In natural systems, nitrogen is lost by denitrification. predict which of the following processes will be most responsible for replacing lost nitrogen in an ecosystem.

a) erosion

b) fixation

c) combustion

d) weathering

Use this diagram of an animal cell to answer the question. where does the first stage of cellular respiration occur? w x y z

Which statement about dna replication is true? a. eukaryotes only have one circular chromosome that unwinds at multiple locations. b. eukaryotes can only replicate one segment of a chromosome at a time. c. prokaryotes can only replicate their single circular chromosome in the nucleus. d. prokaryotes only have one origin of replication to initiate replication.

Of your good in bio kusing a series of preliminary observations; pstate a problem developed from these observations, formulate a hypothesis, design an experiment to test the hypothesis