Statements below show three double-stranded nucleotide sequences. Which;g5;lm8barvsicz4 3- njrg .mhad :j* of these sequences of base pairs is g.cr v-g*i h8a;abm lzrsjj4nd;m 3:5 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 structure ba*b,h0jdc ley r,(rdhyz:9 bl *sed on the tetranucleotide hypothesis proposed by Levene that DNA was made up of equal amounts of adenine, guanine, cytosine and thymine. This hypothesi(c ,jr*erdld* h0 9bzlhby,y:s 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 tinh s7 )c5t1nbhe ribosomes labelled in the micrograph?

  A strand of nucleotides reax.(/:kc 4wbu)+p2; pnhj rmiljd d5 yfds CCUAGAGCUUACCG. Which type of pentose sugar could be found in the nucleotides rnfkudd/(p jibw.);y+25 j phxlcm4: in this strand?

  Which of the following processes is most directly involved in the foyxk vl((f *zo 7 gmbjbe(ti +1v+bkw;2-imh0trmation of nucleic acids such as vml2 *-+h(i ox y m1efg;jvz7w0ittbkkb(+(bDNA?

  What distinguishes uq 0yd2 azfo+;jx,n6 dqracil from thymine?

  Which statements are charab ,37vr.z q4t3zk-h quk5ip rr-ebz6mcteristics 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 t 8 -wmtc16i7yi r+fjxtypecvl 9)8zv3 ef5)csequence and genome size (number of base pairs, bp) for different species)vj ex6- pciz5+lf71w8vt)icyt 3mt c 8re9yf.

Which conclusion can be drawn, based on the table?

  How does the genetic code provide evidence of univers py0j/vcvsj s xqk)hxl p,1*tkm9dw 6z7+g-l3al common ancestry?

  The diagram depicts nucleosomes.d8.mrtm ve-*zba ve23p4 uug3

Gel electrophoresis is a technique often used t;y3r g:yoj)gbqy o9 e9o analyse DNA molecules. It includes a gel and an electric field. The diagram below shows the outcome of gel electrophoresis)oyey9; 3o:r bq9 gygj.


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 ti hl,/y xhse9od7 :vu6hree mature mRNA transcripts where the introns 6udeox,is :9/v lyh7hhave been removed.



What is an advantage of the above process?

  Which of the following is a similarity between transcription waj vob;j(r24and translation?

  The diagram shows the structure of a DNA fragment. Which bonds eas okmc )ucrq1:vui6:u7ta8 /ubily break and reku)rb/ t o6 ucqu:1mcua:7i8vform?

  What would make one DNA mo(x/ xtpv z59olnq 54kblecule 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 wheth*xe *r(yox/xcer DNA or protein serves as the genetic material. They cultured 2 bat/ e*ox (xyxcr*ches 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 in the tj1 9w*st4ko,.yxtuav0 pzh z 1able below?

  Which statement highlights the d*miyc,d s/s 9importance of nucleosomes in DNA supercoiling ?

  The image shows many 8p13:)r loc pz bd4zvhribosomes on a mRNA molecule. How many unique polypeptide chains are being trd4l 1vrb) cz:poz3 8phanslated?

  Which of the labelled structures shows the corrn88+wf-ry8s tcynu ygz 5,je1ect directionality of the DNA moleculer+85 ycy18sn zyg-f8uen,j tw?

The diagram below showsx3 ( rsu(yt*ej) gqp7b 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 expekwq2 mmnij9sjr f i/45q3(a2criment in 1952 involved cultured viruses that were radioactively labelled with either sulf9 krs5ajq ic /( qj3w2imm4n2fur ($^{35}$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 *(9 dhb+ u y1g uvz-y7. lm4db1palwtvpyrimidine?

  How did radioisotopes help make the investigatit,/cer qmnj 3kg0c w6,ons by Hershey and Chase possible?tmr,6c nj3 0eg,cq/wk

  What feature of the DNA molecule was util)1+)si3:d ybmz mw zi)r(no csised by Hershey and Chase in order to identify that viral DNA is able to enter host cells, but most of t 3mi)z(rson1wymcz+:bd )s) iheir protein is not?

.

The image below shows a short fragment of the DNAs k- lr+r 4:dzbe7q+zjc8c9hx 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 nucleox1 h;m4ym yyskp;:*27 z rl54h z zlyp+2wlpsasome?

  Hershey and Chase conducted experiments using the radioapddmp74 hj6ocm7 s3 s1ctive 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 by4w rse +xye*9q a team of researchers investigating the relationship between thewe *ey94qsx +r 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 aci w n,yd q.4 kp3anvgy,n0x/(vn woc-qc1qi18ids 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 4 p3vhmlm9 w,y doqj.56o.rpufragment of the 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.