Geology Exam 2
tidal flats
A broad, extensive area along a coastline that is alternately water-covered at high tide and exposed at low tide.
drift
A collective term for all sediment deposited by glacial activity; includes till deposited directly by ice, and outwash deposited by streams discharging from glaciers
modern synthesis
A combination of ideas of various scientists yielding a view of evolution that includes the chromosome theory of inheritance, mutations as a source of variation, and gradualism; it also rejects inheritance of acquired characteristics.
punctuated equilibrium
A concept holding that new species evolve rapidly, in perhaps a few thousand years, then remain much the same during their several million years of existence.
alluvial fan
A cone-shaped accumulation of mostly sand and gravel where a stream flows from a mountain valley onto an adjacent lowland
mud cracks
A crack in clay-rich sediment that forms in response to drying and shrinkage.
varve
A dark-light couplet of sedimentary laminations representing an annual deposit in a glacial lake.
delta
A deposit of sediment where a stream or river enters a lake or the ocean.
cladogram
A diagram showing the relationships among members of a clade, including their most recent common ancestor.
genes
A specific segment of a chromosome constituting the basic unit of heredity.
meandering streams
A stream with a single, sinuous channel with broadly looping curves.
braided streams
A stream with an intricate network of dividing and rejoining channels.
playa lake
A temporary lake in an arid region.
Cladistics
A type of analysis of organisms in which they are grouped together on the basis of derived versus primitive characteristics.
cross-bedding
A type of bedding in which individual layers are deposited at an angle to the surface on which they accumulate, as in sand dunes.
alleles
A variant form of a single gene.
Variation is always present in populations because ____. a. genes are reshuffled by reproduction and altered by mutations b. genes blend during inheritance c. alleles blend during inheritance d. alleles control multiple genes e. new traits develop when traits that are not expressed are lost
Answer A
The degree to which detrital particles have had their sharp edges and corners smoothed off by abrasion is ____. a. rounding b. sorting c. drift d. varve e. cross-bedding
Answer A
The deposits of a meandering stream system consist mostly of a. mud with subordinate sand b. limestone and evaporites c. sheets of gravel and sand d. fan-shaped deposits adjacent to a mountain range e. interbedded detrital and carbonate rocks
Answer A
The development of similar characteristics in distantly related organisms is called ____. a. convergent evolution b. allopatric speciation c. divergent evolution d. parallel evolution e. parallel speciation
Answer A
The half-life of carbon 14 is ____ years. a. 5,730 b. 561,540 c. 80,220 d. 280,770 e. 40,110
Answer A
The most common chemical sedimentary rock is ____. a. limestone b. coal c. shale d. sandstone e. rock salt
Answer A
The principle of superposition states that ____. a. younger rock layers are found above older rock layers b. younger rock layers are found below older rock layers c. older rock layers are found above younger rock layers d. ages of rock layers can't be determined without fossil evidence e. rock layers with similar lithologies are likely the same age
Answer A
Till is ________ sorted sediment deposited by ________ . a. poorly; glaciers b. poorly; lakes c. well; lakes d. poorly; submarine fans e. well; glaciers
Answer A
What best describes the process that occurs when an element undergoes any type of radioactive decay? a. The element changes to a new element. b. The element becomes an ion. c. The element loses protons. d. The element loses neutrons. e. The element loses electrons.
Answer A
An unconformity indicates that the geologic record is ________ at a particular location, and may indicate a period of ________ . a. vertical; deposition b. complete; deposition c. vertical; erosion d. complete; erosion e. incomplete; non-deposition
Answer E
Any sediment deposited directly by glacial ice is called a. fluvial b. graded c. marine d. outwash e. till
Answer E
From continent to deep-ocean, basin what is the order of offshore environments? a. continental slope, continental shelf, continental rise b. continental rise, continental shelf, continental slope c. continental rise, continental slope, continental shelf d. continental slope, continental rise, continental shelf e. continental shelf continental slope, continental rise
Answer E
Geologists depended solely on relative dating methods prior to the development of ________ dating techniques. a. Old Testament genealogy b. geometric c. spherical cooing rates d. ocean salinity e. radiometric
Answer E
depositional environment
Any area where sediment is deposited; a depositional site where physical, chemical, and biological processes operate to yield a distinctive kind of deposit.
mutations
Any change in the genes of organisms; yields some of the variation on which natural selection acts.
biogenic sedimentary structures
Any feature such as tracks, trails, and burrows in sedimentary rocks produced by the activities of organisms.
homologous structure
Body part in different organisms that has a similar structure, similar relationships to other organs, and similar development, but does not necessarily serve the same function, such as forelimbs in whales, bats, and dogs.
analogous structure
Body parts, such as wings of insects and birds, that serve the same function but differ in structure and development
mitosis
Cell division resulting in two cells with the same number of chromosomes as the parent cell; takes place in all cells except sex cells.
meiosis
Cell division yielding sex cells (sperm and eggs in animals, and pollen and ovules in plants), in which the number of chromosomes is reduced by half.
(TRUE/FALSE) Fossil evidence must be examined for accurate determinations of depositional environments.
FALSE
(TRUE/FALSE) Fossils are useful to a point in that they tell scientists what types of animals and plants existed in the past, but they can't provide climatological data.
FALSE
(TRUE/FALSE) Geologists expect the most noticeable changes that present-day activities will leave in the geologic record will be the relics of concrete and steel from cities, factories, and utilities.
FALSE
(TRUE/FALSE) Geologists use the natural radioactive decay of elements as the foundation for relative time dating.
FALSE
(TRUE/FALSE) In bioturbation, most of the original sedimentary structures are preserved.
FALSE
(TRUE/FALSE) In the process of natural selection, favorable inheritable variations guarantees survival for an individual organism.
FALSE
(TRUE/FALSE) Lava flows and ash falls interbedded with sedimentary rocks are most useful for determining numerical ages.
FALSE
(TRUE/FALSE) Lithostratigraphic properties yield stronger time correlations than biostratigraphic properties.
FALSE
(TRUE/FALSE) Lithostratigraphic units are defined solely on the basis of fossil assemblages.
FALSE
(TRUE/FALSE) Macroevolution involves changes within a species.
FALSE
(TRUE/FALSE) Microevolution results from the cumulative effects of macroevolution.
FALSE
(TRUE/FALSE) Mud cracks are one type of biogenic sedimentary structure.
FALSE
(TRUE/FALSE) Nicolas Steno used a mathematical model and the rate of Earth's cooling to calculate that the age of the Earth must be 20-400 million years old.
