Download Ecology Study Guide

AP Biology
Jones
Study Guide
Ecology
 8-1: Read 1080—1092
Distribution of Species
 Populations, communities, and ecosystems are the hierarchical levels around which the study of
ecology is based.
 In section 50.2, be able to distinguish between, and give examples of, biotic and abiotic factors and
how they affect the distribution and dispersal of species. Skim the subsection on climate.
 Skip Fig 50.10 except to note how the angle at which the sunlight strikes the earth affects how much
energy is received per square meter (therefore the temperature, etc.).
 Look at Fig’s 50.11 and 50.12 Skip Fig 50.13
Questions:
1. Distinguish between biotic and abiotic factors affecting populations.
2. Give examples of some biotic and abiotic factors that might affect a plant and those affecting an
animal of your own choosing.
 8-2: Read 1092—1104, 1136—1143
Biomes, Populations
 Skim the sections on biomes (50.3 and 50.4). Do know the principal vegetation type distinguishing each
major terrestrial biome and have a rough idea of the precipitation in each.
 Fig 52.2 is a good summary of factors affecting population size (or density).
 Skim the subsection Demography.
 In section 52.2, focus on distinguishing the two extremes of reproductive strategies regarding
quantities of offspring (fancy names not required).
Questions:
1. List the principal terrestrial biomes and the major type of vegetation distinguishing each.
2. What are the four factors affecting the size of a given population (or the density of a population).
 8-3: Read 1143—1152
Population Growth
 Figure 52.9 is very important; it shows the potential for populations to grow exponentially when birth
rates exceed death rates. The slope of the curve at any given time shows how fast the population is
growing. The increase in slope shows not only that the population is increasing but that it is increasing
faster over time. This is one of the cornerstones of Darwin’s big idea.
 Be able to state the meaning of the equation on the bottom of page 1144 in your own words.
 If exponential growth persisted, a single bacterium could cover the earth many meters deep within a
few days. Must be something else going on!
 The very important Figure 52.12 shows that as an “ideal” population grows, certain factors act to
reduce the rate of growth until the population stabilizes at a number the environment can support
(the carrying capacity of the ecosystem for that species). The factor that determines the carrying
capacity is often referred to as the limiting factor. Note, in the figure, that exponential growth still
occurs when the population is small enough that resources seem unlimited.
 In real populations the logistic curve often shoots above the carrying capacity resulting in increased
death rate which reduces the population. Populations usually fluctuate around the carrying capacity in
a sort of dynamic equilibrium.
 In Fig 52.18, notice the curve has somewhat of an exponential beginning.
 Fig 52.21 is the classic textbook example!
Questions (8-3):
1. Why, in your own words, can a population increase exponentially in the absence of limiting factors?
2. What are the advantages to the K-selection reproductive strategy? To the r-selection strategy?
Give examples of organisms using each strategy.
3. Give two examples of how density-dependent factors can affect a population.
8-4: Read 1152—1156, 1159—1165
Human Growth, Communities
Figure 52.22, oh, oh! Are humans above the laws of nature?
What feature of Fig 52.25 is responsible for the different rates of growth?
Read section 53.1 well but especially focus on:
- interspecific competition
- the concept of a niche
- predation, parasitism, mutualism, commensalism
Questions:
1. What kinds of factors have allowed humans to still exhibit exponential growth? What do you think
is the limiting factor for the human population in California?
2. Describe your niche.
3. Define, and give examples of, predation, parasitism, commensalism, and mutualism.
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 8-5: Read 1165—1180
Food Webs
 In section 53.2, read carefully until the subsection Species with a Large Impact, then skim.
 Read lightly, section 53.3
 Skim section 53.4
 Lightly read section 53.5
Questions:
1. How are the terms food chain and food web different? Which is best used to describe the flow of
energy through trophic levels? Which best describes how nutrients and energy are transferred in
an actual ecosystem?
2. What types of organisms occupy the “base” of any food web? Why?
3. Why is there a limit to how many trophic levels can exist in a food chain?
4. Briefly describe the process of ecological succession.
 8-6: Read 1184—1194
Ecosystems and Productivity
 In Figure 54.2, notice the major difference between the flow of energy and that of matter in
ecosystems.
 You should understand the equation on page 1187 including the meaning of each of the terms.
 Lightly read from page 1188 to the end of the section.
 But: do study and understand Fig 54.6
 Read section 54.3 carefully. You will not need to make calculations but do be able to explain how the
situation depicted in Fig 54.12(b) can be possible.
 In Fig 54.10, the 67 J is the energy in the food (think glucose for example) which was not converted
to ATP energy during respiration.
 Know Figures 54.11, 54.12, 54.13 and 54.14 well.
Questions:
1. Why is the NPP value for productivity generally more desirable to use?
2. Why is energy transfer between trophic levels less than 20% efficient?
3. So, in Fig 54.12(b), how can there be a greater biomass of consumers than producers?
 8-7: Read 1195—1206
Cycles and Human Interference
 Definitely know the water cycle, carbon cycle and the nitrogen cycle (you can group the nitrifying
bacteria with the nitrogen fixing bacteria).
 Skim pages 1198 and 1199
 Section 54.5 is very important. You should know about each of the issues discussed and be able to
describe how human intervention has interfered with the three cycles listed above.
Questions:
1. State at least one way humans have interfered with the cycling of water, carbon and nitrogen and
describe the consequences.
2. What is meant by biological magnification? Should this be of more concern to you or to a cow?
Why?
 8-8: Read 1209—1215
Biodiversity
 Only six pages, important topic.
Questions:
1. Biodiversity: why do many biologists (and, perhaps, your teacher) consider threats to biodiversity
the most important biological issue of our modern world?
2. Give examples of different threats to biodiversity.
 8-9: Read 1106—1113
Behavior 1
 In section 51.1:
- distinguish between proximate and ultimate causes.
- describe FAP’s, sign stimuli and imprinting
 Focus on Fig’s 51.4 and 51.5 for good examples of applying the proximate/ultimate cause relation to
behavior.
 Be sure to distinguish between kinesis and taxis (lab alert).
 Skim the subsection Animal Signals. . . but be sure you know what a pheromone is and that much
behavior has a genetic component.
 8-10: Read 1113—1133
Behavior 2
 Lightly read section 51.3 But be able to define and give an example of: learning, habituation, classical
conditioning, operant conditioning
 Skim section 51.4
 Skim section 51.5 Do gain an idea of what is meant by “energy costs”.
 Skim section 51.6 except the subsection Inclusive Fitness.
Questions:
1. Describe an example of how habituation, classical conditioning and operant conditioning might
apply in a student’s life.