IB biology: option C (I)

what is the distribution of species affected by?

limiting factors

what are examples of limiting factors on plants?

Light, Temp, Water, Nutrients, Oxygen, pH

what are examples of limiting factors on animals?

food, water, temperature, territory, breeding sites

what are adaptations?

characteristics that help an individual survive (result of evolution)

what is a limiting factor?

a component of an ecosystem which limits the distribution or numbers of a population -

optimal survival conditions according to its effect on a species when in deficiency or excess

what does the Law of Tolerance propose?

populations have optimal survival conditions within critical minimal and maximal thresholds,

as a population is exposed to the extremes of a particular limiting factor, the rates of survival begin to drop

describe the curve on the Law of Tolerance diagram

bell shaped curve -

zones of intolerance (extreme right/left),

zones of stress (right/left of middle zone),

optimal zone (centre)

describe the zones of intolerance in the Law of Tolerance diagram

outermost regions in which organisms cannot survive (represents extremes of the limiting factor)

describe the zones of stress in the Law of Tolerance diagram

regions flanking the optimal zone, where organisms can survive but with reduced reproductive success

describe the optimal zone in the Law of Tolerance diagram

central portion of curve which has conditions that favour maximal reproductive success and survivability

what are plants tolerant to high salt known as?

halophytes 

what are plants tolerant to low salt known as?

glycophytes 

what is the ecological niche?

the functional position and role of an organism within its environment

what is the ecological niche made up of?

habitat, activity, resources ,interactions

true or false: two species cannot survive indefinitely in the same habitat if their niches are identical

true

what happens if two distinct species share an identical niche?

interspecific competition occurs between species

what are the two possible responses to interspecific competition?

Competitive exclusion and resource partitioning

what is competitive exclusion?

one species uses the resources more efficiently, driving the other species to local extinction

what is resource partitioning?

both species alter their use of the habitat to divide resources between them (i.e. niche separation)

what is a fundamental niche?

the entire set of conditions under which an organism can survive and reproduce (where it could live)

what is the realised niche?

the set of conditions used by an organism after including interactions with other species (where it does live)

what is herbivory?

the act of eating only plant matter

what is predation?

biological interaction whereby one organism (predator) hunts and feeds on another organism (prey)

what is symbiosis?

the close and persistent (long-term) interaction between two species

what are examples of symbiosis? (3)

mutualism, commensalism, parasitism

what is mutualism?

ongoing interaction between two species whereby both species benefit from the interaction

what is commensalism?

 an ongoing interaction between two species whereby one benefits and the other is unaffected

what is parasitism?

an ongoing interaction between two species whereby one species benefits at the other's expense

parasitism example?

Ticks infest the skin and fur of host animals (such as humans), feeding off the host and potentially causing disease

commensalism example?

Monarch butterflies can safely store poisonous chemicals produced by milkweeds, discouraging predators from eating it

mutualism example?

Honey bees gather food (nectar) from flowers and distributes pollen between plants (mediating plant life cycle)

what is a key example of a mutualistic relationship involving coral?

coral and zooxanthellae:

The coral provides zooxanthella with a protective environment and source of inorganic compound, provides the coral polyps with a necessary source of nutrition

what are examples of coral bleaching?

when there is a large scale loss of zooxanthellae from the coral, causing the coral to starve and die unless the zooxanthellae are restored

what are conditions that can cause coral bleaching? (3)

Changes in light availability,

Temperature increases,

Ocean acidification.

what is a keystone species?

a species that has a disproportionately large impact on the environment relative to its abundance

what are examples of keystone species?

Predators Mutualism Engineers

how can predators be an example of keystone species?

they can exert pressure on lower trophic levels to prevent them from monopolising certain resources

how can mutualism be an example of keystone species?

they can support the life cycle of a variety of species within a community (e.g. pollinators / seed dispersal)

how can engineers be an example of keystone species?

they can refashion the environment in a manner that promotes the survival of other species