Statements below show three double-strand-q v(va u *eh(*i1hxtved nucleotide sequences. Which of these sequences of base pairs is possible in a DNA ae1tvvi -hx (u(vhq**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 structure based on the tetrag4goho2(noc 21lp g-zs/vbq9b m)c4bnucleotide 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 b m9-44l ons oggp b22qv)1bccg/z h(othe structure, leading to the falsification of the initial hypothesis.

  What is the main role of the riboso84l dog**:xerr +pidlfb 0e. umes labelled in the micrograph?

  A strand of nucleotides reads CCUAGAGCUUACCG. Which type of pento: 6:lgd6rrk suse sugar could be found in the nucleotides in this strand6rdr u:k: sl6g?

  Which of the following processes is most diw4s:+ktekf9 f rectly involved in the formation of nucleiekkf9sf4t+: wc acids such as DNA?

  What distinguishes uracil fromtxmj40 si;,kk; le bt. thymine?

  Which statements are characteristics of a DNA0u yuz-0htds k0d( jq3 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 b vp( :n+exb8rmase pairxm:+ 8(v pbners, bp) for different species.

Which conclusion can be drawn, based on the table?

  How does the genetic code provide evidence of universal common ance+, b)hozp iu94kkyz,zstry?

  The diagram depicts nucleop /zf/ t2ndjm ei6qi6-somes.

Gel electrophoresis is a technique often used to analyse DNA molecules. It udmc1g jj haz1),mx. 1includes a gel ang1xu.ahcm,d 1 j m1)jzd 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 wherehm fvk.s-3198xhhqya8qqbxdp a) 9ep8z+,g f the introns 8kmx8bhsq+ f.v)pex8 apy9 z- a3 fhq, 9dqh1ghave been removed.



What is an advantage of the above process?

  Which of the following is a similarity between t 9-w+axy,dlwrranscription and translation?

  The diagram shows the structure of a DNA fragment. Which ;r+oz rct7i 6pbonds easily break and reform? r7ozip t;r+6c

  What would make one DNAquz+0 2r+8 b-dnuchij 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 experij fnn9o0+hbn-ment to investigate whether DNA or protein serves as the genetic material. They cultured 2 batches of virusesho-90+j fnnnb , one in a medium 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 a bol208rt w6d7ektk+ l2nnp*w wedv)3re correctly matched in the table below?

  Which statement highlights the importance of poss/:m e 92atq 67auqnucleosomes in DNA supercoiling ?

  The image shows many ribosomes on a mRNA molecule. How many unique polypeptiderl jh+iqyt;5ee, r740epqhl f0n 8l5m p:dvk( chains are being translatee( 5pn,i5ed:4fl0mh r;8trklehj vl +qp0q 7y d?

  Which of the labelled structures shows the correct directionalitw iwi :+dob tm0bhoym+r9q.91y of the DNA moleculwb+ob+tyd 0oiw1.irh9:9 mq me?

The diagram below shows f d n2 zciml:jz6+klh(9 d;9c(qpygw*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 e o,9liut e(2deejbx.do7iv- ,7 2dxb cultured viruses that were radioactively labelled with j2vxdbo.b7ie9ix, 2 ed, u-(d7o lteeeither 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 ccc0 4. qx q j mfcungypi-h4 b4y7kd/;t8vu42R if S is a pyrimidine?

  How did radioisotopes help make the investia)ps.yh:,p sbgations by Hershey and Chase possibles a,hsy:.)bp p?

  What feature of the DNA molecule was 1ye7.z)kqvq0c u dhu nsky gb0 649jc7utilised by Hershey and Chase in order to identify that viral DNA is able to enter hosgu0j1y 70u6 4hq)qvdk bkc. e9cnys 7zt cells, but most of their protein is not?

.

The image below shows a short fragmen8d /zk bz.d lfp).7myht 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 nucleky kvhnb82zcr7iqv2i *j;c 8,osome?

  Hershey and Chase conducted experiments using the radioactive isotow4gb d8tj bcqe41,v y+pes $^{35}$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 conducted by a team of rb ub+lnpvdq82f:9 ej7esearchers investigating the relationship between the composition and melting point of different DNA samples. At the 92n pb7d8 vql+:feubj 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 e;a+6o**b,qk se ik wiissential 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 thktl(7(16mut 1odjy f0pw:u hqxyt :b0e DNA molecule.


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.