2. which organelle is responsible for making ribosomes?

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.

Several billion years ago which gas was the least prevailant in the atmosphere

If you want to double a batch of brownies you must have double the ingredients before you start cooking similarity a cell must double its contents including its dna prior to dividing