1.
Which of the following is not an example of a scientific model?
Correct Answer
D. A data table from a plant-growth experiment
Explanation
A data table from a plant-growth experiment is not an example of a scientific model because it is a representation of the actual data collected during the experiment, rather than a simplified or conceptual representation of the phenomenon being studied. Scientific models are typically used to explain or predict scientific phenomena, while a data table is a record of observations and measurements.
2.
Which of the following is the best example of biodiversity?
Correct Answer
D. There are over a million different species in the jungles of Africa.
Explanation
The best example of biodiversity is the fact that there are over a million different species in the jungles of Africa. Biodiversity refers to the variety of life forms in a particular habitat or ecosystem. The presence of a large number of different species in the African jungles indicates a high level of biodiversity in that region. This diversity is important for the overall health and stability of the ecosystem, as different species play different roles and contribute to the functioning of the ecosystem.
3.
___ is the process of maintaining proper internal conditions such as water balance, blood sugar levels, and pH.
Correct Answer
A. Homeostasis
Explanation
Homeostasis is the process of maintaining proper internal conditions such as water balance, blood sugar levels, and pH. It is a crucial mechanism that allows organisms to regulate and stabilize their internal environment, ensuring optimal functioning. Through various physiological processes, homeostasis helps to maintain a stable internal state despite external changes. This includes regulating body temperature, maintaining hydration levels, and balancing chemical reactions. Homeostasis is essential for the survival and well-being of organisms, as it allows them to adapt and respond to different environmental conditions.
4.
Finch species in the Galapagos Islands have a wide variety of beak shapes. The theory of natural selection suggests that these differences arose because
Correct Answer
B. The birds on different islands have different food sources.
Explanation
The correct answer is that the birds on different islands have different food sources. This is because the theory of natural selection states that organisms with traits that are advantageous for their environment are more likely to survive and reproduce. In the case of the finch species in the Galapagos Islands, the different beak shapes evolved in response to the availability of different food sources on each island. Finches with beaks that were well-suited to the specific types of food available on their respective islands had a higher chance of survival and passing on their traits to future generations.
5.
A scientist wants to know how a certain fertilizer affects the growth of tomato plants growing in two different soils. What conclusion can be drawn from the graph shown here?
Correct Answer
C. The fertilizer has a greater effect in Soil 2
Explanation
The graph shows that the tomato plants in Soil 2 have a higher growth rate compared to the plants in Soil 1 when the fertilizer is applied. This suggests that the fertilizer has a greater effect on the growth of tomato plants in Soil 2.
6.
Which of the following groups is most important for bringing energy into an ecosystem?
Correct Answer
B. Producers
Explanation
Producers are the most important group for bringing energy into an ecosystem. They are able to convert sunlight into food through the process of photosynthesis. This food, in the form of organic compounds, is then consumed by other organisms in the ecosystem, such as consumers and decomposers. Without producers, there would be no source of energy for the rest of the ecosystem, making them essential for sustaining life within the ecosystem.
7.
What would most likely result if nitrogen-fixing bacteria in an area were destroyed?
Correct Answer
B. Vegetation in the area would grow at a slower rate.
Explanation
Nitrogen-fixing bacteria play a crucial role in the nitrogen cycle by converting atmospheric nitrogen into a form that plants can use. This process is called nitrogen fixation. If these bacteria were destroyed, the availability of fixed nitrogen would be reduced, limiting the amount of nitrogen that plants can absorb. Nitrogen is an essential nutrient for plant growth and development, so the lack of it would likely result in slower growth rates for vegetation in the area.
8.
A scientist wants to measure the size of a cactus population in a desert valley. What method should she use?
Correct Answer
C. Quadrat sampling
Explanation
Quadrat sampling would be the most appropriate method for measuring the size of a cactus population in a desert valley. This method involves placing a square frame or quadrat in the study area and counting the number of cacti within the frame. It is a practical and efficient way to estimate population size, especially for stationary organisms like cacti. Radio telemetry involves tracking individual organisms using radio signals, which may not be suitable for cacti. Mark-recapture sampling is commonly used for mobile organisms and involves capturing, marking, and releasing individuals to estimate population size. Computer modeling is a theoretical approach that may not provide accurate measurements of the actual population size.
9.
In which direction does energy flow through this energy pyramid?
Correct Answer
A. 1,2,3,4
Explanation
Energy flows through an energy pyramid from the lower trophic levels to the higher trophic levels. In this case, the numbers 1, 2, 3, 4 represent the trophic levels in ascending order. Therefore, energy flows from trophic level 1 to trophic level 2, then to trophic level 3, and finally to trophic level 4.
10.
In the carbon cycle, through what process does carbon move from an abiotic resource into organic matter?
Correct Answer
A. Combustion
Explanation
Combustion is the process in which carbon moves from an abiotic resource (such as fossil fuels) into organic matter. During combustion, carbon-containing substances are burned, releasing carbon dioxide into the atmosphere. This carbon dioxide can then be absorbed by plants through photosynthesis, converting it into organic matter. Therefore, combustion is the process by which carbon is transferred from abiotic resources to organic matter in the carbon cycle.