FALSE
(TRUE/FALSE) Organisms in terrestrial environment have a better chance of being preserved as fossils.
FALSE
(TRUE/FALSE) Originally, the geologic time scale was developed using numerical dates.
FALSE
(TRUE/FALSE) Protons are neutral particles in the nucleus of an atom.
FALSE
(TRUE/FALSE) Punctuated equilibrium is the gradual accumulation of minor changes eventually resulting in the origin of a new species.
FALSE
(TRUE/FALSE) Radiometric dates are unaffected by metamorphism.
FALSE
(TRUE/FALSE) Relative dating approximates how long ago a particular event took place.
FALSE
(TRUE/FALSE) Relative dating of geologic events was not possible before the discovery of radioactivity in the late 19th century.
FALSE
(TRUE/FALSE) Relative dating principles like superposition are rarely applied by stratigraphers, as they rely mostly on numerical dates.
FALSE
(TRUE/FALSE) Rocks in a formation can belong to multiple lithostratigraphic units.
FALSE
(TRUE/FALSE) Rocks in the Grand Canyon are in undisturbed horizontal sedimentary layers. Therefore, the youngest rocks are at the bottom of the sequence, and the oldest rocks are at the top.
FALSE
(TRUE/FALSE) Sand dunes are most likely formed in a wet tropical environment.
FALSE
(TRUE/FALSE) Sedimentary structures are unique to specific environments. For example, ripple marks are only found in stream channels.
FALSE
(TRUE/FALSE) Sedimentary structures form during lithification.
FALSE
(TRUE/FALSE) Soft-bodied organisms are less well represented in the fossil record because they were less common in ancient geologic history.
FALSE
(TRUE/FALSE) Stratigraphy is primarily the study of sedimentary rocks.
FALSE
(TRUE/FALSE) The fossil record reveals that present-day organisms are better adapted to their environments than ancient organisms were adapted to their environments.
FALSE
(TRUE/FALSE) The fossil record shows no significant change in terms of the diversity of organisms through time.
FALSE
(TRUE/FALSE) The mineralogical composition of sedimentary rocks is an indicator of the depositional environment.
FALSE
(TRUE/FALSE) The most important source rocks for fuels we use today are igneous rocks.
FALSE
(TRUE/FALSE) The presence of "missing links" in the fossil records undermines the theory of evolution.
FALSE
(TRUE/FALSE) The principle of lateral continuity states that sedimentary beds are deposited horizontally with the oldest beds on the bottom.
FALSE
(TRUE/FALSE) The science of genetics was developed based on experimental studies using fruit flies.
FALSE
(TRUE/FALSE) The sentence "The Paleozoic Era occurred before the Mesozoic Era" is an example of absolute dating.
FALSE
(TRUE/FALSE) The short half-life of uranium-238 allows it to be used to date ancient events.
FALSE
(TRUE/FALSE) The strongest evidence that rocks are time correlated is derived from lithological similarities.
FALSE
(TRUE/FALSE) Time units are rock units that were deposited during a certain time interval.
FALSE
(TRUE/FALSE) Tree-ring dating, or dendrochronology, is a relative dating method.
FALSE
(TRUE/FALSE) Unconformities can only develop between layers of sedimentary rock.
FALSE
(TRUE/FALSE) Uniformitarianism is a limited concept, because it fails to account for sudden events such as earthquakes, volcanoes, and tsunamis.
FALSE
(TRUE/FALSE) Unlike detrital sedimentary rocks, carbonate rocks do not have cross-bedding, ripple marks, or other sedimentary structures.
FALSE
(TRUE/FALSE) Allopatric speciation occurs when organisms inherit two different alleles.
FALSE
(TRUE/FALSE) William Smith's principle of fossil succession states that fossil assemblages succeed one another through time in regular and determinable order.
FASLE
Inheritance of acquired characteristics
Jean-Baptiste de Lamarck's mechanism for evolution; holds that characteristics acquired during an individual's lifetime can be inherited by descendants.
Fission-track dating
The dating process in which small linear tracks (fission tracks) resulting from alpha decay are counted in mineral crystals.
progradation
The seaward (or lakeward) migration of a shoreline as a result of nearshore sedimentation.
Radioactive decay
The spontaneous change in an atom by emission of a particle from its nucleus (alpha and beta decay) or by electron capture, thus changing the atom to a different element.
Paleogeography
The study of Earth's ancient geography on a global as well as a regional scale.
biogeography
The study of the geographic distribution of organisms and communities of organisms.
theory of evolution
The theory holding that all living things are related and that they descended with modification from organisms that lived during the past.
Till
Sediment deposited directly by glacial ice, as in an end moraine.
(TRUE/FALSE) Current flow direction can be determined by cross-beds and some ripple marks.
TRUE
(TRUE/FALSE) Darwin's studies of animals in the Galapagos Islands were important in the development of the theory of evolution.
TRUE
(TRUE/FALSE) Deltas form when streams or rivers encounter a standing body of water, such as an ocean or lake.
TRUE
(TRUE/FALSE) Dense marine flows composed of a mixture of water and sediment are called turbidity currents.
TRUE
(TRUE/FALSE) Dinosaur bones would be body fossils, and dinosaur tracks would be trace fossils.
TRUE
(TRUE/FALSE) Divergent evolution results in descendants that differ markedly from their ancestors.
TRUE
(TRUE/FALSE) Eras are subdivided into periods.
TRUE
(TRUE/FALSE) Evaporites in the rock record commonly indicate a period of arid climate.
TRUE
(TRUE/FALSE) Evolutionary trends can be reversed.
TRUE
(TRUE/FALSE) Fluvial systems, lakes, and deserts are classified as continental environments.
TRUE
(TRUE/FALSE) Fossils are remains or traces of prehistoric life that have been preserved in rocks of Earth's crust.
TRUE
(TRUE/FALSE) Geologists are able to interpret depositional environments not only by the sedimentary structures they contain, but also by comparing ancient deposits with present-day deposits.
TRUE
(TRUE/FALSE) Growth and development by mitosis results in progeny that are genetically identical to the parent cell.
TRUE
(TRUE/FALSE) Guide fossils are confined to a narrow range of time.
TRUE
(TRUE/FALSE) Homologous and analogous structures provide biological evidence that supports evolutionary theory.
TRUE
(TRUE/FALSE) Humans with normal DNA have 46 chromosomes.
TRUE
(TRUE/FALSE) If sedimentary rocks are tilted steeply, they most likely have experienced an episode of deformation.
