BIO 124: Exam 3 UPDATED ACTUAL
Exam Questions and CORRECT Answers
Hadean Eon - CORRECT ANSWER - (4.6 billion years ago):
- Origin of Earth
- Oldest known rock on Earth's surface
Archean Eon - CORRECT ANSWER - (4 billion years ago):
- Formation of Earth's crust
- Prokaryotes appear
- Atmospheric oxygen increases
Proterozoic Eon - CORRECT ANSWER - (2.5 billion years ago):
- Increase in atmospheric oxygen leads to creation and extinction of some organisms
- Eukaryotic cells appear and flourish
- Algae and soft-bodied animals appear (Ediacaran era)
Phanerozoic Eon - CORRECT ANSWER - (542 million years ago)
Composed of 3 era:
1. Paleozoic Era (542-251 million years ago)
2. Mesozoic Era (251- 65.5 million years ago)
3. Cenozoic Era (65.5 million years ago - now)
Paleozoic Era - CORRECT ANSWER - (542 million years ago)
Cambrian Explosion: most major animal phyla appear
Marine algae, colonization of land by fungi, animals plants
Diversification of vascular plants
Bony fishes
,Tetrapods and insects appear
Seed plants, forest appear
Reptiles and amphibians appear, radiation of reptiles
Extinction of many marine and terrestrial animal
Cambrian explosion - CORRECT ANSWER - A burst of evolutionary origins when most
of the major body plans of animals appeared in a relatively brief time in geologic history;
recorded in the fossil record about 545 to 525 million years ago in the Paleozoic Era
Mesozoic Era - CORRECT ANSWER - (251- 65.5 million years ago):
Dinosaurs evolve and radiate
Mammals appear
Cone-bearing plants (gymnosperms)
Flowering plants (angiosperms)
Dinosaurs disappear and extinct
Cenzoic Era - CORRECT ANSWER - (65.5 million years ago - now):
Radiation of mammals, birds, and insects
Origin of primates (humans, apes, monkey)
Appearance of bipedal human ancestor
Ice ages, origin of the genus Homo
macroevolution - CORRECT ANSWER - the broad pattern of evolution above the species
level.
E.g:
1. Emergence of terrestrial vertebrates
2. Mass extinctions
3. Origins of flights in birds
, fossil record - CORRECT ANSWER - indicates that there have been great changes in the
kinds of organisms on Earth at different points in time. Few individuals have fossilized, and even
fewer have been discovered.
rocks - CORRECT ANSWER - rocks of every age are not preserved on all places on Earth
(e.g Dinosaurs fossils are not found in Pennsylvania)
hard shell - CORRECT ANSWER - Characteristics that made an organism MORE likely
to be fossilized:
1. Soft body with __________
2. Live near the shore of an ocean or river
3. Large population and long existence
4. Lives where oxygen content is low
sedimentary strata - CORRECT ANSWER - This is a layer of sedimentary rock or soil
with internally consistent characteristics that distinguish it from other layers. It reveal the relative
ages of fossils
relative dating - CORRECT ANSWER - Method of determining the age of a fossil by
comparing its placement with that of fossils in other layers of rock (bottom layer is oldest, top
layer is youngest)
absolute dating - CORRECT ANSWER - A technique used to determine the actual age of a
fossil. It can be determined by radiometric dating
radiometric dating - CORRECT ANSWER - a technique used to date materials such as
rocks or carbon.
- A parent isotope decays to a daughter isotope a a constant rate
- Each isotope has a known half-life, the time required for half the parent isotope to decay. -
Since isotopes are not stable, they tend to decay
- The decay rate is then used to measure age of fossil.
Exam Questions and CORRECT Answers
Hadean Eon - CORRECT ANSWER - (4.6 billion years ago):
- Origin of Earth
- Oldest known rock on Earth's surface
Archean Eon - CORRECT ANSWER - (4 billion years ago):
- Formation of Earth's crust
- Prokaryotes appear
- Atmospheric oxygen increases
Proterozoic Eon - CORRECT ANSWER - (2.5 billion years ago):
- Increase in atmospheric oxygen leads to creation and extinction of some organisms
- Eukaryotic cells appear and flourish
- Algae and soft-bodied animals appear (Ediacaran era)
Phanerozoic Eon - CORRECT ANSWER - (542 million years ago)
Composed of 3 era:
1. Paleozoic Era (542-251 million years ago)
2. Mesozoic Era (251- 65.5 million years ago)
3. Cenozoic Era (65.5 million years ago - now)
Paleozoic Era - CORRECT ANSWER - (542 million years ago)
Cambrian Explosion: most major animal phyla appear
Marine algae, colonization of land by fungi, animals plants
Diversification of vascular plants
Bony fishes
,Tetrapods and insects appear
Seed plants, forest appear
Reptiles and amphibians appear, radiation of reptiles
Extinction of many marine and terrestrial animal
Cambrian explosion - CORRECT ANSWER - A burst of evolutionary origins when most
of the major body plans of animals appeared in a relatively brief time in geologic history;
recorded in the fossil record about 545 to 525 million years ago in the Paleozoic Era
Mesozoic Era - CORRECT ANSWER - (251- 65.5 million years ago):
Dinosaurs evolve and radiate
Mammals appear
Cone-bearing plants (gymnosperms)
Flowering plants (angiosperms)
Dinosaurs disappear and extinct
Cenzoic Era - CORRECT ANSWER - (65.5 million years ago - now):
Radiation of mammals, birds, and insects
Origin of primates (humans, apes, monkey)
Appearance of bipedal human ancestor
Ice ages, origin of the genus Homo
macroevolution - CORRECT ANSWER - the broad pattern of evolution above the species
level.
E.g:
1. Emergence of terrestrial vertebrates
2. Mass extinctions
3. Origins of flights in birds
, fossil record - CORRECT ANSWER - indicates that there have been great changes in the
kinds of organisms on Earth at different points in time. Few individuals have fossilized, and even
fewer have been discovered.
rocks - CORRECT ANSWER - rocks of every age are not preserved on all places on Earth
(e.g Dinosaurs fossils are not found in Pennsylvania)
hard shell - CORRECT ANSWER - Characteristics that made an organism MORE likely
to be fossilized:
1. Soft body with __________
2. Live near the shore of an ocean or river
3. Large population and long existence
4. Lives where oxygen content is low
sedimentary strata - CORRECT ANSWER - This is a layer of sedimentary rock or soil
with internally consistent characteristics that distinguish it from other layers. It reveal the relative
ages of fossils
relative dating - CORRECT ANSWER - Method of determining the age of a fossil by
comparing its placement with that of fossils in other layers of rock (bottom layer is oldest, top
layer is youngest)
absolute dating - CORRECT ANSWER - A technique used to determine the actual age of a
fossil. It can be determined by radiometric dating
radiometric dating - CORRECT ANSWER - a technique used to date materials such as
rocks or carbon.
- A parent isotope decays to a daughter isotope a a constant rate
- Each isotope has a known half-life, the time required for half the parent isotope to decay. -
Since isotopes are not stable, they tend to decay
- The decay rate is then used to measure age of fossil.
