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A soil fungus releases an antibiotic into its surroundings. What ecological benefit can this give the fungus? A. It creates additional sunlight beneath the soil B. It suppresses competing microbes that use the same resources C. It guarantees that every…
Which labelled carbon transfer can turn primary production into secondary production? A. A B. B C. C D. D
The model population settles near 220 individuals during the final weeks. What does this late plateau represent? A. Exponential growth sustained by unlimited resources B. A carrying capacity constrained by available resources C. A population that has stopped…
In an isolated meadow, plants accumulate new biomass and herbivores use some of it for growth. Over the same area and time, which comparison of production rates is expected? A. Primary production exceeds secondary production because part of the consumed carbon…
A keystone species disappears from a food web. Which outcome is plausible? A. All interactions necessarily become more stable B. Every remaining species immediately becomes extinct C. The number of trophic levels must increase by one D. Some previously…
Runoff rich in nitrate enters a small pond and stimulates eutrophication. Which pair of changes is expected during the developing algal bloom and subsequent decay? A. Less algal biomass and lower microbial oxygen demand B. More algal biomass and greater…
Which conditions can contribute to natural selection in a population? I. A habitat change that alters relative survival II. Inherited differences in a relevant trait III. Exactly equal reproductive success for every genotype in every generation Choose the…
The diagram represents a feedback involving thawed, waterlogged organic soils. Which combination correctly identifies R and S? A. R: anaerobic decomposition; S: methane B. R: mineral crystallization; S: oxygen C. R: photosynthetic fixation; S: nitrogen D. R:…
Which event creates different combinations of maternal and paternal chromosomes among gametes? A. Copying a chromosome before an ordinary mitotic division B. Equal partition of cytoplasm in a skin cell C. Independent orientation of homologous chromosome pairs…
Why can excess nutrient runoff reduce the diversity of animals in a lake? A. Phosphate necessarily biomagnifies as a poison in every food chain B. Decomposition following excessive algal growth depletes dissolved oxygen C. Additional nutrients make all aquatic…