Unit 1 Review

1. Unit 1 Review There will be multiple choice, fill in the blank, short answer and essay questions.

2. Hydrologic cycle • Also called the water cycle • Sunlight heats water causing evaporation • Hot water molecules rise into the atmosphere • As they cool they condense to form clouds • When clouds become full the molecules fall as precipitation

3. Nitrogen cycle • 78 % of earths atmosphere is nitrogen • Nitrogen fixing bacteria convert nitrogen into ammonia and nitrates • Plants absorb ammonia/nitrates through roots/ use to make amino acids/ proteins • Animals eat plants for amino acids/ proteins • Bacteria break down dead organisms and release the nitrogen back into atmosphere—denitrification • Humans have added extra nitrogen thru artificial fertilizers

4. Oxygen cycle • 21 % of atmosphere is oxygen • Living organisms breathe in oxygen(O2) for cellular respiration • After breaking down glucose, Carbon dioxide(CO2) and water are released • Plants use the CO2 and H2O in photosynthesis to make glucose and O2 • Air pollution traps O2 and forms ozone (O3)

5. Carbon Cycle • CO2-carbon dioxide is in atmosphere • Plants use CO2 in photosynthesis to make glucose • Animals eat plants and break down the glucose with cellular respiration, releasing some CO2 back into air. The rest is used to make all parts of the body. • When plants and animals die and are covered by layers of soil with pressure, they form fossil fuels which release CO2 when burned

6. Phosphorus cycle • Limestone rock is weathered by rain and wind, releasing phosphorus into the soil and water • Plants take phosphorus up through their roots • Animals eat plants, drink water and get phosphorus • Phosphorus is excreted in wastes of animals • Humans add extra phosphorus with artificial fertilizers

7. All energy comes from the sun • Food chain is 1 chain of organisms • Food web is all the interconnected chains in an ecosystem • Energy pyramid represents the different trophic levels and demonstrates how energy is lost as it moves up the levels

8. Food Chains

9. Food Web

10. Trophic Levels

11. Autotroph—makes own food-producer • Heterotroph—eats something else-consumer • Herbivore—eats plants • Carnivore—eats other animals • Omnivore—eats both plants and animals • Detrivore—eats dead animals • Decomposer—breaks down organism to their basic nutrients

12. How can toxins move up a food chain? • When toxins are taken up by plants, they may be small amounts • As herbivores eat the plants the toxin levels increase slightly • As carnivores eat the herbivores toxins become more intense • As tertiary consumers eat carnivores, the toxins reach a deadly level and cause some type of harm--biomagnification

13. Human time line • Hunter-gatherers: 10,000 ya; small nomadic tribes, ate berries, roots, small game, stalked large game; hunted many large mammals to extinction; burned prairies • Agricultural Rev: 2000 ya to 1850s; farmers; grew crops; small towns; domesticated animals; large families; hand drawn plows and wagons; deforestation • Industrial revolution: 1850’s to present; factories; large cities; mechanized equipment; steam engine; train; boat; car; smaller families; pollution

14. Developed vs Developing • Developed countries have good health care, high incomes, high standard of living, slow or stable birth rates • Developing countries have poor health conditions, low income, agricultural based economies, low standard of living, high birth rate, high death rate

15. Tragedy of the Commons • When people have access to a “common” area, they abuse it • They over fish, over hunt, pollute it, trash it, deplete the natural resources • In order to have a public place, someone must create laws and police it. Set limits on things, fines for littering or polluting, etc. • Sustainability is when everyone can have what they need to live comfortably and not deplete our natural resources

16. Decomposers • Decomposers are necessary for all life to exist; • They break down organic matter back to its original molecules so it can be recycled and used again

17. Laws • Law of conservation of matter: matter can neither be created nor destroyed; it just changes form; chemical reactions—reactants equal products; matter is recycled through nutrient cycles. • Law of conservation of energy: energy can neither be created nor destroyed; it just changes forms; radiant to chemical to mechanical, to physical; energy is not recycled but lost in the system as heat--Entropy

18. Biotic vs Abiotic • Biotic factors are any living or once living part of an ecosystem; plants animals, dead tree limbs, wood, leather, etc • Abiotic factors include non living things such as air water, temperature, rocks, soil, nutrients, pH, etc

19. Good Luck