基因组学复习题终极版

1.From your understand, what are the main challenges in genomics that we will confront with in the

future?

1.1 To characterize the structures and functions of human genome

1.2 Better understanding the knowledge of heritable genetic variations in human genome

1.3 Apply new knowledge of gene and metabolic pathway to develop new effecive methods for human disease treatment

1.4 To explain the mechanism of evolution and variation among different species

1.5 To clone and characterize the key functional genes in crop

1.6 Using genomics tools to increase the crop yield and resolve the food crisis in the world

2.What are the advantages of DNA as the genetic material？

2.1. DNA contains a large amount of information.

2.2. Complementary base pairs ensure accurate replication.

2.3. High stability in water

3.How dose DNA function advantage over RNA?

Both can serve as genetic material; many viruses use RNA as their genetic material. DNA probably evolved as the genetic material for cells so that RNA could be used as messenger

RNA which carries the information for protein synthesis to the ribosomes. The mRNA is metabolically unstable because it is rapidly broken down by RNAse. DNA must be stable so

RNA had to evolve to fulfill this function.

Both DNA and RNA have the same coding capacity. They both are polymers with similar potential length. DNA that commonly exists in all living organisms but is not really common with RNA. Some viruses are exceptional because they exist with a single strand of DNA or with a double strand of RNA.

The most important by far is that DNA is typically double stranded. This has a number of advantages, the most immediate being when one strand breaks the entire molecule does not fall apart

if an error is made in one strand on one base the other strand is still there in its original order to help maintain the original sequence on the opposite strand when a correction enzyme comes along to clip out the mismatch

4.Short descriptions the two important experiments which proved that genes are made of DNA

(a)Inject mouse with harmless bacteria, the mouse survive.

Inject mouse with harmless bacteria plus transforming principle, the mouse dies, and extract virulent bacteria from mouse

Inject mouse with harmless bacteria plus transforming principle and treated with protease ribonuclease, the mouse dies, and extract virulent bacteria from mouse

Inject mouse with harmless bacteria plus transforming principle and treated with protease deoxyribonuclease, the mouse survives, and can not extract virulent bacteria from mouse

(b) 35S is only in DNA, 32P is only in protein. Make 35S and 32P marked phage attached to the bacteria, the phage was marked

with 32P and 35S, after the phage detached,centrifuge,we can find 32P in the bottom pellet of bacteria,and 35S in the top phage protein capsid.