chapter 4

Question 1

species

Answer 1

group of organisms: can potentially interbreed to produce fertile viable offspring

cannot produce fertile viable offspring w different species

hybrids offspring of species are reproductively sterile

Question 2

population

Answer 2

group of organisms of same species living in same area at same time

Question 3

organisms living in different regions

Answer 3

=reproductively isolated + unlikely to interbreed, classified as same species if interbreeding = functionally possible

Question 4

community

Answer 4

group of populations living together + interacting in given area

Question 5

habitat

Answer 5

environment where species’ typically live/ location of living organism

Question 6

ecosystem

Answer 6

community + its abiotic environment

Question 7

ecology

Answer 7

study of relationship between living organsims, or between living organisms + environment

Question 8

autotroph

Answer 8

produce own organic molecules, using light or energy derived from oxidation of chemicals

synthesise organic molecules from simple inorganic substances

Question 9

heterotroph

Answer 9

obtain organic molecules from other organisms

Question 10

mixotroph

Question 11

three modes of heterotroph nutrition/ three types of heterotrophs

Answer 11

consumer, detritivore, saprotroph

Question 12

consumer

Answer 12

ingest organic molecules from living/recently killed organism

Question 13

detritivore

Answer 13

ingest molecules from non living organisms remnants (detritus, humus)

eg earthworm, woodlice, snail, crab

Question 14

saprotroph

Answer 14

live on/in non living organic matter release digestive enzyme + then absorb external products of digestion (decomposer)

eg bateria, fungi

Question 15

autotrophs derive energy via

Answer 15

photosynthesis: energy from sunlight

chemosynthesis: oxidation of inorganic chemicals

Question 16

autotrophs obtain simple inorganic substances required from abiotic environment, including

Answer 16

carbon, nitrogen, hydrogen, oxygen phosphorous obtained from air, water, soil

Question 17

heterotrophs may obtain simple organic substances from environment but…

Answer 17

principally obtain carbon and nitrogen from organic molecules produced by autotrophs

Question 18

humus vs detritus

Answer 18

humus: decaying leaf matter mixed with topsoil

detritus: dead matter = decaying organic matter/fecal matter

Question 19

scavenger

Answer 19

consumer that feed on dead decaying carcasses rather than hunting live prey

eg hyenas, vultures crows

Question 20

nutrients

Answer 20

material required by organism (including elements eg carbon, nitrogen phosphorus)

Question 21

supply of inorganic nutrients is finite

Answer 21

chemical elements are recycled after use

Question 22

chemical elements constantly recycling

Answer 22

autotrophs: inorganic nutrients from air, water soil + covert into organic compounds

heterotrophs: ingest the organic compounds, using for growth, respiration, releasing inorganic byproducts

saprotroph: organisms d

Question 23

chemical elements constantly recycling

Answer 23

autotrophs: inorganic nutrients from air, water soil + covert into organic compounds

heterotrophs: ingest the organic compounds, using for growth, respiration, releasing inorganic byproducts

saprotroph: organisms die, so decompose remains of free inorganic molecules into soil

return of inorganic nutrients to soil = continual supply of raw materials for autotroph

Question 24

ecosystem

Answer 24

the interaction between biotic components (eg communities and abiotic components (eg habitat)

self contained and can self sustain over long period

Question 25

components for sustainability of ecosystem

Answer 25

energy availability, nutrient availability, recycling of wastes

Question 26

energy availability (ref; sustainability of ecosystem)

Answer 26

light from sun provides initial energy source for almost all communities

Question 27

nutrient availability

Answer 27

saprotrophic decomposers mean constant recycling of inorganic nutrients in environment

Question 28

recycling of waste

Answer 28

bacteria can detoxify harmful waste byproducts

Question 29

mesocosm

Answer 29

enclosed environments allowing small parts of natural environments to be examined in controlled condition

Question 30

presence of two species in given environment is

Answer 30

dependent on potential interactions between them.

Question 31

two species typically found in same habitat have

Answer 31

positive association (include predator/prey or symbiotic relationships)

Question 32

symbiotic relationship

Answer 32

close and longterm biological interaction between different organisms

Question 33

negative correlation

Answer 33

when two species tend not to occur in same habitat

Question 34

competitive exclusion

Answer 34

1 species may utilise resources more efficiently, preventing survival of other species

Question 35

resource partitioning

Answer 35

species may alter use of environment to avoid direct competition

Question 36

when species don't interact and there is no association between them

Answer 36

no association

Question 37

quadrat sampling

Answer 37

presence of 2 species in given environment, using rectangular frame to establish population densities. are placed inside defined area in either random arrangement or patterned arrangement estimations or counting of species in area occurs sampling process repeated for representative data set

Question 37

quadrat sampling

Answer 37

presence of 2 species in given environment, using rectangular frame to establish population densities. are placed inside defined area in either random arrangement or patterned arrangement estimations or counting of species in area occurs sampling process repeated for representative data set

Question 38

chi squared test

Answer 38

can be applied to data generated from quadrat sampling to determine if theres statistically significant association between distribution of two species

Question 39

chi-squared in 5 steps:

Answer 39

Identify hypotheses (null vs alternative) Construct table of frequencies (observed vs expected) Apply chi-squared formula Determine degree of freedom (df) Identify p value (should be <0.05)

Question 40

chi-squared test seeks to distinguish between

Answer 40

two distinct possibilities therefore requires two contrasting hypotheses (null + alternative hypotheses

Question 41

Null hypothesis (H0):

Answer 41

= no significant difference between distribution of 2 species (i.e. distribution = random)

Question 42

Alternative hypothesis (H1):

Answer 42

=significant difference between distribution of species (i.e. species = associated)

Question 43

for comparison against observed

Answer 43

table must be constructed that identifies expected distribution frequencies for each species

Question 44

expected frequency calculation

Answer 44

(row total x column total) ÷ grand total

Question 45

chi squared formula

Answer 45

x^2 = ∑(O-E)^2 / E

Question 46

degree of freedom

Answer 46

mathematical restriction that designates what range of values fall within each significance level

Question 47

determining degree of freedom

Answer 47

df = (m-1) (n-1) m = n.o rows n= n.o columns when distribution pattern of two species being compared, degree of freedom should always be 1

Question 48

identifying p value

Answer 48

(continue lateer bc confused)

Question 49

all green plants + some. bacteria are _____ bc they use sunlight as energy source

Answer 49

photoautotrophic

Question 50

light

Answer 50

initial source of energ

Question 51

chi squared result