Week 11

Question 1

Niche

Answer 1

combination of a species’ physical habitat and its ecological role in that habitat

Question 2

Grinnell

Answer 2

niche is sum of the habitat requirements needed for a species’ survival and reproduction

Question 3

Elton

Answer 3

niche is the role a species plays in a community, switching emphasis from the habitat to the species itself

Question 4

Hutchinson

Answer 4

niche as a multidimensional habitat that allows a species to practice its way of life

Question 5

abiotic factors

Answer 5

non living, physical
climate
soil chemistry

Question 6

biotic factors

Answer 6

living, biological

interactions with other species

Question 7

fundamental niche

Answer 7

full range of climate conditions and food resources that permits the individual in a species to live

Question 8

realised niche

Answer 8

actual range of habitats occupied by a pecies

Question 9

phylogenetic niche conservatism

Answer 9

usually some aspect of the niches of closely related species is similar and so are evolutionarily conserved

Question 10

competition

Answer 10

interaction in which the use of a mutually needed resource by one individual or group of individuals lowers the availability of the resource for another individual or group

Question 11

intraspecific competition

Answer 11

caused by tension between intrinsic growth rate and environmental carrying capacity; competition between individuals of a single species
Main reason why population growth slows as the species’ environment approaches its carrying capacity

Question 12

interspecific competition

Answer 12

competition occurs between individuals of different species

Question 13

Darwin

Answer 13

‘struggle for existence’ is a primary driver for natural selection

Question 14

Competitive exclusion

Answer 14

competition between two species prevents one from occupying a particular niche

Question 15

resource partitioning

Answer 15

species whose niches overlap diverge and become different subspecies or species
caused by competitive exclusion

Question 16

predation

Answer 16

one organism consumes another, its prey

Predator benefits at expense of prey

Question 17

gause

Answer 17

a simple system with one predator and one prey population is inherently unstable; predator overexploits the prey, driving it to extinction and then becomes extinct itself

Question 18

huffaker

Answer 18

if the prey had refuges where some individuals could escape from predators, they could persist while predator populations declined
Predators and prey cycle repeatedly through periods of increasing and then decreasing density, as predators track their prey and some prey escape predation
A long term, stable oscillation pattern can be achieved

Question 19

parasites

Answer 19

live in close association with another species, gaining nutrition by consuming their hosts’ tissues
Do not kill their host but can reduce host fitness by tapping its resources
Limit the population size of their host, keeping numbers well below the carrying capacity of the environment

Question 20

herbivory

Answer 20

consumption of plant parts, benefits herbivorous plants by providing some nutrients, and harms plants by direct affecting the products of photosynthesis
Most plants are well defended with chemical or physical deterrents to herbivory

Question 21

facilitation

Answer 21

indirect attraction between two attacking species that benefits them both

Question 22

mutualism

Answer 22

interaction when the benefits for each participant outweighs their costs
Each side is acting in its own self interest and bears costs that are weighed against benefits in terms of growth and reproduction

Question 23

symbioses

Answer 23

close interactions between species that have evolved over long periods of time

Question 24

obligate mutualism

Answer 24

when one or both sides of a mutualism cannot survive without the other

Question 25

facultative mutualism

Answer 25

one or both participants can survive without the other

Question 26

commensalism

Answer 26

one partner benefits with no apparent effect on the other

Question 27

ammensalism

Answer 27

one partner is harmed with no apparent effect on the other