Refer to the figure.        According to the figure, how does the amount of nitrogen entering the atmosphere from human activities compare with the amount entering from land-based natural sources? (All values are in units of 1012 grams.)

The animal phylum with the most species is

To measure the amount of a substance, on would use ___ observations.

As sea levels rise because of climate change, some shallow-water marine ecosystems such as coral reefs and seagrass beds will be located in deeper water. What effect will the deeper water likely have on these ecosystems?

Developers are building ten new homes on a parcel of land of one habitat type. Local zoning regulations require that they leave some of the land in its natural condition to conserve native species. They can set aside either one large plot or five small separated plots. The total amount of conserved area is the same in either case. Which choice, if either, would be best for maintaining biodiversity, and why?

Butterfly species A is a Batesian mimic of butterfly species B. If species B were eradicated from a region, what would be the most likely effect on the population of species A?

Unsustainable fishing, or overharvesting, of many ocean fish species is now occurring. What, if any, is a major ecological impact of this overharvesting?

The geographic distributions of wolves and coyotes often do not overlap. A study of wolves and coyotes in an area where they do overlap found that the two species minimized competition by differential use of food resources. Wolves preyed primarily on elk and a few deer, whereas coyotes preyed mostly on deer and rarely on young elk. Coyotes also scavenged abandoned wolf kills. Wolf and coyote behavior illustrates which type of competition?

The structure of the cartilaginous and body fishes that detects vibrations in the water is the

The bones that surround and protect the brain are collectively called the