Unit III Quiz: Eco Question 1 - A Type Of Species Interactio ✓ Solved
Unit III Q Eco Question 1: A type of species interaction whe
Unit III Q Eco Question 1: A type of species interaction where one of the individuals is positively affected to the detriment of the other is known as what? Amensalism Commensalism Mutualism Parasitism
Question 2: Vultures feed largely on carrion (dead animals). Their role in the ecosystem is largely as a scavenger.
Question 3: Cowbirds interact with other bird species in which way? They are brood parasites, letting other species raise their young.
Question 4: Penicillium (the source of the antibiotic penicillin) is a mold that secretes a toxin that kills bacteria and other organisms. Penicillium, however, is not harmed by this toxin. This is an example of: predator-prey. commensalism. mutualism. amensalism.
Question 5: In 2017, the population of striped bass in Lake Texarklahoma is estimated to be around 500,000 fish. If fisheries regulators intend to achieve a maximum sustainable yield of striped bass from the lake, about how many fish should be harvested that year? 150,000
Question 6: Match the organisms to the relationship. orchid / tree coyote / rabbit yucca moth / soapweed yucca cowbird / warbler tapeworm / human
A. mutualism B. brood parasitism C. predator-prey D. amensalism E. parasite F. commensalism
Question 7: Pick the phrase that best matches each term Heterotrophic Autotrophic Producers Primary consumers Secondary consumers
A. organisms that feed on other organisms B. organisms that eat plants (herbivores) C. two species that feed on the same prey organism D. self-feeding organisms, photosynthetic E. organisms at the base of the food web, autotrophs F. organisms that feed on herbivores (carnivores)
Paper For Above Instructions
Ecology studies the interactions among organisms and their environments, and it uses a framework of well-defined interaction types to explain how communities are organized and how energy and nutrients flow through ecosystems. The seven questions in the cleaned prompt touch on core concepts: types of species interactions (parasitism, predation, mutualism, commensalism, amensalism), the functional roles of different organisms (scavengers, brood parasites), the special case of antibiosis (Penicillium and penicillin), maximum sustainable yield (MSY) calculations, and the mapping of ecological relationships. Below, I address these topics in an integrated discussion that demonstrates how these interactions shape community structure, energy transfer, and ecosystem stability. Throughout, I cite foundational ecological theory to support the explanations (Krebs 2009; Begon, Townsend, and Harper 2006; Odum and Barrett 2005).
Parasitism is defined as a type of interaction in which one organism, the parasite, benefits at the expense of another, the host. The host experiences negative effects ranging from reduced fitness to disease, while the parasite gains nutrients, shelter, or a habitat that supports its growth. This interaction contrasts with mutualism, where both species benefit, and with commensalism, where one benefits while the other is unaffected. The prompt asks which interaction is characterized by a positive effect on one participant and a detriment to the other. The answer is parasitism (Begon et al. 2006; Krebs 2009). Parasitism can occur on many ecological scales, from microparasites such as bacteria and protozoa to macroparasites like worms and insects, and it is a central driver of host population dynamics and coevolution (May 1973; Paine 1966).
Vultures play a critical ecological role as scavengers, consuming carrion rather than hunting live prey. This behavior accelerates nutrient recycling and reduces disease risk by removing dead animals from the landscape—a service that supports ecosystem health and stability (Odum and Barrett 2005; Smith and Smith 2015). Scavenging organisms occupy a specific niche in food webs, contributing to energy transfer while often exploiting resources unavailable to strict predators. Understanding scavengers underscores the broader ecological principle that energy flows through trophic levels in a non-linear but interconnected network (Ricklefs 2008).
Cowbirds are classic brood parasites. They lay eggs in the nests of other bird species and rely on the host species to incubate and raise their young, often at no parental cost to the parasite itself. This interaction is a clear example of brood parasitism, a specialized form of parasitism with profound implications for host fitness, nest success, and community composition (Begon et al. 2006; Krebs 2009). Brood parasitism can influence the evolutionary dynamics of both parasite and host through selective pressures on egg coloration, parental care strategies, and nest defense (May 1973).
The Penicillium example illustrates antibiosis, a chemical interaction in which one organism secretes compounds that inhibit or kill other organisms without being harmed itself. In this case, Penicillium produces penicillin, which kills bacteria; the mold remains unaffected by the toxin it releases. This is not predator-prey, mutualism, or commensalism, but amensalism or antibiosis, where one species is harmed and the other is unaffected (Begon et al. 2006; Odum and Barrett 2005). Amensalism is a broader term capturing scenarios in which one participant experiences a negative effect while the other remains neutral, a pattern frequently observed in microbial communities and chemical warfare among microbes (May 1973).
Maximum Sustainable Yield (MSY) is a fisheries management concept that seeks to balance harvest with natural population growth so that the stock can replenish itself. Given a hypothetical striped bass population of 500,000, the harvest target to achieve MSY would be the number of fish that allows the population to replace itself through reproduction and recruitment each year. The exact MSY value depends on growth rates, age structure, fishing effort, and environmental conditions. In some simplified test scenarios, a harvest on the order of 150,000 fish is proposed as a plausible MSY estimate for a large reservoir with rapid growth and high recruitment; however, real-world MSY calculations require population models and empirical data (Krebs 2009; Paine 1966; May 1973). In any case, the core principle remains: harvest should equal natural population growth to maintain long-term stock viability rather than exceed it (Campbell and Reece 2014).
Matching organisms to ecological relationships provides practice in interpreting species interactions. Orchid/tree relationships in many ecosystems are often commensalistic: the orchid gains vertical habitat and access to sunlight while the tree incurs little or no cost. Coyote/rabbit represents a classic predator-prey dynamic, where predators regulate prey populations and influence energy flow through the ecosystem. Yucca moth/soapweed yucca typically forms a mutualistic relationship: the moth pollinates the yucca and, in return, lays its eggs in the flower, providing a larval food source while enabling plant reproduction under mutual benefit. Cowbird/warbler exemplifies brood parasitism, where the cowbird exploits the warbler’s nesting effort. Tapeworm/human is a parasite-host relationship, where the tapeworm benefits at the host’s expense (Krebs 2009; Begon et al. 2006; Gotelli and Ellison 2013).
The terminology for different consumer roles and interactions helps students interpret ecological data. In the terms provided for Heterotrophic Autotrophic Producers Primary consumers Secondary consumers, the correct mappings are: heterotrophs are organisms that feed on other organisms (A); autotrophs are self-feeding via photosynthesis (D); producers are organisms at the base of the food web, typically autotrophs (E); primary consumers are herbivores (B); secondary consumers are carnivores that feed on herbivores (F); and two species that feed on the same prey fall under the category of C (two species feeding on the same prey). These distinctions anchor ecological models such as food webs, energy pyramids, and trophic cascades (Odum and Barrett 2005; Smith and Smith 2015).
In sum, the prompts collectively emphasize core ecological concepts: types of species interactions (parasitism, predation, mutualism, commensalism, amensalism), functional roles (scavengers, brood parasites), chemical interactions (antibiotics and antibiosis), population dynamics (MSY), and the structure of trophic relationships. Understanding these connections fosters better interpretation of community responses to environmental change and informs sustainable management of natural resources (Begon et al. 2006; Krebs 2009; Paine 1966; May 1973; Campbell and Reece 2014).