1.
Total mass of living matter at each trophic level.
Correct Answer
C. Biomass
Explanation
Biomass refers to the total mass of living matter at each trophic level. It represents the amount of organic material produced by organisms in an ecosystem. Biomass is an important measure as it indicates the energy available at each trophic level and the overall productivity of the ecosystem. It can be measured by estimating the weight of all the organisms or by calculating the energy stored in their tissues. By understanding the biomass, we can better understand the flow of energy and nutrients through food chains and food webs in an ecosystem.
2.
Process in which nitrogen gas is captured and converted into a form plants can use.
Correct Answer
I. Nitrogen fixation
Explanation
Nitrogen fixation is the process of capturing and converting nitrogen gas into a form that plants can use. This process is essential for the growth and development of plants as they require nitrogen to produce proteins and other essential compounds. Nitrogen fixation is primarily carried out by certain bacteria and some types of plants. These organisms have the ability to convert atmospheric nitrogen into ammonia or other nitrogen compounds that can be absorbed by plants through their roots. This process plays a crucial role in the biogeochemical cycle of nitrogen and helps to maintain the availability of this essential nutrient in ecosystems.
3.
Model that shows many interconnected food chains and pathways in which energy and matter flow through an ecosystem,
Correct Answer
G. Food web
Explanation
A food web is a model that shows many interconnected food chains and pathways in which energy and matter flow through an ecosystem. It represents the complex interactions between different organisms in an ecosystem, including producers, consumers, and decomposers. Unlike a food chain, which only shows a linear sequence of who eats whom, a food web shows the multiple feeding relationships that exist in an ecosystem. It helps us understand the interconnectedness and interdependence of different species and how energy and nutrients are transferred within the ecosystem.
4.
Heterotroph that eats only plants
Correct Answer
H. Herbivore
Explanation
A herbivore is a heterotroph that eats only plants. In an ecosystem, herbivores play a crucial role as primary consumers, feeding directly on plants. They obtain energy and nutrients from the plant material they consume. Herbivores are an essential component of the food chain and food web, as they serve as a food source for other organisms, such as carnivores and omnivores. By consuming plants, herbivores help regulate plant populations and maintain the balance of the ecosystem.
5.
Heterotroph that consumes both plants and animals.
Correct Answer
J. Omnivore
Explanation
An omnivore is a heterotroph that consumes both plants and animals. This means that it has a varied diet and can obtain nutrients from both plant and animal sources. Unlike herbivores, which only consume plants, and carnivores, which only consume animals, omnivores have the ability to adapt to different food sources and environments. They play an important role in the food chain and food web by consuming both producers (plants) and consumers (animals), and they contribute to the cycling of nutrients through the biogeochemical cycle.
6.
Exchange of matter through the biosphere involving living organisms, chemical processes, andgeological processes.
Correct Answer
A. Biogeochemical cycle
Explanation
A biogeochemical cycle refers to the exchange of matter through the biosphere involving living organisms, chemical processes, and geological processes. This cycle allows for the recycling and redistribution of essential elements such as carbon, nitrogen, and phosphorus, which are necessary for the survival of organisms. It involves processes such as photosynthesis, respiration, decomposition, and nutrient absorption. Through these cycles, elements move between the atmosphere, hydrosphere, lithosphere, and biosphere, maintaining a balance and ensuring the availability of nutrients for living organisms.
7.
All the interacting populations of different species that live in the same geographic location at the same time.
Correct Answer
B. Biological community
Explanation
A biological community refers to all the interacting populations of different species that live in the same geographic location at the same time. It includes all the plants, animals, and microorganisms that coexist and interact with each other within a specific ecosystem. This term emphasizes the interconnectedness and interdependence of different species in a given area, highlighting the complex relationships and interactions that occur within a community.
8.
Simplified model that shows a single path for energy flow through an ecosystem.
