1.
An organism that uses energy to produce its own food supply from inorganic compounds is called a(an)
Correct Answer
D. AutotropH.
Explanation
An autotroph is an organism that is able to produce its own food supply from inorganic compounds, such as sunlight, water, and carbon dioxide. This process is known as photosynthesis. Autotrophs are able to convert these inorganic compounds into organic molecules, such as glucose, which they use as a source of energy. In contrast, heterotrophs rely on consuming other organisms or organic matter for their energy needs, while consumers specifically refer to heterotrophs that obtain energy by consuming other organisms. Decomposers, on the other hand, break down dead organisms and organic matter into simpler compounds.
2.
All the interconnected feeding relationships in an ecosystem make up a food
Correct Answer
D. Web.
Explanation
In an ecosystem, various organisms are interconnected through feeding relationships, forming a complex network. This network, known as a food web, illustrates the flow of energy and nutrients between different species. Unlike a food chain, which represents a linear sequence of organisms where each one is a source of food for the next, a food web shows the multiple interactions and connections between different species within an ecosystem. Therefore, the correct answer is "web."
3.
What animals eat both producers and consumers?
Correct Answer
B. Omnivores
Explanation
Omnivores are animals that eat both producers (plants) and consumers (other animals). They have a diverse diet that includes both plant-based and animal-based food sources. This allows them to obtain a wide range of nutrients and adapt to different environments. Unlike herbivores that only eat plants or carnivores that only eat other animals, omnivores have the flexibility to consume both types of organisms.
4.
The first trophic level of any ecosystem is occupied by organisms such as
Correct Answer
D. Plants, bacteria, and algae.
Explanation
The first trophic level of any ecosystem is occupied by organisms that are capable of producing their own food through photosynthesis or chemosynthesis. This includes plants, bacteria, and algae. Lions, wolves, snakes, humans, bears, pigs, cows, horses, and caterpillars are all consumers and belong to higher trophic levels as they obtain their energy by consuming other organisms.
5.
Approximately 10% of the energy absorbed by one trophic level is transferred to the next successive level. The same number of calories are available at the primary producer level of each of these food chains.
Food Chain 1: phytoplankton --> zooplankton --> smelt --> trout --> humans
Food Chain 2: phytoplankton --> smelt --> humans
How much energy is available to humans in Food Chain 2 as compared to the energy available to humans in Food Chain 1?
Correct Answer
D. 100 times more energy
Explanation
In Food Chain 1, only approximately 10% of the energy absorbed by one trophic level is transferred to the next level. However, in Food Chain 2, humans are directly consuming smelt, which is a secondary consumer. This means that humans in Food Chain 2 are skipping the energy loss that occurs at each trophic level in Food Chain 1. Therefore, humans in Food Chain 2 have 100 times more energy available to them compared to humans in Food Chain 1.
6.
Approximately 10% of the energy absorbed by one trophic level is transferred to the next successive level. The same number of calories are available at the primary producer level of each of these food chains.
Food Chain 1: phytoplankton --> zooplankton --> smelt --> trout --> humans
Food Chain 2: phytoplankton --> smelt --> humans
What is the trophic level for the zooplankton in Food Chain 1?
Correct Answer
D. Primary consumer
Explanation
The trophic level for the zooplankton in Food Chain 1 is a primary consumer because it directly consumes the phytoplankton, which are the primary producers in the food chain.
7.
In the food web above, which is a correct sequence for the flow of energy in a food chain containing the leopard seal?
Correct Answer
A. pHytoplankton --> krill --> penguin --> leopard seal
Explanation
The correct sequence for the flow of energy in a food chain containing the leopard seal is phytoplankton being consumed by krill, which are then eaten by penguins, and finally the leopard seal preys on the penguins. This sequence follows the pattern of energy transfer from primary producers (phytoplankton) to primary consumers (krill) and then to secondary consumers (penguins) before reaching the top predator (leopard seal).
8.
The total amount of living tissue within a given trophic level is called the
Correct Answer
D. Biomass.
Explanation
The correct answer is "biomass". Biomass refers to the total amount of living tissue within a specific trophic level. It includes all the plants, animals, and microorganisms present in that level. Biomass is an important measure as it represents the amount of energy available within a trophic level and can be used to understand the flow of energy through an ecosystem.
9.
Only 10 percent of the energy stored in an organism can be passed on to the next trophic level. Of the remaining energy, some is used for the organism’s life processes, and the rest is
Correct Answer
D. Released as heat.
Explanation
When energy is transferred from one trophic level to the next, only a small portion of it, about 10 percent, is passed on. The remaining energy is used by the organism for its life processes, such as metabolism and growth. The question states that the energy is used in reproduction, which means that it is utilized for the production of offspring. Therefore, the energy that is not used for life processes or reproduction is released as heat. This is because energy is constantly being converted and transformed within an organism, and some of it is lost as heat during these processes.
10.
Which energy pyramid accurately represents the transfer of energy in a desert food chain including cactus, hawk, insect, and snake?
Correct Answer
C.
11.
An oxpecker is a bird that usually feeds on parasites on a rhinoceros’s back. It occasionally picks scabs off the rhinoceros’s back and drinks blood from the wounds. Describe the relationship(s) between the oxpecker and the rhinoceros.
