A biological problem needs to be taught by a high finger, and a biological problem needs to be solve

DNA is more easily degraded than RNA, not because of its large molecular weight, but because DNA is double-stranded, which is held together by two single-stranded hydrogen bonds between bases. RNA is single-stranded, and to degrade RNA, it is necessary to break the phosphodiester bond, which is a covalent bond. Breaking hydrogen bonds is easier than breaking covalent bonds, so DNA is easily degraded.

I don't know exactly how to extract DNA and RNA, but I think that "extracting DNA is easier than extracting RNA because DNA is easily degraded". One of the principles of extraction should be to ensure the integrity of the structure. The picture below is a screenshot of the information of Douding.com.

The vast majority of organisms use DNA as genetic material, and in a cell, the main substance of the nucleus is DNA, so the content of DNA is much larger than RNA, so it is easy to extract. There is not much difference in the molecular weight of the two, the DNA is deoxyribonucleic acid, and the RNA is ribonucleic acid.

It is easier to extract DNA than RNA because DNA is easily degraded" is false, and the correct way to say it is "it is easier to extract DNA than RNA because RNA is easily degraded".

Because the environment is full of various RNA enzymes, it is easy to degrade RNA. In RNA extraction experiments, it is important to ensure that the RNA enzymes are removed from the various reagents and utensils used, and that the reagents are not even exposed to air. If the procedure is not rigorous, RNA degradation products may be obtained.

The distribution of DNA enzymes is not as good as that of RNA enzymes, and the experimental conditions for DNA extraction are much more relaxed.

31 The shuttle vector replicates in both bacteria and yeast, so it contains both bacterial and yeast replication initiation regions.

32 The secondary structure of DNA is usually B, there is no doubt about it.

33 I don't know much about ......Cellular organisms don't look good. The chemokine is supposed to be related to cell signaling. Since AIDS should never be used, it is a good idea to let the cells never be infected.

34 Cancer is a genetic disease, which is caused by alterations in the genetic material of somatic cells and is not passed on to the next generation.

35 It can be selected by elimination, C D is definitely wrong, and A is not good. B makes sense.

36 I don't know ......It's easy to guess ...... though

37 A option of GFP you may not be familiar with, GFP always know it......That's it.

38 a1 1 1 1 1 ratio, normal, not interchangeable, the kind that high school students do. b, the chain is not interchangeable, it is two kinds of gametes. d, interlinked and interchanged, new shapes appeared, and the data used in Morgan's fruit fly experiment was 42:8......

b, as can be seen from the figure, the molecular weight of this protein is slightly greater than 130 when it is complete, and two fragments appear after breaking the disulfide bond, note that two are not two, and the number of each fragment is still uncertain, which is slightly higher than 67 and 30., respectivelyWith only two combinations of 30 and one 67, the total protein will be slightly greater than 130So choose B

From the perspective of molecular weight, this protein is composed of 30kd and 67kd peptide chains (the disulfide bond is broken by adding a reducing agent, + lane), and these two peptide chains must be two 67kd plus a 30kd peptide chain to form a molecule slightly larger than 130kd (-lane), and the answer is c

The molecular weight of the top on the far right is a little blurry, so if it's 110, choose B.

LZ, can you explain that a little bit more?