ch 14- ecology

Question 1

● Cold winters with snowfall
● Warm, rainy summers
● Largest terrestrial biome

Answer 1

taiga
coniferous forest

Question 2

● Cold
● Very little precipitation (mostly snow)
● Ground freezes during winters
● Topsoil thaws during summer, but deeper soil is permafrost
(stays frozen)

Answer 2

tundra

Question 3

● Hot days
● Cold nights
● Extreme temperature fluctuations
● Very little rain
● Plant growth occurs after rainfall
● Animals are often nocturnal and water conservative
(concentrated urine)
● Plants have leather leaves or spines to conserve water

Answer 3

desert

Question 4

● Mild winters
● Hot, dry summers
● Scattered vegetation, often with small, tough leaves to conserve
water
● Common droughts and fires

Answer 4

chaparral

Question 5

● Warm summers
● Cold winters
● Moderate precipitation
● Snows during winter
● Trees shed leaves in the winter due to poor growing conditions

Answer 5

temperate dicidious forest

Question 6

● Cool winters
● Hot summers
● Seasonal rain (less rain than savannas)
● Seasonal droughts and fires

Answer 6

temperate grasslands

Question 7

● High temperatures
● Small amount of rainfall (seasonal)
● tropical grasslands with diffuse trees
● Seasonal droughts and fires

Answer 7

savanas

Question 8

● Consistent, hot temperature
● Consistent, heavy rainfall
● Biome with the greatest amount of diversity

Answer 8

tropical rainforest

Question 9

aphotic zone

Answer 9

No light or photosynthetic
species. Some bioluminescent species. Select
fish can survive off of dead matter descending to
the ocean floor.

Question 10

disphotic zone

Answer 10

zone: Semi-irradiated with sun (not
sufficient for plants). Bioluminescent species
produce light here.

Question 11

euphotic zone

Answer 11

Strong irradiance allows for
plant survival and photosynthesis. Closest to surface.

The littoral zone is the area of the
euphotic zone where sunlight penetrates all the way to the ocean floor.

Question 12

largest earth biome

Answer 12

Aquatic biomes:
Largest of Earth’s biomes (~75% of Earth’s surface).
Photosynthetic algae contribute most of Earth’s
atmospheric O2

Divided into
freshwater biomes (~3%) and
saltwater biomes (~97%).

Question 13

brackish water

Answer 13

at estuaries where salt water meets freshwater

Question 14

eutrophication

Answer 14

process whereby a body of
water becomes enriched with minerals and nutrients. This can lead to an algal bloom, a rapid increase in the population of algae (photosynthetic eukaryotes) and/or cyanobacteria (photosynthetic prokaryotes).

Algal blooms lead to the depletion of oxygen in the water, which can kill off aerobic organisms in the area (e.g., fish), damaging natural aquatic
ecosystems.

Question 15

what causes eutrophication

Answer 15

Eutrophication is often a result of industrial nitrogen-rich fertilizer use. Nitrogen-rich fertilizer can dissolve in rain water, eventually accumulating in an aquatic biome, supporting the growth of algal blooms.

Question 16

keystone species

Answer 16

maintains ecological balance
despite low abundance (eg. keystone predator
hunts other animals and prevents overabundance).

Question 17

secondary succesion

Answer 17

occurs on terrain that has
supported life previously, and has had destruction
following a disturbance (e.g., flood, fire). Follows a
similar pattern as primary succession but begins
with grasses & shrubs.

Question 18

primary succession

Answer 18

occurs after a large disturbance
in an area that has never supported life. Begins with a
pioneer species (e.g., lichen, fungi, algae).

Question 19

The order of organisms colonizing is:

Answer 19

pioneer species → thin soil → vascular plants (grasses,
shrubs) → larger plants (trees) → animals
Eventually a climax community results. A steady
state is reached and a balance of species is achieved.

Question 20

ecological succession

Answer 20

is the predictable process
where an ecological community develops and
changes over time. Occurs in a new habitat or after a
disturbance.

