8 biology questions

1. Compare the embryos of chickens, humans and fish, and describe in detail how pharyngeal arches show a shared evolutionary past?

2. Explain how reproductive barriers result in the development of different species.

3. Explain what is meant by the statement, evolution does not have a goal.

4. Explain why you would or would not expect evolution to proceed more quickly in a rapidly changing environment. Be sure to address all five agents of evolutionary change in your response.

5. Explain why penicillin, once a widely used and effective antibiotic, is now no longer effective against penicillin-resistant bacteria.

6. We all know that bacteria are capable of causing serious illnesses. Research has now shown that bacteria are helpful in many more ways than had previously been known. How is your life influenced by helpful bacteria?

7. Present your view of the early conditions on earth that might have affected the traits of organisms living in that environment and how life may have formed. Explain how extremophiles represent examples of those organisms.

8. Viruses, prions and viroids are non-living organisms that require a living cellular host in order to reproduce. They cannot do it on their own. These parasites may be just a string of RNA, as in a viroid, or a length of DNA enclosed in a protein shell, as in a virus.Is it possible that these parasites may be links to the earliest days of the beginning of life on this planet?

Post your primary response and support your statements with references. Your primary post should be at least 125 words or so. Be sure to cite your references in American Psychological Association (APA) style in-text and include the full APA style reference information at the end of the document.