The level of ecological organization that focuses on a single living individual is the [organism] level, while the level that examines groups of the same species living in the same area is the [population] level.

A) A team of ecologists is studying a population of snails in a marsh. During the first sampling, they capture and mark 120 snails before releasing them back into the population. A week later, they recapture 150 snails, 30 of which are marked. Calculate the size of the snail population. (Need to show calculations to receive full credit). B) After carefully observing the recaptured animals, the researchers discovered that 10% of the marked snails actually lost their marks during the study period. Adjust the population estimate to account for this mark loss. Hint: The true number of marked snails in the second sample (R′) can be recalculated as: R′=R/(1−Mark Loss Rate). (Need to show calculations to receive full credit).

Which of the following best describes a species’ realized niche?

Which of the following scenarios best illustrates optimal foraging in the presence of predation risk?

Which of the following traits is most characteristic of an r-selected population?

Match the abiotic factors with their influence on aquatic biomes:

You are given the following data on population densities for two herbivores, Species X and Species Y, in an experimental plot with varying abundances of the same plant species: Plant Abundance (biomass) Species X Density (ind/km²) Species Y Density (ind/km²) Low 5 15 Medium 10 20 High 18 10 A. Based on the data, what might be a reason for the decrease in Species Y density at high plant abundance? B. What ecological concept could explain the contrasting densities of Species X and Y at high plant abundance?

A metapopulation consists of multiple populations that are separated by space but connected through __________, allowing individuals to move between populations and recolonize areas where local extinctions have occurred.

Which of the following best describes a trade-off in life history strategies?

You are studying a population of grasshoppers and you calculate its population growth using a life table. You get a value for Ro of 1. What would the equivalent value be for the per-capita growth rate, r?