6.3.2 (b) interactions between populations

Question 1

what is the population?

Answer 1

total number of organisms of a species in a habitat

Question 2

what type of factor is competition?

Answer 2

biotic

interacts with populations to cause change

Question 3

what are the three main types of biotic factor?

Answer 3

intraspecific variation
interspecific variation
predation

Question 4

what is intraspecific competition?

Answer 4

competition between members of the same species

Question 5

what is interspecific competition?

Answer 5

competition between different species

Question 6

what is the competitive exclusion principle?

Answer 6

when 2 species are competing for a resource, the more adapted species will eliminate the other and survive

Question 7

what affects intraspecific competition?

Answer 7

availability of a resource determines the size of the population

constant fluctuations of populations size

Question 8

why are there constant fluctuations in population size in intraspecific competition?

Answer 8

when there is a large amount of resources, the population size increases

eventually the population is too large to share the resources so the resource becomes limited which causes a decrease in population size

with a smaller population there is less competition which means that more organisms survive and the population increases

Question 9

what is predation?

Answer 9

relationship when one organism kills and eats another organism

Question 10

what type of competition is predation?

Answer 10

interspecific

between a predator species and prey species

Question 11

what is the common trend in a predator-prey graph?

Answer 11

constant fluctuation

troughs and peaks of both species mirror eachother

Question 12

stage 1 of predation

Answer 12

increase in prey population means more food for the predators

so there is an increase in predator population as there is more food to survive

Question 13

stage 2 of predation

Answer 13

a decrease in prey population due to more predators being in the environment so more prey is eaten

Question 14

stage 3 of predation

Answer 14

eventually the prey population is too small to support a large predator population so the predator population decreases in size as they have no food

Question 15

stage 4 of predation

Answer 15

less predators means less prey are killed which allows them to survive and reproduce

this increases the prey population

Question 16

graph for predation

Answer 16

Question 17

what is the relationship between predator and prey populations?

Answer 17

they are interlinked

Question 18

when might the predator-prey relationship not be interlinked?

Answer 18

when abiotic factors cause change

availability of other food

other predators

Question 19

what is a limiting factor in population growth?

Answer 19

a biotic or abiotic factor which prevents population growth

determines the carrying capacity