Correct Answer
F. Food chain
Explanation
A food chain is a simplified model that shows the flow of energy through an ecosystem. It represents the transfer of energy from one organism to another as they consume each other. The food chain starts with producers, such as plants, which convert sunlight into energy through photosynthesis. Then, primary consumers, such as herbivores, eat the producers. Secondary consumers, such as carnivores, eat the herbivores, and so on. The food chain helps us understand how energy is transferred and passed along in an ecosystem.
9.
Close mutualistic, parasitic, or commensal association between two or more species that livetogether.
Correct Answer
L. Symbiosis
Explanation
Symbiosis refers to the close mutualistic, parasitic, or commensal association between two or more species that live together. It is a relationship where both species benefit (mutualism), one species benefits while the other is harmed (parasitism), or one species benefits while the other is unaffected (commensalism). This term describes the interdependence and interaction between different species, highlighting the intricate connections and dependencies that exist in nature.
10.
Heterotroph that decomposes organic material and returns the nutrients to soil, air, and water,making the nutrients available to other organisms.
Correct Answer
E. Detrivore
Explanation
A detrivore is an organism that decomposes organic material and returns the nutrients to the soil, air, and water. This process is an important part of the biogeochemical cycle, as it makes the nutrients available to other organisms in the ecosystem. Detrivores play a crucial role in breaking down dead plant and animal matter, releasing essential nutrients back into the environment. They are often found in soil, where they break down organic material and contribute to the recycling of nutrients.
11.
Process in which fixed nitrogen compounds are converted back into nitrogen gas and returned to the atmosphere.
Correct Answer
D. Denitrification
Explanation
Denitrification is the correct answer because it refers to the process in which fixed nitrogen compounds, such as nitrates and nitrites, are converted back into nitrogen gas by bacteria. This process occurs in soil, water, and other environments, and it helps to return nitrogen to the atmosphere. Denitrification is an important part of the nitrogen cycle, which is a biogeochemical cycle that involves the movement and transformation of nitrogen through various ecosystems.
12.
Group of organisms of the same species that occupy the same geographic place at the same time
Correct Answer
K. Population
Explanation
A population refers to a group of organisms of the same species that are present in the same geographic location at the same time. It represents the individuals of a particular species living and interacting with each other within a specific area. This term is used to describe the collective characteristics, behaviors, and dynamics of a specific species within a given ecosystem.
13.
The statement, "the cowbird can tolerate a wide range of temperatures,"characterizes the cowbird's habitat.
Correct Answer
B. False
Explanation
This statement does not characterize the cowbird's habitat. The ability of the cowbird to tolerate a wide range of temperatures does not provide any information about its habitat. Habitat refers to the specific environment or location where a species naturally lives and thrives, including factors such as vegetation, climate, and other ecological conditions. The statement only talks about the cowbird's temperature tolerance, which is not directly related to its habitat.
14.
Photosynthetic autotrophs remove water from the air as part of one of themajor biogeochemical cycles.
Correct Answer
B. False
Explanation
Photosynthetic autotrophs, such as plants, do not remove water from the air as part of any major biogeochemical cycle. Instead, they take in carbon dioxide from the air and convert it into oxygen through the process of photosynthesis. Water is obtained by plants through their roots from the soil, not from the air. Therefore, the statement is false.
15.
The species interaction most frequently represented in a food chain ispredation.
Correct Answer
A. True
Explanation
Predation is the most frequently represented species interaction in a food chain because it is a fundamental process in which one organism (predator) hunts, kills, and consumes another organism (prey) for energy and nutrients. This interaction is crucial for maintaining balance and regulating population sizes in ecosystems. Predators help control the population of prey species, preventing them from becoming too abundant and causing negative impacts on the ecosystem. Therefore, predation is a common and essential interaction in food chains.
16.
A bird fluffs its feathers to trap warm air close to its body. Thetemperature of the air next to the bird's skin is a(n) abiotic factor.
