Statements below show three double-stranded nucleotide sequences. Which of theseuo01 s ci n43crrf+6zc sequences of base pcz60riuf 1rcc43 on+s airs is possible in a DNA molecule?

I. 5’- GGA CAG AGC -3’
3’- CCT GTC TCG -5’


II. 5’- GGA CAG AGC -3’
3’- TTC ACT CTA -5’


III. 5’- AGG GAC CGA -3’
3’- TCC CTG GCT -5’

  The diagram below shows the stru-j),tcy jojw l o/vo7.cture based on the tetranucleotide hypothesis proposed by Levene that DNA was made up of equal amounts of adenine, guanine, cy- ocyo/j,)t7 j. jwlovtosine and thymine. This hypothesis was a problem of induction, because it was based on a limited set of data. Subsequent evidence and data revealed a more complex and accurate understanding of the structure, leading to the falsification of the initial hypothesis.

  What is the main role of the ribosomes labelled in the microy ms+.iy0u))qtw pz ).gg+eofgraph?

  A strand of nucleotides reads CCUAGAGidvak 1bu8+u)CUUACCG. Which type of pentose sugar could be found in the nucleotides in this sdk uai+8)bv1 utrand?

  Which of the following processes is most directly.cm4:-aidbwcfju 26 z involved in the formation of nucleic acids such as f2m-dw6bc iazc:4 .juDNA?

  What distinguishes uracil from th xut/0wqiqlu: 4c0e/ iymine?

  Which statements are chcq3rdv1, r 0 c t.8xi4nvt*wbsaracteristics of a DNA molecule?
I. The two strands are identical.
II. The two strands are antiparallel to one another.
III. The sugar-phosphate backbone is held together by covalent bonds.

  The table shows the nucleotide base sequence and genome size (number of base * a;,mrj4 5;mnxmiodl/ t+elvpairs, bp) for different specte,md;4 m+/ x*5in;olv rlmjaies.

Which conclusion can be drawn, based on the table?

  How does the genetic codeo7a5p *782 hl xhntret0jbka 6 provide evidence of universal common ancestry?

  The diagram depicts nucleosomes. 9.ti)x*pq-x7dmrkwc07j zh k

Gel electrophoresis is a technique ofgrgsmka69 ke)qq g,9z hnc71;a lrw/6ten used to analyse DNA molecules. It includes ahm6/agk6ws qlc9;g ag ,e r9q7krnz )1 gel and an electric field. The diagram below shows the outcome of gel electrophoresis.


1.DNA is a type of nucleic acid. State one location where DNA is found in cells.

2.Deduce, with a reason, which direction the DNA fragment moves through the gel.

3.Distinguish between the functions of DNA and RNA in unicellular organisms.

  The diagram below shows pre-mRNA and three mature mRNA transcripts where the i1asbz2aj2u12 man) yhh c9lz)cx zt,-ntrons hazs hl2z j1u,)zy2 bah19axcta2mc-n)ve been removed.



What is an advantage of the above process?

  Which of the following is a similarity between transcrisxcw007 5 e.x)ruhmnvm jw*,i ption and translation?

  The diagram shows the structure of a DNA fragment. Which bonds easily -g sdec/.u:o9rddt g3 break and reformu9.r:/3 ddg- tgce dos?

  What would make one DNA molecule more stable than another DNA molecule0ya4 fi4zp fk)mkl e:*?
I. More G-C base pairs than A-T base pairs
II. More hydrogen bonds between base pairs
III. Greater distance between A-T base pairs than G-C base pairs

  Hershey and Chase conducted an experimenysr2t n1/f p92g5q inqt to investigate whether DNA or protein serves as the genetic material. They cultured 2 batches of viruses, one in a medium containi52npifqtgnq 21/yr s9ng radioactive $^{35}S$ and one in radioactive $^{32}P$. They then introduced each batch of viruses to separate cultures of bacteria. After allowing time for the viruses to infect the bacteria, the culture solutions were centrifuged to separate the viral remains from the bacterial cells, forming two layers, the pellet and the supernatant.


Which component of the tube would provide evidence that DNA is the genetic material?

  Which function and process are correctly ) bops dv*iw,5pv6t q8matched in the table below?

  Which statement highlights the importance of nucleosomes in DNA super5chf jm4b r(obn xw o,w/ebn5995uyl1coiling ?

  The image shows many ribosomes on a mRNA molecule. How many u, * 1v gpodu4m ((gfmf*y1mddpnique polypeptide chains are beingf1*,fom mpd(ydmg p(*d1u 4vg translated?

