1.
The name of the first trophic level in a food chain is.
Correct Answer
B. Producer
Explanation
The correct answer is "Producer" because the first trophic level in a food chain consists of organisms that are capable of producing their own food through photosynthesis or chemosynthesis. These organisms, such as plants and algae, convert sunlight or inorganic compounds into organic matter, which serves as a source of energy for other organisms in the food chain.
2.
What percent of the energy available in each trophic level is lost in each step of the food chain?
Correct Answer
A. 90%
Explanation
In a food chain, energy is transferred from one trophic level to another. However, during each transfer, a significant amount of energy is lost as heat or used for metabolic processes. This loss of energy is known as ecological efficiency. The correct answer, 90%, suggests that 90% of the energy available in each trophic level is lost during each step of the food chain. This means that only 10% of the energy is transferred to the next trophic level, resulting in a decrease in available energy as we move up the food chain.
3.
In a particular food chain there are 550 of species A, and 170 of species B. Species A is most likely what tropic level?
Correct Answer
D. Both B and C.
Explanation
Based on the given information, species A is the most abundant with 550 individuals, indicating that it is likely a primary consumer. Primary consumers are herbivores that feed directly on producers (plants) in a food chain. Therefore, species A can be classified as both a herbivore and a primary consumer.
4.
In the food chain below, how many calories are stored in the tuna for the human to eat if you start with 10000 calories of phytoplankton?
Phytoplankton--> Zooplankton --> Small fish --> medium fish --> tuna -->human
Correct Answer
B. 1J
Explanation
Each level of the food chain transfers only 10% of the energy from the previous level. Therefore, if there are 10000 calories of phytoplankton, only 1% of that energy, which is 1J, will be stored in the tuna for the human to eat.
5.
Which trophic level pyramid did you use to solve question number 3?
Correct Answer
C. Pyramid of Numbers
Explanation
The question asks which trophic level pyramid was used to solve question number 3. The answer is the Pyramid of Numbers. The Pyramid of Numbers represents the number of organisms at each trophic level in an ecosystem. It shows the decreasing number of organisms as you move up the food chain, with fewer individuals at higher trophic levels. This pyramid helps to understand the energy flow and dynamics of an ecosystem by illustrating the relationship between producers and consumers.
6.
In Mongolia there is a village of 300 farmers living on 100 acres of rice paddies and vegetable plots, while in the uplands a clan of 100 herdsmen need 500 acres to live off their herds of yaks and goats. Why do the herdsmen need so much more land for so few people?
Correct Answer
D. All of the above.
Explanation
The correct answer is "All of the above" because all the statements mentioned are true. The herdsmen need more land because they are secondary consumers, meaning they rely on consuming primary consumers (such as the yaks and goats) for their energy needs. Additionally, as energy moves up the food chain, there is a loss of approximately 90% of energy at each step. This means that fewer individuals can be supported at higher trophic levels. Finally, the pyramid of numbers also predicts fewer individuals at higher trophic levels, further explaining why the herdsmen need more land despite having fewer people.
7.
The Producer trophic level is different from all the other levels in that....
Correct Answer
A. They produce their own food from sunlight rather than depending on other levels below them for energy.
Explanation
The correct answer is that the Producer trophic level is different from all the other levels because they produce their own food from sunlight rather than depending on other levels below them for energy. This is known as photosynthesis, where producers, such as plants, use sunlight to convert carbon dioxide and water into glucose and oxygen. In contrast, all other levels in the food chain rely on consuming other organisms for energy.
8.
Even though the herdsmen in Question 6 need more land than the lowland farmers, they are still better off raising animals than crops. Why?
Correct Answer
B. Because crops can't be grown in the highlands.
Explanation
The correct answer is "Because crops can't be grown in the highlands." This explanation suggests that even though herdsmen need more land than lowland farmers, they are better off raising animals because crops cannot be grown in the highlands. This implies that the highlands are not suitable for crop cultivation, making animal husbandry a more viable option for the herdsmen.
