Exam 25: The History of Life on Earth

Larval flies (maggots)express the Ubx gene in all of their segments,and thereby lack appendages.If this same gene continued to be expressed throughout subsequent developmental stages,except in the head region,and if the result was a fit,sexually mature organism that still strongly resembled a maggot,this would be an example of

Use the following information to answer the questions below. The following questions are 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

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. -In order to assign absolute dates to fossils in this sediment core,it would be most helpful if

An organism has a relatively large number of Hox genes in its genome.Which of the following is true of this organism?

If a fossil is encased in a stratum of sedimentary rock without any strata of igneous rock (for example,lava,volcanic ash)nearby,then it should be

If the half-life of carbon-14 is about 5730 years,then a fossil that has one-sixteenth the normal proportion of carbon-14 to carbon-12 should be about how many years old?

Use the following information to answer the questions below. The following questions are 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. -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

Which listing of geological periods is in the correct order,from oldest to most recent?

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. -If arrows indicate locations in the column where fossils of a particular type (see key above)first appear,then which core in the figure has the most accurate arrangement of fossils?