Chapter 3 Online Study Guide

The concept of reproducibility is important in science to detect errors in measurement and conscious and unconscious bias by investigators. Reproducibility refers to the ability to repeat a scientific experiment or study and obtain the same results. It ensures that the findings are reliable and not influenced by external factors or biases. By emphasizing reproducibility, scientists can verify the accuracy of their measurements and minimize the impact of personal biases on the results.

A double-blind experiment is used to test most new drugs. In this type of experiment, one group of patients is given the new drug (the experimental group) while a second similar group of patients (the control group) is given a placebo. To avoid bias, neither the patients nor the physicians involved know who is receiving the experimental drug and who is receiving the placebo. This approach is called double-blind because both the patients and the physicians are "blind" to the treatment being administered.

A synergistic interaction occurs when two or more processes interact in a way that their combined effect is greater than the sum of their separate effects. This means that the interaction results in a synergistic effect, where the whole is greater than the sum of its parts.

The correct answer is "Antarctica, antarctica, antarctic, Antarctic". The question is referring to the severe thinning of the ozone layer over a specific location. Antarctica is known for experiencing this phenomenon for several months each year. The variations in capitalization (Antarctica vs. antarctica) do not change the meaning of the answer.

Isotopes are various forms of an element that have the same atomic number but different mass numbers. The different mass numbers are due to the varying number of neutrons in the nucleus of the atom. Isotopes can have different physical properties, such as different boiling points or densities, but they still exhibit similar chemical behavior. The existence of isotopes allows scientists to study the properties and behavior of elements in more detail.

pH is a measure of the concentration of hydrogen ions in a water solution. Hydrogen ions are positive ions or cations. The higher the concentration of hydrogen ions, the lower the pH value, indicating acidity. Therefore, the correct answer is hydrogen.

Easter Island is an example of the tragedy of the commons because the palm trees on the island were unsustainably harvested. The island's inhabitants used the palm trees for various purposes, including building houses and canoes, as well as for firewood. However, due to overexploitation and lack of proper management, the palm trees became extinct on the island. This led to a collapse in the island's ecosystem and the decline of its civilization. The unsustainable harvesting of palm trees on Easter Island serves as a cautionary tale about the consequences of not properly managing and preserving natural resources.

Precision is a measure of reproducibility because it refers to the consistency or closeness of the values in a set of measurements. In other words, precision indicates how well a set of measurements agree with each other. A high precision means that the measurements are very close to each other, indicating a high level of reproducibility. On the other hand, a low precision suggests that the measurements are spread out and not consistent, indicating a low level of reproducibility. Therefore, precision is a useful measure for assessing the reproducibility of data.

Deductive reasoning is the correct answer because it involves starting with a general statement or premise and then using logical steps to reach a specific conclusion. In the given example, the general statement is "All birds have feathers" and the specific conclusion is "All eagles have feathers." The conclusion is derived from the general premise using deductive reasoning.

The population of Easter Island peaked in 1400. This means that at this particular time, the island had the highest number of inhabitants.

Mercury is a nondegradable pollutant because it cannot be broken down or decomposed into simpler substances by natural processes. It accumulates in the environment and can pose serious health risks to humans and wildlife when ingested or inhaled. Mercury pollution primarily comes from industrial processes, such as coal-fired power plants and mining activities, and can contaminate water bodies, soil, and the food chain.

PCBs are classified as chlorinated hydrocarbons because they are organic compounds that contain both carbon and hydrogen atoms, with chlorine atoms substituted for some of the hydrogen atoms. Chlorinated hydrocarbons are known for their toxicity and persistence in the environment, which is why they are considered harmful and are subject to restrictions and regulations.

As the global warming causes the Arctic ice pack to shrink, more open ocean is exposed. The open ocean absorbs more heat than the ice pack, leading to a more rapid warming of the oceans. This increased warming can then cause more ice to melt, which further accelerates the warming of the ocean's surface. This continuous cycle of warming and melting creates a positive feedback loop, where each step reinforces and amplifies the initial warming.

Radio waves have the longest wavelength among the given options. Gamma rays have the shortest wavelength, followed by X-rays and microwaves. Radio waves have the longest wavelength and lowest frequency among all forms of electromagnetic radiation. They are used for various purposes such as communication, broadcasting, and radar.