Segment 2 Final Exam Review

1. Segment 2 Final Exam Review *We offer tutoring videos for the majority of the lessons in segment 2, if you need additional support. Please ask your teacher for details or go to the student help site.

2. Geologic Time

3. Geologic time scale: A visual display of the history (the age) of the Earth in the form of a scale Huge sections of time are broken down into smaller groups of time: Eons, Eras, Periods, and Epochs Eon is the largest time block(kind of like what we would think of as years). Era is a little less time(like months) Periodwould be shorter time(like weeks) Epochs are even shorter (like days) (**No different then when we take years and divide them into months, weeks, and days.)

4. Geologic Time Scale

5. Fossils “Fossils are rocks that formed from the remnants (what’s left) of once-living things. All living organisms, under the right conditions, can be fossilized.” Types of fossils include…

6. Casts Molds When something is filled with sediment (rocks) and makes it look 3-D. An imprint of something that was once living.

7. Petrification When something is filled with atoms of rock material; this makes them very hard (rock). *Commonly found with wood.

8. When a living organism gets stuck in something sticky (like sap) the sap and the organism harden and get preserved. Freezing An organism gets frozen and the super cold temps prevent it from decaying; therefore preserving it. Crystallization

9. Trace Fossils: The remains of an organism's activities but not of the organism itself. EXAMPLES: -broken eggshells from a dinosaur's nest are trace fossils. -footprints from an organism -chewed section of a plant -”coprolites” fossilized dung or feces (meaning: poop)

10. There are two types of dating which geologists can use to make the timelines: relative dating and absolute dating. Relative dating does not give an exact age (in years) to rocks or geologic events…

11. Instead, relative dating puts the events in sequential order; the oldest comes first, and all the rest of the events follow after, on the “relative dating timeline”. Example of relative dating (putting events in sequential order):

12. Since there weren’t scientists around during the formation of the Earth (or for any of the geologic history of Earth) they (scientists) need to rely on carefully recorded observations, so they can make assumptions about these things. These types of assumptions are called principles, and in these cases, observations made by the scientific community, over time, have repeatedly supported the assumptions. Geologic Assumptions: 1. Uniformitarianism 2. The Principle of Superposition 3. The Principle of Original Horizontality 4. The Principle of Faunal Succession

13. What is the order?

14. More advanced dating techniques have allowed geologists to get more exact dates. SO… Absolute dating is the: The measurement of time in definite periods of time and is measured with something that gives us a definite (exact) time. It assigns specific dates to rocks and geologic events.

15. Radiometric dating: All rocks contain radioactive material that decays over time. The rate of radioactive decay allows scientists to establish the absolute age of a rock. ** the most common radioactive element is carbon-14 found in all living organisms. Radioactive decay starts with only parent element (an unstable isotope). Because it's unstable, it will decay into a stable daughter element. The time it takes for half of the amount of parent element to decay is constant, (and known as half-life). After one half-life, half of the material is the parent element and the other half is more stable daughter element. After another half life, one-fourth will be the parent element. As the substance keeps decaying, the amount of parent element will shrink, although it will never be completely gone. The substance would then mostly consist of the daughter element.

16. Scientists learn about Earth’s geological (the Earth itself) and biological (living things) history through evidence from rocks and fossils. Fossil Record A fossil record helps us to understand the past and why things are the way they are today.

17. Theory of evolution “Life on Earth did not always look the same as it does today. Life has evolved” (changed / altered). “Evolution explains how new species of organisms arise or how existing organisms adapt to new conditions over time.” Dinosaur Modern day bird

18. “An adaptation refers to a characteristic of an organism that allows it to survive in a particular environment. “ When an adaptation (a change) makes an organism more likely to survive and reproduce, the organism may pass the new adaptation on to its offspring (babies); organisms with the new adaptation will produce more babies than organisms that don’t have the new adaptation. This process called: natural selection is why some organisms with certain adaptations survive and others do not, depending on Earth's changing conditions.

19. Chemical evolution: The idea that the appearance of living systems (stuff) on Earth came from non-living molecules.

20. Fossil evolution Living fossils: Creatures that are very similar to species that lived long ago (without much change) are called “living fossils”. • Phylogeny is studying how different organisms (plants/animals/etc.) are connected (related) through evolution (change over time). • We use something called a “cladogram” to show (in an image/diagram) how one organism is related to another one.

