1. By: Mrs. Tokmajian & Mrs. Jackson
MP4 Quarterly Review
By: Mrs. Tokmajian & Mrs. Jackson

2. 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).

3. 2. Define gene flow
Exchange or transfer of alleles/genetic information between populations

4. 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)

5. 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.

6. 5. What are the sources of genetic variation in a population?
-Mutations
-Combination of gametes formed by meiosis during sexual reproduction

7. 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.

8. 7. What is reproductive isolation? What does it lead to?
When two populations of a species can no longer successfully mate - leads to speciation.

9. 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.

10. 8. What type of selection favors phenotypes at both extremes and selects against intermediate phenotypes?
Disruptive selection

11. 9. What type of selection favors phenotypes at only one extreme?
Directional selection: Think about peppered moths.

12. 10. What type of selection favors intermediate phenotypes and selects against extreme phenotypes?
Stabilizing

13. 11. DNA & proteins can be used to determine evolutionary relationships
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

14. 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.

15. 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.

16. 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.

17. Ecology
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

18. 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.

19. 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)

20. Ecology
4. Draw a food chain and a food web and explain the similarities and differences between them.
Food Chain Food Web

21. 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.

22. 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

23. Ecology 6. Define the terms Biotic and Abiotic and give examples.
A. BIOTIC: Living (animals, plants, etc)
B. ABIOTIC: Non-Living (water, light, soil,)

24. 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.

25. 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.

26. Ecology Answer: Approximately on Day 22
9. Use the graph to determine when this population reached its carrying capacity?
Answer: Approximately on Day 22

27. 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.

28. 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.

29. 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.

30. Ecology
Predator/Prey Relationships: Help to maintain balance in ecosystems.