TRUE
(TRUE/FALSE) In the Linnaean Classification Scheme, a species consists of individuals that can interbreed and produce fertile offspring.
TRUE
(TRUE/FALSE) In the early 20th century, Pierre and Marie Curie discovered that radioactive decay produces heat.
TRUE
(TRUE/FALSE) James Hutton is considered the founder of modern day geology.
TRUE
(TRUE/FALSE) James Hutton pioneered the principle that we know today as uniformitarianism.
TRUE
(TRUE/FALSE) Jean-Baptiste de Lamarck developed the theory of inheritance of acquired characteristics.
TRUE
(TRUE/FALSE) Jean-Baptiste de Lamarck proposed a mechanism for evolution called the inheritance of acquired characteristics, but ultimately his mechanism was refuted.
TRUE
(TRUE/FALSE) Lagoons and reefs are sites of carbonate deposition.
TRUE
(TRUE/FALSE) Larger particles indicate higher energy depositional environments.
TRUE
(TRUE/FALSE) Lord Kelvin's estimates of Earth's age were incorrect because he did not account for heat supplied to Earth by radioactive decay.
TRUE
(TRUE/FALSE) Marine transgressions and regressions are events where sea levels change due to tectonic or climatic events.
TRUE
(TRUE/FALSE) Members of a clade can have different derived and primitive characteristics.
TRUE
(TRUE/FALSE) Most sedimentary rocks are deposited by water or underwater.
TRUE
(TRUE/FALSE) Mutations can be harmful, beneficial, or neutral.
TRUE
(TRUE/FALSE) Mutations in sex cells can be induced by ultraviolet radiation or extreme temperature changes.
TRUE
(TRUE/FALSE) Numerical dating was not used until the discovery of radioactive decay.
TRUE
(TRUE/FALSE) Obtaining an absolute age for most sedimentary rocks is difficult.
TRUE
(TRUE/FALSE) One reason sedimentation rates cannot be used to calculate the age of Earth is variations in erosion rates.
TRUE
(TRUE/FALSE) Paleogeographic maps show the distribution of land and seas at various times in Earth's history.
TRUE
(TRUE/FALSE) Pelagic clay deposits are associated with deep marine environments.
TRUE
(TRUE/FALSE) Populations that can interbreed and produce fertile offspring are called species.
TRUE
(TRUE/FALSE) Quartz, feldspar, and clay minerals are the most common constituents of sedimentary rocks
TRUE
(TRUE/FALSE) Range zones indicate the total time a species existed in the geologic record.
TRUE
(TRUE/FALSE) Relative dating principles allow geologists to correlate rock units and interpret the geologic history of an area.
TRUE
(TRUE/FALSE) Rocks above and below a bedding plane may have different physical properties.
TRUE
(TRUE/FALSE) Sand is commonly found in fluvial deposits.
TRUE
(TRUE/FALSE) Sedimentary rocks are important because they preserve evidence of the surface processes responsible for deposition.
TRUE
(TRUE/FALSE) Sediments are originally deposited in horizontal layers.
TRUE
(TRUE/FALSE) Sharks and dolphins show convergent evolution since they have similar features, yet are only distantly related.
TRUE
(TRUE/FALSE) Some scientists have suggested that human intervention in the Earth system has been responsible for a new epoch of geologic time called the Anthropocene.
TRUE
(TRUE/FALSE) Systems of rock units were established on the basis of superposition and fossil content.
TRUE
(TRUE/FALSE) The fossil record contains a sequence from simple to more complex organisms through time.
TRUE
(TRUE/FALSE) The main sources of deep-sea sediments are dust blown from continents or oceanic islands, volcanic ash, and shells of microorganisms that lived in the ocean's surface waters.
TRUE
(TRUE/FALSE) The most common detrital sedimentary rocks are sandstones and mud rocks.
TRUE
(TRUE/FALSE) The phrase "survival of the fittest" has often been used to describe the theory of natural selection.
TRUE
(TRUE/FALSE) The present geologic time scale is based on relative and numerical dating techniques.
TRUE
(TRUE/FALSE) The principle of fossil succession is one of the principles for relative-age determinations of strata and their contained fossils
TRUE
(TRUE/FALSE) The view that species change little during most of their existence and then evolve rapidly into new species is called punctuated equilibrium.
TRUE
(TRUE/FALSE) Walther's law states that facies seen in a conformable vertical sequence will also replace one another laterally.
TRUE
(TRUE/FALSE) We are currently in the Quaternary period of the Cenozoic era.
TRUE
(TRUE/FALSE) When animal breeders select desirable traits and breed animals with these traits, they are practicing artificial selection.
TRUE
(TRUE/FALSE) Whether a mutation is harmful or beneficial can only be judged in respect to the environment.
TRUE
(TRUE/FALSE)By definition, a species is reproductively isolated from other species.
TRUE
(TRUE/FALSE)Evolution can occur via artificial selection.
TRUE
(TRUE/FALSE) Most of the organisms that have ever existed are now extinct.
TRUE
(TRUE/FALSE) Only mutations present in sex cells are inheritable.
TRUE
half-life
The time necessary for one-half of the original number of radioactive atoms of an element to decay to a stable daughter product; for example, the half-life of potassium 40 is 1.3 billion years
ripple marks
Wavelike structure on a bedding plane, especially in sand, formed by (1) unidirectional flow of air or water currents or (2) by oscillating currents as in waves.
(TRUE/FALSE) Evaporites form in moist, humid marine environments.
FALSE
(TRUE/FALSE) Formations consist of rocks that are all the same age.
FALSE
(TRUE/FALSE) Evolutionary change always occurs slowly, over long periods of time.
FALSE
barrier islands
A long sand body more or less parallel with a shoreline but separated from it by a lagoon.
Carbon-14 dating
A numerical dating technique relying on the ratio of to in organic substances; useful back to about 70,000 years ago
(TRUE/FALSE) Evolutionary trends cannot be reversed.
FALSE
principle of cross-cutting relationships
A principle holding that an igneous intrusion or fault must be younger than the rocks it intrudes or cuts across
principle of lateral continuity
A principle holding that rock layers extend outward in all directions until they terminate
principle of superposition
A principle holding that sedimentary rocks in a vertical sequence formed one on top of the other so that the oldest layer is at the bottom of the sequence whereas the youngest is at the top
principle of original horizontality
A principle holding that sediments are deposited in horizontal or nearly horizontal layers.
sand dune
A ridge or mound of wind-deposited sand.
graded bedding
A sediment layer in which grain size decreases from the bottom up.
