Statements below show three dod44huv7ou b 7c8bp3itot;gk( uble-stranded nucleotide sequences. Which of these sequences ofk;t4utoh83cv7g b 7 (4 pdibuo base pairs 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 structure based on the tetranucleotide hypot,7 nk0op) l68norqo0q iv*w rehesis proposed by Levp)o8vw00lerq,k oiq orn6 n7*ene 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, leading to the falsification of the initial hypothesis.

  What is the main role of the ribosomes labelgzwjah 4*g ::i.i*tgga fn);g x*kvm8led in the micrograph?

  A strand of nucleotides reads CCUAh 3;tg084qa5ru zxbrv GAGCUUACCG. Which type of pentose sugar could be found in the nucleotides8r r50u;tzx4v3hqa gb in this strand?

  Which of the following processespgd mhw00wt2 ): ppq,y is most directly involved in the formation of nuc,0dg pytw:2qhm0p w)pleic acids such as DNA?

  What distinguishes u:s x9lq8bg u3h1- x4hht9bvbvracil from thymine?

  Which statements are characteristics of a DNA moc+hqq 9o* pn.7uyz1ij lecule?
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-fg c c5*md*lsase pairsfcsg dl*5-cm *, bp) for different species.

Which conclusion can be drawn, based on the table?

  How does the genetic code prov2fygx+ej0n;* c us0q xide evidence of universal common ancestry?

  The diagram depicts nuc wz75spch(+k 7zk-i anleosomes.

Gel electrophoresis is a technique often used to analyse DNA moleculesz4ge +pb2y 79rg9 g9 jlqm,gxv. It includes a gel and an electric field. The diagram below shows the outcome9gbx peq9g+9 gy2 r7mgljv4,z 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 jkj9m so . j/e:zlh-0cand three mature mRNA transcripts where the introns have been remojh0zc-9 k.mes/joj :lved.



What is an advantage of the above process?

  Which of the following is a similarity between transcription anh, ve+jh:jo (idh. xk1d translation?

  The diagram shows the structure of a DNA fragment. Which bonds easily wdomw +c-gi50a . o6lnbreak and reformg5ia 6+wo w.0cl odn-m?

  What would make one DNA molecule more stable than anotherta j8cujakg:(ulnj00qe;v)p 8x1 e, k 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 conductg km4kp/w .5n7w*4p1lgscx oded an experiment to investigate whether DNA or protein serves as the genetic materiad4gm1lp 4 5kk7wnsxcpg/o.* wl. They cultured 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 in the tabxah ud- gj.t9,le below?

  Which statement highlights the impo0 f if18o3jlhgrtance of nucleosomes in DNA supercoiling ?

  The image shows many riboeg0 h3wqh s7(lsomes on a mRNA molecule. How many unique polypeptide chains are being translated?0 lshg3qhw (e7

  Which of the labelled structures shows the jc4,;, xaq, ,jev kh+c .x,efki+4;lgbmtckfcorrect directionality of the DNA mol,,;4,, k c+jbml k;ax jf,.qxvtcgefk c4+hi eecule?

The diagram below shows tg -lr q m:4+0w)ywxqbzhe 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 viruses that we 08h;fzkc /7th brb7,qhnz 3bnre radioactively labelledbczn /,8zh 7 70rtb;f3hkbqhn 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 if S is ai ,6n;b-fwlcrcrajs) 8*j8 z t pyrimidine?

  How did radioisotopes help make the inve1hsrav0 m (:zustigations by Hershey and Chase possibleu :m01 s(hrvza?

  What feature of the DNA molecule was utck t)k+o92 els -8ku;d rra-zeilised by Hershey and Chase in order to identify that viral DNA is able to enter host cells, but most of their protein is 9d82ra;k rce e)--okk+z sutl not?

.

The image below shows a short fragmen 0pv8+gr) iusffw) c/dt 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 componentsp vm,fct;orvkph +35+ of one nucleosome?

  Hershey and Chase conducted experiments using the radioactive isotj2 luwccx1.c(+t s3+py vcl-;dlgjq9opes $^{35}$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 expof8.)a -.yjdd nr ex)ieriment conducted by a team of researchers investigating the relationship between the composition and melting point of different DNA samples. At the melting point, the DNA double helix sepdf)y .dn ).ia rjeox-8arates 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 to alj 0 zzz3.ia+ifj8a2 g54cnyawl 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 y4kd ,sx7i1-c;4p zdyjfo5u ma short fragment 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.