The human sleep cycle repeats itself about every a) 30 minutes. b) 90 minutes. c) 2 1/2 hours. d) 4 hours.

According to the theory of punctuated equilibrium, at what rate does speciation occur? species change depending on the rate of natural selection. after periods of stasis, new species evolve relatively rapidly. species change slowly and eventually form new species. some species change quickly and others change slowly to balance the overall rate.

What are the three types of counseling established by marine corps policy?

Number and variety of living organism; includes genetic, species, and ecological types