Which of the following statements about cell differentiation is true?

Apopulation has 1000 individuals. over a period of 1 year, 500 newindividuals are born. which equation shows how to calculate the birthrate ofthis population? a. 500 - 1000 = 0.5b. 1000 x 0.5 = 500c. 1000 - 500 = 2d. 1000 + 500 = 1500

Variety of living organisms; includes genetic, species, and ecological types.

Which kind of worm has a closed circulatory system? a planarian b fluke c pinworm d an earthworm