Paleontologists study a. the biochemistry of organisms b. life history as revealed by fossils c. molecular changes in plants d. lateral gene transfer in bacteria e. how animals and plants reproduce
ANSWER B
sedimentary structures
All features in sedimentary rocks, such as ripple marks, cross-beds, and burrows, that formed as a result of physical or biologic processes that operated in a depositional environment.
outwash
All sediment deposited by streams that issue from glaciers.
The basic lithostratigraphic unit is a mappable unit of strata with distinctive upper and lower boundaries called a(n) ____. a. formation b. extrusive c. rock d. biozone e. series
Answer A
living fossil
An existing organism that has descended from ancient ancestors with little apparent change.
living fossils
An existing organism that has descended from ancient ancestors with little apparent change.
A population of similar individuals that in nature interbreed and produce fertile offspring: a. species b. class c. genus d. order e. kingdom
Answer A
About ________ percent of organisms that have existed are now extinct. a. 99 b. 2 c. 78 d. 50 e. 24
Answer A
An erosional surface that separates strata that are parallel with one another is called a(n) ____. a. disconformity b. hiatus c. bedding plane d. nonconformity e. angular unconformity
Answer A
Assigning a specific date to a rock, which is measured in years before present, is known as ____. a. absolute dating b. carbon dating c. fossil succession d. relative dating e. superposition
Answer A
Extensive burrowing by organisms may produce ________ , in which sediments may be so disturbed that other sedimentary structures are destroyed. a. bioturbation b. ripples c. mud cracks d. biodegradation e. cross-bedding
Answer A
Guide fossils are most useful because they ____. a. occur over a brief time interval b. are difficult to identify c. occur over a long period of time d. occur in all rock types e. occur over a small geographic area
Answer A
Humans typically have ________ pairs of chromosomes in their cells. a. 23 b. 46 c. 13 d. 96 e. 69
Answer A
Imagine that you are standing in front of a stack of sedimentary beds. You know the beds at your feet are older than those above your head because of the principle of ________ . a. superposition b. cross-cutting relationships c. original horizontality d. unconformities e. lateral continuity
Answer A
Jean - Baptiste de Lamarck believed that species ________ change with time, as a result of ________ . a. do; inheritance of acquired characteristics b. do not; natural selection c. do; natural selection d. do; survival of the fittest e. do not; inheritance of acquired characteristics
Answer A
Natural selection can best be described as the ________ . a. weeding out of individuals not well-adapted to their environment b. genetic variations that lead to bigger, stronger animals c. uniform and reproducible characteristics in a population d. guaranteed survival of the fittest species e. random variations in individuals that reproduce
Answer A
Range zones are most beneficial for identifying ________ . a. the total time species existed b. sedimentary rocks c. marine transgressions d. guide fossils e. the geographic distribution of an organism
Answer A
Red flowers with the alleles (Rr) are cross-bred: R = dominant allele. r = recessive allele. What is the likelihood of producing a red offspring flower? a. 75 percent b. 100 percent c. 50 percent d. 0 percent e. 25 percent
Answer A
Silt and clay are fine-grained sediment and tend to be deposited in low-flow environments such as ________ . a. lagoons b. fast flowing rivers c. beach dunes d. glacial areas e. desert dunes
Answer A
What is a mass extinction? a. A rapid increase in the rate of extinctions that reduces Earth's biotic diversity b. The result of excessive allopatric speciation c. The result of accumulated harmful mutations d. The continuous extinction of various species e. An occurrence when an entire phylum of cohorts dies off
Answer A
Which feature of sedimentary rocks would be most useful to determine the depositional environment? a. sedimentary structures b. rock body geometry c. texture d. color e. present day location
Answer A
William Smith's principle of fossil succession states that fossil assemblages ________ . a. succeed each other in a predictable manner b. consist of two or more related fossils c. must exist for short geologic time periods to be useful d. are unique to the area they are found e. must exist for long geologic time periods to be useful
Answer A
the concept holding that organisms evolve slowly and continuously is called a. phyletic gradualism b. macroevolution c. modern synthesis d. parallel evolution e. homologous evolution.
Answer A
A half-life is the amount of time required ____. a. to lose half the daughter isotopes b. for half of the parent atoms to decay to daughter atoms c. to accurately date a rock sample d. for the mass of the sample to decrease by one-half e. for the parent atoms to increase by one-half
Answer B
A rock sample containing an isotope with a half-life of 28 million years has an initial mass of 184 grams. How much parent isotope remains after 3 half-lives? a. 46 grams b. 23 grams c. 115 grams d. 161 grams e. 69 grams
Answer B
According to modern evolutionary theory, populations ________ evolve, whereas individuals ________ . a. do not; do as well b. do; do not c. do; do as well d. divergently; convergently e. do not; do not
Answer B
After three half-lives, a radioactive element will have ____ of its original parent atoms. a. 1/2 b. 1/8 c. 1/6 d. 1/32 e. 1/3
Answer B
Atoms of the same element with different numbers of neutrons in the nuclei are known as ____. a. neutrons b. isotopes c. electrons d. nucleotides e. ions
Answer B
Because heat and pressure affect the ratio of radioactive parent to stable daughter, ____ rocks generally are difficult to date accurately by radiometric dating. a. mafic b. metamorphic c. igneous d. felsic e. sedimentary
Answer B
During marine transgressions and regressions, several facies are deposited at the same time, giving rise to vertical and lateral relationships. Which law summarizes these relationships? a. principle of transgressive sequences b. Walther's Law c. Steno's Law d. Facies theory e. principle of lateral continuity
Answer B
Evaporites are ________ common than limestone in the geological record, and consist mostly of ________ . a. less; carbonate minerals b. less, rock salt and rock gypsum c. more, quartz-rich sandstones d. more, rock salt and rock gypsum e. less, quartz-rich sandstones
Answer B
In a sequence of undisturbed sedimentary rocks, the oldest fossils will be ____. a. in the middle rock layer b. in the bottom rock layer c. indistinguishable from the other fossils d. unable to be determined e. in the top rock layer
Answer B
Limestone deposits most likely form in which environments? a. aeolian environments b. carbonate reefs c. lagoons d. fluvial environments e. alluvial fans