Correct Answer
C. Mutualism and parasitism
Explanation
The relationship between the oxpecker and the rhinoceros is described as mutualism and parasitism. Mutualism refers to a symbiotic relationship where both species benefit, as the oxpecker feeds on parasites on the rhinoceros's back, providing it with relief from pests. However, the relationship also involves parasitism, as the oxpecker occasionally picks scabs off the rhinoceros's back and drinks blood from the wounds, causing harm to the rhinoceros.
12.
A flagellated protozoan lives within the intestines of a termite and helps it digest wood. What type of relationship most likely exists between the protozoan and the termite?
Correct Answer
B. Mutualistic
Explanation
The flagellated protozoan and the termite have a mutualistic relationship. This means that both organisms benefit from their interaction. The protozoan helps the termite digest wood, which is its main food source, while the termite provides a suitable environment and a constant food supply for the protozoan. This mutually beneficial relationship enhances the survival and reproductive success of both organisms.
13.
Epiphytes are plants such as orchids and staghorn ferns that grow on the outside of other plants without taking any nourishment from them. The tree is the host and provides the branches that support the epiphytes but the tree is not harmed and receives no benefit. Epiphytes and trees represent what kind of interaction with each other?
Correct Answer
A. Commensalism
Explanation
Epiphytes and trees represent a commensalism interaction with each other. In commensalism, one organism benefits while the other is unaffected. In this case, the epiphytes benefit by using the tree as a support structure, but the tree is not harmed and does not receive any benefit from the epiphytes.
14.
Which ecological pyramid is shown above?
Correct Answer
C. Biomass pyramid
Explanation
The given pyramid represents a biomass pyramid. Biomass pyramids depict the total amount of living organic matter (biomass) at each trophic level in an ecosystem. In this type of pyramid, the biomass decreases as we move up the trophic levels, indicating that energy is lost as it is transferred from one level to the next. This is because only a fraction of the energy from the lower trophic level is transferred to the higher trophic level through consumption and metabolism.
15.
When an ecosystem reaches the last stage of succession, what is it referred to as?
Correct Answer
A. A climax community
Explanation
When an ecosystem reaches the last stage of succession, it is referred to as a climax community. This term describes a stable and mature community of plants and animals that has reached a state of equilibrium and balance with its environment. It is characterized by a diverse range of species that are well-adapted to the prevailing environmental conditions. This stage represents the culmination of ecological succession, where the community has reached its maximum complexity and stability.
16.
Which of the following is NOT and example of symbiosis?
Correct Answer
B. Competition
Explanation
Competition is not an example of symbiosis because it is a type of interaction between organisms where both individuals are negatively affected as they compete for limited resources. In symbiotic relationships, at least one organism benefits from the interaction. Commensalism, parasitism, and mutualism are all examples of symbiosis, where one or both organisms involved benefit from the relationship.
17.
Which of the following occurs during the ecological succession of an ecosystem?
Correct Answer
C. Living organisms modify their environment a little at a time.
Explanation
During ecological succession, living organisms gradually modify their environment. This refers to the process where a community of plants, animals, and microorganisms change over time, leading to a more complex and stable ecosystem. As the organisms interact with their environment, they can alter the physical structure, nutrient availability, and species composition of the ecosystem. These modifications can occur through processes such as nutrient cycling, soil formation, and the establishment of new species. This gradual modification is essential for the development and maintenance of a healthy and diverse ecosystem.
18.
Primary succession would occur
Correct Answer
B. On an island just formed by a volcanic eruption.
Explanation
Primary succession occurs in an area that has no previous soil or vegetation, such as on an island just formed by a volcanic eruption. In this scenario, the island would be completely devoid of any life forms, and the process of primary succession would begin with the colonization of pioneer species, such as lichens and mosses. Over time, these species would break down rocks and create soil, paving the way for the establishment of more complex plant and animal communities. This process can take hundreds or even thousands of years to reach a climax community.
19.
Which of these statements is true of parasitism?
Correct Answer
C. The presence of a parasite may make an animal more susceptible to predation.
Explanation
Parasitism is a relationship in which one organism, the parasite, benefits at the expense of another organism, the host. The presence of a parasite may weaken the host's immune system, making it more vulnerable to predators. This is because parasites can drain the host's resources and energy, making it less capable of defending itself against predators. Therefore, the presence of a parasite may indeed make an animal more susceptible to predation.
20.
When a new volcanic island forms, the pioneer species is the first species to successfully inhabit the island. Which organism is the most likely candidate for a pioneer species?
Correct Answer
C. Lichen deposited on rocks by the wind
Explanation
Lichen is the most likely candidate for a pioneer species because it is able to survive in harsh environments with minimal nutrients. Lichen can grow on rocks and withstand extreme temperatures, making it well-suited for colonizing a new volcanic island. Additionally, lichen can reproduce through spores that can be easily dispersed by the wind, allowing it to quickly establish itself on the island.
21.
The sequential replacement of species in a community after a forest fire is
Correct Answer
B. Secondary succession.
Explanation
After a forest fire, the process of sequential replacement of species in a community is known as secondary succession. This is because secondary succession occurs in an area that has been previously inhabited by plants and has undergone a disturbance, such as a fire. In this process, new plant species gradually colonize the area, replacing the previous ones. Primary succession, on the other hand, occurs in areas where there is no pre-existing vegetation, such as newly formed land, while pioneer succession refers to the initial colonization of an area by pioneer species.