Correct Answer
A. True
Explanation
Birds fluff their feathers to create a layer of warm air that acts as insulation, helping them maintain their body temperature. The temperature of the air next to the bird's skin is not influenced by living organisms, but rather by the abiotic factors such as the environmental temperature. Therefore, it can be concluded that the temperature of the air next to the bird's skin is indeed an abiotic factor.
17.
Carbon is the only biogeochemical cycle that lacks an atmosphericcomponent.
Correct Answer
B. False
Explanation
This statement is false. The carbon cycle does have an atmospheric component. Carbon dioxide (CO2) is released into the atmosphere through processes such as respiration and combustion. It is also absorbed from the atmosphere through photosynthesis by plants and other organisms. This exchange of carbon between the atmosphere, living organisms, and the Earth's surface is a key part of the carbon cycle.
18.
The ultimate source of energy for most biomes on earth is the
Correct Answer
D. Sun
Explanation
The ultimate source of energy for most biomes on earth is the Sun. The Sun provides light and heat energy, which is essential for the process of photosynthesis carried out by autotrophs. Autotrophs, such as plants, algae, and some bacteria, use the energy from the Sun to convert carbon dioxide and water into glucose and oxygen. This process forms the basis of the food chain, as other organisms, such as herbivores, carnivores, and omnivores, rely on autotrophs for energy. Without the Sun's energy, life on Earth would not be sustainable.
19.
A role and position a species has in its environment is its
Correct Answer
B. Niche
Explanation
A niche refers to the specific role and position that a species occupies within its environment. It includes the interactions and relationships that the species has with other organisms and the resources it uses. The niche of a species determines its behavior, diet, and habitat requirements. It is a fundamental concept in ecology that helps to understand how different species coexist and interact within an ecosystem.
20.
The base of a pyramid of energy is the
Correct Answer
D. Both of these
Explanation
The base of a pyramid of energy represents the primary source of energy in an ecosystem. Producers, also known as autotrophs, are organisms that can produce their own food through photosynthesis or chemosynthesis. They convert sunlight or inorganic compounds into organic compounds, which serve as energy for other organisms. Therefore, the correct answer is both of these, as the base of a pyramid of energy consists of both producers and autotrophs.
21.
A food chain
Correct Answer
A. Is linear
Explanation
A food chain is a linear representation of the flow of energy and nutrients from one organism to another in an ecosystem. It shows the sequence of organisms, with each one being eaten by the next in line. This linear structure helps to illustrate the transfer of energy and the feeding relationships within a community.
22.
A leech feeding on a host organism is an example of a_____ relationship.
Correct Answer
D. Parasitic
Explanation
A leech feeding on a host organism is an example of a parasitic relationship because the leech benefits by obtaining nutrients from the host while the host is harmed or negatively affected. The leech relies on the host for survival and reproduction, while the host experiences negative consequences such as blood loss or potential infection. This type of relationship is characterized by one organism benefiting at the expense of another.
23.
In the movie "Finding Nemol the clownfish gets protection from predators, while the seaanemone is neither harmed nor helped. This relationship represents ____
Correct Answer
C. Commensalim
Explanation
In commensalism, one organism benefits while the other is neither harmed nor helped. In the movie "Finding Nemo," the clownfish receives protection from predators by living among the sea anemone. The clownfish benefits from the shelter provided by the sea anemone, while the sea anemone is unaffected by the presence of the clownfish. This relationship exemplifies commensalism because only one organism benefits, while the other remains neutral.
24.
In an ecological pyramid,_______ of energy is transferred from one trophic level to the next.
Correct Answer
C. 10%
Explanation
In an ecological pyramid, 10% of energy is transferred from one trophic level to the next. This is known as the 10% rule. It means that only a small fraction of the energy available at each trophic level is passed on to the next level. The rest of the energy is lost as heat or used for the organism's own metabolic processes. This decrease in energy transfer is due to inefficiencies in energy conversion and is a fundamental principle in understanding the flow of energy in ecosystems.
25.
