| A | B |
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| * Evolution above the species level (ie - the kind that creates new species) is called _______. | macroevolution p459 |
| * ____ genes determine such basic features as where a pair of wings and a pair of legs will develop on a bird or how a flower’s parts are arranged. | Homeotic genes p474 |
| * The products of one class of homeotic genes called ____ genes provide positional information in animal embryos. | Hox (Examples include the development of fins in fish and limbs in tetrapods) p474 |
| * The number of years it takes for 50% of an original sample of a radioactive isotope to decay is called the isotope's _____. | half-life p461,  |
| * Scientific data indicates that Earth formed about _____ years ago. | 4.6 billion p462 |
| * Each era is a distinct age in the history of Earth and its life, with boundaries marked by ________ seen in the fossil record. | mass extinctions p462 |
| * The earliest known fossils date back about _____ years ago. | 3.5 billion p462 |
| * Earth's early atmosphere was much different than today's atmosphere in that it lacked _____. | oxygen p462 (The book no longer makes this explicit, but it's true and important) |
| * What type of rocks are most fossils in? | sedimentary p460 |
| * The _____ refers to a relatively brief period of time in geologic history when many present-day phyla of animals first appeared in the fossil record. This burst of evolutionary change occurred about 535 to 525 million years ago and saw the emergence of the first large, hard-bodied animals. | Cambrian Explosion p463 |
| * What caused the major mass extinctions at the end of each era? | DUH!!! (Actually, some scientists, now dead, believed that the extinctions were caused by disruptive global environmental changes, but Chuck took issue with this) p521,  |
| * How long ago did dinosaurs go extinct? | 66 million years ago p469 |
| * Evolutionary change often occurs due to adaptations to a _______. | changing environment p471 |
| * Carbon -14 is a radioactive isotope of carbon that has a half-life of 5,730 years. The amount of carbon-14 in the atmosphere is a small but stable percentage. It is formed by the bombardment of nitrogen in the atmosphere by cosmic particles coming from the sun. When plants photosynthesize, they incorporate carbon as CO2. The percentage of radioactive carbon-14 incorporated into plant tissues is the same as the relative abundance of carbon-14 in the atmosphere. That carbon is then passed up the food chain, so that all living organisms have the same relative abundance of carbon-14 in their tissues. However, after an organism dies, the carbon-14 slowly changes back into nitrogen-14 (a stable non-radioactive isotope of nitrogen). Let's say that and human dies. What percentage of carbon of the original carbon-14 will still be in it's bones after 5,730 years? After 11,460 years? | 50%, 25% (Remember, from 5730 years until 11,460 years after the human dies, you will go from having half the original amount of carbon-14 to having half of THAT. So half of 50% is 25%) p461 |
| * TRUE or FALSE: Scientists would use carbon-14 to date fossils that are thought to be several million years old. | FALSE: (Since the half-life of of carbon-14 is only 5730 years, there would be practically nothing left of it several million years after an organism dies. You would have to use an isotope of an element with a much longer half-life and look for it in volcanic rock layers above and below the sediments where the fossil was found, since sedimentary rock can't be radiometrically dated. The reason for this is that sedimentary rock contains particles from rocks of all different ages) p461 |
| * TRUE or FALSE: Fossils can be found in volcanic rock layers. | FALSE: (When volcanic rock is first formed, it is molten lava which would destroy any fossils) p461 |
| * TRUE or FALSE: The age of sedimentary rocks CANNOT be determined by radiometric dating. | TRUE (Sedimentary rocks are made from particles of rocks from many different places that are all different ages) p461 |
| * TRUE or FALSE: If a fossil is found in sedimentary rock that has a volcanic rock layer radiometrically dated at 400 million years below it and another volcanic rock layer dated at 390 million years old above it, the fossil can be assumed to be between 390 and 400 million years old. | TRUE p461 |
| * The collision of two tectonic plates causes the formation of ______. | mountains |
