Organisms maintain the right number of cells by regulating the cell cycle. what are "cell cycle regulators"?

Trichodesmium is a nitrogen-fixing cyanobacteria. Why might this cyanobacteria be important to other organisms in nitrogen-poor waters? They convert atmospheric nitrogen (N2) to organic compounds including ammonia (NH3).

What is the idea developed by Charles Lyell stating that the geologic processes that shaped Earth in the past continue to operate today? a. inheritance of acquired characteristics b. catastrophism c. uniformitarianism d. descent with modification

Why in sudden outbreaks, it may be better to test for disease antigens rather than for antibodies?

What is the part of the earth that contains all living things?

A lot of microbes such as E. coli can be used in modern scientific research because A) E. coli has genetic and metabolic similarity with other organisms B) E. coli is totally different from any other species C) E.

Describe two factors that cause variations in climate?

A demonstration is performed during a lecture on muscle physiology in which a student is asked to fully extend his right arm with the palm up. Two large textbooks are placed on his palm, one at a time.

How is it that the heartworm is able to multiply in numbers at such a fast rate?

Ground squirrels are found in many areas of the United States. They live in underground burrows and are often attacked by birds of prey, coyotes, and boBCats. Which of the following is a limiting factor for a ground squirrel population?

10. Which of the following is an emerging dis- ease that was unknown 50 years ago? a. malaria b. dengue fever C. Lyme disease d. schistosomiasis