Energy is "lost" at each trophic level in the form of _______ energy
Correct Answer
D. Heat
Explanation
Energy is "lost" at each trophic level in the form of heat. This is because energy is transferred from one trophic level to another through the consumption of organisms, but not all of the energy is absorbed and used by the consumer. Some energy is lost as heat during metabolic processes such as respiration. This heat energy is unable to be converted back into usable energy by other organisms, resulting in a net loss of energy as it moves up the food chain.
26.
The water in the atmosphere is returned to the earth by
Correct Answer
B. Precipitation
Explanation
Precipitation is the correct answer because it refers to the process by which water vapor in the atmosphere condenses into liquid or solid form and falls to the Earth's surface. This includes rain, snow, sleet, and hail. Precipitation is an essential part of the water cycle, as it replenishes the Earth with freshwater, which is important for the survival of plants, animals, and humans. It is through precipitation that the water in the atmosphere returns to the Earth.
27.
The transformation of water from a liquid to a gas as it passes through pores in plants' leaves is referred to as
Correct Answer
C. Transpiration
Explanation
Transpiration is the correct answer because it refers to the process of water movement through a plant and its evaporation from aerial parts, such as leaves, stems, and flowers. This process involves the transformation of water from a liquid to a gas as it passes through pores in plants' leaves, known as stomata. Transpiration plays a crucial role in plant physiology, as it helps in the absorption of nutrients from the soil and the regulation of temperature in plants.
28.
Which of the following convert nitrogen in the air into a form plants can use?
Correct Answer
C. Lightning & bacteria
Explanation
Lightning and bacteria are the correct answer because lightning converts nitrogen gas in the air into nitrate, which is a form that plants can use. Bacteria also play a crucial role in this process by converting nitrogen gas into a usable form through a process known as nitrogen fixation. Therefore, both lightning and bacteria are responsible for converting nitrogen in the air into a form that plants can utilize.
29.
Animals return nitrogen to the environment when they
Correct Answer
A. Urinate
Explanation
Animals return nitrogen to the environment when they urinate. Urine contains urea, which is a waste product that contains nitrogen. When animals urinate, the urea is released into the environment, where it can be broken down by bacteria and converted into ammonia, which is then used by plants as a source of nitrogen for growth. Therefore, urination plays a crucial role in the nitrogen cycle, as it helps to recycle nitrogen back into the environment.
30.
Deepest, coldest area of a large lake with little light and limited biodiversity.
Correct Answer
K. Profundal zone
Explanation
The profundal zone is the correct answer because it refers to the deepest and coldest area of a large lake with little light and limited biodiversity. This zone is characterized by low oxygen levels and is inhabited by organisms adapted to survive in these extreme conditions. The term "profundal" comes from the Latin word "profundus," meaning deep, which accurately describes this zone's location in the lake.
31.
Area of a lake or pond closest to the shore.
Correct Answer
I. Littoral zone
Explanation
The littoral zone refers to the area of a lake or pond that is closest to the shore. It is the shallowest part of the body of water and is characterized by the presence of rooted plants and a high level of sunlight penetration. This zone is important for many aquatic organisms as it provides them with food, shelter, and a suitable environment for reproduction.
32.
Stable, mature ecological community with little change in the composition of species.
Correct Answer
D. Climax community
Explanation
A climax community refers to a stable and mature ecological community where there is minimal change in the composition of species. It is the final stage of ecological succession, where the community has reached a state of equilibrium and is well-adapted to the prevailing environmental conditions. This community represents a balance between the various species and their interactions, resulting in a relatively stable and self-sustaining ecosystem.
33.
Narrow band of shoreline where the ocean and land meet that is alternatelysubmerged and exposed and is home to constantly changing communities.
Correct Answer
F. Intertidal zone
Explanation
The intertidal zone refers to the narrow band of shoreline where the ocean and land meet. This zone is alternately submerged and exposed due to the tides. It is home to constantly changing communities of organisms that have adapted to the harsh and dynamic conditions, such as exposure to air, waves, and fluctuating water levels. The intertidal zone is characterized by a high level of biodiversity and serves as an important habitat for various species.
