If you run into a Reading Comprehension question on the GRE that deals with science, it may cover a range of biological and physical science topics, including physics, astronomy, and chemistry.
Keep in mind that all Reading Comprehension questions are based directly on what's in the passage. You don't need to know anything about the subject outside the passage, so if it's a question on the space-time continuum, or black holes, all the information you need will be included in the passage.
If you're familiar with the topic, this may even work against you! Even though you may easily comprehend the passage, you must be careful not to mix your own knowledge of the topic with what's in the passage.
The following practice questions are based on this sample passage.
Sample passage
Although parasites represent almost 50 percent of all the life forms on the planet, their existence is often regarded as deleterious and with disdain. Scientists at the American Museum of Natural History have discovered that a majority of researchers have portrayed parasites as nothing more than disease spreading, life-killing pests, mainly because of their blight on many useful and popular species. However, a number of parasitic organisms are vital for the continued success of certain biological and ecological processes, and promotion of parasitic conservation is just as important as any other creature.
For instance, parasites serve as a major player in evolution and population by causing the host species to continually adapt and evolve as the parasite continues to adjust and thrive. Furthermore, scientists are exploring many health benefits of parasitic activity in humans, such as that concerning the sickle-cell gene and malaria. The relationship between how the protein make-up of the gene affecting the red blood cells and providing protection from the Plasmodium falciparum, the parasite that causes severe forms of malaria, is still unknown, but evidence suggests that the parasite itself is serving as the vehicle transporting the red blood cells into the body. More information is needed to fully understand the varied roles of parasites in the natural world.
Practice questions
The author thinks that parasites are
A. deleterious.
B. endangered.
C. complex.
D. a blight.
E. diseased.
What is the central idea of the passage?
A. Parasites are no longer considered disgusting creatures.
B. Maintaining a viable parasite population is important for researching their function in biological processes.
C. Scientists see parasite activity as groundbreaking for the advancement of disease prevention.
D. Parasites have the ability to cause the breakdown and extinction of certain biological processes.
E. Conservation is not a realistic option for parasites.
Answers and explanations
C. complex.
Parasites may be thought of in all the terms, but Choices (A), (B), (D), and (E) — deleterious, endangered, a blight, and diseased, respectively — are not the focus of the passage. The author discusses these characteristics of parasites but also puts forth the idea that they may be beneficial to other organisms. This logic creates a complexity in the function of parasites. Choice (C) is correct.
B. Maintaining a viable parasite population is important for researching their function in biological processes.
Choices (A) and (E) introduce ideas about parasite conservation that are not presented in the passage, namely that parasites are no longer considered disgusting creatures and conservation is not a realistic option for parasites. Choices (C) and (D) twist the information provided into conclusions about parasitic activity (scientists see parasite activity as groundbreaking for the advancement of disease prevention and parasites have the ability to cause the breakdown and extinction of certain biological processes), but these conclusions are not presented by the author. Only Choice (B) represents the theoretical nature of the discussion of parasitic activity and the possible need for conservation.