A、All scientists accept its definition. B、It is a sequence of DNA. C、People know very little about it. D、It is the smallest unit

W: Everybody is talking about genes today, but do genes determine everything about us?
M: Genes and environment work together to shape who we are. As the environment includes everything we experience and come into contact with from birth through to death, it also plays an extremely complex role.
W: What is a gene, then?
M: Even scientists disagree on exactly how to define a gene. Generally a gene is a sequence of DNA that tells us what a single protein does. Proteins do the work of the body, building structures and stimulating biochemical reactions.
W: How genetically similar are we to one another?
M: Individual humans are extremely similar to each other. They share 99.9 percent of their DNA no matter which race they belong to.
W: How genetically similar are we to other species?
M: Scientists have been amazed at how genetically similar humans are to other species. Humans share 80 percent of their genes with mice, about 99 percent of their DNA with chimpanzees. That means that chimpanzees are more closely related to humans that to other animals, such as monkeys, whales, or cats.
W: Will this lead to a cure for cancer and other serious diseases?
M: Of course! Virtually every disease has some genetic cause. Some are simple misspellings that can be corrected with gene therapy, although this technology is still in its infancy. As scientists gain more knowledge about genes, they will develop new treatments based on that knowledge. The outlook is especially good over the next few decades for some cancers and other diseases.
Questions 12 to 15 are based on the conversation you have just heard.
12. What are the determinants to shape who we are?
13. What do we learn about a gene?
14. Which pair is the most closed related to each other?
15. What is the man’s attitude toward the effects of future genetic technology?