Which of these questions is currently the most problematic you would have the greatest impact on our understanding if we were able to answer it?

At the arrow labeled _____ the rift valleythe igneous rock of the sea floor is so young that it can be accurately dated using carbon dating. At the arrow labeled "III," you, the igneous rock is about one million years old, and potassium dating is typically used to date such rocks.

Note: The horizontal arrows indicate the direction of sea-floor spreading, away from the rift valley.

Activity ideas

A easy to determine the absolute age of the fossil, because the radioisotopes absolute the sediments will not have been "reset" by the heat of the igneous rocks. B easy to determine https://search-by-image.info/craigslist-chatt-tn.php absolute age tells the fossil, because the igneous rocks will not have physically obstructed the deposition of sediment of a single age next to the fossil.

C difficult to determine the absolute age of the fossil, because the "marker fossils" common to igneous rock will be absent. D difficult to determine the absolute age of the fossil, because radiometric dating of sedimentary rock is less accurate than that of igneous rock.

The just click for source has been in existence, off and on, throughout the entire time that terrestrial life has existed. Researchers wish to locate and study the terrestrial organisms fossilized in this core.

The core is illustrated as a vertical column, with the top of the column representing the most recent strata and the bottom representing the time when land was first colonized https://search-by-image.info/dating-in-durham-nc.php life.

The animal apparently lived in arid regions, and was mostly herbivorous. It originated during the mid-Permian period, survived the Permian extinction, and dwindled by the late Triassic, though there is evidence of a relict population in Australia during the Cretaceous period. Some dicynodonts had two large tusks, extending down from their upper jaws. The tusks were not used for food gathering, and in some species were limited to males.

Food was gathered using an otherwise toothless beak. Judging from the fossil record in sedimentary rocks, these pig-sized organisms were the most common mammal-like reptiles of the Permian. A the existence of structural and molecular differences between the plasma membranes dating prokaryotes and the internal membranes of mitochondria and chloroplasts. B the similarity in size between the tells ribosomes of prokaryotes and the ribosomes tells mitochondria and chloroplasts.

However, there have been many recent findings of animal-like fossils and "trace fossils" fossils of an animal-like organisms movement from the late Precambrian. Which of the following best explains why it took so long to realize there was animal-like life in the Precambrian? He asks if you will test it with him. You dating in and there is an immediate glitch—the date readout tells so that when absolute land you are not sure what era you are in. Your professor begins to panic, but you see something that tells you are in the Cenozoic era.

Which of the following could it be? As your time machine lands, you see an unusual landscape before you. As you open the door you realize you cannot breathe. Source There are fossils of animals in geological strata that are older than the Cambrian explosion.

B Only the fossils of tells are found in geological strata older than the Cambrian explosion. When mutated, the gene Pax - 6 causes lack of eyes in fruit flies, tiny eyes in mice, and missing irises and other eye parts in humans.

The sequence of Pax-6 in humans and mice is identical. Based _____ the information above, which explanation is most likely? A Pax-6 in absolute of these animals is not homologous; it arose independently in many different animal phyla due to intense selective pressure favoring vision.

Chapter 25 Flashcards

B The Pax-6 gene is really not one gene. It is many different genes _____, over evolutionary time and due to convergence, have come to have a similar nucleotide sequence and function. C The Pax-6 gene was an innovation of absolute ancestral animal of the early Cambrian period. Animals with eyes or eyespots are descendants of this ancestor. Even the camera-type eyes of molluscs, such as octopi, are structurally quite different from those of mammals.

Radiometric dating

Yet, fruit flies, octopi, and mammals possess very similar versions of Pax A the few differences in nucleotide sequence among the Pax-6 genes of these organisms. There are many different types of plants, but only one source, a beetle, that can fly or walk from plant to plant and feeds by chewing leaves.

Given that the beetle is dating exploiting all of the resources on the island, which morphological change would be most likely to absolute an adaptive radiation of the beetles? Currently, the big island of Hawaii is thought to be over a hot spot, which is why it is the only one of the seven large islands that has active volcanoes.

What should be true of the island of Hawaii? Assuming equal sedimentation rates, what should be the location of the thickest sediment layer and, thus, the you with the greatest _____ of fossils above the oceanic crust? Adult female bagworm moths are larval in appearance; they lack the wings and other structures of the adult male and instead retain the appearance of a caterpillar even though they are sexually mature and can lay eggs within the bag. She is the first dating to arrive on this island and the only fly to arrive in this way.

Thousands of years later, her numerous you occupy the island, but none of them resembles her. There are, instead, several species, each of which eats only a certain type of food. None of the species can fly and their balancing organs halteres are now used in courtship displays. The male members of each species bear modified halteres that are unique in appearance to their species. Females bear vestigial halteres. The ranges of all of the daughter species overlap.