21. Oceans:

22. Earth…the water world

24. Water covers about 71 percent of Earth's surface

25. The distribution (how it is divided or broken up) of Earth's water is shown in the image below.

26. Ocean basins: ***The image above is an interactive from: Lesson 1, Discover page 1, “water world” tab

27. Ocean basins: The areas between land masses. 5 major ocean basins: 1. 2. 3. 4. 5.

28. Ocean basins: The areas between land masses. 5 major ocean basins: 1. 2. 3. 4. 5. ***The image above is an interactive from: Lesson 1, Discover page 1, “water world” tab

29. Ocean basins: The areas between land masses. 5 major ocean basins: 1. 2. 3. 4. 5. Artic Ocean ***The image above is an interactive from: Lesson 1, Discover page 1, “water world” tab

30. Ocean basins: The areas between land masses. 5 major ocean basins: 1. Artic Ocean 2. Indian Ocean 3. 4. 5. ***The image above is an interactive from: Lesson 1, Discover page 1, “water world” tab

31. Ocean basins: The areas between land masses. 5 major ocean basins: 1. Artic Ocean 2. Indian Ocean 3. Pacific Ocean 4. 5. ***The image above is an interactive from: Lesson 1, Discover page 1, “water world” tab

32. Ocean basins: The areas between land masses. 5 major ocean basins: 1. Artic Ocean 2. Indian Ocean 3. Pacific Ocean 4. Antarctica Ocean 5. ***The image above is an interactive from: Lesson 1, Discover page 1, “water world” tab

33. Ocean basins: The areas between land masses. 5 major ocean basins: 1. Artic Ocean 2. Indian Ocean 3. Pacific Ocean 4. Antarctica Ocean 5. Atlantic Ocean ***The image above is an interactive from: Lesson 1, Discover page 1, “water world” tab

34. The ocean plays a major role in the water cycle. All life on Earth depends on the ocean in some way. All water eventually flows into the ocean, where it evaporates and is recycled by rain back onto land.

35. Formation of the Oceans **Please view the video clip on the formation of the oceans, on “Discover pg. 1” under the “Formation of the Oceans” tab.

36. Salty Water Ocean water is salt water containing a variety of salts. Salts in soils and rocks that are continually eroded from land cause the ocean's saltiness. Rivers and streams carry small amounts of salt to the ocean day after day. As the water in the ocean is evaporated by the sun in the water cycle, the salts get left behind. Therefore, in areas where there is a lot of evaporation, the ocean water is actually saltier. The amount of salt in water is a measure of its salinity. Ocean salinity varies by climate. On average, salinity is about 3.5 percent. This means that 3.5 percent of all ocean water is made of salt. In areas with a high evaporation rate, the salinity is higher. When freshwater mixes with ocean water, such as where a river meets the ocean, the salinity is lower than normal. Water with dissolved salts has a higher density than freshwater without dissolved salts.

37. The ocean temperature can vary (change) depending on the location (closer to the equator – warmer; closer to the poles – colder) OR it can vary depending on how deep the water is: *Three main temperature zones (areas) in the ocean: Surface Water Thermocline Deep Water

38. Warm water rises Cold water sinks As it rises and sinks in the ocean, water circulates from bottom to top and back down again.

39. What things impact (or causes) water movement?

40. What things impact (or causes) water movement? The movement of water depends on its density, which in turn depends on temperature and salinity. Warm water is less dense than cold water. Saline (salt) water is denser than freshwater. Differences in temperature and the amount of dissolved solids within the water drive its circulation (cause water to move) from shallow to deep and back again. This process is called thermohaline circulation.

41. Movement:

42. Ocean floor: Like the land we inhabit, the ocean floor is full of mountain ranges, valleys, and plains.

43. ** Please do this interactive activity in lesson 1, under “Discover” page 2, “The Ocean floor” tab:

44. ** Please do this interactive activity in lesson 1, under “Discover” page 2, “The Ocean floor” tab: continent: The landmass surface where the water from the ocean meets at the shoreline. The BEACH!

45. ** Please do this interactive activity in lesson 1, under “Discover” page 2, “The Ocean floor” tab: continental shelf: The edge of a continent where the water is relatively shallow.

46. ** Please do this interactive activity in lesson 1, under “Discover” page 2, “The Ocean floor” tab: continental slope: A sharp drop in depth where the ocean basin truly begins and the continental crust ends. Looks like a half pipe ramp:

47. ** Please do this interactive activity in lesson 1, under “Discover” page 2, “The Ocean floor” tab: volcanic island arc: A line of volcanic islands caused by subduction and the melting of either oceanic or continental crust. An arc, like the “golden arches”

48. ** Please do this interactive activity in lesson 1, under “Discover” page 2, “The Ocean floor” tab: abyss: The deepest portions of the ocean basin (abyss comes from the Greek word for “bottomless”), excluding ocean trenches.

49. ** Please do this interactive activity in lesson 1, under “Discover” page 2, “The Ocean floor” tab: mid-ocean ridge: A location where sea floor spreading occurs. The release of magma at these active volcanic sites forms new rocks and rows of mountains.

50. ** Please do this interactive activity in lesson 1, under “Discover” page 2, “The Ocean floor” tab: abyssal plain: A large, flat, and deep portion of the ocean surrounding either side of a mid ocean ridge.