tailieunhanh - The official guide to the toefl ibt third edition part 46

The TOEFL iBT uses reading passages from university-level textbooks that intro-duce a discipline or topic. The excerpts are changed as little as possible so the TOEFL iBT can measure how well students can read academic material. | TOEFL iBT Practice Test 1 Female Student So do you remember what those genes are called Male Student Umm . . . Female Student Resistance genes. Male Student Resistance genes. Right. Resistance genes. OK. Female Student And that makes sense right Because they help the bacteria resist the antibiotics. Male Student Yeah that makes sense. OK. Female Student OK. But the question is how do bacteria get the resistance genes Male Student How do they get the resistance genes They just inherit them from the parent cell right Female Student OK yeah that s true. They can inherit them from the parent cell but that s not what I m talking about. Male Student OK. Female Student I m talking about how they get resistance genes from other cells in their environment you know from the other cells around them. Male Student Oh I see what you mean. Umm is that that stuff about hopping genes or something like that Female Student Right. Although actually they re called jumping genes not hopping genes. Male Student Oh OK. Jumping genes. Female Student Yeah but they have another name too that I can t think of. Umm . . . lemme see if I can find it here in the book . . . Male Student I think it s probably on . . . 306 Answers Explanations and Listening Scripts Female Student Oh OK. Here it is. Transposons. That s what they re called. Male Student Lemme see. OK. Trans . . . po . . . sons . . . trans . . . posons. So transposon is another name for a jumping gene Female Student Right. And these transposons are you know like little bits of DNA that are able to move from one cell to another. That s why they re called jumping genes. They kind of you know jump from one cell to another. Male Student OK. Female Student And these transposons are how resistance genes are able to get from one bacteria cell to another bacteria cell. What happens is that a resistance gene from one cell attaches itself to a transposon and then when the transposon jumps to another cell . . . Male Student The other cell gets .