Ecology and Environment

In terrestrial ecosystems, nitrogen moves continuously between the atmosphere, soil, and living organisms through biochemical transformations. Arrange the following stages of the nitrogen cycle in sequential order, starting from the capture of atmospheric nitrogen gas and ending with its return to the atmosphere.

In a coastal salt marsh, cordgrass captures sunlight to produce energy, marsh snails feed on the cordgrass, and blue crabs prey on the snails. In this food chain, which ecological role do the blue crabs occupy?

Ecological terms describe the specialized roles and distribution patterns of organisms within biological communities. Which definition correctly matches each ecological term?

In a grassland biome, vegetation captures sunlight and generates $10{}000\text{ kcal}$ of available energy. Approximately how much of this energy is incorporated into the bodies of the herbivorous rodents that feed directly on these plants?

When agricultural runoff washes into a freshwater lake, it initiates a sequence of ecological changes. Arrange the stages of cultural eutrophication in chronological order from the initial nutrient influx to the resulting hypoxic dead zone.

In a desert community, harvester ants gather seeds from saguaro cacti, and horned lizards feed directly on the ants. In this ecological chain, which trophic role do the horned lizards occupy?

Terrestrial biomes are shaped by specific climatic regimes and support distinct ecological communities. Match each terrestrial biome on the left with its defining ecological characteristic on the right.

In a wetland ecosystem, submerged vegetation synthesizes glucose using dissolved carbon dioxide. Through which metabolic process do both living plants and aquatic animals release carbon dioxide back into their surroundings?

Following the retreat of a glacier, exposed bedrock undergoes primary ecological succession over centuries. In what sequential order do plant communities establish and transition from pioneer species to a stable climax community?

In an open ocean food chain, microscopic phytoplankton are consumed by zooplankton, which are then eaten by juvenile herring. Which trophic role do the juvenile herring fulfill in this marine ecosystem?

Organisms within a biological community interact through distinct symbiotic and ecological relationships that influence population dynamics. Match each ecological interaction type on the left with its characteristic real-world scenario on the right.

In a temperate forest ecosystem, bracket fungi and soil bacteria break down fallen oak branches, returning minerals and carbon compounds to the topsoil. Which ecological group do these organisms belong to?

Atmospheric nitrogen cannot be directly absorbed by most living organisms to synthesize essential proteins. In what sequential order does nitrogen travel from the air into animal body tissues?

In a freshwater wetland, certain species of bacteria and fungi break down dead plant material and animal waste, returning vital nutrients to the ecosystem. Which ecological role do these organisms fulfill?

In a desert ecosystem, a rattlesnake preys on kangaroo rats, which eat seeds from desert shrubs. In this food web, what ecological role does the rattlesnake fill?