Answer B
Sedimentary structures are formed during ________ or shortly thereafter. a. transportation b. deposition c. erosion d. weathering e. lithifaction
Answer B
Structures like bat and fly wings have similar functions, but they evolved in different ways. What would these types of structures be called? a. equivalent structures b. analogous structures c. comparative structures d. homologous structures e. vestigial structures
Answer B
Studies show that the Navajo sandstone is made up of well-rounded, well-sorted quartz grains with tracks of land dwelling animals, including dinosaurs, and it has cross-beds up to 30 meters high. These are good indicators that this was formed in a ________ environment. a. glacial b. coastal dune c. lake d. fluvial e. deltaic
Answer B
The basic, mappable, lithostratigraphic unit is the ________ , which has ________ upper and lower boundaries. a. platform; variable b. formation; distinct c. bed; variable d. facies; distinct e. bed; distinct
Answer B
The most common way to numerically date a sedimentary rock is to ________ . a. numerically date the sedimentary rock b. numerically date an associated igneous or metamorphic rock c. use Walther's Law d. numerically date a fossil in the rock e. rely on superposition
Answer B
The statement that "the same facies following one another in a conformable vertical sequence will also replace one another laterally" is known as ____. a. principle of fossil succession b. Walther's Law c. Gressly's principle d. Steno's axiom e. Smith's Law of Conformity
Answer B
The time necessary for one-half of the original number of radioactive atoms of an element to decay to a stable daughter product is known as a(n) ____. a. relative age b. half-life c. alpha decay d. metamorphosis e. scale
Answer B
Uranium-238 (U-238) that undergoes alpha decay becomes ____. a. U-234 b. Th-234 c. Pa-234 d. Th-232 e. Pu-242
Answer B
What is the correct time unit for the Quaternary, Pennsylvanian, Ordovician and Cretaceous? a. eons b. period c. epoch d. eras e. system
Answer B
What is the development of similar characteristics in distantly related organisms called? a. parallel evolution b. convergent evolution c. analogous evolution d. divergent evolution e. homologous evolution
Answer B
You have the most characteristics in common with members of your own ____. a. kingdom b. species c. genus d. class e. phylum
Answer B
____ are transitional environments because they ____. a. Submarine fans; involve marine and continental processes b. Barrier islands; involve marine and continental processes c. Glaciers; straddle the boundary between the mountains and the plains d. Alluvial fans; straddle the boundary between the mountains and the plains e. Sand dunes; involve marine and continental processes
Answer B
____ would indicate deposition occurred in a high-energy environment. a. Clay-rich rocks b. Conglomerates c. Shales d. Glacial till e. Pelagic oozes
Answer B
________ are least likely to be preserved in the fossil record because ________ . a. Clams; they are very scarce b. Jellyfish; they consist mainly of soft parts c. Brachiopods; they frequently undergo mineral replacement d. Corals; they frequently undergo mineral replacement e. Horse teeth; horses live in areas not conducive to fossilization
Answer B
________ evolution specifically involves the development of similar characteristics in distantly related organisms. For example insects, birds, and bats are not closely related but all have evolved to have wings. a. Divergent b. Convergent c. Punctuated equilibria d. allopatric e. Parallel
Answer B
A ________ consists of similar individuals that in nature can interbreed and produce fertile offspring. a. Family b. Genus c. Species d. Order e. Phylum
Answer C
A clast of granite found in a breccia is dated at 450 million years old. What can you conclude about the breccia? a. The breccia was metamorphosed more than 450 million years ago. b. The breccia is older than 450 million years. c. The breccia is younger than 450 million years old. d. The breccia was metamorphosed fewer than 450 million years ago. e. You can't draw any conclusions.
Answer C
A rock sample containing an isotope with a half-life of 28 million years has an initial mass of 184 grams. How much time has elapsed after three half-lives? a. 9.3 million years b. 32 million years c. 84 million years d. 56 million years e. 6.5 million years
Answer C
A sample of deep-sea sediments would be expected to contain ____. a. sand b. limestone c. fine-grained clays and ooze d. coral reefs e. sand and ooze
Answer C
According to natural selection, ________ variations are more favorable than others, and ________ variations are more likely passed on to further generation. a. no; unfavorable b. no; favorable c. some; favorable d. some; unfavorable e. no; only helpful
Answer C
As long as a mutation takes place in a ________ , it is inheritable. a. allele b. lateral cell c. sex cell d. meiotic cell e. mitotic cell
Answer C
Cell division resulting in two cells with the same number of chromosomes as the parent cell is ____. a. mutation b. natural selection c. mitosis d. meiosis e. divergent evolution
Answer C
Determining specific, quantitative dates for rock units or events expressed in years before the present is known as ____ dating. a. correlative b. sedimentary c. absolute d. blind e. relative
Answer C
From land to sea, the order of marine environments is ________ . a. continental slope, continental shelf, and continental rise b. continental shelf, continental rise, and continental slope c. continental shelf, continental slope, and continental rise d. continental slope, continental rise, and continental shelf e. continental rise, continental slope, and continental slope
Answer C
Guide fossils should be geographically ________ , with a relatively ________ geologic range. a. limited; short b. limited; intermediate c. widespread; short d. widespread; long e. limited; long
Answer C
If a fault cuts three beds of rock, it must be ________ the three beds of rocks. We know this because of the principle of ________ . a. older than; lateral continuity b. younger than; superposition c. younger than; cross-cutting relationships d. the same age as the top bed; cross-cutting relationships e. older than; cross-cutting relationships
Answer C
In a well-sorted rock, ____. a. grains are graded b. there are no signs of bioturbation c. all grains are about the same size d. all grains have cross-bedding e. all rocks are about the same size
Answer C
Lead-214 (Pb-214) that undergoes beta decay becomes ____. a. Bi-210 b. Tl-214 c. Bi-214 d. Pb-212 e. Tl-210
Answer C
Lord Kelvin calculated Earth was 20-400 million years old. Why was he wrong? a. He didn't account for the erosion of sediments. b. His thermometer was incorrectly calibrated. c. He didn't know Earth had an internal heat source. d. He wrongly assumed the oceans were initially fresh. e. He didn't account for the presence of salt deposits.
