population and community ecology

Question 1

what is a population?

Answer 1

groups of individuals of the same species that inhibit a shared environment

Question 2

since populations are dynamic, what makes them fluctuate?

Answer 2

-seasonal/yearly changes
-natural diasters
-competition for resources
-disease

Question 3

what factors affect the size of a population?

Answer 3

-increases are due to births and immigration
-population decreases as a result of death and emigration

Question 4

what is demography?

Answer 4

-statistical study of population dynamics and how populations respond to abiotic and biotic changes

Question 5

what are the metrics of demography?

Answer 5

-population size which is the number of individuals
-population density which is the number of individuals in a specific area or volume

Question 6

what is damuth’s law?

Answer 6

-There is an inverse relationship between body size and population density
-the bigger the species, the fewer number of individuals cohabitate a given area.

Question 7

what are the methods used to determine population sizes?

Answer 7

-count
-quadrant
-mark and capture

Question 8

What is the quadrant method of population determination?

Answer 8

looking at a sample population in a defined area and extrapolate

Question 9

what is the mark and capture method?

Answer 9

involves catching-marking-releasing and recapturing of animals
-the ratio of marked to unmarked can determine population size

Question 10

what is the equation of mark and recapture method?

Answer 10

(# marked on first catch)X(total # captured in second catch)/(# caught that were marked in second chance)

Question 11

what are the types of spacing and dispersion patterns?

Answer 11

-uniform, which is common in plants that secrete toxins and animals with territory requirements
-random, which is common in plants with wind blown seeds
-clumped, which is common in plants where seed falls to ground, animals that form herds/groups

Question 12

what is the type I of survivorship curve?

Answer 12

high percentage of offspring live in early years and middle years and die in old age
-usually organisms with low numbers of offspring and strong parental care

Question 13

what is the type II of survivorship curve?

Answer 13

organisms that die equally at each age

Question 14

what is the type III of survivorship curve?

Answer 14

few organisms survive younger age, but those that do make it to old age survive for a relatively long time

Question 15

what is exponential growth of population?

Answer 15

growth with unlimited natural resources and populations grow rapidly

Question 16

what is the logistic growth of population?

Answer 16

organisms will compete with members of their own species and members of other species until a carrying capacity is reached

Question 17

what is a carrying capacity?

Answer 17

the maximum population size a particular environment can sustain
good for starting point

Question 18

why is the human population growing exponentially?

Answer 18

because humans can alter the environment and thus the carrying capacity

Question 19

what is the ecological footprint?

Answer 19

land and water area required to produce what is needed by each person per country

Question 20

what is community ecology?

Answer 20

study of all populations occupying the same habitat at the same time and their interactions

Question 21

what is the competitive exclusion principle?

Answer 21

two species cannot occupy the same niche and different species cannot coexist in the same community if they compete for same resources

Question 22

what is an ecological niche?

Answer 22

a specific set of abiotic and biotic resources an organism uses in its environment

Question 23

what is resource partitioning?

Answer 23

similar species can occupy the same niche if natural selection results in one species using a different or similar resources

Question 24

how can a species niche be influenced by interspecies competition?

Answer 24

a species realized niche is much smaller than its fundamental niche because of the competition between species

Question 25

what are the negative type of interactions in a community?

Answer 25

-predation where predator kills and eats prey
-herbivory where herbivore eats part of a plant
-parasitism where parasite derives nourishment from host

Question 26

what are the types of prey defense adaption?

Answer 26

-mechanical defense
-chemical defense
-aposematic coloration
-cryptic coloration
-batesian mimicry
-mullerian mimicry

Question 27

what are the types of plant defense adaption?

Answer 27

-chemical toxins
-thorns and spines
-bad taste (cloves, cinnamon, peppermint)

Question 28

what are the types of positive interactions in a community?

Answer 28

-mutualism which benefits both species
-commensalism where one species benefits and other does not

Question 29

what are some characteristics of communities?

Answer 29

-they are complex and characterized by the types and number of species and the dynamics of how it changes

Question 30

what are foundation species?

Answer 30

base or bedrock species of a community that influences the overall community structure

Question 31

what are the keystone species of a community?

Answer 31

a species whose presence is key to maintaining biodiversity within a ecosystem that are necessary

Question 32

what are the invasive species of a community?

Answer 32

a non-native organism that is introduced to an area out of natural range and threatens balance of natural habitat