Exam 25: The History of Life on Earth

A genetic change that caused a certain Hox gene to be expressed along the tip of a vertebrate limb bud instead of farther back helped make possible the evolution of the tetrapod limb. This type of change is illustrative of ________.

If one organ is an exaptation of another organ, then these two organs ________.

In 2013, researchers constructed a vesicle with replicated RNA. Why was this significant evidence for abiotic origin of life?

What major innovation of the three radiations was associated with defying gravity to facilitate life on land?

According to the theory of seafloor spreading, oceanic islands, such as the Hawaiian Islands, form as oceanic crustal plates move over a stationary "hot spot" in the mantle. 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? I. Scientists in search of ongoing speciation events are more likely to find them here than on the other six large islands. II. Its species should be more closely related to those of nearer islands than to those of further islands. III. It should have a rich fossil record of terrestrial organisms. IV. It should have species that are not found anywhere else on Earth. V. On average, it should have fewer species per-unit surface area than the other six islands.

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

Which hypothesis for the abiotic formation of organic molecules suggests that early Earth's atmosphere was a neutral atmosphere?

Bagworm moth caterpillars feed on evergreens and carry a silken case or bag around with them in which they eventually pupate. 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. This is a good example of ________.

Fossilised stromatolites

A genetic change that caused a certain Hox gene to be expressed along the tip of a vertebrate limb bud instead of further back helped make possible the evolution of the tetrapod limb. This type of change is illustrative of

You are the lucky student of a wacko professor who develops a time machine. He asks if you will test it with him. You get in, and there is an immediate glitch-the date readout fails so that when you land, you are not sure what era you are in. As your time machine lands, you see an unusual landscape before you. As you open the door, you realise you cannot breathe. You quickly shut the door, realising you are in the ________.

If the half-life of carbon-14 is about 5,730 years, then a fossil that has 1/16 of the normal proportion of carbon-14 to carbon-12 should be about how many years old?

Which of the following is a defining characteristic that all protocells had in common?

Fossils of Lystrosaurus, a dicynodont therapsid, are most common in parts of modern-day South America, South Africa, Madagascar, India, South Australia, and Antarctica. 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. What is thought to be the correct sequence of these events, from earliest to most recent, in the evolution of life on Earth? 1) origin of mitochondria 2) origin of multicellular eukaryotes 3) origin of chloroplasts 4) origin of cyanobacteria 5) origin of fungal-plant symbioses

A swim bladder is a gas-filled sac that helps fish maintain buoyancy. The evolution of the swim bladder from the air-breathing organ (a simple lung) of an ancestral fish is an example of

What concept explains the evolution of complex eyes?

The following question is based on the observation that several dozen different proteins comprise the prokaryotic flagellum and its attachment to the prokaryotic cell, producing a highly complex structure. -If the complex protein assemblage of the prokaryotic flagellum arose by the same general processes as those of the complex eyes of molluscs (such as squids and octopi), then ________.

Why would gene duplication events, such as those seen in the Hox gene complex, set the stage for adaptive radiation?

One hypothesis that has been proposed regarding the origin of life suggests that life evolved from an "RNA world" to today's "DNA world". Considering the properties of RNA and DNA molecules, which questions would direct an investigation of the most insightful test of this hypothesis?

Hawaii is the most south-eastern of the seven largest islands and is also closest to the seafloor spreading centre from which the Pacific plate originates, which lies about 5,600 km further to the southeast. Assuming equal sedimentation rates, what should be the location of the thickest sediment layer and thus the area with the greatest diversity of fossils above the oceanic crust?