Question 1

A hypothesis is

Accepted Answer

A hypothesis is a proposed explanation for a set of observations, which is testable through experimentation or further observation. It is different from a theory, which is a well-established, broad explanation supported by a large body of evidence. A hypothesis can lead to the development of a theory if it is tested and supported by evidence. It is also different from a widely accepted idea or concept, which may or may not be based on empirical evidence.

Question 2

Which level in the hierarchy shown is a community?

Accepted Answer

The answer of Which level in the hierarchy shown is...

Question 3

Which of the following statements is not an example of evolution that has resulted from human activity?

Accepted Answer

This statement describes a decrease in populations of certain organisms due to human hunting, which is not an example of evolution but rather a direct impact on population size. The other statements describe evolution in response to human activity, such as the development of antibiotic resistance in bacteria, larger domesticated crops, and pesticide resistance in insects.

Question 4

When a lepidopterist examined museum specimens of a particular moth species, she noticed that the variation in color was distributed as shown in the first graph. She was surprised because her data indicated the distribution of colors shown in the second graph. Which of the following hypotheses about the cause of this shift in the range of genetic variation is the most likely to be supported by examination of the distribution of colors in a collection assembled at a time between that of the collection of the museum specimens and her current specimens?

Accepted Answer

The shift towards darker coloration is likely due to natural selection favoring darker moths over time. This could be because darker moths are less visible to predators on darker tree bark, or because they are more thermally efficient in cooler environments, both of which could increase their likelihood of survival and reproductive success. Examining the distribution of colors in an intermediate collection could help confirm this hypothesis.

Question 5

Which of these models is best studied through a systems approach?

Accepted Answer

The biogeochemical cycling of nutrients involves multiple interconnected components such as the atmosphere, soil, water bodies, organisms, and their interactions. This interconnectedness and complexity of the system make it best studied through a systems approach.

Question 6

Which of the following statements about ecosystems is false?

Accepted Answer

Energy does not cycle through the atmosphere, but rather through the food chain within the ecosystem. The statement in option A is incorrect as it suggests that energy cycles through the atmosphere.

Question 7

A scientist performs a controlled experiment. This means that

Accepted Answer

A controlled experiment is one where two versions of the experiment are conducted, one varying from the other by only a single variable. This allows the scientist to determine the effect of that specific variable on the outcome of the experiment, while keeping all other variables constant. This type of experiment is important in determining cause-and-effect relationships.

Question 8

A theory is

Accepted Answer

A theory is a scientific explanation of a phenomenon that is backed up by a significant amount of supporting evidence. It is broad in scope and has been tested repeatedly over time. It is not necessarily "proven," but the evidence supports it as the most likely explanation for a given phenomenon.

Question 9

Which of the following statements provides the best evidence that there is a common genetic code that demonstrates the unity of life?

Accepted Answer

The ability to insert a gene from one organism into another and have it function properly indicates that there is a common genetic code shared among all living organisms. This demonstrates the unity of life and suggests that all living things have a shared ancestry.

Question 10

Which of the following organisms belongs to the group represented in box 1?

Accepted Answer

The answer of Which of the following organisms belongs to...

Question 11

After reading the paragraph below, answer the questions that follow.
Researchers set up a study to determine whether large doses of a nutritional supplement would shorten the length of time it takes to recover from a cold. Three thousand volunteers were split into two groups. For two weeks, members of group A took 3,000 mg of the supplement daily. Group B received 3,000 mg of a placebo. At the end of the two-week period, the researchers inserted live cold viruses directly into the noses of all the volunteers. The volunteers in both group A and group B continued to take their daily pills. All the volunteers got colds, and there was no significant difference in the length of time the colds lasted.
-Which was the experimental group?

Accepted Answer

Group A was the experimental group as they were given the nutritional supplement being tested. Group B was the control group as they were given a placebo. The researchers and all 3,000 volunteers were not the experimental group.

Question 12

You notice that over the past month, many students on campus have started wearing a new style of school sweatshirt. You think to yourself that perhaps the bookstore has recently started selling this new sweatshirt style. This is an example of

Accepted Answer

The answer of You notice that over the past month,...

Question 13

During a discussion about ecosystems, a student says, "Plants eat sunlight, and animals eat other organisms." Which of the following responses to the student's comment is most accurate?

Accepted Answer

Plants use the energy from sunlight to convert carbon dioxide and water into sugars through the process of photosynthesis. Therefore, they do not eat sunlight, but rather use it as a source of energy to produce their own food.

Question 14

Basic science discoveries often lead to the development of technology, and the development of technology often leads to new scientific discoveries. Which of the following is not an accurate pairing of a technology and a discovery?

Accepted Answer

The invention of the microscope led to the discovery and study of microorganisms, cells, and other small structures, but it did not directly lead to the creation of evolutionary trees. Evolutionary trees were developed through the analysis of multiple lines of evidence, including comparative anatomy, genetics, and fossil records.

Question 15

To be scientifically valid, a hypothesis must be

Accepted Answer

For a hypothesis to be scientifically valid, it must be testable and falsifiable. This means that it can be rigorously tested and potentially proven false if contrary evidence is found. While being part of a theory or reasonable can also be important aspects of a scientific hypothesis, they are not necessary for it to be valid. Controlling variables is important in the experimental process, but it does not directly impact the validity of the hypothesis itself.

Question 16

Consider the following statement: "If all vertebrates have backbones, and turtles are vertebrates, then turtles have backbones." This statement is an example of

Accepted Answer

Deductive reasoning is the process of drawing conclusions based on premises or assumptions. In this statement, the premise is that all vertebrates have backbones, and the assumption is that turtles are vertebrates. Therefore, the conclusion drawn is that turtles have backbones. This is an example of deductive reasoning because the conclusion is logically derived from the premises and assumption.

Question 17

Watching salt crystals form as ocean water evaporates, a student says, "Look-more and more crystals are appearing. The ocean water is alive!" Which of the following statements is an accurate evaluation of the student's remark?

Accepted Answer

Crystals forming from evaporating ocean water do not exhibit characteristics of living organisms, such as variation and adaptation.

Question 18

Which of these sequences is not a correct pathway of energy through an ecosystem?

Accepted Answer

Bacteria do not typically serve as a primary energy source for plants in an ecosystem. Instead, plants are primary producers that convert solar energy into chemical energy, which then flows to consumers like insects and birds.

Question 19

The role of a control in an experiment is to

Accepted Answer

The control group is used to provide a comparison to the experimental group. It allows scientists to determine if the effect they are observing is actually due to the treatment that the experimental group is receiving or if it is due to some other factor. This is an important part of experimental design and helps to ensure that the results are reliable and accurate. B, C, and D are not accurate descriptions of the role of a control in an experiment.

Question 20

The box numbered 2 represents which of the following?

Accepted Answer

Box 2 represents the cycling of matter, as it shows the exchange of nutrients and minerals between the biotic and abiotic components of the ecosystem. Box 1 represents the cycling of energy, as it shows the flow of energy through the food chain. Box 3 represents decomposers acting on all parts of the system, as it shows the breakdown of organic matter by decomposers. Box 4 represents gases in the atmosphere that can block sunlight, as it shows the impact of human activities on the environment, such as air pollution. Therefore, the best choice for box 2 is C.

Quiz 1: Biology: Exploring Life