Calculator Policy

1. Calculator Policy • A four-function calculator (with square root) is permitted on both the multiple-choice and free-response sections of the AP Biology Exam since both sections contain questions that require data manipulation. No other types of calculators, including scientific and graphing calculators, are permitted for use on the exam. Four-function calculators have a one line display and a simple layout of numeric keys (e.g., 0–9), arithmetic operation keys (e.g., +, -, ×, and ÷), and a limited number of special-use keys (e.g., %, +/-, C, and AC). Simple memory buttons like MC, M+, M-, and MR may also be included on a four-function calculator. Scientific calculators have a more complicated, multi-row layout that includes various special-use keys, including ones for trigonometric and logarithmic functions such as SIN, COS, TAN, TRIG, LOG, and LN. In contrast to scientific calculators, four-function calculators do not include trigonometric and logarithmic functions, statistical capabilities, or graphing capabilities. Students may bring up to two four-function calculators (with square root) to the exam.

2. What is a community? • A biological community is an assemblage of populations of various species living close enough for potential interaction

3. What are the types of interactions? • relationships between species in a community interspecific interactions • Examples are competition, predation, herbivory, and symbiosis (parasitism, mutualism, and commensalism) • Interspecific interactions can affect the survival and reproduction of each species, and the effects can be summarized as positive (+), negative (–), or no effect (0)

4. Competition • Interspecific competition (–/– interaction) occurs when species compete for a resource in short supply • Strong competition can lead to competitive exclusion, local elimination of a competing species • The Gause competitive exclusion principle states that two species competing for the same limiting resources cannot coexist in the same place

5. Ecological Niches • The total of a species’ use of biotic and abiotic resources is called the species’ ecological niche • An ecological niche can also be thought of as an organism’s ecological role • It is the functional position of an organism in its environment, comprising its habitat and the resources it obtains, periods of time it is active, etc.

6. Adaptations for Locomotion Biorhythms Tolerance Predator avoidance Reproduction feeding Physical conditions Substrate Humidity Sunlight Temperature Salinity pH Exposure Attitude depth Resources offered by the habitat Food Shelter Mating sites Nesting sites Predator avoidance Other organisms

7. Ecologically similar species can coexist in a community if there are one or more significant differences in their niches • Resource partitioning is differentiation of ecological niches, enabling similar species to coexist in a community

8. Fig. 54-2 A. distichus perches on fence posts and other sunny surfaces. A. insolitus usually perches on shady branches. A. ricordii A. insolitus A. aliniger A. christophei A. distichus A. cybotes A. etheridgei

9. The full range of environmental conditions under which an organism can exist is its fundamental niche. Due to interactions and evironmental pressures, organisms are usually forced to occupy a niche that is narrower than this…their realized niche.

10. Fig. 54-3 EXPERIMENT High tide Chthamalus Chthamalus realized niche Balanus Balanus realized niche Ocean Low tide RESULTS High tide Chthamalus fundamental niche Ocean Low tide

11. Question: Two species of Anolis lizards are often found perched and feeding in the same trees, with species I in the upper and outer branches, and species II occupying the shady inner branches. After removing one or the other species in test trees, an ecologist observes the following results: Species I is found throughout the branches of trees in which it is now the sole occupant. Species II is still found only in the shady interior when it is the sole occupant. What do these results indicate about the niches of these two species? The realized niche of Species I is smaller than its fundamental niche when it is in competition with SpeciesII. Species I Species II’s fundamental and Realized niche are the same. Species II

12. Predation • Predation (+/– interaction) refers to interaction where one species, the predator, kills and eats the other, the prey • Some feeding adaptations of predators are claws, teeth, fangs, stingers, and poison • Prey display various defensive adaptations - hiding, fleeing, forming herds or schools, self-defense, coloration patterns, mimicry, and alarm calls

13. Predator-Prey Graph Lag time – Peak to peak or Trough to trough About 4 months here months

14. Coloration Patterns and Mimicry

15. Herbivory • Herbivory (+/– interaction) refers to an interaction in which an herbivore eats parts of a plant or alga • It has led to evolution of plant mechanical and chemical defenses and adaptations by herbivores

16. Fig. 54-6 A manatee is feeding on water hyacinth, an introduced species, in Florida.

17. Symbiosis • Symbiosis is a relationship where two or more species live in direct and intimate contact with one another • parasitism (+/– interaction) • mutualism (+/+ interaction), is an interspecific interaction that benefits both species A mutualism can be • Obligate, where one species cannot survive without the other • Facultative, where both species can survive alone • commensalism (+/0 interaction)

18. Fig. 54-7 The tree and the ant are locked into relationship where the survival of both partners depends on the other. The ants provide the Acacia with protection from herbivores and from competing plants, while the tree provides the ants with food and shelter. Facultative mutualism (a) Acacia tree and ants (genus Pseudomyrmex) (b) Area cleared by ants at the base of an acacia tree

19. Clownfish and Sea Anemones Facultative Mutualism

20. Fig. 54-8 Facultative Mutualism

21. Parasitism

22. Commensalism – epiphytes

23. protists in termite guts Obligate Mutualism

24. In general, a few species in a community exert strong control on that community’s structure Two fundamental features of community structure are species diversity and feeding relationships

25. Species Diversity • Species diversity of a community is the variety of organisms that make up the community • It has two components: species richness and relative abundance • Species richness is the total number of different species in the community • Relative abundance is the proportion each species represents of the total individuals in the community

26. Fig. 54-9 A B C D Community 1 Community 2 A: 80% B: 5% C: 5% D: 10% A: 25% B: 25% C: 25% D: 25% Two communities can have the same species richness but a different relative abundance

27. Shannon Diversity Formula • H' = - Σ piln pi • Where pi = the proportion of individuals of species i. • Notice that there is a negative sign in front of the summation sign.

