Statements below show three double-sahok0cqc8xi8jg/53*n.rv.k ue slr6 n 5fq6ytranded nucleotide sequences. Which of these sequences of base pairs is possible in a DNA molec5krklx/e .q0nncu*y.gc s3 qj 5v 8o6ar68fhiule?

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 showubn bp0 ux34:bs the structure based on the tetranucleotide hypothesis proposed by Levene that DNA was made up of equal amounts of adenine, guanine, cytosine 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, leabp0 b :uun4xb3ding to the falsification of the initial hypothesis.

  What is the main role of the ribosomes labelled in the 7wczcz/ l(xo/fof7; b1) 4 k fkaczzz+micrograph?

  A strand of nucleotides reads CCUAGAGCUUACCG. Which typels-6srg. rv z7 of pentose sugar could be found in the nucleotides in this stranr.-6 v 7zlgssrd?

  Which of the followi8/cc 7h kzf pq/ya6i 4q8rla8wng processes is most directly involved in the formation of nucleic 88 kwzqh 7rcay 8a6pcl fq/i4/acids such as DNA?

  What distinguishes uracilj65lpqqvu*0izo+q wd,nysuq8 el7 -/ from thymine?

  Which statements are characteri e k)ejo.gr/,,xn m,jxstics 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 (numbt,qpq ,5d0bxuojrodh /6b v *0er of base pairs, bp) for different 56 ,d dbjxh,*qq/ bpo0ov0tur species.

Which conclusion can be drawn, based on the table?

  How does the genetic cod/mq).h4 7 v ivxfkv083vqzq g3m m7jf i)riw:ee provide evidence of universal common ancestry?

  The diagram depicts nuc *-lvfx ;+ml ic:2prl9nxcw0o leosomes.

Gel electrophoresis is a technique often used to analyse DNA molecules. It iz i dyj-jqdo.6bxnh34uzhh(6 5y /e7 fncludes a gel anfdhy h.xzubnoih7-zj6e/d3y6 4( jq5d 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 transcriptstdd)v6i 8up* l where the introns hul8v )d*6p ditave been removed.



What is an advantage of the above process?

  Which of the following is a similarity between trans- u31(zww)g1rm)y 5j svok r 7gq9qfwzcription and translation?

  The diagram shows the structure of a DNA fragment. Which bonds k, woappw23b4gyf 1f(easily break and refor ff4w(,o ka2p wp13gbym?

  What would make one f.ypxzmfny 9 b0jg,h)9ku 6z, ey 0r-vDNA molecule more stable than another DNA molecule?
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 experiment to investi/7xyl2wa8 jrvgate whether DNA or protein serves as the genetic material. They cultured 2 batches of viruses, one in a mej/ax yv27w 8rldium containing 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 mt z9, m.c :kx rolmoci5.ba-m8atched in the table below?

  Which statement highlights the importance of nucleosomes in DNA si1js.d+yuq:n upercoiling ?

  The image shows many ribosomes on a mRNA molecule. How many unique ps1 x:z3jbklno m6t12 kolypeptide chains are being translated n6kbjol131:2xks z tm?

  Which of the labelled structures shows the correct d;t fr6b;8+ ewgr*nr :huw+mjcirectionality of the DNA molecug *+r8bm ; jwf e:r+wurc;t6hnle?

The diagram below shot8 * qbvqy;c6kws the structure 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 viruse 6tt:mh(:)b0s woqldys that were radioactively labelled with either dh: )6(wql:s0oby tmtsulfur ($^{35}$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 pyrimidiny*c ,z6c2usvne?

  How did radioisotopes help make the investigations by Hershey e.6+lqidke. cl,ojt- and Chase possible+.iq e- l.jdl6ekto ,c?

  What feature of the DNA molecule was utilised by Hershey and Chase in ordu/la0qw(7t q dh(kqwu9h3wq1 er to identify that viralk 0wuwl qw7ht/a(1 q(qhq 93ud DNA is able to enter host cells, but most of their protein is not?

.

The image below shows a short fra4wo*9w5fo /c u6acztagment 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 c xy ony wav9*rj*-6k3somponents of one nucleosome?

  Hershey and Chase conducted ex0b*ireyi8:0 15v4l0oa l oh otsijh*qperiments using the radioactive 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 an experiment conducem7(42gia bpa8 0*jb kjn:vam ted by a team of researchers investigating the relationship between the composition and melting point of differeb ejka (n:j0i2*vp4b gaam87mnt 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 nucleic acids that are essential ig u04l/u8krp 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 molec;b30+gjf+ t3x; 9wp uw;og;bfex tw7o vxy6d gule.


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.