A massive farm near our school has recently had a decrease in crop production (e. g., not as many plants are
successfully growing). A soil ecologist was notified. She
immediately noticed that there were no worms, bacteria, or
other microorganisms in the soil, even though she knew that
many organisms were present in the soil five years ago. Based
on this information, she would probably say that the population
density of microorganisms had
a. Increased
b. Decreased
c. Immigrated
d. None of the above

After getting the slide and microscope ready, stella is eager to see the microscopic pond water specimen! she crouches around her microscope and aligns her eye with the microscope’s eyepiece. but she's only able to see a bright white light. at this point, no specimens or cells are visible on stella's pond water slide. after taking a moment to collect her thoughts, stella realizes she can't see any lifeforms because .

Examine the two squirrel populations in the accompanying figure. the populations are separated by a geographic barrier. if after a long period of time the two species are no longer separated, what evidence is needed to determine if speciation has occurred? the figure shows two populations of squirrels separated by a geographic barrier. examine the two squirrel populations in the accompanying figure. the populations are separated by a geographic barrier. if after a long period of time the two species are no longer separated, what evidence is needed to determine if speciation has occurred? the figure shows two populations of squirrels separated by a geographic barrier. polyploidy is creating new species. the two populations are not interbreeding freely. hybrid offspring of the two populations begin to appear. one species will increase into a population size twice as large as the other species.

Anne, an intern in a microbiology lab, was observing the characteristics of various specimens of protists. match each specimen to the category of protist to which it belongs.