1) What does it mean when scientists say that living organisms share a universal genetic code? Genetic code means DNA and when organisms share a univeral genetic code they share a structure of DNA.
2) How does a universal genetic code relate to the hypotheses about the origin of life on Earth?Universal Genetic code would indicate that all organisms descended from a common ancestor, seeing how all organsims share a universal genetic code.
3) How are self-replicating molecules, such as RNA molecules in the “RNA World” hypothesis, essential to the most popular hypotheses about the origin of life on Earth? Becuase, RNA is able to store genetic info just like DNA, and is also able to catalyze chemical reactions like an enzyme, so RNA could have played a big role in the evolution of cellular life.
4) How might similarities and differences in genetic codes, or the proteins built as a result of these codes, be used to determine how closely related different species are? DNA sequences change by accumulating mutations over many generations. So, the more similar two DNA sequences are, the more recently they share a common ancestor.
5) Based on the amino acid sequence data for the Cytochome-C protein, chimpanzees and humans share an identical coding sequence. What other species identified on the chart has a coding sequence that is most closely related to the humans and chimpanzees and most distantly related? Explain your answer. The Pekin duck is the most closely related organism thats the most distant becuase it only has 3 differences in its coding sequence. CHART:
Humans vs. Rhesus Monkey: 0 differences
Humans vs. Horse: 3 differences
Humans vs. Donkey: 3 differences
Humans vs. Common Zebra: 3 differences
Humans vs. Pigs, Cow, Sheep: 3 differences
Humans vs. Dog: 3 differences
Humans vs. Gray Whale: 3 differences
Humans vs. Rabbit: 3 differences