bio exam #1 Flashcards
(112 cards)
1
Q
what is a hypothesis
A
testable statement to a possible explanation
2
Q
what is a theory
A
explanation based on evidence
3
Q
what is a controlled experiment
A
scientific study in which a variable is manipulated or changed (independent variable)
4
Q
what is the dependent variable
A
(variable being tested and measured in the experiment) depends on changes from the independent variable
5
Q
what is the independent variable
A
variable being manipulated or changed in the experiment to observe the affect on the dependent variable
6
Q
does science have fundamental limitations
A
yes! science doesn’t tell us what color a bomb is it just tells us how to build it (like instruction book)
7
Q
hypothesis or theory: if I put more soil on my plants they will grow more
A
hypothesis
8
Q
evolution is fact or no fact? why?
A
fact! due to natural selection
9
Q
evolution
A
change in a population/species over time
10
Q
can hypothesis and theories be changed
A
yes! they can be modified and proven wrong
11
Q
what is natural selection
A
survival and reproductive success to adapt to the environment, helps lead to best characteristics suited for that environment
12
Q
can you choose a mutation
A
no it just happens, have to adapt to survive
13
Q
fitness
A
individuals who are better adapted to environments have higher reproductive success
14
Q
what is sexual selection
A
form of natural selection through preference by one sex for a particular characteristics in individuals of the other sex (traits increase attracting a mate)
15
Q
what does sexual selection lead to
A
non-random mating
16
Q
what is sexual dimorphism
A
differences between sexes (men have larger necks than women
17
Q
which of the following are variables:
a)body length in a fish
b)sex in honey bees
c)the mass of an electron
A
a) the body length in a fish
18
Q
matched variable
A
multiple environmental variables (time of year, temp, etc)
19
Q
independent variable
A
variable being tested (ex: tail length being tested: normal, long, short)
20
Q
dependent variable
A
variable being measured
21
Q
what is a scientific fact
A
an objective and verifiable observation
22
Q
what is genetic drift
A
the change in genetic makeup of a population due to random events
23
Q
what can evolution be caused by
A
1)genetic mutations
2)natural selection
3)non-random mating
4)drift
5)migrations
24
Q
is natural selection the only mechanism driving evolution
A
no, not the only one but is important
25
migration/gene flow
individuals move from one population to another & take new genes with them altering the new population
26
what is a biome
defined by their predominant vegetation
27
alaska is an example of what biome
tundra
28
boreal forest/tiaga forest
forest with lake (canada)
29
chicago is an example of what biome
deciduous
30
colorado is an example of what biome
grassland/prarrie
31
arizona is an example of what biome
desert
32
brazil is an example of what biome
tropical rainforest
33
what factor is the most influential to terrestrial biomes
precipitation & temp
34
what can determine if it's grassland or forest
soil (nutrients), sunlight, wind (evaporation), disturbances (tornado, flood..)
35
ex: bluff has a forest are and area with grass
different biomes on same bluff (in winter grassland has rabies, etc. because snow is able to fall down it.
36
why do we have seasons
earths tilt; can influence biomes
37
what conditions affect temp and rainfall
-latitude
-altitude
-mountains
-oceans
38
why are seasons more pronounced at higher altitudes
the tilt of the earths axis
39
what determines the global position of desert biomes?
climate (mountain ranges, ocean currents, atmospheric patterns)
40
what is a hadley cell
light energy hits water forming clouds, air above clouds is dense, can't fall on equator bc cloudy (hence why deserts are in the middle of the earth)
41
what is the main factor dictating earths temp distribution
the amount of sunlight per unit area
42
what are the aquatic ecosystem zones
photic-receives light
aphonic-does't receive light
benthic- bottom of lake/ocean/river
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Intertidal zone
alternates between dry and wet
44
benthic zone
organisms living on ocean bottom
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estuary
where river meets ocean
46
thermoclines & lake turnover
winter: top-colder (frozen) bottom: warmer (fish swim)
summer: top-hotter (sunlight) bottom: colder (less light)
47
difference between marsh, swamps, bogs
marsh: non-woody plants
swamps: trees & shrubs
bogs: stagnant & acidic
48
bottom of a lake is called
benthic zone
49
a lake turning over in the spring and fall is important for
carrying sediments and nutrients up from the benthic zone
50
a lake with low levels of nutrients is called
oligotrophic
51
what is population ecology
study of how/why the # of individuals in a population changes over time (projects&predicts)
52
how do you estimate population side in a natural system
"mark and recapture"
capture & tag random sample individuals (s) in a pop.
capture a second sample of individuals (n) and note how many are marked (x)
population size (N) is estimated
53
model used to collect population size: N=sn/x
x=(marked recaptures)
n=(total in second sample)
s=(marked initially)
N=(total pop. size)
54
models that predict change in pop. size
exponential model (J-curve)
logistic model (S-curve)
55
what four demographic factors determine pop. number (size)
-births
-deaths
-immigration (migration in)
-emigration (migration out)
56
why do ecologists determine pop. size
to predict future size of pop. at various initial conditions as possible
57
exponential model makes several assumptions:
-pop. is closed w/o immigration/emigration
-pop. is small
-no competition (resources are unlimited)
-conditions do not change
58
how to find pop. in next generation
change in pop. size = births - deaths
a pop. will grow when B>D
a pop. will shrink when B
59
how to find pop. growth rate
r= birth rate (b) - death rate (d)
if b > d, then r is positive
if b < d then r is negative
60
per-capita rate of increase (r) is influenced by:
1. age of first repro.