  Which of the labelled structures shows the correct directionalityirul;; ztg3,of jm6 zb8+i mh5 of the DNA molmt+;86z jb3;g l for5uiih, mzecule?

The diagram below shows the sth2dxp1g (1 d9 0ne(nnrkbeix r;.ajk- ructure of DNA nucleotides.

1.State the component of DNA that is attached at position X.

2.Identify the type of bonding shown as dotted lines in the diagram.

3.The 5’ and 3’ linkages in DNA play an important role in replication, transcription and translation.

3.1.On the diagram, label the 5’ prime and 3’ prime ends on both strands to show the direction of the DNA.

3.2.Outline how the processes of transcription and translation occur with regards to the formation of 5’ and 3’ linkages.

4.Explain how the DNA helix maintains its stability.

5.Erwin Chargaff’s data on the relative amounts of purine and pyrimidine bases played an important role in determining the structure of DNA.

5.1.Outline how Chargaff’s data contributed to our understanding of the structure of DNA.

5.2.State a proposed model of DNA that was falsified by Chargaff's data.

The Hershey-Chase experiment in 1952 involved cultured virus)k4a 09.8h nkls8qc amfmzl-ses that were radioactively labelled with4s.ak l)q-f kzc88a shmnm90 l either sulfur ($^{35}$S) or phosphorus ($^{32}P) in two separate flasks. Each batch of viruses was then added to separate cultures of bacteria. After allowing time for the viruses to infect the bacteria, the culture solutions were centrifuged to separate the viral remains from the bacterial cells, forming two layers, the pellet and the supernatant.


1.State reasons for using radioactive sulfur ($^{35}$S) and phosphorus ($^{32}$P).

2.Suggest one technological development, other than radioisotopes, that helped open up possibilities in understanding the overall structure of DNA.

3.1.Outline the results of the experiment that provided evidence to support the conclusion that DNA is the genetic material.

3.2.Describe how the 4 nitrogenous bases of DNA enables polypeptides to be coded for.

4.Explain how DNA can be packaged into compact units to form chromatin.

  What bases are P, Q, and R if S is a /; c-u8h3p,d(zeui y5hnqe bkpyrimidine?

  How did radioisotopesfb g/gv29 g/hx help make the investigations by Hershey and Chase possible 2h/vf9g/ ggxb?

  What feature of the DNA moleculj0 bzebva 4r)-l*ke f:e was utilised by Hershey and Chase in order to identify that viral DNA is able to enter host cells, but most of their protein is bjf)-4v* l: bk0azreenot?

.

The image below shows a short fragmez7 ku cxkkn4n4d9c5: knt of the DNA molecule.



1.Suggest one possible outcome if DNA consisted of two parallel strands instead of two antiparallel strands.

2.The structure of DNA is described as being a 'double helix'. Explain how this structure is related to the DNA function.

3.Compare and contrast the nitrogenous bases thymine and uracil.

  Which of the following shows the correct components of one nucle q. oh2e 3459f(5gzau mnddjunosome?

  Hershey and Chase conducted experiments using the rano z2xqn-)8e:e;fu r k;*ay itdioactive isotopes $^{35}$S and $^{32}$P which demonstrated that DNA is the genetic material. What would they have observed about the distribution of isotopes in the centrifuged sample if protein, rather than DNA, were the genetic material?

  The graph below shows the results of andoda s.n:l-m6/jkgf 56da)tk experiment conducted by a team of researchers investigating the relationship between the composition/fm jl:skd.5a-6 agn6) kd otd and melting point of different DNA samples. At the melting point, the DNA double helix separates into two individual strands.

Two DNA samples were compared, one consisting of only PQ pairs and another one consisting of only RS pairs. Letters P, Q, R and S represent different nitrogenous bases found in the DNA.


Based on the results presented in the graph, and your knowledge of nucleotide base pairing (between purines and pyrimidines), deduce which nitrogenous bases correspond to the letters P, Q, R and S.

DNA and RNA are nucleig/;o n.5k:fpgm ay+ej c acids that are essential to all living organisms.
1.Draw and label a diagram of a nucleotide.

2.Explain how the variation in base sequences leads to the ability of DNA to have an enormous capacity for storing genetic information.

3.DNA is a polymer of nucleotides. Describe the structure of DNA.

The image below shows a short fragment of the DNA molecule gjs;14+ ymxs akwylz1zj*q -s24kfh5.


1.Suggest one possible problem that could arise if DNA consisted of two parallel strands instead of two antiparallel strands.

2.State one place where DNA is found in cells.

3.Compare and contrast the structure of DNA and RNA.