Answer C
Many limestones are made up of sand- and gravel-sized particles and calcium carbonate mud called a. drift b. fossils c. micrite d. graded bedding e. varve
Answer C
The geologic time scale is a dual scale based on ________ sequences with radiometric dates expressed as years before the present. a. carbon b. tree-ring c. rock d. isotope e. biotic
Answer C
The most notable trace in the geologic record of human activities is likely to be a(n) ____. a. more diverse pollen record b. concrete and metal debris field left from cities c. increase in carbon dioxide levels, as recorded by ice cores d. more alkaline ocean e. expansion of farmland
Answer C
The theory of evolution as proposed by ________ states ________ . a. Lamarck; small changes in inheritance are random and insignificant over time b. Lysenko; only the fittest survive c. Darwin; present day organisms have descended with Modifications from ancestors d. Darwin; characteristics are acquired via inheritance from parents e. Lamarck; animal traits are inherited
Answer C
Tree-ring dating is useful for ________ dating of ________ events. a. relative; radiometric b. numerical; recent c. relative; recent d. numerical; ancient e. relative; ancient
Answer C
Uniformitarianism is the assumption that ____. a. younger sedimentary rocks are at the top of rock sequences b. catastrophic events don't impact Earth processes c. present-day geological processes also occurred in the past d. principles of one branch of science apply to other branches of science e. current rates of atmospheric warming are unsustainable
Answer C
What is the best example of a biogenic sedimentary structure? a. dinosaur bone b. brachiopod shell c. fossil footprint d. horse tooth e. laminations
Answer C
What is the meaning of the phrase "the present is the key to the past"? a. Geologists must be able to assign numerical dates to events in order to understand the geologic record. b. What happened in the past has no bearing on what happens today. c. The natural laws that operate today operated precisely the same in the past. d. Relative dating can only be applied to recent geological events. e. Earth is aging at a uniform rate.
Answer C
What theory proposes that the same processes seen today have operated throughout geologic time (i.e. the present is the key to the past)? a. inclusion b. fossil succession c. uniformitarianism d. evolution e. conformitarianism
Answer C
When a marine transgression occurs, the shoreline migrates ________ , and sea level ________ . a. seaward; rises b. landward; is unaffected c. landward; rises d. landward; falls e. seaward; falls
Answer C
Which depositional environment is considered to be marine? a. fluvial b. delta c. continental shelf d. glacial e. desert
Answer C
Which of the following do geologists use to determine ancient current directions? a. Playa lake deposits b. Varves c. Cross-bedding d. Glacial drift e. Bioturbation
Answer C
Which piece of evidence would best illustrate that rocks in widely separated areas were deposited at the same time? a. identical position in the geologic column b. identical rock types c. species-identical fossil assemblages d. inclusion in the same formation e. similar sediment compositions
Answer C
Which scientist used a mathematical model and the rate of Earth's cooling to calculate that the age of the Earth must be 20-400 million years old? a. James Hutton b. James Ussher c. Lord Kelvin d. Charles Lyell e. John Joly
Answer C
Why are cities unlikely to be preserved in the geologic record? a. They focus their efforts on environmentally friendly buildings. b. They will eventually be submerged in the oceans. c. They are situated on land, which tends to erode. d. They consume large quantities of natural resources. e. They are situated on land, where most sediments are deposited.
Answer C
Fluvial is a term referring to ____. a. glaciers and glacial deposits b. turbidity currents and turbidites c. river activity and river deposits d. waves and wave deposits e. chemical processes and evaporites
Answer C
Allopatric speciation is most likely to occur after a(n) ____. a. pond is dredged b. pet is lost c. volcanic eruption d. mountain building e. earthquake
Answer D
An erosional surface that separates older metamorphic or plutonic rocks from younger overlying sedimentary rocks is called a(n) ____. a. bedding plane b. disconformity c. hiatus d. nonconformity e. angular unconformity
Answer D
As a rock ages, the percentage of parent isotopes ________ , whereas the percentage of daughter isotopes ________ . a. increases; increases b. decreases; does not change c. increases; decreases d. decreases; increases e. decreases; decreases
Answer D
Cell division yielding sex cells, sperm and eggs in animals, and pollen and ovules in plants, in which the number of chromosomes is reduced by half is ____. a. mitosis b. evolution c. natural selection d. meiosis e. mutation
Answer D
Charles Darwin did not use evidence from ____ to support the theory of evolution. a. classification b. geographic distribution c. comparative anatomy d. inheritance mechanisms e. embryology
Answer D
Cladistics is a type of biological analysis in which organisms are grouped together based on ________ characteristics. a. identical, primitive b. original, primitive c. identical, shared d. shared, derived e. unique, primitive
Answer D
Deltas build ________ by a geologic process called ________ . a. seaward; erosion b. landward; progradation c. landward; erosion d. seaward; progradation e. seaward; retrogradation
Answer D
Geologists use a rock sample that is a(n) ________ system to date events that occurred early in Earth's history as well as a radioactive isotope with a relatively ________ half-life. a. clean; long b. open; short c. closed; short d. closed; long e. open; long
Answer D
Graded bedding forms when ____. a. turbidity currents deposit first fine-grained sediment then coarse-grained sediment b. sediment is deposited on a steep slope or grade c. erosion planes off a portion of the sea bottom d. turbidity currents deposit first coarse-grained sediment then fine-grained sediment e. cross-bedding is truncated at top and curved (or tangential) at bottom
Answer D
Imagine a stack of tilted sedimentary beds. We know that these beds were deposited horizontally, and then later tilted, because of the principle of ________ . a. superposition b. cross-cutting relationships c. lateral continuity d. original horizontality e. inclusions
Answer D
In evolution, the organisms that win are ____. a. more complex b. those that are not subjected to harsh environments c. able to keep the environment adapted to them d. able to adapt to their environment e. big, mean, or smart (preferably all three)
Answer D
In the 1600s, ________ analyzed the Old Testament and determined that Earth was formed on October 23, 4004 B.C. a. George Louis de Buffon b. James Joly c. James Hutton d. James Ussher e. Nicolas Steno
Answer D
Lord Kelvin analyzed ________ rates for Earth to determine the age of Earth. He believed that his work ________ uniformitarianism as outlined James Hutton-Charles Lyell. a. radioactive decay; refuted b. radioactive decay; supported c. cooling; supported d. cooling; refuted e. cooling; was not relevant to
Answer D
One important conclusion of Mendel's genetic studies with pea plants is ____. a. mutation is the only important factor in change b. if particular traits do not appear in each generation, they are lost from the species c. the traits that an organism inherits are the average of the two alleles d. genes controlling traits do not blend during inheritance, but are transmitted as discrete entities e. once a trait becomes recessive, it is lost to the population forever
Answer D
Preserved records of prehistoric organic activity such as tracks, trails, burrows, and nests are called ____. a. casts b. carbonizations c. permineralizations d. trace fossils e. molds
Answer D
Radiometric dating is based on ____. a. superposition b. cross-cutting relationships c. the presence of fossils d. spontaneous decay of radioactive elements e. dendrochronology
Answer D
The ____ states that sediment extends laterally in all directions until it thins and pinches out, or terminates, against the edge of the depositional basin. a. principle of superposition b. principle of original horizontality c. principle of uniformitarianism d. principle of lateral continuity e. principle of cross-cutting relationships
Answer D
The basic unit of heredity, ____, is found in segments of ____. a. chromosomes; genes b. DNA; genes c. DNA; chromosomes d. genes; chromosomes e. genes; DNA
Answer D
The binomial species name is composed of the ____ name first, followed by the ____ name. a. family; species b. species; class c. species; order d. genus; species e. phyla; order
Answer D
The direction of ancient wind and water currents can be deduced from analyzing ________ . a. graded bedding and laminations b. laminations and ripple marks c. mud cracks and graded bedding d. cross-bedding and ripple marks e. ripple marks and mud cracks
Answer D
Unlike igneous rocks, sedimentary rocks are important because they ________ . a. formed entirely from volcanic eruptions b. are easily identified by coarse grains c. are younger and give clues about more recent events d. may contain fossils e. are easy to numerically date
Answer D
What has occurred when organisms of one species develop a resistance to pesticides? a. allopatric mutations b. homologous evolution c. macroevolution d. microevolution e. analogous evolution
Answer D
Which of the following is a trace fossil? a. mammal tooth b. clam shell mold c. preserved mosquito in amber d. dinosaur footprint e. frozen mammoth
Answer D
Which of the following is not a component of the Darwin-Wallace theory of natural selection? a. Some variations are more favorable than others. b. The parts of organisms are fully evolved and functional at any one time. c. Not all young survive to maturity. d. All organisms can knowingly select their genetic direction. e. All populations contain heritable variations.
