Statements below show three double-strab1a 6i3x v/z7yj qis;tnded nucleotide sequences. Which of these sequences of base paitq1xva/s7i36;ib zyj rs 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 wo ri8( 0cmf d93zhig(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 dath90wf dg(m(zor8ici 3a. 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 o(51iaokq f1hw *swg3of the ribosomes labelled in the micrograph?

  A strand of nucleotides read/b hfu e;bq c ,iftd5gc+w;8h5q i;5pn m;zo7is CCUAGAGCUUACCG. Which type of pentose sugar could be found c/hequbfoqcd8n+fg5;t i z5im7 5w bh pi;;;, in the nucleotides in this strand?

  Which of the following processes is most directly involvrw (2/ zgf dckh3w9hy9ed in the formation of nucleic acids such a z(/h c3fgwwrd99 hk2ys DNA?

  What distinguishes uracil from tl cvc+5v (+wiig; t:inhymine?

  Which statements are characteristics of a DNA molec5tu; 7-hkz :wham2cyvu*i )wtule?
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 sequencep2p icw77 ss;l and genome size (number of base pairs, bp) for differentps cw;s72i pl7 species.

Which conclusion can be drawn, based on the table?

  How does the genetic code provide evidence of u2r: zrj;37 apss+ vccnishw +;niversal common ancestry?

  The diagram depicts npupk79*z5o,mu czb/wr1s kc ,ucleosomes.

Gel electrophoresis i)2f7l prqlrictjd5 )2 y6nmp z4: yb*it86 edds a technique often used to analyse DNA molecules. It includes a gel and6fb 6njy:l rpl dz ddq272i5r*t4p)ye8ic t)m 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 tr8cb8 1z3d(x4t )5vielaqqd7o ts;yat anscripts where the introns have been removed. b4 xv q7ozidtdy q)3al;8a5s(tc1 e8t



What is an advantage of the above process?

  Which of the following is a similarity between transcriptiob6em, j()jjl z385eqc6iywpz n and translation?

  The diagram shows the structure of a DNA fragment. Which bonds easily brk:ps9p)wj;. ntb fn 1oeak and re) fo9:1bptjn snp ;.kwform?

  What would make one D6 j7sbn8 o6o0ce -sigkz ke,d8NA 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 investigate whether DNA or p f r..b84rlhxis eaz v(vg2n+y5.+ uelrotein serves as the genetic material. They cuhl5r4 8nzs er.v.uix+2abf. (v ylg+eltured 2 batches of viruses, 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 are correctly matched intieu9)) vwbl ( the table below?

  Which statement highlights the importance of nucleosomes in DNA supercoilixnuh9s36i 5wb3 ut z2png ?

  The image shows many ribosomes on a mRNA molecule. How many unique polypeptide o;f6jps9d8 buc 9b d8;sfjpo6uhains are being translated?

  Which of the labelled structures shows the correct directionality of the DNA mo pqym7pll42 t6lecuyl6t 7p24pql mle?

The diagram below shows the structuroqm8 7* zdt-fi 4pg+dqe 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 experimentvnpe-j5mu0se*1 k g,p in 1952 involved cultured viruses that were radioactivel-05sjnue* v1pk,pm eg y labelled with 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 i..: fw, q+il vwg 7+ x gp:hprpr6y8wxtru+n)uf S is a pyrimidine?

  How did radioisotopes help make the investigations by Hersw+mpe t,s2g(zhey and Chase possiblem2g,p sze+(wt?

  What feature of the DNA molecule was uaeac 8jvjc 1:l0gcb87tilised by Hershey and Chase in order to identify that viral DNA is able to entg av18al cb0ec7j c8:jer host cells, but most of their protein is not?

.

The image below shows ac0 hlp ;dnb2f4o5q s.p0hc1-bfua3or9 ai ,q r short fragment 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 nucleo5/k m( e k1cq67yzuwsjsome?

  Hershey and Chase conducted experiments using the radik-ear +k;t u ho4i9dp7sm 0vb6;ei ys6oactive 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 conducted 4oxk u0 yc/t;b27g -ifwifdw9by a team of researchers investigat fko/dw7c;igtyu0i -9w4bx 2fing the relationship between the composition 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 nucleic acids that l86:sjnhll:f5ka : ceare 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 molecule0t-qf :d, wrwo b/qv1kbk1w g).


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.