9.
It takes 10 acres of ocean to raise a tuna while 10000 pounds of rice can be grown on 10 acres of land. Why does it still make sense, in terms of energy, to eat tuna?
Correct Answer
A. Because you can't raise rice on the ocean.
Explanation
The given correct answer is "Because you can't raise rice on the ocean." This answer explains that even though it takes more land to grow rice compared to raising a tuna, it is not possible to grow rice on the ocean. Therefore, in terms of energy, it still makes sense to eat tuna as an alternative source of food.
10.
The carrying capacity of an ecosystem means...
Correct Answer
B. The number of a particular species the ecosystem can support.
Explanation
The carrying capacity of an ecosystem refers to the maximum number of individuals of a particular species that the ecosystem can sustainably support. It represents the balance between available resources and the needs of the species, taking into account factors such as food availability, habitat suitability, and competition. When the population of a species exceeds the carrying capacity, it can lead to resource depletion, competition, and ultimately a decline in population size. Therefore, the carrying capacity is a crucial concept in understanding the dynamics and sustainability of ecosystems.
11.
If the carrying capacity of minnow for a particular pond is 2000, what will happen if 2200 minnow are introduced?
Correct Answer
C. They will all survive for a bit and then more than 200 will die.
Explanation
When the carrying capacity of the pond is 2000, it means that the pond can sustain a population of up to 2000 minnows. If 2200 minnows are introduced, initially all of them will survive as the pond can support their population. However, as the population exceeds the carrying capacity, the resources in the pond will become limited, leading to competition for food, space, and other resources. This competition will result in a decline in the overall population, causing more than 200 minnows to die.
12.
Why is the lynx population going up around 1865?
Correct Answer
C. Because the hare population is very high.
Explanation
The lynx population is going up around 1865 because the hare population is very high. This suggests that there is an abundance of food available for the lynx, which leads to increased reproduction and survival rates for the lynx population. As the hare population provides a primary food source for the lynx, a high hare population would naturally result in an increase in the lynx population.
13.
Why is the lynx population dropping around 1925?
Correct Answer
A. Because the hare population has been dropping for a while.
Explanation
The correct answer is because the hare population has been dropping for a while. This suggests that the decrease in the lynx population is a result of the decline in the hare population, which is the main food source for lynxes. As the hare population decreases, it becomes more difficult for lynxes to find enough food to survive and reproduce, leading to a decrease in their population.
14.
In a boreal forest ecosystem, the wolf population has suffered from a severe outbreak of mange for 2 years. What impact will this have on the carrying capacity of the ecosystem for caribou?
Correct Answer
C. It will go up.
Explanation
The severe outbreak of mange in the wolf population will likely lead to a decrease in the number of wolves, as many may die or become weakened by the disease. With fewer wolves preying on caribou, the caribou population is expected to increase. This is because the reduced predation pressure will allow for more caribou to survive and reproduce, leading to an increase in their population. Therefore, the carrying capacity of the ecosystem for caribou will go up.
15.
In the Antarctic food chain above, what will likely happen to the population of Crabeater seals if hunters capture 5% of the Blue whale population?
Correct Answer
B. It will increase.
Explanation
If hunters capture 5% of the Blue whale population, it will likely decrease the population of Blue whales. Since Crabeater seals primarily feed on krill, which is also a food source for Blue whales, a decrease in the Blue whale population would result in less competition for krill. This would allow the Crabeater seal population to increase as they would have more access to their primary food source.
16.
For the Antarctic food chain in the previous question, what will likely happen to the population of Krill if the population of Crabeater Seals continues to rise quickly?
Correct Answer
A. It will crash down.
Explanation
If the population of Crabeater Seals continues to rise quickly, it will likely lead to a decrease in the population of Krill. Crabeater Seals feed primarily on krill, so as their numbers increase, they will consume more krill, putting pressure on the krill population. This increased predation will cause a decline in the krill population, ultimately leading to a crash in their numbers.