amounts of energy or matter contained within each trophic level in a food chain or food web

Energy pyramid

a specific type of ecological pyramid, showing the energy transfers (amount lost as heat, and amount that is transferred going up the trophic levels, which is about 10%)

R-type

Exponential curve (j-curve), low parental care, offspring mature and reproduce quickly, tend to be smaller organisms, usually prey, short-lived, lives in unstable environment, uncontrolled growth (reproduces no matter what)

K-type

Logistic curve (s-curve), take care of offspring, offspring are more complex and takes a while to mature, fewer offspring, usually more intelligent, live longer, usually predator, bigger organism sizes, more stable environment

Predator/prey graphs

Prey population goes up/down first, then the predator follows, because predator takes time to respond (takes time to find prey to eat, takes time to die, etc.)

Density dependent

the density changes the effect/intensity of what happens; the greater the population, the greater the impact (EX. disease, fire, competition/predation, etc.)

Density independent

not determined by population density (amount of individuals). EX. weather, natural disasters (excluding fires)

Replacement level

2.1 (pair of parents → more than 2 offspring, in case some die, or other individuals in the population don’t reproduce). It is a little bit over the population because not everyone will have offspring, or some offspring may die, etc.

Population density

D=m/v (Density=mass/volume)