MP4 Quarterly Review
By: Mrs. Tokmajian & Mrs. Jackson
1. Define genetic drift: Change in allele frequencies due
to chance
Define both types of g.d. and give examples:
Bottleneck Effect: Random event decreases population and
genetic variation in population. Ex.: Overhunting of
elephant seals
Founder Effect: Individuals leave old population and start
new population with decreased genetic variation. Ex.: Owl
Island (Some of you left and started over with much less
variation than the original population you belonged to).
2. Define gene flow
Exchange or transfer of alleles/genetic
information between populations
3. Define natural selection. How
does it affect species diversity?
-Organisms with traits that make them well-suited
to their environment are more likely to survive,
reproduce, and pass their beneficial traits on to the
next generation.
-Natural selection increases species diversity (led
to 2 types of tortoises on diff. islands - those with
long necks/legs, those with short necks/legs, birds
with different beaks fit for that food source on that
island)
4. Explain how environment can cause a shift in the
phenotype of a species (think of the black and white pocket
mice in the desert).
-Environment can cause an increase in the
number of individuals with beneficial
phenotypes and a decrease of individuals
without beneficial phenotypes.
-Black pocket mice increased due to phenotype
helping them blend in with new dark
environment from black hardened lava rock.
5. What are the sources of genetic
variation in a population?
-Mutations
-Combination of gametes formed by meiosis
during sexual reproduction
6. Which produces more genetic variation:
sexual or asexual reproduction?
Sexual reproduction. Asexual reproduction
produces genetically identical offspring with NO
variation. Natural selection does not work if
there is NO variation.
7. What is reproductive isolation?
What does it lead to?
When two populations of a species can no
longer successfully mate - leads to speciation.
7. (continued) 3 isolating
mechanisms...
-Behavioral isolation: differences in courtship or mating
behaviors.
-Geographic isolation: physical barriers that divide a
population into two or more groups.
-Temporal isolation: timing prevents reproduction between
populations.
8. What type of selection favors phenotypes at both
extremes and selects against intermediate phenotypes?
Disruptive selection
9. What type of selection favors phenotypes at only one
extreme?
Directional selection: Think about peppered
moths.
10. What type of selection favors intermediate phenotypes
and selects against extreme phenotypes?
Stabilizing
11. DNA & proteins can be used to determine evolutionary relationships.
3 different species have a similar protein. Explain how you could tell
which 2 species are less closely related by looking at the protein.
Compare the amino acid sequences of the proteins - species with more
differences are less closely related
12. Explain what vestigial structures are and what they
tell us about evolution (think of wings on flightless
birds).
Structures that had a function in an ancestor
but don’t in modern day organisms.
Ex.: Wings on flightless birds show they
evolved from ancestors that flew. They’ve since
evolved adaptations to travel efficiently in other
ways.
13. Explain embryology and how it
shows evidence of evolution
Embryology compares similarities in
developmental stages of different organisms to
provide evidence that they share a common
ancestor.
14. Explain what homologous structures are and how they provide
evidence for evolution
Homologous structures are structures in
different organisms that share similar structures
but perform different functions - provides
evidence of a common ancestor. Ex.: forelimbs
of humans and cats.
Ecology
1. The 5 levels of ecology in order are listed below. Next to
each category name, write the biotic or abiotic factor
that belongs with each level.
1. Organism: Alligator
2. Population: 5 Alligators
3. Community: Alligators, Birds, Grass, Frogs, Trees
4. Ecosystem: Alligators, Birds, Grass, Frogs, Trees, Soil, Water, Sunlight
5. Biome: Temperate Deciduous Forest
Ecology
2. Bacteria plays a major role in nitrogen fixation in the nitrogen cycle.
Bacteria in the soil and in plant roots fixes the nitrogen into ammonia so
that plants can readily use it. How does nitrogen get into the soil so that
bacteria can use it?
Answer: Decomposers break down
dead plants and animals.
This process returns nitrogen
to the soil so that bacteria can fix it
for plants.
Ecology
3. How is the carbon cycle related to the oxygen cycle?
Answer: In the carbon cycle, plants take
in carbon. Plants receive this carbon
in the form of carbon dioxide from the
process of photosynthesis.
Remember: CO2 + H2O + light
(all inputs of photosynthesis)
Ecology
4. Draw a food chain and a food web and explain the similarities and
differences between them.
Food Chain
Food Web
Ecology
Question 4 Continued:
Similarity: A food web contains multiple related food chains. (Both
show feeding relationships)
Difference: Food chains show one feeding relationship, food webs
show multiple feeding relationships.
Ecology
5. Symbiotic relationships between organisms are relationships where
the 2 organisms have close interactions with each other usually in a
positive way. Name and explain the 3 types of symbiotic relationships.
A. Mutualism: Both organisms benefit from the relationship. Ex: bee
and flower
B. Commensalism: One organism benefits and the other is neither
helped nor harmed. Ex: clownfish and sea anemone
C. Parasitism: One organism benefits from the relationship while the
other is harmed. Ex: tick and human
Ecology
6. Define the terms Biotic and Abiotic and give
examples.
A. BIOTIC: Living (animals, plants, etc)
B. ABIOTIC: Non-Living (water, light, soil,)
Ecology
7. According to this food web, if the grasshoppers were removed, how
would the other organisms be affected?
Answer: Most obvious answer is that
lizards and hawks would go down.
Ecology
8. Give an example of competition between two organisms and
predation between two organisms.
Answer:
Competition: 2 male lions fight for a female, or for food. 2 species of
plants fight for the same sunlight and soil.
Predation: A fox hunts, kills, and eats a rabbit.
Ecology
9. Use the graph to determine when this population reached its carrying
capacity?
Answer: Approximately on Day 22
Ecology
10. According to the diagram, if lizards were
removed, what would happen to the locusts
and the snakes?
Answer: Snakes would DECREASE because they have nothing
to eat. Locusts would INCREASE because nothing is eating
them.
Ecology
11. Using your knowledge of renewable
resources from class, explain 2 ways in which
humans can reduce the waste/pollution
produced on Earth.
Answer: Reduce CO2 emissions to cut back
on global warming, use renewable energy like
solar energy to cut back on burning fossil fuels
like oil and gas. Recycle to cut down on
waste,etc.
Ecology
12. Give 2 reasons why invasive/non-native
species can be harmful to a new area.
Answer: They have no natural predators so
they can easily take over a new area. They
take space and food away from the native
species that lives there.
Ecology
Predator/Prey Relationships: Help to maintain
balance in ecosystems.