Statements below show three double-stranded nucleotide sequences. Which of thb(z :r 11gwyew0v1tcfese sequences of bae 11:zvtwc w0r (fyb1gse 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 h qh mtkp0l*g5+sj 9pe.ypothesis 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 andl p.tj*0pq5 k+e9hgm s accurate understanding of the structure, leading to the falsification of the initial hypothesis.

  What is the main role of the ribos/du0 sm;jhj-/,n xm 4f r z;v.gojd-yiomes labelled in the micrograph?

  A strand of nucleotides reads CCUAGAGCUUACCG. Which ty-f txb:puv63d3yyx h,pe of pentose sugar could be found in the nuclehyu:3xyd3tx p bv-6,fotides in this strand?

  Which of the following processes is 1-qpk yd e369fa4vzj,d jthj1most directly involved in the formation of nucleic acid4ytj9h1p v3jdz1 kf q 6-je,das such as DNA?

  What distinguishes uracil fromqjb 5d)nro8t- thymine?

  Which statements are characteristics of a DNA mole* w2rn0yk9y 2n( xcynxcule?
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 base uap*78kyomg90 .kt k3kpait1 pairs, bp) for differa* u k8.ap1kyit0gt km9p 73koent species.

Which conclusion can be drawn, based on the table?

  How does the genetic code provide evidence of univerau;2)koyqg5 ksal common ancestry?

  The diagram depicts nucleoso7eg3brj )3cl hmes.

Gel electrophoresis is a techniqud)8assg( c6;s dhwti )e often used to analyse DNA molecules. It includes a gel and an electric field. The diagram below shows the outcome ofh is8gdwd;6a ( c)s)ts 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 pr p8 t(lo8t+nk)ytx-pn e-mRNA and three mature mRNA transcripts where the introns have been renp)n+tk tt yo 8-p(l8xmoved.



What is an advantage of the above process?

  Which of the following is a similarity betwet:om;irq:d4f en transcription and translation?

  The diagram shows the structure of a DNA fragment. Which bonds easily breakh1 0y ,f0:8betih,n5dsrpjqf and reform :h ytpqsjn,, ide8 0fh0fr1b5?

  What would make one DNA molecule more stable than another DNA molecu w) 5+fyeadcbso,5u4hf r8 a/ale?
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 (urgq//bnv 8g protein serves as the genetic materib uv/qng 8r(g/al. 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 ias).ys9 vkzgh7fp.ej8 dc-t 5n the table below?

  Which statement highlights the importance wm9n4 n ztv s/vold;b.(;4gz jof nucleosomes in DNA supercoiling ?

  The image shows many ribosomes on a mRNA molecule. How many unique polypeptide9 *c2nkmdan ak w7*-he chains aa2h * k*ca7kmnend-9wre being translated?

  Which of the labelled structures shows the correct directionality opzgz u dbch:k +s.h+d1lt:t3,f the DNA moleculeh1:td+ +.z plz, hudbs3k:cg t?

The diagram below shows the structure of DNA:s3i ,qnjao b( 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 n gu(9,vxko p5that were radioactively label o,5pv gukxn(9led 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 a pyri-yhkso: dewqgy. q 9:0midine?

  How did radioisotopes help make2iceq 4v7m3v68tb mrf b u/hk3 the investigations by Hershey and Chase possible? 3hrmkbivq32b8m4/vf6ce ut 7

  What feature of the DNA molecule was utilised by Hershey and Chase in orj o+ l3aw1or0rder to i 0jo o+3a1rwrldentify that viral DNA is able to enter host cells, but most of their protein is not?

.

The image below shows a short fragment of the DNA zasdpb p w)6uhr vm9)t,y3u-5c u-o o*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 k-e/dy.fx7v myr6 -1ds2rw ll of one nucleosome?

  Hershey and Chase conducted e:gqx2d nhs7s: (3xlu jxperiments 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 conducted by a team of rjihj+ u5 9a:czesearchers investigating the relationship between the composition and melting + cjuji:5z9a hpoint 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 are essential to all living organisms.k ew3fgidm2 map2/g *1u po7r.
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 +g d(lt9b)zq+.lgvxqw1+on+ e6qnrr 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.