Exam 25: The History of Life on Earth

How many of the following statements concerning the loss of hind limbs during whale evolution are true? 1)It is well documented by a series of transitional fossils. 2)It explains why modern whales have vestigial pelvic girdles. 3)It involved changes in the sequence or expression of Hox genes. 4)It is an example of macroevolution. 5)It, and the loss of limbs by snakes, are an example of similar adaptations to a similar environment.

The major evolutionary episode corresponding most closely in time with the formation of Pangaea was the

The following questions refer to this hypothetical situation. A female fly, full of fertilized eggs, is swept by high winds to an island far out to sea. She is the first fly to arrive on this island, and the only fly to arrive in this way. Thousands of years later, her numerous offspring 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, for their flight wings are absent, and their balancing organs (in other words, 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. -If these fly species lost the ability to fly independently of each other as a result of separate mutation events in each lineage, then the flightless condition in these species could be an example of

Which of the following characteristics should have been possessed by the first animals to colonize land? 1)were probably herbivores (ate photosynthesizers) 2)had four appendages 3)had the ability to resist dehydration 4)had lobe-finned fishes as ancestors 5)were invertebrates

Which of these observations gives the most support to the endosymbiotic theory for the origin of eukaryotic cells?

On the basis of their morphologies, how might Linnaeus have classified the Hawaiian silverswords?

The first terrestrial organisms probably were considered which of the following? 1)burrowers 2)photosynthetic 3)multicellular 4)prokaryotes 5)eukaryotes 6)plants and their associated fungi

The oxygen revolution changed Earth's environment dramatically. Which of the following took advantage of the presence of free oxygen in the oceans and atmosphere?

Which of the following is the correct sequence of events in the origin of life? I.formation of protobionts II.synthesis of organic monomers III.synthesis of organic polymers IV.formation of DNA-based genetic systems

Fossil evidence indicates that several kinds of flightless dinosaurs possessed feathers. If some of these feather-bearing dinosaurs incubated clutches of eggs in carefully constructed nests, this might be evidence supporting the claim that

Certain proteins of the complex motor that drives bacterial flagella are modified versions of proteins that had previously belonged to plasma membrane pumps. This evidence supports the claim that

Refer to the following information to answer the questions below. Fossils of Lystrosaurus, a dicynodont therapsid, are most common in parts of modern-day South America, South Africa, Madagascar, India, South Australia, and Antarctica. It 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. The 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. -How many of Lystrosaurus' features below can help explain why these organisms fossilized so abundantly? I.the presence of hard parts, such as tusks II.its arid environment III.its persistence across at least two geological eras IV.its widespread geographic distribution V.its mixture of reptilian and mammalian features

Fossilized stromatolites

The loss of ventral spines by modern freshwater sticklebacks is due to natural selection operating on the phenotypic effects of Pitx1 gene

Figure 25.3 -Upon being formed, oceanic islands, such as the Hawaiian Islands, should feature what characteristic, leading to which phenomenon?

The following questions refer to the paragraph below. A sediment core is removed from the floor of an inland sea. The sea 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 by life. Figure 25.2 -In order to assign absolute dates to fossils in this sediment core, it would be most helpful if

If the half-life of carbon-14 is about 5,730 years, then a fossil that has one-sixteenth the normal proportion of carbon-14 to carbon-12 should be about how many years old?

All animals with eyes or eyespots that have been studied so far share a gene in common. 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. There are so few sequence differences with fruit fly Pax-6 that the human/mouse version can cause eye formation in eyeless fruit flies, even though vertebrates and invertebrates last shared a common ancestor more than 500 million years ago. -Fruit fly eyes are of the compound type, which is structurally very different from the camera-type eyes of mammals. Even the camera-type eyes of molluscs, such as octopi, are structurally quite different from those of mammals. Yet, fruit flies, octopi, and mammals possess very similar versions of Pax-6. The fact that the same gene helps produce very different types of eyes is most likely due to

Which of the following statements provides the strongest evidence that prokaryotes evolved before eukaryotes?

Refer to the following information to answer the questions below. Fossils of Lystrosaurus, a dicynodont therapsid, are most common in parts of modern-day South America, South Africa, Madagascar, India, South Australia, and Antarctica. It 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. The 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. -Anatomically, what was true of Lystrosaurus?