2. frequency of repro.
3. fecundity: the avg. # of offspring
4. length of reproductive life span
5. survival of young
61
Low mortality in young
produce fewer young and care for them until adulthood
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high mortality in young
produce many young which must fend for themselves
63
intermediate
less common, some invertebrates and rodents
64
what is fecundity
the # of female offspring produced by each female in a population
65
what is age-specific fecundity
the avg. # of female offspring by a female in age class x
66
environmental factors that restrict population growth
-availability of food and resources
-competition within species
-interactions between species
67
in an S curve early growth is rapid when
at the beginning of the curve
68
in an S curve when does growth begin to slow
the middle of the curve
69
in an S curve when does later growth fall to 0
at the top of the curve
70
what are some limiting factors affecting pop. size
weather, human activities (pollution, pesticides, habitat destruction), predator and prey pop.
71
population growth rate beings slowing where
middle of the S curve
72
what does a negative pop. growth rate tell you abt. the dynamics of the pop.
the pop. size is decreasing instead of increasing
73
A community is defined by its
biodiversity, prevalent forms of vegetation (temp, rainfall, nutrients), stability (resistance or resilience), trophic structure (movement of energy)
74
host-specific
need to find right host or they can't reproduce
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biological communities
populations of different species living together and interacting in a particular area
76
"+" "-" "0"
+ beneficial to one of the organisms
- detrimental to one of the organisms
0 neutral to one of the organisms
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parasitism
(+/-)
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mutualism
(+,+)
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commensalism
(-,-)
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symbiosis "living together"
parasitism, mutualism, commensalism
81
ecological niche
the role a species plays in the community
82
what is the difference between a fundamental niche & realized niche
fundamental niche- all conditions under which all organisms can live
realized niche- set of conditions under which it exists in nature
83
competitive exclusion
if one species is better adapted to an environment than a competing species, eventually the first species will drive the second species out of that environment
84
Interspecific competition
if members of different species require the same resource (limited resource) (ex: food, pollinators, light, shelter...)
natural selection favors individuals that do not compete
85
ways to decrease competition
resource partitioning (feeding at different times, or feeding off different habitats)
86
examples of competition
fast vs slow repro.
natural predators vs no natural pred.
host required vs no host required
86
what can control the spread of a overpopulated species
competition, predation, parasites/diseases
87
role of predators in community
prey on young & old animals
88
population with a keystone predator vs without
results in diverse adaptations in predator and prey
89
predation
form of consumption (individual consumes another)
90
coevolution
when predators evolve to catch they prey they've caught, and prey evolve to avoid getting caught
91
preditor vs prey adaptations
prey- camouflage, deceptive coloring, mimicry
predator- sight, smell, stronger jaws (evolution)
92
potential vs kinetic energy
potential= stored energy (chemical)
kinetic=energy of motion (movement, light, heat)
93
trophic levels
feeding levels based on organisms role in the flow of energy through communities
94
producers and consumers in tropic levels
producers- convert kinetic energy (solar) into potential energy (chemical)
consumers-convert potential energy back into kinetic energy movement & heat
95
autotroph
(auto = self , troph = feeder
96
heterotroph
hetero = other , troph = feeder
97
primary, secondary, tertiary consumers
primary consumers (herbivores) feed exclusively on producers
secondary consumers (carnivores) eat the flesh of other animals
tertiary consumers eat other carnivores
98
trophic levels within a food chain
primary producer-plant (flower)
primary consumer-herbivore (cricket)
secondary-carnivore (rat)
tertiary- carnivore (snake)
quaternary- carnivore (eagle)
99
decomposer/detritivore food web
bacteria and fungi digest food outside of the body and release nutrients into soil and water
100
detritus feeders
live off waste and dead remains of other organisms (worms)
101
what percentage of energy is passed from one trophic level to the next
10% energy will lower through each consumer > lowest will be top of pyramid (can NEVER be 100%) some goes to decomposer food web, some lost as heat, others support growth, so 10% is left for consumer food web
102
how much energy is passed from one trophic level to the next
(chart going down) take primary consumers total and divide it by the primary producer (work backwards) ex: 3,368/20,810=0.1618.. so 16%
103
benefits of biodiversity to humans
food, drugs & medicine, cultural & ecological benefits,
104
what is biomagnification
toxins will rise as you get to top predator because the concentration of toxins in an organism are more widely disbursed
105
a population is more likely to evolve by genetic drift when..
the population is small
106
what is genetic drift
a mechanism of evolution that can lead to traits disappearing from a population or becoming very common (evolution of a species)
107
when looking at age pyramids what can we not determine
the success of future generations
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