Unit 9 Target 2: Habitat, Niche, And Resources

The specific physical location in which a given species lives is called its habitat. This refers to the natural environment or home of a particular organism, where it can find the necessary resources, such as food, water, and shelter, to survive and reproduce. A habitat can vary greatly depending on the species and can include forests, deserts, oceans, or even urban areas. Understanding a species' habitat is crucial for conservation efforts and managing ecosystems.

An organism's niche refers to the range of physical and biological conditions in which it lives and how it utilizes those conditions. This includes factors such as temperature, availability of resources, interactions with other organisms, and other environmental factors. It is not limited to just the physical and biological factors in the organism's environment or the range of temperatures it requires to survive. Option 1 accurately describes the concept of an organism's niche.

No two species can occupy the same niche in the same habitat at the same time because of the competitive exclusion principle. This principle states that two species competing for the same limited resources cannot coexist indefinitely, and one species will eventually outcompete and exclude the other. This is because resources such as food, space, and mates are limited, and any advantage one species has over the other will lead to its dominance in the niche. Therefore, in order to avoid competition and ensure their survival, species must occupy different niches or habitats.

Different species can share the same habitat, but competition among them is reduced if they occupy different niches. This means that each species has its own specific role or position within the ecosystem, utilizing different resources or occupying different parts of the habitat. By occupying different niches, the species can coexist without directly competing for the same resources, reducing competition and promoting biodiversity within the habitat.

A biotic or an abiotic resource in the environment that causes population size to decrease is called a limiting factor. This refers to any factor that restricts the growth, abundance, or distribution of a population within an ecosystem. Limiting factors can include factors such as food availability, predation, disease, competition for resources, and environmental conditions. These factors can prevent a population from reaching its maximum potential size and can ultimately lead to a decrease in population size.

The number of chromosomes an organism has would not be included in a description of its niche. A niche refers to the specific role and position that an organism has within its ecosystem, including its interactions with other organisms and its physical environment. The trophic level, humidity and temperature preferences, and reproductive timing are all factors that can influence an organism's niche, but the number of chromosomes is not relevant to its ecological role.

Biodiversity is a renewable resource because it refers to the variety of life forms on Earth, including plants, animals, and microorganisms. Biodiversity can be sustained and replenished through natural processes such as reproduction, regeneration, and evolution. Unlike non-renewable resources like oil and coal, which are finite and take millions of years to form, biodiversity can be conserved and managed to ensure its long-term availability for future generations. Water is also considered a renewable resource as it is continuously replenished through the water cycle.

A small, scattered population would be least likely to be affected by a density-dependent limiting factor because the individuals in the population are spread out and have more space and resources available to them. Density-dependent limiting factors, such as competition for resources and increased risk of disease transmission, are more likely to occur in populations that are large and dense, where individuals are in close proximity to each other and resources are limited. In contrast, a small, scattered population would have less competition for resources and a lower risk of disease transmission, making them less susceptible to density-dependent limiting factors.

Shortly after the 10th generation, a fatal disease infected a large proportion of the rabbits in this population. This best explains why the number of rabbits in the population dramatically decreased between Points A and B.

Density-independent limiting factors are factors that affect a population regardless of its size or density. Severe weather is a density-independent limiting factor because it can impact a population regardless of how many individuals there are. It can cause destruction of habitats, food scarcity, and even death, which can affect the population size and growth. Therefore, severe weather is a density-independent limiting factor.

Competitive exclusion occurs when a species is eliminated from a community because of competition. This means that when two or more species compete for the same limited resources, the species that is better adapted or more efficient at utilizing those resources will outcompete and eventually eliminate the other species from the community. This leads to a decrease in biodiversity as only the dominant species survives and thrives.

Natural disasters, seasonal cycles, availability of water, and human activity are all examples of density-independent limiting factors. These factors affect populations regardless of their density or size. Density-independent limiting factors are typically external factors that can have a significant impact on population size and growth. Option 2 is the correct answer because it is the only option that is not a density-independent limiting factor.