Answer:
c) Nucleoside reverse transcriptase inhibitors may interfere with DNA replication by the host, not just by the virus.
Explanation:
A drug that targets the structures or processes specific to the pathogen or microbe has fewer side effects than the drugs that target the more general structures and processes exhibited by both the pathogen and host cells.
According to the given information, the nucleoside reverse transcriptase inhibitors resemble thymine and terminate the process of DNA replication. Thymine base is also one of the nitrogenous bases present in the human cells and other organisms. Therefore, the nucleoside reverse transcriptase inhibitors would terminate the process of DNA replication in both the virus and the host organism.
On the other hand, the non-nucleoside reverse transcriptase inhibitors specifically target the reverse transcriptase enzyme that is not present in host organisms. Therefore, the non-nucleoside reverse transcriptase inhibitors have fewer side effects than the nucleoside reverse transcriptase inhibitors.
Answer:
A. 17,100
Explanation:
The half life of carbon-14 is around 5,700 years. When the shell contains 50% of its original carbon-14, 5,700 years have passed. 25% means another 5,700 years have passed, meaning 11,400 years in total have passed. 12.5% means another 5,700 years have passed, meaning 17,100 years have passed in total.
Answer:
A) Any butterfly allele that allowed milkweed toxin storage would be likely to persist because butterflies that had it were more likely to survive.
Explanation:
Butterflies are natural preys to birds. Over time, some butterflies evolved adaptive strategy such as developing an allele which enables storage of toxin from milkweed as a form of defense mechanism. This stored toxins repel birds from eating the butterflies having this allele giving rise to the survival of these butterflies overtime. Butterflies that had it are likely to be highly favored for survival against predatory birds, while those butterflies without this allele are likely to be heavily preyed upon by birds.
Answer: There are few ‘laws’ in science. Those ‘laws’ are so named for historical reasons, but they are theoretical in nature. They set out what happens when a theory is applied in practice. A theory is simply the best explanation we have for understanding why some process takes place and predicting what the result will be.
Explanation: Anyone who describes something as “just a theory” does not understand what a theory is. Laws are arbitrary human rules. Theories are severely tested and re-tested explanations of why things happen in the real physical world and can be used to make predictions about outcomes.
Some would say that theories are about why something happens and laws (in science) describe what happens. But this simply makes a scientific ‘law’ a subset of a scientific theory, explaining how to make predictions.
