C4.1 Populations and communities

Question 1

Population

Answer 1

group of individual organisms of the same species in a defined area, where members can interbreed with each other

Question 2

Standard deviation

Answer 2

Measure of the variability of data in dataset
Lower SD shows little variation between values
High SD shows lots of variation

Question 3

Sessile organisms

Answer 3

Organisms that are fixed in one place

Question 4

Quadrat

Answer 4

square sample area

Question 5

Motile organisms

Answer 5

Organisms that are capable of moving from place to place

Question 6

Carrying capacity

Answer 6

Max size of population that the environment can support due to limited availability of resources

Question 7

Density dependent factors

Answer 7

Factors that have increasing effects as population increase
eg. competition, predation

Question 8

Density independent factors

Answer 8

Factors that have same effect regardless of population size
eg. flooding, fires

Question 9

Lag phase

Answer 9

Population still small but starting to increase

Question 10

Exponential growth phase

Answer 10

Population increases rapidly, limited threats, abundant resources

Question 11

Transitional phase

Answer 11

DDF start to impact population growth

Question 12

Plateau phase

Answer 12

Population remains close to carrying capacity

Question 13

Stable equilibrium

Answer 13

When population aligns with carrying capacity

Question 14

Intraspecific relationships

Answer 14

Interactions between members of same species
Competition or cooperation

Question 15

Competition

Answer 15

Same species have same ecological niche and need same resources

Question 16

Coorperation

Answer 16

Relationships where both species benefit

Question 17

Community

Answer 17

Group of populations living together in an area and interacting with each other
Includes all populations in a specific area

Question 18

Herbivory

Answer 18

Primary consumers eating plants
Producer may or may not be killed

Question 19

Predation

Answer 19

One consumer species killing and eating another

Question 20

Interspecific competition

Answer 20

Two or more species using the same resource

Question 21

Mutualism

Answer 21

Two species living in close association
Both species benefit

Question 22

Parasitism

Answer 22

One specifies (Parasite) lives on/in another species (host)
Parasite benefits, host is harmed

Question 23

Pathogenicity

Answer 23

One species (pathogen) living inside other (host), causing disease in host
Pathogen benefits, host harmed

Question 24

Commensalism

Answer 24

Relationship where one species benefits from another while the other is not affected

Question 25

Antibiosis

Answer 25

Two organisms interact in a way that harms one of both of them

Question 26

Endemic species

Answer 26

Species that occur naturally in an area

Question 27

Alien species

Answer 27

Species introducted to an area by humans

Question 28

Invasive species

Answer 28

If alien species increase in number and spreads

Question 29

Dynamic equilibirum

Answer 29

Balance between opposing forces

Question 30

Cyclical oscillations

Answer 30

Rise and fall of populations in a cyclical nature

Question 31

Direct interaction

Answer 31

Predator feeds on prey/herbivore feeds on producer

Question 32

Indirect interaction

Answer 32

Population size of predator can affect the population of producers from impact on herbivore prey

Question 33

Top down control

Answer 33

Process where higher level species regulate lower level species

Question 34

Bottom up control

Answer 34

Process where lower level species regulate higher level species

Question 35

Antibiotics

Answer 35

Compounds secreted by microorganisms to kill or prevent growth of other microorganisms

Question 36

Penicillium

Answer 36

A saprotrophic fungi that lives in soil that secretes digestive enzymes and absorb digestion of organic molecules, reducing competition that interfere with bacterial cell wall formation

Question 37

Allelopathic agents

Answer 37

Compounds secreted into soil by plants to influence growth, survival or reproduction of others Inhibiting nearby growth reduces competition, increases availability of resources

Question 38

Chi squared test

Answer 38

Statistical test used to examine whether two variables are independent in influencing test statistic

Question 39

Statistical significance

Answer 39

Outcome of statistical hypothesis test

Question 40

Usual significance level

Answer 40

5%/p=0.05

Question 41

Chi squared test method

Answer 41

1. State null and alternative hypothesis 2. Contingency table with observed values 3. Contingency table with expected values and calculate expected frequency 4. Determine degrees of freedom 5. Find critical value 6. Find Chi squared value 7. Compare Chi squared value to critical value, if X^2> critical value, reject null and accept H1

Question 42

Expected frequency formula

Answer 42

(Row totale * column total)/Grand total

Question 43

Degrees of freedom formula

Answer 43

(m-1)(n-1) m = number of rows n = number of columns