Use the drop-down menus to complete each sentence.
During
membranes form around the uncoiling chromosomes.
During
chromosomes line up along the middle of the cell.
During
chromosomes split apart.
During
spindle fibers form.

Rotenone is an insecticide that is toxic

Which of the following types of pollution is most responsible for large numbers of deaths worldwide because of unsafe drinking water? (a) nutrient pollution (b) thermal pollution (c) pathogen pollution (d) sediment pollution

There are only about 250,000 known fossil species. true or false