1.
If the flow of energy in an Arctic ecosystem goes through a simple food chain from seaweeds to fish to seals to polar bears, then which of the following is TRUE?
Correct Answer
C. Polar bear meat probably contains the highest concentrations of fat-soluble toxins.
Explanation
In an Arctic ecosystem, the flow of energy moves from seaweeds to fish to seals to polar bears. As energy is transferred up the food chain, each level accumulates more toxins. Since polar bears are at the top of the food chain, they consume a large amount of fish and seals that have already accumulated toxins. Therefore, it is likely that polar bear meat contains the highest concentrations of fat-soluble toxins.
2.
The high levels of pesticides found in birds of prey is an example of
Correct Answer
B. Biomagnification
Explanation
The high levels of pesticides found in birds of prey is an example of biomagnification. Biomagnification refers to the process where the concentration of a substance increases as it moves up the food chain. In this case, the birds of prey consume smaller organisms that have been exposed to pesticides, and as the pesticides are not easily eliminated from their bodies, the concentration builds up over time. This phenomenon highlights the potential harmful effects of pesticides on higher trophic levels in the food chain.
3.
In the nitrogen cycle, the bacteria that replenish the atmosphere with N2 are:
Correct Answer
A. Denitrifying bacteria
Explanation
Denitrifying bacteria are responsible for replenishing the atmosphere with N2 in the nitrogen cycle. These bacteria convert nitrate (NO3-) back into nitrogen gas (N2) through the process of denitrification. Denitrification occurs in anaerobic conditions where oxygen is limited, such as in waterlogged soils or sediments. During denitrification, the bacteria use nitrate as an electron acceptor, converting it into nitrogen gas and releasing it back into the atmosphere. This process helps to maintain the balance of nitrogen in the environment and recycle it for future use by other organisms.
4.
In which Canadian biome would you expect to find the most acidic soil?
Correct Answer
E. Boreal forest biome
Explanation
The boreal forest biome is characterized by cold temperatures and a large amount of coniferous trees. These trees have needle-like leaves that take a long time to decompose, resulting in a thick layer of acidic organic matter on the forest floor. This organic matter, known as "mor," releases acids as it decomposes, making the soil in the boreal forest biome more acidic compared to other biomes.
5.
In which biome would you find a root system that involves tap roots that run deep into the soil?
Correct Answer
C. Temperate deciduous forest biome
Explanation
In the temperate deciduous forest biome, you would find a root system that involves tap roots that run deep into the soil. This is because the temperate deciduous forest biome consists of trees that have tap roots, which are long and thick roots that grow straight down into the soil. These tap roots help the trees to anchor themselves firmly in the ground and access water and nutrients from deep within the soil.
6.
Which of the following would NOT be an example of a density-dependent factor?
Correct Answer
D. Spraying with pesticides
Explanation
Spraying with pesticides would not be an example of a density-dependent factor because it does not depend on the population density of the organisms. Density-dependent factors are influenced by the size or density of a population, such as increased predation or competition for resources. However, spraying with pesticides is a human intervention that is not influenced by the population density but rather aims to control or eliminate pests and diseases.
7.
Which of the following factors that determine biotic potential describes the number of offspring that reach reproductive age?
Correct Answer
B. Capacity for survival
Explanation
The factor that determines the number of offspring that reach reproductive age is the capacity for survival. This refers to the ability of the offspring to survive and reach the age at which they can reproduce. It takes into account various factors such as the availability of resources, environmental conditions, and the ability to avoid predators or other threats. The higher the capacity for survival, the more offspring are likely to reach reproductive age and contribute to the biotic potential of a population.
8.
For the following graph of survivorship, which curve represents a species that displays little parental care and high biotic potential?
Correct Answer
C. Type III
Explanation
The Type III survivorship curve represents a species that displays little parental care and high biotic potential. This curve shows a high mortality rate at a young age, indicating that individuals of this species have a low chance of surviving to adulthood. This suggests that the species produces a large number of offspring, but provides little parental care or protection, resulting in a high mortality rate.
9.
Organic substances always contain atoms of which of the following elements?
Correct Answer
A. Hydrogen and carbon
Explanation
Organic substances are compounds that contain carbon and hydrogen atoms. These two elements are the essential building blocks of organic molecules. Carbon forms the backbone of organic compounds, while hydrogen atoms are often attached to carbon atoms. This combination allows for the formation of a wide variety of organic compounds, including carbohydrates, lipids, proteins, and nucleic acids. Oxygen, nitrogen, and other elements may also be present in organic substances, but hydrogen and carbon are always found in them.
10.
Approximately what percentage of the atmosphere is made up of nitrogen gas?