34.
Organism's ability to survive biotic and abiotic factors.
Correct Answer
L. Tolerance
Explanation
Tolerance refers to an organism's ability to withstand or endure unfavorable conditions, such as extreme temperatures, high salinity, or low oxygen levels. It is a measure of an organism's adaptability and ability to survive in different environments. Organisms with a high tolerance can thrive in a wide range of conditions, while those with a low tolerance are more limited in their ability to survive. Tolerance is an important factor in determining an organism's distribution and ecological success in different habitats.
35.
Deepest, very cold region of the open ocean.
Correct Answer
A. Abyssal zone
Explanation
The given correct answer is "abyssal zone". The abyssal zone refers to the deepest, very cold region of the open ocean. It is characterized by extremely high pressure, low temperatures, and total darkness. This zone is located below the bathyal zone and is home to a variety of unique and specialized organisms that have adapted to survive in this extreme environment.
36.
Biotic or abiotic factor that restricts the number, distribution, or reproduction of a population within a community.
Correct Answer
G. Limiting factor
Explanation
A limiting factor is a biotic or abiotic factor that restricts the number, distribution, or reproduction of a population within a community. It can be any factor that prevents a population from reaching its maximum potential. This could include factors such as availability of food, water, shelter, or the presence of predators or competitors. Limiting factors play a crucial role in regulating population sizes and maintaining balance within ecosystems. Without limiting factors, populations could grow uncontrollably and lead to overpopulation and resource depletion.
37.
Open-ocean zone shallow enough for sunlight to penetrate.
Correct Answer
J. pHotic zone
Explanation
The photic zone refers to the open-ocean zone that is shallow enough for sunlight to penetrate. This means that this zone is located closer to the surface of the water where sunlight can reach, allowing for photosynthesis to occur. This zone is important for supporting a wide variety of marine life, as it provides the necessary light energy for primary production.
38.
Process by which one community replaces another community because of changing abiotic and biotic factors.
Correct Answer
E. Ecological succession
Explanation
Ecological succession refers to the process by which one community replaces another community due to changes in abiotic and biotic factors. This process occurs over a period of time and involves the colonization of new species and the gradual replacement of existing ones. It is a natural and continuous process that allows ecosystems to adapt and change in response to environmental conditions.
39.
Open-ocean zone through which sunlight cannot penetrate.
Correct Answer
B. ApHotic zone
Explanation
The aphotic zone is the correct answer because it refers to the open-ocean zone through which sunlight cannot penetrate. This means that the area is too deep for sunlight to reach, resulting in a lack of photosynthesis and limited plant and animal life. The absence of sunlight in this zone also means that it is characterized by low temperatures and high pressure.
40.
Ocean-floor area consisting of sand, silt, and dead organisms.
Correct Answer
C. Benthic zone
Explanation
The answer "benthic zone" is the correct choice because it refers to the ocean-floor area consisting of sand, silt, and dead organisms. This zone is characterized by its proximity to the ocean floor and the types of sediments and organisms found there. The benthic zone is an important part of the marine ecosystem and supports a diverse range of organisms that rely on the nutrients and resources found in this area.
41.
Well-lit, open-water area of a lake or pond.
Correct Answer
H. Limnetic zone
Explanation
The limnetic zone refers to the well-lit, open-water area of a lake or pond. This zone is characterized by abundant sunlight penetration, allowing for photosynthesis to occur. It is typically located beyond the littoral zone, which is the shallow, near-shore area. In the limnetic zone, many aquatic organisms such as phytoplankton, zooplankton, and fish thrive due to the availability of sunlight and nutrients. This zone plays a crucial role in the food chain and nutrient cycling within the aquatic ecosystem.
42.
An area of forest that experiences very little change in species composition is a pioneer species.