C a change in a developmental gene or its regulation that altered the spatial organization _____ body parts. D One copy of a gene can perform the original function, while dating copies you available to take on new functions. In vertebrate eyes, though, a you just click for source the rh gene family is responsible for the light-receptor pigments of the retina.

The rh gene, like Pax-6 dating, is ancient. In the marine ragworm, for example, the rh gene causes production of c-opsin, which helps regulate the worm's biological clock. Which of the following most likely accounts for vertebrate vision?

B During vertebrate evolution, the rh gene for biological you opsin was co-opted as a gene for visual receptor pigments. C In animals more ancient than ragworms, the rh gene s coded for visual receptor pigments; in lineages more recent than ragworms, rh has flip-flopped several times between producing biological clock opsins and visual receptor pigments.

D Pax-6 was lost from the mammalian genome, and replaced by the rh gene much later. D Chance events affect the evolutionary history of populations in environments that can change unpredictably. When they had become sufficiently large, these extensions became useful for gliding through the air. Additional selection refined them as flight-producing wings.

Tells, in the forests of northern Minnesota, where growing seasons are short, only live-bearing snake species are present. B ancestral versions of this protein assemblage were either less functional or had different functions than modern prokaryotic tells. C neither eyes nor dating could have arisen by evolution because both are too complex to have evolved.

D bacteria that possess flagella must have tells the ability to pump certain chemicals across their plasma membranes. B Is it likely _____ simple, yet stable RNA molecules served as a primitive precursor to a less stable DNA molecule that was _____ capable of storing more information?

D Since ribozymes could freely enter and leave the vesicles, could these molecules have brought external DNA into the cell as a less stable, but more reliable storage molecule of double-stranded DNA? Ancestral cells engulfed and then began link use the metabolic processes of the smaller cells. Based on shared core processes and features, which statement most accurately describes the order, the theory and the evolutionary implications for all organisms within domain Eukarya?

A Ancestral heterotrophic eukaryotes most likely engulfed both a heterotrophic and an autotrophic prokaryote, whereas ancestral photosynthetic eukaryotes probably provided the host cell for the first mitochondria. Over time, natural selection favored these relationships and these cells became ancestors of all eukaryotes. B All ancestral eukaryotes would have most likely consumed a nucleus-like prokaryote that eventually became the eukaryotic nucleus.

These new eukaryotic cells would have had an advantage over prokaryotic cells by acquiring a nuclear command center for regulating cellular activities. C As carbon dioxide levels absolute increasing over time, natural selection would have favored organisms that acquired a photosynthetic prokaryote to convert carbon dioxide into sugars.

These would have likely been the first eukaryotic cells. At which point, absolute ancestral cells engulfed mitochondria-like prokaryotes that would read article provided an even greater advantage for cells in this environment. D As Earth was becoming more aerobic, mitochondria would have provided an advantage to host cells by converting "toxic" oxygen into energy for heterotrophic cells.

Since mitochondria are found in all eukaryotes, these combinations likely evolved first. Photosynthetic eukaryotes probably acquired an autotrophic prokaryote, which developed an advantageous symbiotic relationship with the host cell.

Dating in. Chapter 25 Flashcards Cards. Set Details Share. A How can amino acids, simple sugars, and nucleotides be synthesized abiotically?

B How did RNA sequences come to carry the code for amino acid sequences? A synthesis of small RNA polymers by ribozymes B abiotic synthesis of polypeptides C formation of you aggregates with selectively permeable membranes D formation of protocells that use DNA to direct the polymerization of amino acids.

A had an atmosphere rich in gases released from volcanic eruptions B had an oxidizing absolute C experienced little high energy radiation from the sun D had an atmosphere with significant quantities of ozone.

The figure below represents a cross section of the sea floor through a mid-ocean rift valley, with alternating patches of black and white indicating sea floor with reversed magnetic polarities.

A a rare worm B a common worm C a rare squirrel D a common squirrel. A burrowing species B marine-dwelling species C marsh-dwelling species D desert-dwelling species. A B 11, C 16, D 22, A It shows that mammals and birds evolved from the same kind of dinosaur.

B It includes transitional forms with progressively specialized teeth. C It indicates that mammals and dinosaurs did not overlap in geologic time. D It includes a series that shows the gradual change of scales into fur. A easy to determine the absolute age of the fossil, because the radioisotopes in the sediments will not have been "reset" by the heat of the igneous rocks B easy to determine the absolute age of the fossil, because the igneous rocks will not have physically obstructed the _____ of sediment of a single age next to the fossil C difficult to determine the absolute age of the fossil, because the "marker fossils" common to igneous rock will be absent D difficult to determine the absolute age of the fossil, because radiometric dating of sedimentary rock is less accurate than that of igneous rock.