Information and Ideas

Chief Editor

Mar 23, 2024

Take all 3 MCQs in interactive quiz mode with timer and progress tracking

In a study of the mechanisms underlying associative memory--or the ability to learn and remember connections between inherently unrelated things--neuroscientists Kei Igarashi, Jasmine Chavez, and others presented mice with memory tests. The team discovered that fan cells, a type of cell found in the medial temporal lobe of the brain, are necessary for the acquisition of new associative memories. They also found that fan cell activity requires dopamine, a chemical the brain produces in response to pleasure and rewards. Consequently, receiving a reward should likely help to _________Which choice most logically completes the text?

Difficulty: Medium

decrease an individual's capacity to utilize dopamine.

increase an individual's capacity to recognize differences between unrelated things.

increase an individual's capacity to form associative memories.

decrease an individual's capacity to create fan cells.

Although military veterans make up a small proportion of the total population of the United States, they occupy a significantly higher proportion of the jobs in the civilian government. One possible explanation for this disproportionate representation is that military service familiarizes people with certain organizational structures that are also reflected in the civilian government bureaucracy, and this familiarity thus _______Which choice most logically completes the text?

Difficulty: Medium

makes civilian government jobs especially appealing to military veterans.

alters the typical relationship between military service and subsequent career preferences.

encourages nonveterans applying for civilian government jobs to consider military service instead.

increases the number of civilian government jobs that require some amount of military experience to perform.

Scientists studying Mars long thought the history of its crust was relatively simple. One reason for this is that geologic and climate data collected by a spacecraft showed that the crust was largely composed of basalt, likely as a result of intense volcanic activity that brought about a magma ocean, which then cooled to form the planet's surface. A study led by Valerie Payre focused on additional information--further analysis of data collected by the spacecraft and infrared wavelengths detected from Mars's surface--that revealed the presence of surprisingly high concentrations of silica in certain regions on Mars. Since a planetary surface that formed in a mostly basaltic environment would be unlikely to contain large amounts of silica, Payre concluded that ________Which choice most logically completes the text?

Difficulty: Hard

the information about silica concentrations collected by the spacecraft is likely more reliable than the silica information gleaned from infrared wavelengths detected from Mars's surface.

high silica concentrations on Mars likely formed from a different process than that which formed the crusts of other planets.

having a clearer understanding of the composition of Mars's crust and the processes by which it formed will provide more insight into how Earth's crust formed.

Mars's crust likely formed as a result of other major geological events in addition to the cooling of a magma ocean.