Biology Semester 1 Final Exam Practice Quiz

An ecosystem is defined as a community of living organisms interacting with one another and with their surrounding physical environment. This holistic view encompasses both biotic (living) and abiotic (non-living) components.

Solar energy is a renewable resource because it is naturally replenished and abundant. Unlike fossil fuels, solar power does not deplete over time and is considered environmentally sustainable.

Condensation is the process in which water vapor cools and changes into liquid droplets, forming clouds. It is a key step in the water cycle that eventually leads to precipitation.

Biodiversity refers to the variety of living species present in a particular area. This includes the different plants, animals, and microorganisms that contribute to a complex and balanced ecosystem.

The Sun is the primary source of energy for most ecosystems, driving processes such as photosynthesis in plants. This energy supports the growth and sustenance of virtually all life forms on Earth.

Nitrogen fixation is the process through which certain bacteria convert atmospheric nitrogen (N2) into ammonia, a form that can be taken up by plants. This process is crucial for replenishing usable nitrogen in the soil.

Leguminous plants, such as beans and peas, form symbiotic relationships with Rhizobium bacteria that can fix nitrogen from the air. This association helps to naturally enrich the soil with nitrogen compounds.

Biotic components refer to all the living elements in an ecosystem, such as animals, plants, and microorganisms. The animals in a forest represent one of these living components.

Non-point source pollution does not come from a single, identifiable source. Instead, it originates from diffuse sources, such as runoff from agricultural fields that carries fertilizers and pesticides into nearby water bodies.

Carrying capacity is defined as the maximum number of individuals that an environment can support without degrading. It takes into account the availability of resources such as food, water, and shelter.

Transpiration is the process by which water is absorbed by plant roots, moves through the plant, and is released as vapor through the leaves. This process is essential for maintaining water balance in both plants and the atmosphere.

Sulfur dioxide, when released into the atmosphere, reacts with water vapor to form sulfuric acid, a major component of acid rain. This process can lead to environmental damage and harm aquatic ecosystems.

Deforestation decreases the number of trees and plants available to absorb carbon dioxide during photosynthesis, thereby reducing the overall carbon sequestration capacity of an area. This contributes to higher concentrations of carbon dioxide in the atmosphere.

Pioneer species are the first organisms to colonize barren or disturbed environments. Their presence initiates soil formation and nutrient cycles, making it possible for other species to establish and for the ecosystem to mature.

Eutrophication is primarily caused by the excessive runoff of nutrients, such as nitrogen and phosphorus from fertilizers, into freshwater systems. This nutrient overload promotes rapid algae growth, which can disrupt aquatic ecosystems and reduce oxygen levels.

Biomagnification refers to the increasing concentration of toxins as they move up the food chain, whereas bioaccumulation is the process by which toxins build up in a single organism over time. Together, these processes can have a significant negative impact on top predators.

The albedo effect is crucial in climate science as it determines the reflectivity of the Earth's surface. Surfaces with a high albedo reflect more solar energy, which can help mitigate warming, while darker surfaces absorb more heat.

Invasive species can disrupt native ecosystems by outcompeting local species, often leading to a loss in biodiversity and simplification of food webs. This reduction in complexity can compromise the resilience of ecosystems to environmental changes.

Keystone species play a critical role in maintaining the structure of an ecosystem despite not being the most abundant. Their activities, such as predation or pollination, have a large impact on the composition and diversity of the community.

Sustainable agricultural practices, such as crop rotation, reduced chemical input, and conservation tillage, can lower greenhouse gas emissions and improve the soil's ability to store carbon. These practices also promote biodiversity, which further bolsters ecosystem resilience against climate change.