Why do we need primers in order to replicate dna?

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.

This aquarium exhibits biotic and abiotic factors in an aquatic environment. one of the abiotic factors is

Aboy with an extra x chromosome probably has which of the following syndromes?