Answer D
You observe two shale beds separated by 300 kilometers. The rocks in the two shale beds are similar, but one bed is several million years older than the other. You can conclude both beds ____. a. are time-correlated b. are time correlated and contain the same guide fossils c. are unrelated d. are lithologically correlated e. contain the same guide fossils
Answer D
________ , the protein-generating segments of ________ , are the hereditary units of all organisms. a. DNA; alleles b. DNA; chromosomes c. Alleles; genes d. Genes; chromosomes e. Genes; alleles
Answer D
________ used an unscientific method to determine the age of Earth. a. George Louis de Buffon b. James Joly c. Lord Kelvin d. James Ussher e. James Hutton
Answer D
A division on the geologic time scale represents ____. a. the passage of 500,000 years. b. an increase in reptilian population by 100,000 c. an increase in population of all living organisms by one million d. the passage of 250 million years e. a distinctive event in the rock record
Answer E
A geologist is least likely to collect good data on recent climate change (within the past 1,000 years) from what source? a. tree rings b. instruments (e.g., thermometers) c. journals and diaries d. pollen e. rocks
Answer E
A good example of analogous structures are a. eyes of dogs and cats b. scales of reptiles and amphibians c. flippers of whales and porpoises d. legs of deer and horses e. wings of bats and insects
Answer E
A rock sample containing an isotope with a half-life of 28 million years has an initial mass of 184 grams. How much daughter isotope is present after three half-lives? a. 46 grams b. 69 grams c. 23 grams d. 115 grams e. 161 grams
Answer E
A(n) ________ is an erosional surface cut into plutonic or metamorphic rocks that is overlain by sedimentary rocks. a. angular unconformity b. disconformity c. conformity d. compositional unconformity e. nonconformity
Answer E
According to Mendel's work on inheritance, a flower with "Aa" alleles, where "A" is dominant over "a" and "A" is red and "a" is white, will be ____. a. white b. more red than white c. pink d. half red and half white e. red
Answer E
According to the principle of ________, the sedimentary rocks on the top layer, are ________ than those on the bottom layer. a. inclusions; older b. cross-cutting relationships; younger c. superposition; older d. inclusions; younger e. superposition; younger
Answer E
Although the branch of geology known as stratigraphy applies to all the major rock groups, it focuses primarily on ________ rocks. a. extrusive b. igneous c. metamorphic d. intrusive e. sedimentary
Answer E
Herringbone crossbeds develop in tidal flats because ____. a. sediment frequently washes over b. a large supply of fine sediment is available c. a large supply of coarse sediment is available d. alternating cycles of wet and dry conditions e. tidal inflows and outflows
Answer E
Human wisdom teeth are examples of ____ since their functionality has changed over time. a. homologous structures b. superfluous organs c. analogous structures d. extra appendage e. vestigial structures
Answer E
Large-scale cross-beds (greater than 10 ft. in height) commonly indicate a ___________ sedimentary environment. a. fluvial b. lacustrine c. deltaic d. glacial e. desert dune
Answer E
Paleogeography deals primarily with producing maps of ________ . a. historical climate on a global scale b. current animal distribution on a global scale c. historical fossil distribution at points of convergence d. current continental distribution on a global scale e. historical distribution of the continents at various times
Answer E
Parallel evolution occurs when a. unrelated species develop similar characteristics that are dependent on one another b. unrelated species have evolved structures with similar functions c. related species have identical vestigial organs d. unrelated organisms develop different adaptations to similar environments e. closely related animals have developed similar characteristics that have evolved independently
Answer E
Placing geologic events in a chronological order from their position in the rock record is called ____. a. positioning b. numerical dating c. sequencing d. absolute dating e. relative dating
Answer E
The degree to which all the particles in a detrital sedimentary rock are of about the same size is referred to as a. lithification b. compaction c. graded bedding d. angularity e. sorting
Answer E
The fossil record provides evidence for evolution because it ________ . a. shows that farther back in time, organisms in the same family are remarkably different b. supports the concept of missing links c. refutes the concept of missing links d. shows current organisms are more fit that ancient organisms e. shows a sequence of connected species appearing through time
Answer E
The origin of amphibians from fish is an example of ____. a. homologous evolution b. microevolution c. analogous evolution d. parallel evolution e. macroevolution
Answer E
The theory of evolution____. a. says evolutionary change takes place by chance. b. states humans are direct descendants of monkeys. c. states the same principles of change apply to organic and inorganic systems. d. explains how life originated. e. states organisms have changed since life originated
Answer E
The theory of genetics was initially developed by studying ____. a. mice b. cyanobacteria c. giraffes d. humans e. peas
Answer E
The work of Gregor Mendel serves as the basis for a. inheritance of acquired characteristics; b. background extinction; c. punctuated equilibrium; d. natural selection e. genetics.
