Which one of the following is not a major pollutant of Chesapeake Bay? a. Toxins
b. Wastes from aquatic organisms
c. Nutrients, particularly nitrogen and phosphorus
d. Soil and other sediments

Aresearcher has developed two stains for use with seed plants. one stains sporophyte tissue blue; the other stains gametophyte tissue red. if the researcher exposes pollen grains to both stains, and then rinses away the excess stain, what should occur? a) the pollen grains will be pure red. b) the pollen grains will be pure blue. c) the pollen grains will have red interiors and blue exteriors. d) the pollen grains will have blue interiors and red exteriors.

Adoctor is trying to diagnose a patient with dry skin. which of the following resources would be the most ? a magazine ad about soft skin a growth chart online articles about dry skin medical books

The concept of keystone species is controversial among ecologists because most organisms are highly interdependent. if each of the trophic levels is dependant on all others how can we say one is most important