28. H' = - (0.52 X -0.65) + (0.29 X -1.24) + (0.19 X -1.66) • H' = -(-0.338) + (-0.360) + (-0.315)  • H' = -(-1.01) = 1.01

29. Trophic Structure • Trophic structure is the feeding relationships between organisms in a community • It is a key factor in community dynamics • Food chains link trophic levels from producers to top carnivores

30. Fig. 54-11 Quaternary consumers Carnivore Carnivore Tertiary consumers Carnivore Carnivore Secondary consumers Carnivore Carnivore Primary consumers Herbivore Zooplankton Primary producers Plant Phytoplankton A terrestrial food chain A marine food chain

31. Fig. 54-12 A food web is a branching food chain with complex trophic interactions Humans Smaller toothed whales Sperm whales Baleen whales Elephant seals Leopard seals Crab-eater seals Squids Fishes Birds Carnivorous plankton Euphausids (krill) Copepods Phyto- plankton

32. Limits on Food Chain Length • Two hypotheses attempt to explain food chain length: • The energetic hypothesis suggests that length is limited by inefficient energy transfer • The dynamic stability hypothesis proposes that long food chains are less stable than short ones • Most data support the energetic hypothesis

33. Experimental data from the tree hole communities showed that food chains were longest when food supply (leaf litter) was greatest. Which hypothesis about what ali its food chain length do these results suggest? energetic

34. Fig. 54-14 5 4 3 Number of trophic links 2 1 0 High (control): natural rate of litter fall Medium: 1/10 natural rate Low: 1/100 natural rate Productivity

35. Species with a Large Impact • Certain species have a very large impact on community structure • Such species are highly abundant or play a pivotal role in community dynamics • Dominant species are those that are most abundant or have the highest biomass (the total mass of all individuals in a population)

36. One hypothesis suggests that dominant species are most competitive in exploiting resources Another hypothesis is that they are most successful at avoiding predators Why are they dominant?

37. Invasive Species • Speciestypically introduced to a new environment by humans, often lack predators or disease

38. Kudzu • Kudzu is a vine which was brought to North America from Asia in 1876 to help prevent soil erosion, which has since become an utter nuisance in some areas of the country. It can grow up to 6.5 feet a week and its roots are nearly impossible to eradicate entirely.

39. Other examples • Dutch Elm Disease – caused by a fungus and accidentally spread into the United States. • Potato Blight – caused by a fungus that caused the Great Potato Famine in Ireland in the 1840’s. Spores have been carried all over the world. • Small Pox – spread of virus from Asia to all over the world. Dutch Elm Disease

40. Dutch elm disease (DED) is caused by a member of the sac fungi (Ascomycota) affecting elm trees, and is spread by the elm bark beetle. Although believed to be originally native to Asia, the disease has been accidentally introduced into America and Europe, where it has devastated native populations of elms which had not had the opportunity to evolve resistance to the disease. The name "Dutch elm disease" refers to its identification in 1921 in the Netherlands by Dutch phytopathologists.

41. Potato Blight caused by a fungus. Smallpox caused by a virus.

42. Keystone Species • Keystone species exert strong control on a community by their ecological roles, or niches • In contrast to dominant species, they are not necessarily abundant in a community

43. Fig. 54-15 EXPERIMENT Field studies of sea stars exhibit their role as a keystone species in intertidal communities They keep the number of mussels controlled that outcompete other species. RESULTS 20 With Pisaster (control) 15 Number of species present 10 Without Pisaster (experimental) 5 0 1963 ’64 ’65 ’66 ’67 ’68 ’69 ’70 ’71 ’72 ’73 Year

44. Fig. 54-16 100 80 60 Otter number (% max. count) 40 Observation of sea otter populations and their predation shows how otters affect ocean communities 20 Keystone species 0 (a) Sea otter abundance 400 After orcas entered the food chain and preyed on the otters, notice the change in the sea urchins and kelp. 300 Grams per 0.25 m2 200 100 0 (b) Sea urchin biomass 10 8 Number per 0.25 m2 6 4 2 0 1972 1985 1989 1993 1997 Year (c) Total kelp density Food chain

45. This resulted in a loss of kelp forests.

46. Ecological Succession • Ecological succession is the sequence of community and ecosystem changes after a disturbance • Primary succession occurs where no soil exists when succession begins • Secondary succession begins in an area where soil remains after a disturbance

48. Successive species can • Inhibit growth of new organisms sphagnum moss making boggy areas in poorly drained sites • Promote growth of new organisms Dryas and Alder trees raising N content • Tolerate conditions that resulted from former species

49. Fig. 54-22-4 Succession on the moraines in Glacier Bay, Alaska, follows a predictable pattern of change in vegetation and soil characteristics 1941 1907 2 Dryas stage Pioneer stage, with fireweed dominant 1 0 5 10 15 Kilometers 1860 Glacier Bay Alaska 1760 4 Spruce stage 3 Alder stage

50. Succession at Mt. St. Helen’s in 1980