The first cells were probably ____.
A、aerobic
B、anaerobic and autotrophic
C、anaerobic and heterotrophic
D、auxotrophic
E、autotrophic
A、aerobic
B、anaerobic and autotrophic
C、anaerobic and heterotrophic
D、auxotrophic
E、autotrophic
A.malignant cells in him were unable to develop into deadly ones
B.he was a generous man with immense energy and curiosity
C.the Lithic Lab at the Ohio State Museum employed him
D.he was determined that he was able to deter the disease
In particular, Dr Hwang claimed he had created 11 colonies of human embryonic stem cells genetically matched to specific patients. He had already admitted that nine of these were bogus, but had said that this was the result of an honest mistake, and that the other two were still the real McCoy. A panel of experts appointed by the university to investigate the matter, however, disagreed. They found that DNA fingerprint traces conducted on the stem-cell lines reported in the paper had been manipulated to make it seem as if all 11 lines were tailored to specific patients. In fact, none of them matched the volunteers with spinal-cord injuries and diabetes who had donated skin cells for the work. To obtain his promising "results", Dr Hwang had sent for testing two samples from each donor, rather than a sample from the donor and a sample of the cells into which the donor's DNA had supposedly been transplanted.
The panel also found that a second claim in the paper-that only 185 eggs were used to create the 11 stem-cell lines-was false. The investigators said the actual number of eggs used was far larger, in the thousands, although they were unable to determine an exact figure.
The reason this double fraud is such a blow is that human embryonic stem-cell research has great expectations. Stem cells, which have not yet been programmed to specialise and can thus, in principle, grow into any tissue or organ, could be used to treat illnesses ranging from diabetes to Parkinson's disease. They might even be able to fix spinal-cord injuries. And stem cells cloned from a patient would not be rejected as foreign by his immune system,
Dr Hwang's reputation, of course, is in tatters. The university is now investigating two other groundbreaking experiments he claims to have conducted-the creation of the world's first cloned human embryo and the extraction of stem cells from it, and the creation of the world's first cloned dog. He is also in trouble for breaching ethical guidelines by using eggs donated by members of his research team.
And it is even possible that the whole farce may have been for nothing. Cloned embryos might be the ideal source of stem cells intended to treat disease, but if it proves too difficult to create them, a rough-and-ready alternative may suffice.
From the passage we may learn that Hwang Woo-suk______.
A.made up all his experience
B.is a famous geneticist in Seoul National University
C.was an employee in Seoul National University
D.published an authentic paper in Science with his 24 colleagues
听力原文:W: ok, last night you were supposed to read an article about human bones. Are there any comments about it?
M: well, to begin with, I was surprised to find out there were so much going on in bones. I always assumed they were pretty lifeless.
W: Well, that's an assumption many people make. But the fact is bones are made of dynamic living tissue that requires continuous maintenance and repair.
M: Right. That's one of the things I found so fascinating about the article the way the bones repair themselves.
W: Ok. So can you tell us how the bones repair themselves.
M: Sure. See, there are two groups of different types of specialized cells in the bone that work together to do it. The first group goes to an area of the bone that needs repair. This group of cells produce the chemical that actually breaks down the bone tissue, and leaves a hole in it. After that the second group of specialized cells comes and produce the new tissue that fills in the hole that was made by the first group.
W: Very good. This is a very complex process. In fact, the scientists who study human bones don't completely understand it yet. They are still trying to find out how it all actually works. Specifically, because sometimes after the first group of cells leaves a hole in the bone tissue, for some reason, the second group doesn't completely fill in the hole. And this can cause real problems. It can actually lead to a disease in which the bone becomes weak and is easily broken.
M: ok, I get it. So if the scientists can figure out what makes the specialized cells work, maybe they can find a way to make sure the second group of cells completely fills the hole in the bone tissue every time. That'll prevent the disease from every occurring.
(31)
A.Two different types of bones in the human body.
B.How bones help the body move.
C.How bones continuously repair themselves.
D.The chemical composition of human bones.
In particular, Dr Hwang claimed he had created 11 colonies of human embryonic stem ceils genetically matched to specific patients. He had already admitted that nine of these were bogus, but had said that this was the result of an honest mistake, and that the other two were still the real McCoy. A panel of experts appointed by the university to investigate the matter, however, disagreed. They found that DNA fingerprint traces conducted on the stem-cell lines reported in the paper had been manipulated to make it seem as if all 11 lines were tailored to specific patients. In fact, none of them matched the volunteers with spinal-cord injuries and diabetes who had donated skin cells for the work. To obtain his promising "results", Dr Hwang had sent for testing two samples from each donor, rather than a sample from the donor and a sample of the cells into which the donor's DNA had supposedly been transplanted.
The panel also found that a second claim in the paper — that only 185 eggs were used to create the 11 stem cell lines — was false. The investigators said the actual number of eggs used was far larger, in the thousands, although they were unable to determine an exact figure. The reason this double fraud is such a blow is that human embryonic stem-cell research has great expectations. Stem cells, which have not yet been programmed to specialise and can thus, in principle, grow into any tissue or organ, could be used to treat illnesses ranging from diabetes to Parkinson's disease. They might even be able to fix spinal-cord injuries. And stem cells cloned from a patient would not be rejected as foreign by his immune system.
