competition

Question 1

define competition

Answer 1

an interaction between individuals brought about by the sharing of a resource leading to a reduction in survivorship, growth and reproductioon

Question 2

define intraspecific competition

Answer 2

the combined demand for a resource exceeding immediate supply from individuals in the same species

Question 3

how can intraspecific competition cause decreased populations

Answer 3

increased energy spent to locate food, as well as reduced food intake means there is reduced contribution to the next generation

Question 4

what the different modes of competition

Answer 4

1) exploitation - where an individual of as species reduces amount of resources for other individuals
2) interference - more of a direct competition where individuals prevent another from exploiting a resource

Question 5

why does a population not increase as a result of competition

Answer 5

they face comp for resources, exploitation and interference decrease survivorship preventing increased growth

Question 6

what determines the intensity of intraspecific competition

Answer 6

1) the density of a population
2) the extent of crowding in an immediate area = unequal distribution of resoruces in less dense

Question 7

what is the law of constant final yield

Answer 7

when density is very high and resources are limited the effects of competition result in a constant biomass between individuals due to proportional decreases in the size of individuals
- there are more individuals, however they are all smaller

Question 8

what is territoriality

Answer 8

the active interference (directly preventing access to resources) between individuals to depend an exclusive area against intruders using a pattern of behaviour

Question 9

how is terriroriality a cost benefit stratergy

Answer 9

the defence of a resource must be offset against the benefit of the occupation of the area
e.g. may involve combat and energy to maintain so benefits must exceed the costs to be favoured by natural selection

Question 10

define interspecific compeitition

Answer 10

where one individuals of a species deprives another of a different species from a vital resource leading to slower growth and greater risk of death

Question 11

what are some resources which can be consumed or depleted causing competition

Answer 11

• food
• water
• light or nurtients for plants
• PH

Question 12

define exploitation competition

Answer 12

species compete indirectly through mutual effects on availability of a shared resource

Question 13

what is interference competition

Answer 13

species compete direclty for access to a resource such as combat or territioariality

Question 14

how does the acorn barnacle demonstrate intereference competition

Answer 14

crushes or smothers nearby individuals of another barnacle species as it grows, preventing the other species from living there

Question 15

define allelopathy

Answer 15

a form of interference competition in which individuals of one species release toxins that harm another species

Question 16

how does knapweed demonstrate allelopathy

Answer 16

releases a toxin called catechin into soils reducing germination of native grasses

Question 17

what is the competitive exclusion principle

Answer 17

when two species use a limting resource in the same way, they can not coexist and one is driven to extinction

Question 18

what is resource partioning

Answer 18

when species use a limtied resource in a different way

Question 19

what is competitive reversal

Answer 19

where the species which was the inferior competitior in one habitat becomes the superior in another as a result of a change in environmental conditions

Question 20

what is character displacement

Answer 20

where natural selection can influenced the morphology of a competing species resulting in the species becoming more different over time