Transcript Ecology Test Review - Northwest ISD Moodle

Ecology Test Review
Explain primary succession
The development of an ecosystem following a
catastrophic event (such as a volcanic
eruption), a new land mass forming, or a
depression filling in with water for the first
time
Explain secondary succession
Development of an ecosystem after a
disruption, such as a tornado or fire, with soil
still remaining.
Hydrilla is an invasive aquatic weed that forms thick mats on
the water surface in the absence of natural enemies. The fastgrowing weed takes away habitat from the other aquatic plants
and open-water inhabiting organisms. Thick mats on the water
surface reduce the amount of sunlight reaching plants in deeper
water, reducing their ability to photosynthesize.
How might this weed affect the functioning of this ecosystem?
 The mats of hydrilla would keep the sunlight
from penetrating the water, which in turn keeps
photosynthesis from taking place. Reduced
photosynthesis means less oxygen in the water.
What is the role of decomposing
bacteria in the food chain?
Decomposing bacteria break down dead and
decaying matter releasing nutrients back to
the soil for plants to take up.
What organisms are responsible for
taking up nitrogen in the environment
and incorporating it into their tissue for
other organisms to get when they eat?
 Plants
What will be the effect on this
ecosystem if bacteria infect and begin
to kill off the frog population?
Increase in the insect population, especially the
mosquitoes which can lead to disease in other organisms
What might have caused the decline in
species diversity in 1980?
Catastrophic events such as a volcanic
eruption since it wiped out most populations.
In primary succession how must the
land develop before it can sustain
trees and larger animals
 Barren rock such as lava
 Pioneer species such as lichens appear to
break down rock
 Early colonizers
 Opportunists
 Climax Community
What causes the overgrowth of algae
and how might this effect an aquatic
ecosystem?
 Nutrient run-off from over fertilized
terrestrial areas cause algae overgrowth. Algae
overgrowth can keep light from penetrating
the water which will in turn keep aquatic
plants from photosynthesis. Lack of
photosynthesis decreases oxygen in the water.
What factors contribute to an excess of
carbon output into the atmosphere?
 Burning and destroying terrestrial biomes
 Respiration by organisms
 Burning of fossil fuels
 Decomposition
What effect could a dam being built at
the end of a river that flows into the
ocean have on the marine ecosystem?
 A dam would keep nutrients that are
flowing in the water from reaching other
plants and animals beyond that point.
How does the adaptation of the iris to
open and close the pupil benefit
organisms with eyes?
 During the day and in brightly lighted areas
the iris will constrict allowing less light to
enter
 During the evening the iris dilates allowing
more light to enter
Why are there very few tertiary
consumers in a food chain?
 There is more competition for the available
energy since energy decreases as it goes up
the trophic levels
From our pond water web activity, what
was the possible effect of introducing
Asian carp into the pond ecosystem?
 Asian carp will compete for the
phytoplankton in the ecosystem. This
decreases the availability of phytoplankton
to other organisms.
What is the possible reasoning for
omnivores to be able to adapt to
changing environments better than
carnivores or herbivores?
 Omnivores eat both plants and animals. This
ability benefits them when food sources
become limited.
Define exponential growth.
 Steady, sustained growth of populations
when resources are unlimited.
Define logistic growth.
 Growth of a population when resources
become limited and carrying capacity is
reached
Define carrying capacity.
 The maximum number of organisms an
ecosystem can sustain with the available
resources.
Can photosynthesis take place without
light?
NO
Can cellular respiration take place
without oxygen?
NO
Grassland Characteristics
 Temperate grasslands are characterized as
having grasses as the dominant vegetation.
Trees and large shrubs are absent.
Temperatures vary more from summer to
winter, and the amount of rainfall is less in
temperate grasslands than in savannas.
Immigration vs. Emigration
 Immigration – movement of organisms
into the population
 Emigration – organisms exiting the
population
What are antibiotics?
 Medications made to kill bacterial
infections. Some of these medications are
made from the toxins given off by fungi
(such as penicillin).
Define succeed
 take the place of, take over from, follow,