AP Biology Ecology Quiz 1

In an energy pyramid, only about 10% of the energy is transferred from one level to the next as you move from the bottom to the top. This is due to the fact that energy is lost as heat during metabolic processes and only a small fraction is transferred to the next trophic level. This phenomenon is known as the 10% rule, where each level of the pyramid can only support about 10% of the energy from the level below it.

Energy is lost at each trophic level in a food chain because energy is transferred from one level to another through the consumption of organisms. As energy is transferred, some of it is lost as heat or used for metabolic processes, resulting in a decrease in available energy for the next level. This energy loss limits the number of trophic levels that can be supported in a food chain, as there is not enough energy to sustain a large number of levels.

Type III (frog) would indicate a r-strategist because r-strategists are characterized by their ability to produce a large number of offspring with little parental investment. Frogs typically lay a large number of eggs and provide minimal care or protection to their young, which aligns with the reproductive strategy of r-strategists. In contrast, humans (Type I) and songbirds (Type II) have fewer offspring and invest more time and resources in their care, indicating a different reproductive strategy.

Type I (humans) would indicate a K-strategist because K-strategists are characterized by having a low reproductive rate, longer lifespan, and investing more resources into the survival and development of fewer offspring. Humans fit this description as they have a relatively low reproductive rate compared to other species, a longer lifespan, and invest a significant amount of time and resources into the care and development of their offspring.

Innate behaviors are expressed in most individuals in a population across a wide range of environmental conditions. This means that these behaviors are not influenced by genes and are not limited to a specific group of animals. Instead, they are exhibited by a majority of individuals in a population and are consistent across different environmental conditions.

The trophic structure refers to the feeding relationships among the species in a community. It describes the flow of energy and nutrients through different levels of the food chain, including producers, consumers, and decomposers. The trophic structure determines the overall organization and dynamics of the community, as it influences the abundance and distribution of species and the stability of the ecosystem. It also plays a crucial role in regulating population sizes and controlling the transfer of energy and matter within the community.

Aposematic coloration refers to the bright and conspicuous coloration of certain animals, such as red or orange, which serves as a warning signal to potential predators. The vibrant colors act as a visual deterrent, indicating that the animal is toxic, venomous, or otherwise dangerous. This warning allows predators to associate the bright colors with potential harm and avoid attacking these animals, reducing the risk of predation.

Kin selection is related to altruistic behavior because it is a theory in evolutionary biology that explains how individuals can increase their own genetic fitness by helping relatives, even at a cost to themselves. Altruistic behavior, such as sacrificing one's own well-being for the benefit of others, can be explained by kin selection because individuals share a proportion of their genes with their relatives, and by helping their relatives survive and reproduce, they indirectly increase the chances of their own genes being passed on to future generations.

Classical conditioning refers to the process of learning through association. In this case, Pavlov's dogs learned to associate the sound of a bell with the presence of food. Over time, the dogs began to automatically salivate upon hearing the bell, even without the presence of food. This demonstrates how a neutral stimulus (the bell) can become a conditioned stimulus that elicits a response (salivation) through repeated pairing with an unconditioned stimulus (food).

The carrying capacity of a population refers to the maximum number of individuals that a given environment can sustainably support. This capacity is not fixed and can change as environmental conditions change. For example, if there is an increase in available resources or a decrease in competition or predation, the carrying capacity may increase. On the other hand, if there is a decrease in resources or an increase in competition or predation, the carrying capacity may decrease. Therefore, the carrying capacity of a population is not constant and can be influenced by changes in the environment.

The effect of grazing intensity by bison on plant species diversity can be considered a top-down control on a grassland community. Grazing by bison can directly impact the abundance and diversity of plant species in the grassland. Bison grazing can selectively consume certain plant species, leading to changes in the composition of the community. This top-down control can have cascading effects on other trophic levels, such as herbivores and predators, ultimately shaping the structure and dynamics of the grassland community.

The ultimate explanation for the observation that adult salmon return from the ocean to spawn in the stream in which they hatched is that spawning in the home stream results in higher survival of young salmon. This suggests that the salmon have evolved to return to their birthplace because it provides the most favorable conditions for the survival of their offspring. By returning to the home stream, the salmon ensure that their young have access to the necessary resources and habitat for their development and growth. This behavior increases the chances of survival for the next generation of salmon.

The competitive exclusion principle states that two species with the exact same niche cannot coexist in a community. This is because they would compete for the same resources and one species would eventually outcompete the other. When two species have identical ecological requirements and occupy the same habitat, they will directly compete for limited resources such as food, water, and shelter. This competition will lead to the dominance of one species over the other, resulting in the extinction or emigration of the less competitive species. Therefore, the principle suggests that species with similar niches cannot stably coexist in the long term.

Dispersal occurs on various time scales, not just on an evolutionary time scale. Dispersal is a common component of the life cycles of plants and animals, allowing them to colonize new areas and avoid competition. It is especially important in the colonization of devastated areas after natural disasters like floods or volcanic eruptions. Seeds play a crucial role in the dispersal of most flowering plants, allowing them to spread their offspring over long distances. Therefore, the statement that dispersal occurs only on an evolutionary time scale is false.

In a terrestrial food web, the species with the smallest biomass would be represented by letter S. Biomass refers to the total mass of living organisms in a given area or ecosystem. Since the question asks for the species with the smallest biomass, letter S must represent a species that has the least amount of mass compared to the other options.

The correct answer is "iteroparous; K-selected." This is because wolves, as a stable population, exhibit iteroparity, meaning they have multiple reproductive cycles throughout their lifetime. Additionally, they are considered K-selected species, which means they have a longer lifespan, produce fewer offspring, and provide more parental care. This combination of iteroparity and K-selection is characteristic of species like wolves that have a slower population growth rate and invest more in each individual offspring.

The observation that members of a population are uniformly distributed suggests that the members of the population are competing for access to a resource. If the resources were distributed evenly, the population would not need to compete for access and the distribution would not be uniform. This suggests that there is competition among the members for limited resources, leading to a more even distribution across the area.

In this depiction of a terrestrial food web, the letter "Z" would represent a producer. Producers are organisms that can produce their own food through photosynthesis or chemosynthesis. They are usually plants or algae that convert sunlight or inorganic compounds into energy-rich organic molecules. Since "Z" is the only option given and it represents a producer, it is the correct answer.

The male ostrich's head bobbing is a releaser. A releaser is a specific signal or behavior that triggers a response from another individual of the same species. In this case, the male's head bobbing serves as a releaser to initiate the mating dance with the female ostrich. The head bobbing behavior is a clear and recognizable signal that communicates the male's intention to mate, prompting the female to respond and engage in the ritualized mating dance.

A releaser is a sign stimulus that triggers a specific behavior in another member of the same species. It acts as a signal that elicits a particular response or behavior. Releasers are often specific and unique to each species, and they play a crucial role in communication and social interactions among individuals of the same species.