user: Q: I read this background article the other day: Protozoa generally feed by engulfing and digesting other organisms. As consumers, they have various roles in food chains and webs. Some are predators. They prey upon other single-celled organisms, such as bacteria. In fact, protozoa predators keep many bacterial populations in check. Other protozoa are herbivores. They graze on algae. Still others are decomposers. They consume dead organic matter. There are also parasitic protozoa that live in or on living hosts. For example, the protozoan that causes malaria lives inside a human host. For their part, protozoa are important food sources for many larger organisms, including insects and worms.  I am facing a new situation today: Two biologists studied different living creatures. Matt studied protozoa, while his friend Greg studied nematodes and insects.  Using the knowledge I acquired from the background article, how should I answer correctly the following question regarding my new situation: Which friend studied less about predatory protozoa?
A: Greg

Q: I read this background article the other day: New species develop naturally through the process of natural selection . Due to natural selection, organisms with traits that better enable them to adapt to their environment will tend to survive and reproduce in greater numbers. Natural selection causes beneficial heritable traits to become more common in a population and unfavorable heritable traits to become less common. For example, a giraffe’s neck is beneficial because it allows the giraffe to reach leaves high in trees. Natural selection caused this beneficial trait to become more common than short necks.  I am facing a new situation today: Mike lives in a cold mid-western city, where there is not much predator prey interaction. Mike noticed that in his city some squirrels have darker coat, while others have lighter coat. He also knew that darker coats are more suitable in cold environment with less predator prey interaction. He started thinking why the squirrels developed different coat colors.  Using the knowledge I acquired from the background article, how should I answer correctly the following question regarding my new situation: Which squirrels would most likely reproduce in greater numbers, lighter or darker?
A: darker

Q: I read this background article the other day: Predators play an important role in an ecosystem. For example, if they did not exist, then a single species could become dominant over others. Grazers on a grassland keep grass from growing out of control. Predators can be keystone species . These are species that can have a large effect on the balance of organisms in an ecosystem. For example, if all of the wolves are removed from a population, then the population of deer or rabbits may increase. If there are too many deer, then they may decrease the amount of plants or grasses in the ecosystem. Decreased levels of producers may then have a detrimental effect on the whole ecosystem. In this example, the wolves would be a keystone species.  I am facing a new situation today: Two teams studied two types of animals: team A studied predators, while team B studied grazers. They learned a lot from this experience.  Using the knowledge I acquired from the background article, how should I answer correctly the following question regarding my new situation: Which team didn't learn that if all of the wolves are removed from a population, then the population of deer or rabbits may increase?
A: team B

Q: I read this background article the other day: If all the other factors influencing humidity remain constant, at ground level the relative humidity rises as the temperature falls. This is because less vapor is needed to saturate the air, so vapor condenses as the temperature falls. In normal conditions, the dew point temperature will not be greater than the air temperature because relative humidity cannot exceed 100%.[4]  I am facing a new situation today: Sam lived in Chicago for many years and experienced those high humidity days during the summer, the Indian summers in October and harsh and humid winters, so he decided to move to San Diego, in a warmer and much dryer climate.  Using the knowledge I acquired from the background article, how should I answer correctly the following question regarding my new situation: Which city experiences less saturation of air with water vapor?
A:

assistant: San Diego