Read the passage from Darwin's journal. These two species of Amblyrhynchus agree, as I have already stated, in their general structure, and in many of their habits. Neither have that rapid movement so characteristic of the genera Lacerta and Iguana. They are both herbivorous; although, the kind of vegetation on which they feed is so very different. Mr. Bell has given the name to the genus from the shortness of the snout; indeed, the form of the mouth may almost be compared to that of the tortoise: one is led to suppose that this is an adaptation to their herbivorous appetites. It is very interesting thus to find a well-characterized genus, having its marine and terrestrial species, belonging to so confined a portion of the world. The aquatic species is by far the most remarkable because it is the only existing lizard which lives on marine vegetable productions. As I at first observed, these islands are not so remarkable for the number of the species of reptiles; as for that of the individuals, when we remember the well-beaten paths made by the thousands of huge tortoises—the many turtles—the great warrens of the terrestrial Amblyrhynchus—and the groups of the marine species basking on the coast-rocks of every island—we must admit that there is no other quarter of the world where this order replaces the herbivorous mammalia in so extraordinary a manner. What differences did Darwin find about the two species? One is fast, while the other is slow. One eats plants, while the other eats meat. One lives inland, while the other lives in the water. One has a long snout, while the other has a short snout.

One lives inland, while the other lives in the water.

Explanation:

Amblyrhynchus cristatus is a marine reptile that lives in the Galápagos Islands. This species attracted the attention of Darwin because it is a marine iguana that lives exclusively in the Galapagos and, interestingly, their close relatives inhabit in land, also in the Galápagos Islands. The marine and land iguanas from Galápagos form a phylogenetic clade that is characterized by high diversification levels, which are evidenced by conspicuous phenotypic differences. These species can hybridize with each other, but the offspring are infertile. Recently, it has been shown by using phylogeographic analysis that both species diverged 8-10 million years ago.

They both eat plants.

Explanation:

They are both herbivorous; although, the kind of vegetation on which they feed is so very different.

step 1: initiation

initiation is the beginning of transcription. it occurs when the enzyme rna polymerase binds to a region of a gene called the promoter. this signals the dna to unwind so the enzyme can ‘‘read’’ the bases in one of the dna strands. the enzyme is now ready to make a strand of mrna with a complementary sequence of bases.

step 2: elongation

elongation is the addition of nucleotides to the mrna strand. rna polymerase reads the unwound dna strand and builds the mrna molecule, using complementary base pairs. there is a brief time during this process when the newly formed rna is bound to the unwound dna. during this process, an adenine (a) in the dna binds to an uracil (u) in the rna.

step 3: termination

termination is the ending of transcription, and occurs when rna polymerase crosses a stop (termination) sequence in the gene. the mrna strand is complete, and it detaches from dna.