Biotic Factors

Question 1

Mutualism

Answer 1

a biotic interaction where all organisms/species are positively affected

Mutual exploitation- Not cooperation!

Question 2

Mutualism Examples

Answer 2

Clown fish/sea anemone

Shark/remora fish

Pollinators/flowering plants

Plants/fungi
Mycorrhizae

Question 3

Ectoparasites

Answer 3

live on the outside of their hosts (ecto- outer)

Question 4

Endoparasites

Answer 4

live on the inside of theirs hosts (endo- inside)…

Question 5

Commensalism

Answer 5

a biotic interaction where one species benefits and the other is neutrally affected

Question 6

There are three main types of commensalism:

Answer 6

Phoresy- commensal transport

Inquilinism- use of an organism for housing

Metabiosis- indirect dependency

Question 7

Population

Answer 7

consists of individuals of the same species that live, interact in the same niche and habitat at a particular time

Question 8

Density-dependent factors?

Biotic factors, like…

Answer 8

Resource availability (food supply, territory, etc.)
Competition (intraspecific vs. interspecific)
Predator/prey interactions
Spread of disease

These factors control a population based on how many individuals there are

Question 9

Density independent factors?

Abiotic factors, like…

Answer 9

Drought
Flooding
Temperature
Fire

These factors control a population regardless of how many individuals there are

Question 10

Unifrom Distrubution

Answer 10

individuals are evenly spaced
Rare in nature, but usually due to competition for space or resources
ex: penguins

Question 11

Random Distribution

Answer 11

individuals haphazardly located for no real reason
Rare in nature, but usually resulting from stochastic drivers
ex: flowers in a field

Question 12

Clumped Distibution

Answer 12

individuals arranged in groups, minimizing distance
Most common in nature, usually due to patchy resources or for safety
ex: flock of birds

Question 13

Clumped distribution

Why is this the most common distribution seen in nature?

Answer 13

Safety in numbers- fish school, game herds

Hunting as a team- wolves, whales/dolphins

Social organisms- bees, wasps, ants

Reproduction…

Question 14

Demography

Answer 14

population structure

Sex ratio- Males:Females

Can vary based on reproductive mode

Age structure

Factors like age of maturity can influence population demographics

Question 15

Fecundity

Answer 15

number of offspring produced by each female

Question 16

Mortality

Answer 16

proportion of individuals in an age class that die before reaching the next age class

Question 17

Survivorship

Answer 17

proportion of individuals that are alive at each age