Sister chromatids of each chromosome move apart  and end up at opposite spindle poles during _______. 

Which of the following is a gastropod?

Amoebas, foraminiferans, radiolarians, and heliozonas are all classified as _____.

Following a line of longitude from the equator along the west coasts of the United States and Canada and to the North Pole, a person would pass through biomes in which order?

During succession, two plant species become established at different times. Species A is a perennial with roots that secrete chemicals to maintain a distance between members of the species and similar species. Species B is a low-growing annual with nitrogen-fixing bacteria in its root nodules. Which (if either) of these two species most likely appears first during succession, and why?

The tendency for dogs to bark while trailing is determined by a dominant gene, S, whereas silent trailing is due to the recessive gene, s. In addition, erect ears, D, is dominant over drooping ears, d. What combination of offspring would be expected from a cross between two erect-eared barkers who are heterozygous for both genes?

Herbaceous stems are supported by

Which is the best example of a coupled human–natural system?

In many areas of the Rocky Mountains, both squirrel and bird species extract and eat the pine seeds from cones of lodgepole pines. In a few areas, however, birds called red crossbills are the only consumers of the pine seeds. Where this one-on-one relationship occurs, both the birds and the pine trees have changed over generations. The crossbills have developed deeper, shorter, and straighter bills that are more efficient at extracting pine seeds, and the pines have developed larger, thicker scales on the cones that defend the seeds from extraction. This bird–tree interaction appears to be an example of

All organisms in the kingdoms Protista, Plantae, Fungi, and Animalia are: