Ecology

Arrange the following microbial and biochemical transformations of nitrogen in sequential order, beginning with the fixation of atmospheric dinitrogen ($N_2$) gas by symbiotic root nodule bacteria and ending with the release of gaseous dinitrogen back into the atmosphere.

Match each ecological pyramid structural characteristic or anomaly on the left with its correct ecological or thermodynamic explanation on the right.

Match each ecosystem component or ecological factor on the left with its correct description on the right.

Match each ecological structural term on the left with its corresponding definition on the right.

Match each ecological pyramid concept on the left with its correct biological or structural feature on the right.

An ecologist set up a standard rain gauge to record precipitation in a tropical grassland ecosystem over a one-month period. Which of the following procedural precautions is essential to obtain accurate rainfall measurements?

Match each type of ecological succession or community stage in List I with its correct environmental context or characteristic in List II.

A biological study of a freshwater lake ecosystem recorded the trophic interactions among several species. Arrange the following organisms in sequence from the HIGHEST available energy content to the LOWEST available energy content.

Match each fundamental ecological concept on the left with its precise structural or functional definition in ecosystem dynamics on the right.

During ecological succession, predictable structural and functional changes occur as an early pioneer stage progresses toward a mature climax ecosystem. Which of the following statements accurately characterizes the trends in community bioenergetics, biomass accumulation, and species interactions during this succession?

An ecologist studying abiotic factors in a lotic freshwater habitat estimated the surface water velocity by timing a float that travelled a distance of $60\text{ m}$ downstream in $24\text{ s}$. To record a precise, depth-specific measurement of this ecological factor across different river strata, which calculated velocity and instrument choice are correct?

An ecologist conducted a survey in an abandoned oil palm plantation in Edo State to determine the density of Siam weed (*Chromolaena odorata*). Using a $1\text{ m} \times 1\text{ m}$ quadrat frame thrown randomly 20 times across the field, a total of 160 Siam weed plants were counted. What is the estimated population density of Siam weed in this plantation?

Match each ecological succession process or stage in List I with its corresponding characteristic bioenergetic, structural, or environmental mechanism in List II.

Match each ecological organization level on the left with its correct biological description on the right.

Match each nitrogen cycle microorganism on the left with its correct biological role on the right.

In a humid tropical forest ecosystem, the producers capture solar energy resulting in a Gross Primary Productivity (GPP) of $40{}000\text{ kJ/m}^2/\text{yr}$. Autotrophic respiration accounts for $55\%$ of this captured energy. Primary consumers assimilate $10\%$ of the Net Primary Productivity (NPP) available to them, while spending $60\%$ of their assimilated energy on cellular respiration. What is the total energy available for secondary consumers at the third trophic level?

In ecological systems, energy transformations and trophic interactions dictate the structure and dynamics of food webs. Match each ecological energy concept on the left with its corresponding defining feature or ecosystem attribute on the right.

Arrange the following organisms in a coastal estuarine food chain in sequence of DECREASING available energy per unit area per year (from the trophic level with the highest available energy to the trophic level with the lowest available energy).

Match each nitrogen cycle process listed on the left with its correct biological transformation on the right.

In an experiment to investigate the water-retaining capacity of three different soil types, equal masses ($100\text{ g}$) of dried soil samples $P$, $Q$, and $R$ were placed into separate filter-lined funnels. A volume of $100\text{ cm}^3$ of water was poured over each sample, and the volume of filtrate collected in the measuring cylinders beneath after $15\text{ minutes}$ was recorded as follows:

- Sample P: $25\text{ cm}^3$ of filtrate collected
- Sample Q: $55\text{ cm}^3$ of filtrate collected
- Sample R: $85\text{ cm}^3$ of filtrate collected

Which of the following correctly identifies Sample R and the primary edaphic factor responsible for its observed drainage rate?