Ecosystems and Living Organisms Lecture 5

Question 1

What is evolution?

Answer 1

cumulative genetic changes that occur in a population overtime

Question 2

How does evolution occur?

Answer 2

through natural selection

Question 3

Who proposed evolution theories

Answer 3

charles darwin, a 19th century naturalist

Question 4

What is natural selection?

Answer 4

individuals with more favorable genetic traits are more likely to survive and reproduce

Question 5

What observations is natural selection based on?

Answer 5

1. high reproductive capacity
2. heritable variation
3. limits on population growth or a struggle for existence
4. differential reproductive success

Question 6

What is High Productive Capacity?

Answer 6

produce more offspring than will survive to maturity

Question 7

What is Heritable Variation?

Answer 7

individuals vary in traits that may impact survival

Question 8

What are limits on population growth or struggle for existence?

Answer 8

outside pressure on which individuals will survive

Question 9

What is Differential Reproductive Success?

Answer 9

best-adapted individuals reproduce more successfully than less adapted individuals

Question 10

What is the Modern Synthesis?

Answer 10

ecologists synthesized Darwin’s theory with growing knowledge of genetics, molecular biology, developmental biology, and the fossil record

Question 11

What is Archaea?

Answer 11

frequently live in oxygen-deficient environments; often adapted to harsh conditions

Question 12

What is bacteria?

Answer 12

all other prokaryotes; thousands of species; important in biochemical cycles

Question 13

What are prokaryotes?

Answer 13

do not possess a cell nucleus or any other membrane-bound organelles

Question 14

What are eukaryotes?

Answer 14

possess a high degree of internal organization (nuclei, mitochondria, chloroplasts, etc)

Question 14

What are eukaryotes?

Answer 14

possess a high degree of internal organization (nuclei, mitochondria, chloroplasts, etc)

Question 15

What is Population Ecology?

Answer 15

study of populations; how and why numbers change over time

Question 16

What is population ecology important for?

Answer 16

endangered species, invasive species, proper management

Question 17

What is population density?

Answer 17

the number of individuals of a species per unit area or volume at a given time

Question 18

What is growth rate?

Answer 18

rate of change of a population’s size, expressed as a percent per year

Question 19

What is the growth rate formula?

Answer 19

r= b-d

Question 20

What does “r” stand for in r=b-d?

Answer 20

growth rate

Question 21

What does “b” stand for in r=b-d?

Answer 21

births/1000 people

Question 22

What does “d” stand for in r=b-d?

Answer 22

deaths/1000 people

Question 23

What formula accounts for dispersal?

Answer 23

r= (b-d) + (i-e)

Question 24

What does "i" stand for in r=(b-d)+(i-e)?

Answer 24

immigration rate

Question 25

What does "e" stand for in r=(b-d)+(i-e)?

Answer 25

emigration rate

Question 26

What is dispersal?

Answer 26

movement of individuals in or out of an area

Question 27

What is intrinsic rate of growth (biotic potential)?

Answer 27

exponential growth under ideal conditions

Question 28

What are the rates with larger organisms?

Answer 28

larger organisms, smaller rates

Question 29

What are the rate with smaller organisms?

Answer 29

smaller organisms, faster reproduction rates, larger intrinsic rates of increase

Question 30

What characteristics determine a species' growth rate?

Answer 30

1. age of onset of reproduction 2. fraction of lifespan for reproduction 3. # of reproductive periods 4. # of offspring per reproductive period

Question 31

What are environmental limits (resistance to intrinsic growth)?

Answer 31

prevent indefinite reproduction and unfavorable food, water, shelter predation, etc

Question 32

What is negative feedback mechanism?

Answer 32

change in condition triggers response that reverses condition

Question 33

What is carrying capacity (K)?

Answer 33

maximum # of individuals an environment can support

Question 34

What does carry capacity cause?

Answer 34

causes leveling off of exponential growth and s-shaped curve of logistic population growth

Question 35

What factors affect population size?

Answer 35

density- dependent and density- independent factors

Question 36

What is a density-dependent factor?

Answer 36

effect on population changes as population density changes (predation, disease, and competition)

Question 37

What is a density-independent factor?

Answer 37

factors that affects population size, but is not influenced by changes in population density (killing frost, severe blizzard, or fire)

Question 38

What can density-dependent factors lead to?

Answer 38

to boom-or-bust population cycles

Question 39

What are biological communities?

Answer 39

communities vary greatly in size and lack precise boundaries

Question 40

What is an ecological niche?

Answer 40

totality of an organism's adaptations, its use of resources, and the lifestyle to which it is fitted

Question 41

What aspects does an ecological niche take into account?

Answer 41

all aspect of an organisms existence

Question 42

What is a fundamental niche?

Answer 42

potential idealized ecological niche

Question 43

What is a realized niche?

Answer 43

the actual niche the organism occupies

Question 44

What are limiting resources?

Answer 44

any environmental resource that restricts the ecological niche of an organism

Question 45

What is intra-specific?

Answer 45

competition between individuals in a population

Question 46

What is inter-specific?

Answer 46

competition between individuals in two different species

Question 47

What is competitive exclusion?

Answer 47

one species excludes another from a portion of the same niche as a result of competition for resources

Question 48

What is resource partitioning?

Answer 48

coexisting species' niche differ from each other

Question 49

What is symbiosis?

Answer 49

an intimate relationship between members of two or more species

Question 50

What are the three types of symbiosis?

Answer 50

mutualism, commensalism, parasitism

Question 51

What is mutualism?

Answer 51

symbiotic relationship in which both members benefit

Question 52

What is commensalism?

Answer 52

symbiotic relationship where one species benefits and the other is neither harmed nor helped

Question 53

What is parasitism?

Answer 53

symbiotic relationship in which one species is benefited and the other is harmed

Question 54

What is a keystone species?

Answer 54

a species, often a predator, that exerts profound influence on a community

Question 55

When do keystone species get noticed?

Answer 55

the dependence of other species on the keystone species is apparent when the keystone species is removed

Question 56

What is species richness?

Answer 56

the number of species in a community

Question 57

What is species richness related to?

Answer 57

the abundance of potential ecological niches

Question 58

What can species richness do to communities?

Answer 58

make them more stable