Question 21

malthus

Answer 21

scientist best known for his principle
of population theory. This theory proposes that the
human population increases geometrically (2, 4, 16,
132..) while food production increases arithmetically
(2, 4, 6, 8…) and will not be able to keep up with
population growth.

Question 22

Type II survivorship species:

Answer 22

● Mortality rate is roughly constant throughout the organism’s life span (survival chances do not significantly increase or decrease at any stage of
life).
● Examples: Many birds, small mammals, and some reptiles.

Question 23

r- selected species

Answer 23

● Type III survivorship curve.
● Produce a high number of offspring with lower survival rates.
● Short gestation periods with quick development and early maturation.
● Greater number of offspring ensures some will survive, despite low parental care and unstable environmental conditions
● Population size fluctuates wildly. Population densities well below carrying capacity of the environment.
● Examples: Insects, frogs.

Question 24

k- selected species

Answer 24

● Type I survivorship curve.
● Produce fewer offspring with higher survival rates.
● Long gestation periods with slow development and late maturation.
● High parental care and investment in fewer offspring to ensure survival and competitive success.
● Population size is relatively stable and near the carrying capacity of the environment.
● Examples: Elephants, humans.

Question 25

carrying capacity

Answer 25

The maximum population size
an ecosystem can sustain.

Question 26

biotic potential

Answer 26

A species’ ability to undergo its
highest population growth (highest births, lowest
deaths) when conditions are ideal.

Question 27

autotrophs vs heterotrphs

Answer 27

Autotrophs are able to fix carbon, therefore they
use CO2 as its primary carbon source. Heterotrophs,
however, are unable to fix carbon and derive its
carbon from organic compounds.

Question 28

photoautotrphs energy and carbon source

Answer 28

light

cO2

Question 29

chemoautotrophs energy and carbon source

Answer 29

inorganic compounds

CO2

Question 30

photoheterotrophs energy and carbon source

Answer 30

light

organic compounds

Question 31

chemoheterotrophs energy and carbon source

Answer 31

inorganic compounds

organic compounds

Question 32

symbiosis

Answer 32

(living together) is a close, long-term
interaction between two organisms (symbionts).

mutualism (+/+)
commensalism (+/0)
parasitism (+/-)

Question 33

ecological pyramid

Answer 33

Graphical representation of
the accumulation of biomass at each trophic
level.

Question 34

autotroph

Answer 34

produces organic compounds from
abiotic factors (sunlight, water, CO2
, etc.)

Question 35

lithotroph

Answer 35

utilize inorganic compounds as their
electron donors during cell respiration.

Question 36

herbivore

Answer 36

plant eater. Has longer intestinal
tract and cecum to eat plants.

Question 37

naturalized species

Answer 37

a type of non-native
species that spreads beyond origin that
showcases sufficient reproduction to maintain its population.

Question 38

exotic species

Answer 38

a type of non-native species that
lives outside of its native-distributional range due to human activity.

Question 39

how much of the energy stored in a trophic level is converted to organic tissue in the next trophic level

Answer 39

10% of the energy

bc energy transfer is inefficient between trophic
levels. As energy moves up each trophic level in the
pyramid, ~90% of it is lost as heat.

Question 40

scavengers

Answer 40

Scavengers (carnivores or herbivores) consume
other dead animals (or plants). E.g., vultures, some
beetles.

Question 41

decomposers

Answer 41

Decomposers (saprophytes, fungi,
detritivores) breakdown and recycle dead
plant/animal material.

fungi are the most important decomposers

Question 42

saprophytes

Answer 42

Saprophytes (plants, fungi,
microorganisms) consume dead or decaying organic
material, and work with scavengers in organic
recycling.

Question 43

detrivores

Answer 43

Detritivores (worms and slugs) consume detritus,
exposing more organic material for decomposers.

detritus is formed by Fungi (most important decomposers) and
some bacteria decompose organisms, forming
detritus (feces and decomposing matter). m,˜≥÷b