About 4000 americans die each year from allergies. however, this is only about 0.2% of the total deaths in the united states per year. is the medical research and expense for allergy and asthma treatment really necessary? explain.

Apopulation of black bears depends on salmon from a stream for food. if a drought causes the stream to run dry one year, how will this likely impact the black bear population?

The current thought on the structure of the cell membrane is: a. a static phosphate sandwich of lipids b. a fluid-mosaic of phospholipids and proteins c. a bilayer of proteins with static lipid molecules d. an impermeable bilayer of protein molecules e. a static and permeable phospholipid single layer

Which of the following is a reason why early living organisms on earth could not have survived on the surface? 1. the lack of an ozone layer 2. the lack of oxygen in the atmosphere 3. the fact that these organisms were single-celled