Populations Prey and Predation

Question 1

what is a population
what factors can affect population size

Answer 1

members of the same species living in the same place at the same time that can interbreed successfully

-affected by biotic (density dependent) and abiotic factors (density independent)

Question 2

explain each stage of the population growth curve

Answer 2

1) lag phase - rate of growth is low initially only few individuals still getting used to environment, low rate of reproduction = slow population growth

2)log phase- pop increases quickly with reproduction rate exceeding death rate- plentiful resources

3) Stationary- population has reached maximum capacity (maximum pop a habitat can support), slight fluctuations around cc, reproduction and death rates are equal

4) Death - pop may start to decline- death rate may be greater than birth rate as resources start to run out

Question 3

what does a limiting factor do to a population

Answer 3

slow down the rate of population growth

Question 4

define density-dependent factors and give some examples

Answer 4

-dependent on size of population , influence population more strongly as population size increases

e.g competition for food, water, light, levels of parasitism and predation

Question 5

define independent factors and examples

Answer 5

factors limit population size irrespective of the size of the population, kill same proportion regardless of size of poop

e.g low temperature

Question 6

explain k-strategists

Answer 6

based on carrying capacity, will grow gradually overtime to reach carrying capacity
-stable environment
-large body size
-long life expectancy
-high parental care
-fewer offspring

Question 7

explain r-strategists

Answer 7

-based on growth rate
-unstable environment
-high fecundity = reproduce fast
=small body
-short generation time
-dispersed offspring

Question 8

explain the link between predator and prey fluctuations

Answer 8

prey pop increases = predator pop increases = prey pop decreases = predator pop decreases

Question 9

why does competition occur
what does it result in

Answer 9

-occurs when resources are limiting/ insufficent to support population

-will result in a decrease n reproduction and increase in death = pop size will fall

Question 10

what is
intraspecific competition
interspecific competition

Answer 10

-competition between organisms of the same species

-competition between organisms of different species