问题 问答题

什么是物理图谱如何用序列标签位点绘制物理图谱

答案

参考答案:物理图谱(physical map):指DNA序列上两点间的实际距离。序列标签位点(STS)是指序列已知、染色体定位明确且可用PCR扩增的单拷贝序列。(1)以已定位的DNA序列标记位点(STS)为位标,以DNA实际长度为图谱距离的基因组图谱。(2)由YAC和/或细菌人工染色体(BAC)连续克隆重叠群组成的物理图谱。

单项选择题

"I was just like you--I’ thought I was invincible," says Adam Blomberg, standing before 400 students in a darkened auditorium at Miami’s Coral Reef Senior High School. A photo of a bloodied and unconscious teenager, a breathing tube protruding from his mouth, flashes on the wall.

"That was me," he says. There’s a collective gasp before the room grows silent and Blomberg,31, an anesthesiologist who trained at Brigham and Women’s Hospital in Boston, begins the story of what happened one night in February 1995.

He created a presentation illustrating the dangers of behaving irresponsibly in a car, from not buckling up to speeding to driving under the influence of alcohol and drugs. He tracked down photos of teen crash victims from the center’s archives, then incorporated statistics and his own experience. He spoke the first time to a local Boy Scout troop and was soon giving his talk, "A Survivor’s Story," at high schools around the state.

The Blomberg family had reason to celebrate. Adam had fully recovered and was on his way to fulfilling his lifelong dream of becoming a doctor. But in January 2000, Blomberg’s 22-year-old step-brother, Michael, was killed in a crash while driving to his Atlanta home late one night. He wasn’t wearing a seat belt. After the accident, Blomberg stopped telling his story to crowds, racked with guilt over his inability to reach Michael. If Blomberg had failed his own brother, he reasoned, how could he possibly make a difference to a roomful of strangers Requests from schools continued to roll in, but he turned down every one.

Then Blomberg got a call from a high school counselor. As he started into his standard excuse-lack of time—he looked across the room at a stack of thank-you notes from students who had heard him speak. He realized that kids needed to hear what he had to say. He agreed to visit the school and began contacting others on the waiting list for his talks.

Blomberg leaves the school hoping he has changed someone’s behavior. He recalls a letter he received from a student who heard him speak and got into a crash later that same day but was unharmed. " She told me she was wearing her seat belt because of me."

Letters like this reinforce his belief that he survived the accident for a reason. "There are a lot of physicians in the world, and we all save lives," he says. "I have a special opportunity to save lives not just as a doctor but also as a human being.\

What makes him regain his belief in the value of his speeches()

A. Constant invitation calls from schools

B. The death of his stepbrother Blomberg

C. The thank-you letters confirming his speeches’ values

D. Numerous accidents he heard of

单项选择题