1.
- If a lobster is 3 steps up a food chain from phytoplankton ( a producer), how much phytoplankton (in grams) would be needed to provide a human with a 600 g lobster dinner?
Correct Answer
C. 600,000 grams
Explanation
This question becomes more visual if we were to draw the food chain that is being discussed. Here is what it would look like:
Producer (Phytoplankton) ---> ____________ ---> ______________ ----> Lobsters
Recall that as you move up the food pyramid, energy is lost....only 10% is kept at each Tropic level. This means that you must divide by 10 for each step on the way up. On the other hand, as you move DOWN a food chain, the energy INCREASES 10% at a time. This means that you must Multiply by 10 for each step down.
Since we only know the mass of the Lobster and nothing else, we would need to work our way backwards and go DOWN the food chain, multiplying by 10 each step of the way.
2.
If the leeches were removed from the food web, which of the outcomes below might occur?
Correct Answer
E. B and D
Explanation
If the leeches were removed from the food web, two possible outcomes might occur. First, the bloodworm population might increase in size because they would lose a predator. This could lead to an increase in their numbers. Second, there would be less algae because leeches feed on algae. Therefore, removing leeches from the food web could result in an increase in bloodworm population and a decrease in algae.
3.
A hawk weighs about 15 pounds. What is the weight of grass that will be needed to support the life of 1 hawk.
Correct Answer
C. 150,000 pounds
Explanation
The weight of the grass needed to support the life of 1 hawk would be significantly more than the weight of the hawk itself. Since a hawk weighs about 15 pounds, it would require a much larger amount of grass to sustain its life. Therefore, the correct answer is 150,000 pounds.
4.
The Sun is an example of a/an:
Correct Answer
B. Source of energy
Explanation
The Sun is considered a source of energy because it emits light and heat, which are essential for various processes on Earth. It provides energy for photosynthesis in plants, which is the basis of the food chain. The Sun's energy also powers weather patterns, ocean currents, and the water cycle. Additionally, solar energy is harnessed by humans through solar panels to generate electricity. Therefore, the Sun can be classified as a source of energy.
5.
Which of the following statements best describes the interaction of the two populations shown in the graph above?
Correct Answer
D. Species B is the predator; Species A is the prey.
Explanation
Recall that the food source (Prey) has to be present and reproducing BEFORE the predators can reproduce. If the predators reproduced first then they would not have enough food (prey) to survive. If you look at the graph, the red line on the far left side starts to rise first, followed by a delay...and THEN the blue line starts to rise. That means that the red line is showing the prey, whereas the blue line is indicating the predator.
6.
Bracket fungi return the nutrients in a dead log to the soil. They are classified as:
Correct Answer
D. Decomposers
Explanation
Bracket fungi are classified as decomposers because they play a crucial role in breaking down the organic matter in dead logs and returning the nutrients back to the soil. Decomposers are organisms that break down dead plant and animal material, releasing nutrients that can be used by other organisms in the ecosystem. Bracket fungi do this by secreting enzymes that break down the complex organic compounds in the dead log into simpler forms that can be absorbed by other organisms. This process is essential for nutrient cycling and maintaining the health of the ecosystem.
7.
The role of plants in maintaining the flow of energy in an ecosystem is to:
Correct Answer
D. Capture energy and convert it into an abiotic form.
Explanation
Plants capture the energy from the sun (abiotic source) and convert it into sugar. Sugar is an abiotic entity.
8.
Which of the following is true regarding the pyramid of numbers?
Correct Answer
D. Herbivores occupy a central position in the pyramid immediately above the producers.
Explanation
Herbivores occupy a central position in the pyramid immediately above the producers because they consume the producers for energy. This means that they are directly dependent on the producers for their survival. Additionally, herbivores serve as a food source for carnivores and other higher trophic levels in the pyramid. Therefore, they play a crucial role in energy transfer and nutrient cycling within the ecosystem.
9.
Both food webs and food chains can be used to illustrate the passage of energy in an ecosystem. What is the difference between a food web and a food chain?
Correct Answer
C. A food web contains all possible paths of energy while a food chain does not.
Explanation
A food web is a more complex representation of the flow of energy in an ecosystem compared to a food chain. While a food chain shows a linear sequence of organisms where energy is transferred from one organism to another, a food web includes multiple interconnected food chains. It represents all the possible paths of energy transfer between different organisms in an ecosystem, including the various feeding relationships and interactions. In contrast, a food chain only shows a single pathway of energy transfer from producers to consumers, without considering the complexity of the ecosystem.
10.
Which of the following statements is true regarding the energy flow model?
Correct Answer
A. Most of the energy in the food chain is concentrated in the producers.
Explanation
According to the given answer, most of the energy in the food chain is concentrated in the producers. This means that organisms such as plants, which are at the beginning of the food chain, have a higher amount of energy compared to other organisms in the chain. This is because producers convert sunlight into energy through photosynthesis, which is then passed on to the consumers. As energy is transferred from one trophic level to another, there is a decrease in the amount of energy available. Therefore, the producers have the highest concentration of energy in the food chain.
11.
Based on the information provided in this food web, which animal would be classified as an omnivore?
Correct Answer
B. Black bear
Explanation
The black bear would be classified as an omnivore because it is known to have a diet that consists of both plants and animals.
12.
Based on the information provided in this food web, which of the following would happen if the owl went extinct.
Correct Answer
D. The deer population would face an immediate shortage of berries.
Explanation
If the owl went extinct, the deer population would face an immediate shortage of berries. This is because the owl preys on small mammals such as rabbits, which in turn eat berries. Without the owl to control the rabbit population, the rabbit population would increase, leading to increased consumption of berries. As a result, the deer population, which relies on berries as a food source, would suffer from a shortage of berries.
13.
Which of the following would be true if a predator-prey graph was made between the black bear and the rabbit?
Correct Answer
D. The black bear population would follow the rabbit population, but only after a delay of a few years.
Explanation
The correct answer is that the black bear population would follow the rabbit population, but only after a delay of a few years. This means that when the rabbit population increases, there will be a delay before the black bear population starts to increase as well. This is because black bears rely on rabbits as a food source, so when the rabbit population increases, it provides more food for the black bears, allowing their population to grow. However, it takes some time for the black bear population to respond to the increase in food availability.