1. Two organisms that are closely related would have a. very similar DNA sequences. b. exactly the same DNA sequences. c. no proteins in common.
d. completely different DNA sequences.
2. The fossil footprint of a dinosaur is an example of a(n)
a. amber-preserved fossil. b. chemically preserved fossil. c. trace fossil. d. permineralized fossil.
3. The amount of time it takes for half of a radioactive isotope to decay is known as the
a. isotope. b. half-life. c. product. d. radiocarbon.
4. Fossils that are useful for dating, because they are common, easy to identify, widespread, and existed for a
brief time are called
a. trace fossils. b. extinct fossils. c. index fossils. d. key fossils.
5. The evolution of humans occurred in which of the following time periods?
a. Cenozoic Era b. Mesozoic Era c. Paleozoic Era d. Precambrian Time
6. What discovery supports the hypothesis that RNA was the genetic material in the earliest organisms?
a. Ribozymes are RNA that can self-replicate. b. DNA does not require enzymes to replicate. c. RNA
stores genetic information on ribozymes. d. Chains of RNA will form lipid membranes.
7. Two gases that probably existed in Earth’s early atmosphere are
a. oxygen and water vapor. b. water vapor and carbon trioxide. c. oxygen and carbon monoxide.
d. hydrogen cyanide and carbon monoxide.
8. Paleontology is the study of
a. ecosystems. b. genetics. c. fossils. d. rocks and minerals.
9. During the Cenozoic era, which group of organisms underwent the most dramatic radiation?
a. true birds b. mammals c. ray-finned fish d. flowering plants
10. Fossils that consist of minerals that have filled in an open mold of an organism are called
a. chemically preserved fossil. b. natural casts. c. amber encased fossil. d. trace fossils.
11. Many scientists think that early aerobic prokaryotes invaded larger cells and eventually gave rise to
a. chloroplasts. b. DNA. c. mitochondria. d. ribosomes.
12. The smallest unit of geologic time is a(n)
a. epoch. b. period. c. era. d. eon.
13. The table below shows four radioactive isotopes used in radiometric dating. How much uranium-238 would
be left after a total time of 13.5 billion years?
(Remember: Total time ÷ half life time= # of half lives used.)
a. 75% of the parent isotope b. 50% of the parent isotope c. 25% of the parent isotope d. 12.5% of the
parent isotope
14. The Age of Reptiles is a term often used to describe the
a. Mesozoic era. b. Paleozoic era. c. Cenozoic era. d. Precambrian Time.
15. Fossilized evidence of Earth’s first forms of life would consist of
a. vertebrates from the Precambrian. b. invertebrates from the Precambrian. c. eukaryotes from the
Precambrian. d. prokaryotes from the Precambrian.