Ecology

Arrange the following sequential stages of cultural eutrophication in a freshwater ecosystem, starting from the initial entry of excess agricultural runoff to the final impact on aquatic animals.

Crude oil spillage on marine ecosystems causes severe damage to aquatic life by forming an impenetrable surface layer. Which of the following methods represents an eco-friendly biological control measure used to clean up such oil spills?

Match each organism exhibiting specialized survival strategies with its corresponding morphological or physiological adaptation to its environmental stress.

A soil sample taken from an uncultivated grassland with no leguminous plants shows a steady increase in fixed nitrogen compounds. Laboratory analysis confirms the activity of free-living, aerobic bacteria capable of directly fixing atmospheric nitrogen ($N_2$) into biological compounds without forming root nodule associations. Which microorganism is responsible for this nitrogen fixation process?

Kangaroo rats (*Dipodomys* species) are physiologically adapted to desert environments by relying primarily on metabolic water generated from the oxidation of dietary lipids and producing highly hypertonic urine made possible by exceptionally long loops of Henle.

In natural resource management, game cropping is recognized as a valid biological conservation strategy because the controlled harvesting of wild animal populations prevents habitat degradation caused by overpopulation when natural predator numbers are insufficient.

Match each environmental pollutant listed on the left with its corresponding primary ecological or physiological impact on the right.

An ecologist conducting a survey in a coastal wetland classifies ecological units to understand structural hierarchy. Arrange the following ecological units in order of increasing complexity and scope, from the simplest individual unit to the broadest global system:

Match each ecological succession term on the left with its corresponding description or scenario on the right.

Freshwater teleost fishes maintain osmotic balance in their environment by continuously drinking surrounding water and excreting small amounts of highly concentrated urine.

Arrange the following ecological events of the phosphorus cycle in the correct chronological order, starting from the initial abiotic release of phosphorus to its recycling back into soil sediments by decomposers.

Match each ecological pyramid concept or trophic phenomenon on the left with its corresponding characteristic description on the right.

Arrange the following sequential events demonstrating the biomagnification of persistent synthetic pesticides in an aquatic food web, starting from initial environmental contamination to the final impact on apex predators.

A biology researcher used a $0.5\text{ m}^2$ quadrat thrown 20 times at random to estimate the population of Mexican sunflower (*Tithonia diversifolia*) in a cashew orchard measuring $500\text{ m}^2$ in Ilorin. If a total of 160 plants were counted across all quadrat throws, what is the estimated total population size of *Tithonia diversifolia* in the orchard?

Match each structural or physiological adaptive feature with its primary survival function in its specific environmental habitat.

Which of the following environmental changes occurs in a freshwater river immediately following the discharge of untreated domestic sewage?

In a tropical savanna ecosystem, energy fixed by photosynthetic plants is transferred through a sequential feeding hierarchy. Based on the thermodynamic principles governing energy loss across trophic levels, arrange the following organisms in sequence from HIGHEST available energy per unit area to LOWEST available energy per unit area.

Following the application of an ammonium-based fertilizer to well-aerated agricultural soil, which soil bacterium carries out the initial oxidation of ammonium ions ($NH_4^+$) into nitrite ions ($NO_2^-$)?

Match each environmental agency or conservation body on the left with its primary function in natural resource management on the right.

Submersed hydrophytes growing completely under water typically exhibit poorly developed xylem vessels and lack stomata on their leaf surfaces. Which of the following statements explains why xylem tissue is greatly reduced in these aquatic plants?