user: 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.  Large birds are natural predators of rodents. Unfortunately, rodents consume crops in farmlands. In recent years, use of chemicals in agriculture has seen reduced number of large birds in Germany. But in some places in France farmers are cautions about using chemicals in agriculture. As a result, large bird population had been stable in France.  Would France see less or more crops porduced than Germany?
Ans: more

A paradox is a statement that, despite apparently valid reasoning from true premises, leads to an apparently-self-contradictory or logically unacceptable conclusion.[1][2] A paradox involves contradictory-yet-interrelated elements that exist simultaneously and persist over time.[3][4][5]  In ancient Greece King Juno asked two of his court philosophers, philosopher A and philosopher B, to come up with two interesting problems. Philosopher A devised a clever paradox and presented it before the court. He called the  paradox Problem A. But philosopher B didn't come up with a paradox. He too presented a clever problem which was not a paradox - he called it problem B.  Would problem A more likely or less likely have self contradiction than problem B?
Ans: more likely

Many respiratory diseases are caused by pathogens. A pathogen is an organism that causes disease in another organism. Certain bacteria, viruses, and fungi are pathogens of the respiratory system. The common cold and flu are caused by viruses. The influenza virus that causes the flu is pictured below ( Figure below ). Tuberculosis, whooping cough, and acute bronchitis are caused by bacteria. The pathogens that cause colds, flu, and TB can be passed from person to person by coughing, sneezing, and spitting. Illnesses caused by bacteria can be treated with antibiotics. Those caused by viruses cannot.  Big city and Large city are situated 50 miles apart, on opposite sides of a mountain range. Both cities have lots of people with respiratory diseases. Big city has more people getting infected by viruses, while Large city has more people infected by bacteria and fungi.  Which city has fewer people catching the flu?
Ans: Large

Shown in the Figure below is a cylinder of gas on the left that is at room temperature (300 K). On the right, the cylinder has been heated until the Kelvin temperature has doubled to 600 K. The kinetic energy of the gas molecules increases, so collisions with the walls of the container are now more forceful than they were before. As a result, the pressure of the gas doubles. Decreasing the temperature would have the opposite effect, and the pressure of an enclosed gas would decrease.  David was trying to see how steam engines work. For that, he conducted two tests, test A and test B. In test A, he used low temperature. On the other hand, in test B, he used high temperature. David started thinking about how he could use the results of his tests in everyday life.  Would test A see less or more forceful collisions of molecules than test B?


assistant: Ans: less