题目内容

With only about 1,000 pandas left in the world, China is desperately trying to clone the animal and save the endangered species. That’s a move similar to what a Texas A&M University researcher has been undertaking for the past five years in a project called “Noah’s Ark.”Dr. Duane Kraemer, a professor in Texas A&M’s College of Veterinary Medicine and a pioneer in embryo (胚胎) transfer work and related procedures, says he salutes the Chinese effort and “I wish them all the best success possible. It’s a worthwhile project, certainly not an easy one, and it’s very much like what we’re attempting here at Texas A&M — to save animals from extinction.”Noah’s Ark is aimed at collecting eggs, embryos, semen and DNA of endangered animals and storing them in liquid nitrogen. If certain species should become extinct, Kraemer says there would be enough of the basic building blocks to reintroduce the species in the future.It is estimated that as many as 2,000 species of mammals, birds and reptiles will become extinct over the next 100 years. The panda, native only to China, is in danger of becoming extinct in the next 25 years.This week, Chinese scientists said they grew an embryo by introducing cells from a dead female panda into the egg cells of a Japanese white rabbit. They are now trying to implant the embryo into a host animal.The entire procedure could take from three to five years to complete. “The nuclear transfer of one species to another is not easy, and the lack of available panda eggs could be a major problem.” Kraemer believes. “They will probably have to do several hundred transfers to result in one pregnancy. It takes a long time and it’s difficult, but this could be groundbreaking science if it works. They are certainly not putting any live pandas at risk, so it is worth the effort.” adds Kraemer, who is one of the leaders of the Missyplicity Project at Texas A&M, the first-ever attempt at cloning a dog.“They are trying to do something that’s never been done, and this is very similar to our work in Noah’s Ark. We’re both trying to save animals that face extinction. I certainly applaud their effort and there’s a lot we can learn from what they are attempting to do. It’s a research that is very much needed.”6. The aim of “Noah’s Ark” project is to ________.

A. implant embryo into a host animal
B. salute the Chinese efforts in saving pandas
C. save endangered animals from extinction
D. introduce cells from a dead female panda into the egg cells of a Japanese white rabbit

查看答案
更多问题

The word “groundbreaking” can be interpreted as ________.

A. especially new
B. pioneering
C. damaging
D. trouble-making

分压式偏置单管放大电路的发射极旁路电容因损坏而断开,则该电路的电压放大倍数将()。

A. 大
B. 减小
C. 不变

工作在放大区的某三极管,如果当IB从12uA增大到22uA时,IC从1mA变为2mA时,那么它的β约为()。

A. 90
B. 100
C. 110

固定偏置放大电路中,晶体管的β=50,若将该管调换为β=80的另外一个晶体管,则该电路中晶体管集电极电流IC将( )。

A. 增加
B. 基本不变

答案查题题库