Answer E
What is punctuated equilibrium? a. another word for phyletic gradualism b. the idea that new species originate from small changes c. a phenomenon that occurs in divergent, but not convergent, evolution d. an idea that would garner more support if missing fossil links could be found e. the idea that species remain stable for long periods, then evolve rapidly
Answer E
What process is used to demonstrate that two rock strata are equivalent? a. interpolation. b. extrapolation. c. equivalency. d. integration e. correlation.
Answer E
When minerals replace the bodily remains during fossilization, we say the fossil has been ____. a. dissolved b. molded c. regurgitated d. indexed e. altered
Answer E
Which item is a trace fossil? a. bones b. teeth c. shells d. jellyfish e. burrows
Answer E
Which rock type is predominant in deep ocean basins? a. mudstone and sandstone in fining-upward sequences b. rock salt and rock gypsum c. poorly sorted conglomerate d. well-sorted sandstone e. pelagic clay and calcareous and siliceous oozes
Answer E
Who developed the principle of uniformitarianism? a. Abraham Werner b. Charles Darwin c. Alfred Wegener d. William Smith e. James Hutton
Answer E
You are hiking in the mountains and come across a cliff in which a vein of igneous rock is cutting across the layers of sedimentary rock in the area. The igneous rock is ____ than the sedimentary rock. a. thicker b. thinner c. older d. dipping more steeply e. younger
Answer E
_____ structures probably indicate descent from a common ancestor with modifications for different functions. a. Primitive b. Analogous c. Derived d. Vestigial e. Homologous
Answer E
________ structures are remnants of structures that were fully functional in a species' ancestors but have reduced function in descendants. a. Homologous b. Analogous c. Genetic d. Correlated e. Vestigial
Answer E
Fine-grained clays, silts and muds would always indicate a ____ environment. a. shoreline b. glacial c. barrier island d. high-energy e. low-energy
Answer E
Numerical dating
Assigning an age in years before the present to geologic events before the present; numerical dates are determined by radioactive-decay dating techniques
(TRUE/FALSE) Fluvial deposits are considered part of the transitional sedimentary environment.
FALSE
chromosones
Complex, double-stranded, helical molecule of deoxyribonucleic acid (DNA); specific segments of chromosome are genes.
(TRUE/FALSE) Early naturalists used various scientific methods to date Earth, and erred by only +/- 2-3 million years.
FALSE
parallel evolution
Evolution of similar features in two separate but closely related lines of descent as a result of comparable adaptations
Macroevolution
Evolutionary changes that account for the origin of new species, genera, orders, and so on.
microevolution
Evolutionary changes within a species.
(TRUE/FALSE) A formation is the basic subdivision of biostratigraphic units.
FALSE
(TRUE/FALSE) Alpha decay involves the emission of two protons and two electrons.
FALSE
(TRUE/FALSE) At times in Earth's history, volcanoes have been more active and large ice sheets have covered the continents. The fact that this is not observed today contradicts uniformitarianism.
FALSE
(TRUE/FALSE) Carbon-14 dating technique is generally used to date living matter.
FALSE
(TRUE/FALSE) Chromosomes, like DNA, are only found in the sex cells of organisms.
FALSE
(TRUE/FALSE) Darwin's theory of evolution states that only the fittest organisms survive.
FALSE
(TRUE/FALSE) Divergent evolution results in descendants with characteristics that are very similar to their ancestors' characteristics.
FALSE
(TRUE/FALSE) Divisions of the geologic time scale are divided into equal increments of 250 million years.
FALSE
mass extinction
Greatly accelerated extinction rates resulting in marked decrease in biodiversity, such as the mass extinction at the end of the Cretaceous.
allopatric speciation
Model for the origin of a new species from a small population that became isolated from its parent population.
fluvial
Relating to streams and rivers and their deposits.
(TRUE/FALSE) Cross-bedding allows geologists to determine ancient wind directions.
TRUE
(TRUE/FALSE) A bat's wing and a bird's wing are examples of analogous structures.
TRUE
(TRUE/FALSE) A great example of a trace fossil would be the impression left by a crawling trilobite, an extinct arthropod.
TRUE
(TRUE/FALSE) A transgression occurs when the sea advances landward.
TRUE
(TRUE/FALSE) A varve consists of a pair of dark and light colored laminations that represent deposition in lakes produced by glacial processes over a one-year period.
TRUE
(TRUE/FALSE) After a rock is metamorphosed, it is impossible to determine an accurate date for when the original rock formed.
TRUE
(TRUE/FALSE) All atoms of the same element have the same atomic number.
TRUE
(TRUE/FALSE) All unconformities are created during periods of erosion and/or non-deposition.
TRUE
(TRUE/FALSE) Alleles are alternate expressions of genes.
TRUE
(TRUE/FALSE) Although igneous rocks are the easiest to date radiometrically, most fossils are preserved in sedimentary rocks.
TRUE
(TRUE/FALSE) Any time an element undergoes radioactive decay, it becomes a new element.
TRUE
(TRUE/FALSE) Atoms with an unequal number of protons and neutrons are called isotopes.
TRUE
(TRUE/FALSE) Biostratigraphic units are based on fossil assemblages and are called biozones.
TRUE
(TRUE/FALSE) Charles Darwin wrote On the Origin of Species.
TRUE
continental rise
The area where the seafloor slopes gently seaward between a shoreline and the continental slope
continental shelf
The area where the seafloor slopes gently seaward between a shoreline and the continental slope.
bioturbation
The churning of sediment by organisms that burrow through it.
phyletic gradualism
The concept that a species evolves gradually and continuously as it gives rise to new species
mosaic evolution
The concept that not all parts of an organism evolve at the same rate, thus accounting for organisms with features retained from the ancestral condition as well as more recently evolved features.
stratification (bedding)
The layering in sedimentary rocks; layers less than 1 cm thick are laminations, whereas beds are thicker.
rounding
The process involving abrasion of sedimentary particles during transport so that their sharp edges and corners are smoothed off.
tree ring dating
The process of determining the age of a tree or wood in a structure by counting the number of annual growth rings.
Relative dating
The process of placing geologic events in their proper chronological order with no regard to when the events took place in terms of the number of years ago.
sorting
The process whereby sedimentary particles are selected by size during transport; deposits are poorly sorted to well sorted, depending on the range of particle sizes present.
continental slope
The relatively steep part of the seafloor between the continental shelf and continental rise or an oceanic trench.
paleontology
The use of fossils to study life history and relationships among organisms.
divergent evolution
the diversification of a species into two or more descendant species.