Correct Answer
E. 80%
Explanation
Approximately 80% of the Earth's atmosphere is made up of nitrogen gas. Nitrogen is the most abundant gas in the atmosphere and plays a crucial role in supporting life on Earth. It is an essential component of proteins and nucleic acids, which are the building blocks of life. Nitrogen gas is relatively inert and does not easily react with other substances, making it a stable and reliable component of the atmosphere. Its high concentration helps regulate the overall composition and balance of gases in the atmosphere, contributing to the stability of our planet's climate and ecosystems.
11.
For the hare-lynx population-time graph below, what is the approximate carrying capacity for the lynx?
Correct Answer
B. 40
Explanation
The approximate carrying capacity for the lynx population can be determined by looking at the graph. The graph shows that the lynx population reaches its highest point at around 40 individuals. This suggests that 40 is the approximate carrying capacity for the lynx, as it is the maximum number of individuals that the environment can sustain.
12.
The following table is taken from the "Guide to Eating Ontario Sportfish." Based on the data presented, which fish would have accumulated the greatest amount of toxins?
Correct Answer
E. Northern pike
Explanation
Based on the data presented in the "Guide to Eating Ontario Sportfish," the fish that would have accumulated the greatest amount of toxins is the Northern pike.
13.
The following table is taken from the "Guide to Eating Ontario Sportfish." Based on the data presented, the fish that would be safest to eat would be:
Correct Answer
D. The smallest fish at lower tropHic levels.
Explanation
Based on the data presented, the safest fish to eat would be the smallest fish at lower trophic levels. This is because smaller fish at lower trophic levels tend to have lower levels of accumulated toxins compared to larger fish higher up in the food chain. As fish consume other fish, toxins from the prey can accumulate in their bodies, making larger carnivorous fish more likely to have higher levels of contaminants. Therefore, choosing smaller fish at lower trophic levels reduces the risk of ingesting harmful toxins.
14.
The Canadian Shield is a region that was once exposed bedrock due to glacial retreat. After being covered initially with lichen, other grass-like vegetation grew. This added more nutrient to the soil eventually allowing larger trees like spruce, pine, and balsam to grow. This is an example of:
Correct Answer
A. Primary succession
Explanation
The given scenario describes the process of primary succession. Primary succession occurs in an area where there is no existing soil or vegetation. In this case, the Canadian Shield was initially exposed bedrock. The process began with the growth of lichen, which helped break down the rock and create a thin layer of soil. Over time, other grass-like vegetation grew, adding more nutrients to the soil. Eventually, larger trees like spruce, pine, and balsam were able to grow. This gradual colonization and development of plant life in an area without previous vegetation or soil is characteristic of primary succession.
15.
Trees that grow with deep tap roots would most likely be an adaptation for which biome?
Correct Answer
D. Temperate deciduous forest
Explanation
Trees that grow with deep tap roots would most likely be an adaptation for the temperate deciduous forest biome. In this biome, the soil is often nutrient-rich but can be shallow, so trees with deep tap roots are able to access water and nutrients from deeper layers of the soil. This adaptation helps the trees withstand the seasonal changes in temperature and moisture that occur in the temperate deciduous forest.
16.
Which of the following processes is NOT involved in the carbon cycle?
Correct Answer
E. Ecological succession
Explanation
Ecological succession is not involved in the carbon cycle. The carbon cycle primarily involves processes such as cellular respiration, decomposition, combustion, and photosynthesis. Cellular respiration is the process by which organisms release carbon dioxide into the atmosphere. Decomposition breaks down organic matter, releasing carbon back into the environment. Combustion, such as burning fossil fuels, releases carbon dioxide. Photosynthesis, on the other hand, is the process by which plants and other organisms convert carbon dioxide into oxygen. Ecological succession, however, refers to the gradual change in the species composition of a community over time and does not directly involve the cycling of carbon.
17.
Which of the following is FALSE regarding nitrogen-fixation?
Correct Answer
A. Nitrogen-fixation involves the conversion of ammonia to nitrates.
18.
If you were to move from lower altitudes to higher altitudes, what would be the progression of biomes would you experience based on local vegetation?
Correct Answer
D. Tropical forest --> temperate deciduous forest --> boreal forest --> tundra
Explanation
As you move from lower altitudes to higher altitudes, the progression of biomes based on local vegetation would be as follows: tropical forest, temperate deciduous forest, boreal forest, and finally tundra. This is because as you move higher in altitude, the temperature decreases and the conditions become more harsh, leading to changes in vegetation and the types of biomes present.
19.
Wetlands experience ecological succession when they become invaded by aquatic plants, to eventually become swamps, and ultimately they develop into a peat bog. This is an example of:
Correct Answer
C. EutropHication