Correct Answer
B. False
Explanation
A pioneer species refers to the first organisms to inhabit a barren or disturbed area, such as after a forest fire or volcanic eruption. They are characterized by their ability to colonize and adapt to harsh conditions. In contrast, an area of forest that experiences very little change in species composition would be considered a climax community, where a stable and diverse ecosystem has been established. Therefore, the given statement is false, as pioneer species are associated with areas undergoing rapid change, not areas with little change.
43.
The profundal zone contains communities that are layered depending on how long they are submerged by tides.
Correct Answer
B. False
Explanation
The statement is false because the profundal zone is not influenced by tides. The profundal zone is a region in a body of water, such as a lake, that is too deep for sunlight to penetrate. It is characterized by low oxygen levels and is inhabited by organisms adapted to these conditions. The layering of communities based on tide duration is more commonly seen in intertidal zones, where organisms must withstand both submersion and exposure to air.
44.
Temperature is a major limiting factor of the tundra biome.
Correct Answer
A. True
Explanation
The tundra biome is characterized by extremely cold temperatures, with average temperatures rarely rising above freezing. This extreme cold is a major limiting factor for the growth and survival of plant and animal species in the tundra. The low temperatures restrict the availability of liquid water, limit the growth of plants, and make it difficult for animals to find food. Therefore, it is true that temperature is a major limiting factor of the tundra biome.
45.
Primary succession is the most rapid form of succession.
Correct Answer
B. False
Explanation
Primary succession is actually the slowest form of succession. Primary succession occurs in an area that is completely devoid of life, such as a newly formed volcanic island or a retreating glacier. In this process, pioneer species gradually colonize the area and pave the way for other species to establish themselves over time. This process can take hundreds or even thousands of years before a stable community is established. Therefore, the statement that primary succession is the most rapid form of succession is false.
46.
Any biome in which the annual rate of evaporation exceeds the rate of precipitation is classified as desert.
Correct Answer
A. True
Explanation
A desert is defined as a biome where the rate of evaporation is higher than the rate of precipitation. This means that more water is lost through evaporation than is gained through rainfall. Therefore, if the annual rate of evaporation exceeds the rate of precipitation in any biome, it is classified as a desert.
47.
Pioneer species generally pave the way for other species during succession because they help form soil.
Correct Answer
A. True
Explanation
Pioneer species are the first to colonize an area that has been disturbed or devoid of life. They play a crucial role in the process of succession by breaking down rocks and other materials, contributing organic matter, and facilitating the formation of soil. This newly formed soil provides a suitable environment for other plant species to establish and thrive. Therefore, pioneer species indeed pave the way for other species during succession by helping to form soil.
48.
Primary succes-sion describes the events that take place on a hillside that has experienced a destructive mudslide.
Correct Answer
B. False
Explanation
Primary succession refers to the process of ecological succession that occurs in an area that has never been colonized before, such as a newly formed volcanic island or bare rock. In the given question, it states that the hillside has experienced a destructive mudslide, indicating that the area has been previously colonized and therefore does not meet the criteria for primary succession. Hence, the correct answer is False.
49.
A plausible hypothesis for the fact that mostly consumers live in marine abyssal zones and benthic zones is that temperature is a limiting factor.
Correct Answer
B. False
Explanation
The given statement suggests that the reason why mostly consumers live in marine abyssal zones and benthic zones is that temperature is a limiting factor. However, this statement is false. While temperature can be a limiting factor for some organisms, there are various other factors such as food availability, pressure, and oxygen levels that also play a significant role in determining the distribution of consumers in marine abyssal and benthic zones. Therefore, temperature alone cannot be considered as the sole limiting factor for their presence in these zones.
50.
The amount of oxygen in a fish tank is a limitinq factor that affects the number of fish that can live in the tank.
Correct Answer
A. True
Explanation
The amount of oxygen in a fish tank is a limiting factor because fish require oxygen to survive. If there is not enough oxygen in the tank, it can lead to low oxygen levels in the water, which can be harmful or even fatal for the fish. Therefore, the number of fish that can live in the tank is directly influenced by the amount of oxygen available.