Download Unit_8_MHS_Bio_Review_Guide_ANSWERS

BIOLOGY – Mr. Channell
NAME: _______________________
Biology Unit 8 Review Guide ANSWERS
Complete on a separate sheet of paper if needed.
1. Define ecology. What does it study?
Ecology is the study of interactions between organisms and their
environment.
2. Give an example of each of the following: population, ecosystem, community.
Population – a group of rabbits of the same species living together.
Community – rabbit, deer, grass, trees, squirrel, and wolf species populations
living together.
Ecosystem – all of the previously mentioned species populations in that
community PLUS the Michigan forest they live together in.
3. Put in order from least to most inclusive: population, ecosystem, biosphere,
community, organism.
(most inclusive) biosphere, ecosystem, community, population,
organism (least inclusive)
4. Explain the difference between acclimation & adaptation. Give an example of
acclimation and an example of an adaptation.
Acclimation = changes that increase individual function in response to
environmental changes that will not be passed along to offspring (EX:
exercise)
Adaptation = changes that increase individual function in response to
environmental changes that will be passed on to offspring (EX: snake’s
camoflauge)
5. Explain the difference between an organism's habitat and its niche.
Habitat = where an organism lives (EX: in trees, in water)
Niche = the role an organism plays in its ecosystem (EX: what it eats, what
eats it)
6. Define biotic factors and give 2 examples.
Biotic factors = activities of living organisms that affect other organisms (EX:
predation, parasitism, disease)
7. Define abiotic factors and give 2 examples.
Abiotic factors = non-living factors that affect organisms (EX: weather,
water, pH, pollution, light)
8. When conditions change or become unsuitable, what could an organism do? What
may happen to it?
An organism could potentially have traits that allow it to adjust while others
do not. It could also potentially migrate to another area that is more suitable.
The organism could also simply not be able to adjust and die.
9. What is the ultimate source of energy in ecosystems?
The sun
10.How is biological energy stored in ecosystems?
Energy for organisms is stored in the bonds that hold chemical compounds
together within organisms
11.What process adds biomass to ecosystems?
Biomass is an example of a chemical compound that holds energy. It is
mainly comprised of Carbon, Hydrogen, and Oxygen. It can be added to
ecosystems by either organism growth or death of organisms.
12.What is a “trophic level”?
A trophic level describes the hierarchy of producers, consumers, and
decomposers in the scheme of energy transfer in an ecosystem.
13.Why isn't all of the energy transferred from one trophic level to the next?
-Energy transfer is only about 10% efficient for each level. Around 90% of
the energy is lost as heat due to metabolic processes.
14.Define each of the following AND give an example of each in a food chain:
primary consumer, producer, secondary consumer, decomposer, tertiary
consumer.
Producer = uses sunlight to make food (EX: plants)
Primary consumer = eats producers (EX: mice)
Secondary consumer = eats primary consumers (EX: snake)
Tertiary consumer = eats secondary consumers (EX: hawk)
Decomposer = eats dead matter (EX: bacteria, fungi)
15.Which of the above 4 groups has the most energy available to it? Why?
Producers. They are closest, in terms of the origin of energy, to the original
energy source (the sun)
16.Define each of the following AND give an example of each: herbivore, carnivore,
omnivore, detrivore.
Herbivore = eats only plant matter (EX: giraffe)
Carnivore = eats only meat (EX: lion)
Omnivore = eats both plants and meat (EX: human)
Detrivore = eats dead matter (EX: vulture)
17.Explain the difference between a food web and a food chain.
A food chain shows only a single path telling what eats what, one at a time.
A food web shows all possible paths of what eats what as many connected
food chains.
18.What percent of energy is transferred from one trophic level to the next?
About 10% between each level
19.Draw a trophic pyramid with 3 levels. Write an example organism that would be
on each level. (Ex: grass, hawk, etc.)
20.What is biomagnification?
Concentrations of human-introduced contaminants (pesticides, chemicals,
etc) increase as you move up a food chain
21.Which would have the highest concentration of toxins due to biomagnification:
producer, 1st consumer, 2nd consumer? Explain.
The 2nd consumer would have the highest level of concentration. This is
because as you move up the food web, the amount of biomass taken in
increases. This also increases the amount of contaminants ingested (EX:
pesticides are dumped and taken in by algae in pond…fish eat the algae, but
not enough toxicity to kill the fish…birds eat multiple fish and die from
toxicity)
22.Be able to identify which organisms would be located where on a trophic pyramid
and the effects on a food web of removing an organism from it.
23.What processes increase the size of populations?
Increased reproduction, lack of predation/competition, plenty available
resources, large habitat
24.What processes decrease the size of populations?
Decreased reproduction, lots of predation/competition, limited available
resources, small habitat
25.Explain the difference between the following terms: migration, immigration,
emigration.
Migration = movement from locations that may not be permanent (EX: bird
migration from north/south)
Immigration = coming to new area to live (EX: moving from US to Canada)
Emigration = exiting current area one lives in (EX: moving to Canada from
US)
26.Give an example of each type of limiting factor: density dependent, density
independent.
