The mediastinum contains which of the following organs? A. Heart B. Esophagus C. Trachea D. All of the above

Darius is observing a family of geese, which includes a male goose, female goose, and several goslings. when a dog approaches the geese, the male goose hisses at the dog and flaps its wings threateningly. is the behavior of the male goose an example of an adaptation?

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.

The greenhouse effect a. something that has occurred for millions of years b. an unnatural phenomenon caused by humans that maintains earths temperature range. c. the results of the differences in the angle of the suns rays d. an unnatural phenomenon that causes heat energy to be radiated back into the atmosphere