Community Interactions Quiz Questions

The cheetah hiding inconspicuously in the grass is an example of camouflage. Camouflage is a defense mechanism used by animals to blend in with their surroundings, making them difficult to detect by predators or prey. In this case, the cheetah's ability to hide in the grass helps it to remain unseen by its potential prey, the grazing antelope. This increases the cheetah's chances of successfully hunting and capturing its prey.

A keystone species is a particular species that plays a major role in determining community structure. This means that the presence or absence of a keystone species can greatly impact the overall balance and diversity of an ecosystem. These species often have a disproportionate effect on the ecosystem compared to their abundance or biomass. They may have a critical role in regulating population sizes of other species or in shaping the physical environment. Overall, keystone species are essential for maintaining the health and stability of an ecosystem.

Aggressive mimicry is a type of mimicry in which a predator mimics a harmless or beneficial species in order to attract its prey. In this situation, the female fireflies mimic the flashing pattern of a different species to attract males and then kill and eat them. This behavior can be considered as an example of aggressive mimicry because the predator (female fireflies) is mimicking a behavior (flashing pattern) to deceive and capture its prey (males).

Resource partitioning is the evolutionary adaptation that occurs when species with similar ecological niches coexist and compete. This adaptation allows species to divide and specialize in their use of resources, reducing competition and allowing them to coexist. By utilizing different resources or using the same resources at different times or in different ways, species can avoid direct competition and maximize their chances of survival. This strategy promotes species diversity and allows for the coexistence of multiple species in the same ecological niche.

Coevolution refers to a process wherein two interacting species act as agents of natural selection on one another. This means that the evolution of one species is influenced by the evolution of the other species, and vice versa. They both exert selective pressures on each other, leading to adaptations that enhance their survival and reproduction in the presence of the other species. This process can result in mutual benefits, as both species evolve traits that allow them to coexist and thrive together.

The given correct answer is "a parasite exerting selective pressure on evolution of its host". This is because the malaria parasite infects human red blood cells, but a mutation in the hemoglobin gene in some people in Africa prevents infection. This mutation provides a selective advantage to those individuals, as they are resistant to malaria. Over time, this resistance can spread through the population, leading to the evolution of a higher percentage of individuals who are resistant to the parasite. This demonstrates how the presence of the parasite is exerting selective pressure on the evolution of the host population.

The reference to the "biotic portion of an ecosystem" implies the "living" portion of the ecosystem. This includes all living organisms within the ecosystem, such as plants, animals, and microorganisms. It excludes the non-living components of the ecosystem, such as air, water, and soil.

Competition occurs between individuals of the same or different species when they attempt to use the same limited resources, particularly energy, nutrients, or space. This means that when there is a scarcity of resources, individuals will compete with each other in order to obtain those resources for their own survival and reproduction. This competition can occur within a species, where individuals of the same species compete with each other, or between different species that have similar resource requirements. Ultimately, competition is driven by the need to acquire and utilize limited resources effectively.

The purpose of the bird as an intermediate host in the life cycle of the parasite is to disperse the parasite to other uninfected ant colonies, ensuring the survival of the parasite. The parasite manipulates the ant's abdomen to resemble a berry, attracting birds to eat the infected ants. The birds then spread the parasite eggs through their droppings, infecting the larvae of other ants and continuing the life cycle of the parasite.

Resource partitioning refers to the division of limited resources among different species in order to reduce competition. In the case of the related species of finches in the Galapagos Islands, each species has evolved different beak shapes and sizes to specialize in feeding on different types of food sources, such as seeds, insects, or nectar. This allows them to utilize different resources and reduce competition for food within their habitat. Thus, the related species of finches of the Galapagos Islands is an example of resource partitioning.

Lichen is a mutualistic symbiotic relationship between a fungus and an alga. The alga is responsible for providing food through photosynthesis, which benefits both the fungus and the alga. The fungus, on the other hand, provides a protective environment and absorbs water and nutrients for both participants. Therefore, the statement "The alga provides the food for the two mutualistic participants" is true.

The correct answer is removal of a keystone species. This is because the overfishing of lobsters, which are considered a keystone species in this ecosystem, has caused a disruption in the natural balance. Lobsters are predators of sea urchins, and their removal has allowed the sea urchin population to grow unchecked. As a result, the sea urchins have become overabundant and are causing negative impacts on the ecosystem, such as overgrazing on kelp forests. This demonstrates the important role that keystone species play in maintaining the structure and function of an ecosystem.

Different species share many aspects of their niche with others, but no two species ever occupy exactly the same ecological niche within the same community. This means that while different species may have overlapping requirements and utilize similar resources, they will always have some differences in their ecological niche, such as different behaviors, preferences, or adaptations. This is because if two species were to occupy exactly the same niche, they would directly compete for the same resources, leading to competition and potentially one species outcompeting or displacing the other.

Coevolution is the process that has provided the predator, the mountain lion, with tearing teeth and claws and its prey, the fawn, with dappled spots that serve as camouflage. Coevolution refers to the reciprocal evolutionary changes between two or more species that interact with each other. In this case, the mountain lion's predatory adaptations and the fawn's camouflage have evolved together over time as a result of their interactions and the selective pressures they impose on each other. This process has allowed both species to better survive and succeed in their respective roles in the predator-prey relationship.

Invasive species are the second leading cause pushing endangered species toward extinction. Invasive species are non-native organisms that are introduced to an ecosystem and disrupt the balance by outcompeting native species for resources. They can cause harm to the native plants, animals, and their habitats, leading to the decline and extinction of endangered species. This can occur through predation, competition for resources, or the introduction of diseases. Therefore, the presence of invasive species poses a significant threat to the survival of endangered species.

Lichen is a correct answer because it is a symbiotic mutualistic relationship between two different species. Lichen is formed through a partnership between a fungus and an alga or cyanobacterium. The fungus provides structure and protection, while the alga or cyanobacterium provides nutrients through photosynthesis. This mutually beneficial relationship allows both organisms to survive and thrive in environments where they may not be able to survive alone.