Density dependent = rely on density/size of population (EX: disease being
spread)
Density independent = do not rely on population density/size (EX: flood, fire,
natural disasters)
27.What is carrying capacity?
Maximum population size of species the environment can sustain indefinitely
28.Explain the difference between exponential and logistic growth.
Exponential = no upper limit, fast growth, ultimately not sustainable
Logistic = finite upper limit, rapid growth followed by leveling off,
sustainable
29.Draw a sketch of each of the two types of growth curves studied.
30.Why is a population with greater genetic diversity less likely to die out than one
with less genetic diversity?
A population with greater genetic diversity will have a better chance to have
individuals with traits that allow them to survive if a large scale
environmental change occurs (EX: giraffe population has both long and
short necks to feed on both high and low lying plants…if all low lying plants
die, the giraffes with short necks will die, but the long necked giraffes will
survive, and thus the species survives).
31.What is competitive exclusion?
2 species cannot coexist in the same niche (role in ecosystem) very long
without one of the species being driven out by competition or going extinct.
32.Explain the difference between the 3 types of symbiotic relationships and give an
example of each: mutualism, parasitism, commensalism.
Mutualism = relationship where 2 species both benefit (EX: bees and
flowering plants)
Parasitism = relationship where 1 species benefits and other is harmed (EX:
tick on a dog)
Commensalism = relationship where 1 species benefits and other is
unaffected (EX: algae on turtle’s shell)
33.What is succession?
A change in plant species in a community over time.
34.What is the difference between primary & secondary succession?
Primary succession = colonization of a new area that was previously
uninhabited by a pioneer species…very slow process
Secondary succession = regeneration of a pre-existing community after a
major disturbance such as wildfire…can be faster than primary succession
as soil is already developed and pioneer species may still have roots in tact
underground
35.A forest ecosystem is destroyed by a disaster such as fire. Describe the stages of
succession it would go through. What would be the ultimate result?
This is secondary succession:
1 – disaster destroys the community
2 – grasses grow
3 – small bushes and trees grow
4 – fast growing evergreens grow
5 – slow growing deciduous tree grow, overtake evergreens while smaller,
shade tolerant trees grow in understory
36.What is a pioneer species?
A pioneer species is a hardy species (such as grass, moss, lichen) that move
into uninhabited areas or previously inhabited areas first
37.What is a climax community?
A climax community is a plant community that’s fully established and
reached a steady state
38.What are the main gases found in our atmosphere?
Nitrogen, Oxygen, Argon, and Carbon Dioxide
39.How are the root nodules found in many plants important to the nitrogen cycle?
Plant root nodules (‘legumes’) have a symbiotic relationship with plants. The
nodules contain nitrogen-fixing bacteria that help plants process nitrogen
from the atmosphere
40.How do photosynthesis and respiration affect the carbon cycle?
Photosynthesis is needed for photosynthesis by plants. This pulls in Carbon
Dioxide from the atmosphere and processes back to oxygen.
Respiration (NOT breathing, that’s ventilation! Respiration is consuming
resources for energy) by bacteria and consumers processes matter that
contain carbon and release it back into the atmosphere.
41.Be able to describe, in general, the processes involved in the water, nitrogen and
carbon cycles.
42.Describe the main characteristics of each of the following biomes: Desert,
Temperate Grassland/Prairie, Taiga/Coniferous Forest, Temperate Deciduous
Forest, Tundra, Tropical Rainforest.
Desert = dry…almost no plants…found in mountain rain shadows towards
continental center
Temperate Grassland (Prairie) = moderate temperatures with variable
rainfall…subject to draughts…tall and short grass…good soil for farming
Coniferous Forest (Taiga) = moist and cold…full of coniferous trees (pine,
spruce, etc)
Temperate Deciduous Forest = moderate temperatures…moist…trees shed
leaves in fall/winter (oak, maple, etc)
Tundra = cold…short growing season…found at high mountain altitudes or
high latitudes
Tropical Rain Forest = abundant precipitation…very established forests with
variety of animals and insect species
43.Name several examples of invasive species introduced to the Great Lakes.
Zebra mussel, sea lamprey, alewife
44.How have invasive species affected the ecosystems where they have been
introduced?
Many native species have been forced towards extinction due to over-feeding
by the invasive species and being outcompeted for resources by them
45.How did most of the invasive species enter the Great Lakes?
Humans have introduced them through trade ships. Some species attach to
ship hulls, other are introduced through dumps of ballast water (water from
point of origin kept on ship to stabilize the ship at sea)
46.What is the greenhouse effect?
Increasing greenhouse gases absorb and radiate heat to Earth.
47.Describe how global warming occurs and the consequences of it.
An increase in greenhouse gases (produced by cars, factories, etc) increases
the heat retained by our atmosphere. This produces changes in weather and
temperature patterns, and could ultimately lead to the melting of our glaciers
and ice caps. This would destroy the ecosystems in those regions.