Friday (February 18, 2011)

1. Friday (February 18, 2011) Today’s Agenda: (1) Journal Question: What is a biome? *(2) Lecture III: Ecosystems & Responses to a Changing Environment (slide 33) (3) Begin working on Biome Project a. Select a biome b. Follow the instructions in your unit packet (4) Homework: Each group member should do some research on their biome for Wednesday -Read Chapter 22 (pp. 414 – 435)

2. Lecture III: Ecosystems & Responses to a Changing Environment By Dr. Rick Woodward

3. Food Chains

4. Species A. The first step in investigating a biotic community may be simply to catalogue all the species present. (You will be doing this for your group biome project today)

5. Recall: Taxonomy

6. Species B. Species are the different kinds of plants, animals, and microbes in the community.

7. Species C. The biological definition of a species is the entirety of a population that can interbreed to produce fertile offspring, whereas members of different species generally do not interbreed.

8. Speciation A. Two species arise from one. (1). Allopatric • Speciation that occurs when 2 or more populations of a species are geographically isolated from one another • The allele frequencies in these populations change • Members become so different that that can no no longer interbreed (2). Sympatric • Populations evolve with overlapping ranges • Behavioral barrier or hybridization or polyploidy

9. Adapted to cold through heavier fur, short ears, short legs, short nose. White fur matches snow for camouflage. Northern population Arctic Fox Spreads northward and southward and separates Different environmental conditions lead to different selective pressures and evolution into two different species. Early fox population Adapted to heat through lightweight fur and long ears, legs, and nose, which give off more heat. Southern population Gray Fox Speciation

10. Populations A. Each species in a biotic community is represented by a certain population; that is, by a certain number of individuals that make up the interbreeding, reproductive group.

11. The Ecosystem Concept A. Ecosystems join together the biotic community (fish) and the abiotic conditions (salt water) that it lives in.

12. The Ecosystem Concept C. Examples of ecosystems: 1. Polar 2. Tundra 3. Coniferous Forest 4. Deciduous Forest 5. Grassland 6. Tropical Rain Forest 7. Temperate Rain Forest 8. Ocean (Marine); Coral Reefs 9. Freshwater Biome (Lakes, Ponds, Rivers, Streams) (Biome Project Presentations) (1) Terrestrial Biomes –on land. (2) Aquatic Biomes –water. -You select one of the above for your project. (pp. 767-776)

13. Ecology B. The study of ecosystems and the interactions that occur among organisms and their environment belongs to the science of ecology.

14. An Ecotone A. Ecosystems are not isolated from one another.

15. An Ecotone B. One ecosystem blends into the next through a transitional region called an ecotone. C. An ecotone contains many species common to both systems.

16. Land zone Transition zone Aquatic zone Number of species Species in land zone Species in aquatic zone Species in transition zone only Ecosystem Boundaries:Ecotones

17. The Biosphere A. All the species on Earth, along with all their environments, make up one vast ecosystem, often called the biosphere.

18. Overlapping of the Spheres

19. Biosphere Biosphere Ecosystems Communities Populations Organisms Ecosystem Organization • Organisms • Made of cells • Eukaryotic vs Prokaryotic • Species • Groups of organisms that resemble one another in appearance, behavior, and genetic make up • Sexual vs Asexual reproduction • Production of viable offspring in nature • 1.5 million named; 10-14 million likely • Populations • Genetic diversity • Communities • Ecosystems • Biosphere Fig. 4.2, p. 66

20. Biosphere Carbon cycle Phosphorus cycle Nitrogen cycle Water cycle Oxygen cycle Heat in the environment Heat Heat Heat Sustaining Life on Earth… • One way flow of high quality energy • The cycling of matter (the earth is a closed system) • Gravity • Causes downward movement of matter

21. Community Association of different populations of organisms that live and interact together in the same place at the same time.

22. Responses to a Changing Environment A. Organisms are able to survive within a wide range of environmental conditions. (1) Temperature Conditions

23. Responses to a Changing Environment B. Tolerance Curve (1) A graph or performance versus values of an environmental variable, such as temperature, is called a tolerance curve.

24. Acclimation A. Some organisms can adjust their tolerance to abiotic factors through a process of acclimation.

25. Acclimation B. Spending a few weeks at a high elevation, you will acclimate to reduced oxygen levels, or “thin air.” –over time the number of red blood cells in your body will increase. (i.e. training for a marathon)

26. Control of Internal Conditions A. Ways an organism deals with changes to its environment: (1) Conformers (2) Regulators

27. Conformers A. Conformers are organisms that do not regulate their internal conditions; they change as their external environment changes.

28. Conformers (1) Example: The body temperature of desert lizards rises and falls with the temperature of the lizard’s environment.

29. Regulators A. Regulators are organisms that use energy to control some of their internal conditions. (1) Regulators can keep an internal condition within the optimal range over a wide variety on environmental conditions. -Example: Humans –Our body temperature remains constant throughout the day.

30. Escape from Unsuitable Conditions 1. Dormancy 2. Migration

31. Dormancy A. Entering into a state of reduced activity is called dormancy. (1) During the winter many reptiles and amphibians survive by hiding underground and becoming dormant until spring.

32. Migration A. Moving to a more favorable habitat with better climate conditions is referred to as migration. (1) A familiar example of migration is the seasonal movements ofbirds, which spend spring and summer in cooler climates and migrate to warmer climates in the fall.

33. Stop Here! • Group Project Today -Work in groups of four -Select a biome -Draw pictures to describe your selected biome 1. List and draw 4-8 animals. 2. List and draw 4-8 plants. 3. List climate conditions and the location of your specific biome. -Present your poster to the class. a. Take notes in your composition book on your classmates biomes. (You will be tested on your classmates projects)