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Geology 103 Review Questions

Terms in this set (89)

a. Think of the prevailing processes and the resulting sedimentary features. A shallow marine setting is well-oxygenated and subject to wave and storm energy. The abundance of light would result in an active plant and animal community. If this seafloor were adjacent to a delta or other source of silicate sand and gravel, the resulting deposits would be light-colored (tan or greenish-gray), moderately well-sorted, cross-bedded sandstone with abundant trace fossils. If the seafloor was protected from influx of clay and sand, the dominant sediment source of would be the remains of plants and animals living on the seafloor. As a result, a light gray, fossilrich limestone would be deposited.
b. Deep marine rocks of the continental rise will reflect deposition by turbidity currents in an oxygen-starved setting. Graded bedding and dark coloration would be the two biggest clues to this setting.
c. Deltas are characterized by river and wave energy and an influx of sand, gravel, and mud. Swamps often form on the top of the delta plain. Interbedded sandstones, coals, and clays would result.
d. Wind is the dominant means of sediment transport in a desert. Desert sediments are readily distinguished by the high degree of sorting. Coarse sand and gravel cannot be moved, and silt and clay are blown into the atmosphere, leaving behind the fine- to medium-sized quartz particles. These grains are bounced along the ground through a process known as saltation. As the grains bounce, the corners are knocked off, leaving the grains rounded. The surface is scratched and pitted giving a frosted appearance under the microscope. Wind shapes the sand into large dunes with internal cross-beds that might be tens of feet high. Hence, sedimentary rocks deposited under desert conditions will be well-rounded, quartzose, well-sorted, light colored (tan to reddish-tan), and crossbedded.
a. Both mitosis and meiosis are methods of cell division. Mitotic division produces daughter cells in which each nucleus contains exactly the same complement of chromosomes as the parent cell. Meiotic division involves two successive cell divisions, resulting in daughter cells having one-half the number of chromosomes as the original cell.
b. Haploid cells contain only one set of chromosomes; diploid cells contain two sets of paired chromosomes.
c. These are the flowerless and flowering plants, respectively. Gymnosperms, such as cycads and conifers, evolved early and are still present. Angiosperms are more advanced plants in which the seeds are protected by an ovary. Gymnosperms made their appearance in the early Paleozoic. Angiosperms did not evolve until the late Mesozoic.
d. Stratophenic phylogeny is the traditional method of reconstructing ancestordescendant relationships. Under this model, organisms are arranged in an ancestor-descendant tree chiefly based on geological age, with older forms near the bottom and younger forms at the tips of the branches. Using cladistics, family trees are based upon the state and presence or absence of structural characteristics such as limbs, appendages, and so forth.
e. Domains and kingdoms represent major taxonomic subdivisions of the Linnean classification scheme. Everyone is familiar with the kingdoms Plantae and Animalia. With the invention of the microscope, it became clear that some living things were neither plant nor animal; consequently, the kingdoms of Protoctista, Fungi, and Monera were added. Recently, the term domain has been added to encompass two or more kingdoms. The three domains currently recognized are Archaea, Bacteria, and Eukarya. The domain called Eukarya is divided into four kingdoms known as Protoctista, Plantae, Animalia, and Fungi.