Chapter 50 Reading Quiz 1.Nonliving chemical & physical factors in an environment are known as _____ components. 2.All of the living portions of an individual’s environment are known as _____ components. 3.The study of the past & present distribution of individual species is known as ____. 4.The four comprehensive levels of ecological study are ____, populations, ______ & ecosystems.

1. Describe ecology and its biotic and abiotic factors. Ecology  the scientific study of the interactions of organisms and their environments Biotic  include all other organisms that are a part of any individual organism’s environment Abiotic  the nonliving chemical and physical factors to which an organism is exposed (temperature, light, water, nutrients)

2. Define organismal ecology, and describe the levels of organization. Organismal ecology  studies the behavioral, physiological, and morphological ways individuals meet abiotic environmental challenges 1.Organism 2.Population 3.Community 4.Ecosystem

3. List and describe the five major abiotic factors. 1.Temperature  animals must regulate their own temperature despite environment 2.Water  essential for life, needs to be balanced and conserved 3.Sunlight  animals are sensitive to photoperiod 4.Wind  amplifies heat loss & transpiration, mechanical pressure can affect growth 5.Rocks and Soil  structure, pH, mineral composition

4. How does climate dictate where organisms will be distributed? Climate is the prevailing weather conditions at a locality Determines biomes, which are major types of ecosystems (ex: desert vs rain forest) Species’ tolerances to water, temperature, and sunlight ranges can dictate where that species will live

5. Overview the global climate patterns. About 50% of the solar energy that reaches the atmosphere’s upper layers is absorbed before it reaches the surface Much that reaches earth is reflected back Some is absorbed by water, land, or organsims Due to the earth’s tilt of 23.5’ to its orbit, only the tropics receive direct sunlight year-round Seasonal variation increases steadily toward the poles Global circulation of air creates precipitation and wind (results from intense solar radiation at equator)

6. How do local and seasonal effects affect climate? Local variations exist due to bodies of water and topographical features that create patchiness in climatic conditions Ex: coastal communities vary less due to water nearby Ex: deserts vary widely due to land cooling and heating quickly Ex: mountain ranges keep moist air on one side - air temperature declines 6’C for each 1000m increase in elevation

7. Describe the aquatic biome. How is it “stratified”? Fresh and salt water biomes Cover over 75% of the earth’s surface Vertical stratification due to decrease in light intensity with increasing depth as light is absorbed by the water and suspended microorganisms Photic vs aphotic zones Thermocline  a narrow vertical zone between the warmer and colder waters where a rapid temperature change occurs Benthic zone  bottom, benthos organisms

8. Distinguish among freshwater biomes, wetlands, and estuaries. Freshwater  standing bodies of water that vary greatly in size - littoral zone: shallow, well-lit shore area - limnetic zone: open, well-lit area away from shore - profundal zone: deep, aphotic zone beneath the limnetic Lakes can be classifies as oligotrophic, eutrophic or mesotrophic Wetlands  an area covered by water that supports aquatic vegetation; very rich & valuable Estuaries  an area where freshwater meets salt water - salinity varies, very productive

9. Differentiate among the various marine zones, and describe characteristics of each. Photic zone: where light can penetrate Aphotic zone: below light penetration Intertidal zone: shallow zone where terrestrial habitat meets the ocean’s water Neritic zone: extends from the intertidal zone to the end of the continental shelf Oceanic zone: extends over deep water from one continental shelf to the next, reaches great depth Pelagic zone: the open waters of any depth Benthic zone: the seafloor

10. How are terrestrial biomes distributed? On what basis? List and describe each. Geographical distribution of terrestrial biomes is based mainly on regional variations in climate Latitudinal patterns (ex: tropical rain forest found around equator) Vertical stratification is an important feature (canopy, understory, ground) Main biomes 

#10 continued… Arctic  icecaps, around poles Tundra  permafrost, mosquitos, lemmings, elk Taiga  coniferous forest, more rainfall Temperate forest  deciduous trees, more animals Grassland  prairies & savannahs, grazing animals Desert  <25 cm rain, adaptations to survive Tropical rain forest  > 600cm rain, layering of biome results in many niches, most life anywhere

11. Distinguish between regulators and conformers. Regulators  maintain homeostasis of their bodies through behavioral and physiological mechanisms Conformers  allow their internal conditions to vary with the external conditions Some species can be both under different conditions

12. What is the “principle of allocation”? Principle of allocation  an important concept for assessing the responses of organisms to a complex environment Holds that each organism has a limited amount of energy that can be allocated for obtaining nutrients, escaping predators, coping with environmental fluctuations, growth, and reproduction

13. List and describe the three types of organismal responses to variation. 1.Physiological  when a human moves from low altitude to high altitude (less O 2 ); centered around regulation and homeostasis; shift is called acclimation 2.Morphological  when body form is altered; ex: increase in coat fur or feather density in winter 3.Behavioral  can be instantaneous, is a reaction; ex: burrowing, migrating, huddling