Q: 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. Two students studied animal behavior for the biology class. Ned studied more about predators, while Kim studied more about herbivores. Which student studied more about keeping grass from growing out of control?
A: Kim

Question: Ionizing radiation has many practical uses in medicine, research and construction, but presents a health hazard if used improperly. Exposure to radiation causes damage to living tissue; high doses result in Acute radiation syndrome (ARS), with skin burns, hair loss, internal organ failure and death, while any dose may result in an increased chance of cancer and genetic damage; a particular form of cancer, thyroid cancer, often occurs when nuclear weapons and reactors are the radiation source because of the biological proclivities of the radioactive iodine fission product, iodine-131. However, calculating the exact risk and chance of cancer forming in cells caused by ionizing radiation is still not well understood and currently estimates are loosely determined by population based data from the atomic bombings of Hiroshima and Nagasaki and from follow-up of reactor accidents, such as the Chernobyl disaster. The International Commission on Radiological Protection states that "The Commission is aware of uncertainties and lack of precision of the models and parameter values", "Collective effective dose is not intended as a tool for epidemiological risk assessment, and it is inappropriate to use it in risk projections" and "in particular, the calculation of the number of cancer deaths based on collective effective doses from trivial individual doses should be avoided." Tom and Jerry are two friends who have always had competitions with one another throughout their whole lives. Yesterday, they just finished their most unique competition so far. Each man was given a room to sit in that had several highly radioactive objects in it. The challenge was to see who would stay in the chamber longer. Tom didn't stay in his room for very long, but Jerry felt determined to win and stayed in his chamber almost the entire day. Is Tom's chance of dying within the next year higher or lower than Jerry's?
Answer: lower

[Q]: Consider the antlers of the Irish elk, (often supposed to be far too large; in deer antler size has an allometric relationship to body size). Obviously, antlers serve positively for defence against predators, and to score victories in the annual rut. But they are costly in terms of resource. Their size during the last glacial period presumably depended on the relative gain and loss of reproductive capacity in the population of elks during that time. As another example, camouflage to avoid detection is destroyed when vivid coloration is displayed at mating time. Here the risk to life is counterbalanced by the necessity for reproduction.Stream-dwelling salamanders, such as Caucasian salamander or Gold-striped salamander have very slender, long bodies, perfectly adapted to life at the banks of fast small rivers and mountain brooks. Elongated body protects their larvae from being washed out by current. However, elongated body increases risk of desiccation and decreases dispersal ability of the salamanders; it also negatively affects their fecundity. As a result, fire salamander, less perfectly adapted to the mountain brook habitats, is in general more successful, have a higher fecundity and broader geographic range. John is a biologist. Last summer, he was studying the evolution of two different salamander species, species A and species B. Species A salamander was Gold-striped salamander while species B salamander was fire salamander. He found it interesting that they took different approaches to adapt to different habitats. Which species would have larger habitat, species A or species B?
****
[A]: species B

input: Please answer the following: 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. Scientists studied two groups of mammals. Group One developed natural selection after a few decades, while group Two didn't. It was yet to be determined why that happened. Which group will survive in smaller numbers?
++++++++++
output: group Two

Please answer this: Because of human activities, there is more carbon dioxide in the atmosphere today than in the past hundreds of thousands of years. Burning fossil fuels and has released great quantities of carbon dioxide into the atmosphere. Cutting forests and clearing land has also increased carbon dioxide into the atmosphere because these activities reduce the number of autotrophic organisms that use up carbon dioxide in photosynthesis. In addition, clearing often involves burning, which releases carbon dioxide that was previously stored in autotrophs. When comparing village A from ten thousand years ago to village B from today, we reached the conclusion that today's villagers release much more carbon into the atmosphere by their activities. Which village indirectly reduced the number of autotrophic organisms?
++++++++
Answer: village B

Question: Soil is well developed in the forest as suggested by the thick humus layers, rich diversity of large trees and animals that live there. In forests, precipitation exceeds evapotranspiration which results in an excess of water that percolates downward through the soil layers. Slow rates of decomposition leads to large amounts of fulvic acid, greatly enhancing chemical weathering. The downward percolation, in conjunction with chemical weathering leaches magnesium (Mg), iron (Fe), and aluminum (Al) from the soil and transports them downward, a process known as podzolization. This process leads to marked contrasts in the appearance and chemistry of the soil layers. Two brothers were land owners. Bill owned 40 acres of forest, , with very well developed soil. His brother Rick owned 40 acres of grasslands, with a poor soil. Rick decided to sell his land. Which brother had fewer animals on his property?
Answer:
Rick