Dr Hwang's reputation, of course, is in tatters. The university is now investigating two other groundbreaking experiments he claims to have conducted — the creation of the world's first cloned human embryo and the extraction of stem cells from it, and the creation of the world's first cloned dog. He is also in trouble for breaching ethical guidelines by using eggs donated by members of his research team.
And it is even possible that the whole farce may have been for nothing. Cloned embryos might be the ideal source of stem cells intended to treat disease, but if it proves too difficult to create them, a rough-and-ready alternative may suffice.
From the passage we may learn that Hwang Woo-suk ______.
A.made up all his experience
B.is a famous geneticists in Seoul National University
C.was an employee in Seoul National University
D.published an authentic paper in Science with his 24 colleagues
M: Well, to begin with, I was surprised to find out there was so much going on in bones. I always assumed they were pretty lifeless.
W: Well, that's an assumption many people make. But the fact is bones are made of dynamic living tissue that requires continuous maintenance and repair.
M: Right. That's one of the things I found so fascinating about the article the way the bones repair them selves.
W: Ok. So can you tell us how the bones repair them selves.
M: Sure. See, there are two groups of different types of specialized cells in the bone that work together to do it. The first group goes to an area of the bone that needs repair. This group of cells produces the chemical that actually breaks down the bone tissue, and leaves a hole in it. After that' the second group of specialized cells comes and produces the new tissue that fills in the hole that was made by the first group.
W: Very good. This is a very complex process. In fact, the scientists who study human bones don't completely understand it yet. They are still trying to find out how it all actually works. Specifically, be cause sometimes after the first group of ,cells leaves a hole in the bone tissue, for some reason, the second group doesn't completely fill in the hole. And this can cause real problems. It can actually lead to a disease in which the bone becomes weak and is easily broken.
M: Ok, I get it. So if the scientists can figure out what makes the specialized cells work, maybe they can find a way to make sure the second group of cells completely fills the hole in the bone tissue every time. That'll prevent the disease from ever occurring.
(23)
A.How bones help the body move.
B.How bones continuously repair themselves.
C.The chemical composition of human bones.
D.Two different types of bones in the human body.
What is the logical order of the following paragraph? The cloning of Dolly involved several steps. First, cells that had previously been taken from Dolly’s mother were starved for five days, which caused them to stop dividing. This interruption of the cells’ division cycle made it easier for them to reprogram themselves to start growing a new organism. After five days, the nuclei of these cells were removed and transferred into an unfertilized sheep egg, from which the natural nucleus had previously been removed. In the next step, the egg was grown in the laboratory for a period of time. Then the egg was implanted into a different sheep, where it grew normally. When the sheep finally gave birth, the lamb was an exact genetic copy, or clone, of the sheep that had provided the transferred nucleus, not of the sheep that had provided the egg.
A、Chronological order
B、Logical division of ideas
C、Cause and effect
D、Inductive method
E、Deductive method
A.the effects of altering cells
B.the human growth hormone
C.insulin resistance
D.U.S.Supreme Court rulings
A. the effects of altering cells
B. the human growth hormone
C. insulin resistance
D. U.S.Supreme Court rulings
The investigators performed a series of tissue-transplant experiments with hamsters (仓鼠). Some of the animals were normal hamsters, which have a circadian cycle of 24 hours; the others were mutant(变异型)hamsters whose cycles were only 20 or 22 hours long.
The scientists first removed the SCN from the brans of the hamsters in both groups. They then implanted an SCN from a mutant hamster into the brain of each normal animal, and vice versa. When the hamsters had recovered from their operations, the circadian rhythms of the two groups were reversed. The normal hamsters had a daily cycle of 20 to 22 hours, and the mutants were on a 24-hour cycle.
The identification of the internal clock is an important stepping-stone in understanding the basic, automatic mechanisms of brain function. It may also help in finding ways to relieve human sleep disorders.
The purpose of the experiments was to fund out how the clock works.
A.Right
B.Wrong
C.Not mentioned
During preschool years the children in the early-education group showed IQ advantages of 10 to 20 points. The highest-risk children showed the【6】gains, and at age 15 they had higher reading and math scores.
What【7】for these gains? Ramey and other scientists say early childhood experiences【8】brain growth.
An infant is born【9】billions of brain cells called neurons. Some are wired to other cells before birth to regulate the【10】of life, such as heartbeat and breathing. Others are waiting to be wired to【11】him or her interpret and respond to the outside world. Experience dictates the hookups. As the child【12】, cells reach out and set up pathways to other cells needed to determine a【13】. For instance, the neurons in the eye send branches to the【14】cortex, which interprets【15】eye sees and, via other branches,【16】the person to react to what is seen. Each time an experience is repeated, the【17】are strengthened.
The first two years of life are an explosion of brain【18】and connections. By age two the【19】has more than 300 trillion connections. At the same time, cells that aren't being connected or used are being【20】.
(1)
A.worked
B.stayed
C.studied
D.talked
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