Organisms can be classified based on homology, which is shared characteristics inherited from a common ancestor. In the past, homologies were based on studies of anatomical structures and patterns of embryonic development. In more recent years, the use of molecular biology techniques has allowed homologies to be compared at the level of nucleotide sequences. Nucleotide sequence comparisons are possible because all organisms share which of the following?

Place the steps tor the formation of the enzyme pepsinogen in correct order

20 the compound al(nh3)2 has atoms of nitrogen.

How is anaerobic respiration affected by changes in temperature? (5 points)based on the conditions of early earth, what conclusion can you draw about the amount of anaerobic respiration that was occurring at earth’s beginning? explain your answer.(5 points)if there was a sudden drop in temperature after the evolution of the first living cells, predict how that might have affected the changes in the atmosphere and the evolution of cyanobacteria and other autotrophs. explain your answer. (5 points)