Statements below show three d+w k osa .rstzcq9; qwsp3+n68ouble-stranded nucleotide sequences. Which of these sequences s+a;szq q.t6k rw9+p cos w83nof 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 l3 mp)u z2eu:xy2nxjb 7mh:i8h ua;y1based 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 data. Subsequent evidence and data revealed a more complex and accurate understanding of the structure, leading to :3 iya:l bp7;yh2u)jzm2 uun81xxehm the falsification of the initial hypothesis.

  What is the main role of the ribosomes labeluq -3ph nx64vmled in the micrograph?

  A strand of nucleotides reads CC+b;x dnn( fryw)d+n.oUAGAGCUUACCG. Which type of pentose sugar could be found in t ;d.)rofn(wby +dnn+ xhe nucleotides in this strand?

  Which of the following processes is most directly involved inezhedci2yd3ijs0 -f1 +y8v7p the formation of nucleic acids such as e y z12e-d si 0i7yv3+pf8hcdjDNA?

  What distinguishes urlex; cz.01.63vos czsk01wj irw hsr.acil from thymine?

  Which statements are characteristics of a DNA moleculek9a.8rep l uxy7ul k9-?
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 gt.gnufrj 8 iu*8c j:9lh9u8asize (number of base pairs, bp) for diffjjgr8*ac un.8tilf8 ghuu99 :erent species.

Which conclusion can be drawn, based on the table?

  How does the genetic code provide evidence of universal cz:bs78 rg93ak* aw xurommon ancestry?

  The diagram depicts nucleosomes.g ahel.mk4l)3kd)l b(

Gel electrophoresis is a(j9 bbl esy60k technique often used to analyse DNA molecules. It includes a gel and an electric field. The diagram below 6bl kjy9bs 0e(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 pe x mh3.afr :df+wk(6dre-mRNA and three mature mRNA transcripts where the introns hakd:fm3rwx df6e .+a( hve been removed.



What is an advantage of the above process?

  Which of the following:vc(nng te 67 m2z1kfu is a similarity between transcription and translation?

  The diagram shows the structure of a DNA fragment. Which bonds easily break b6i 412 o2 abh (waj*ljrfb,uqand reform? i,b6fh b(214aqujw o*2 ajlrb

  What would make one DNA molecule more stable than anj*m(:yt ymb4p other 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 proteiny0cro4tq3zs4dp* :p x,vf8om 4fd8y3qp trm o,4*z v:oxpc s0serves as the genetic material. 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 mat nohle)eapx:zecs5x+ 1d7o2 x7.z .uxched in the table below?

  Which statement highldntozx50wqhmu0/( tw38f7 l v d9g,kmights the importance of nucleosomes in DNA supercoiling ?

  The image shows many ribosomes on a mRNA molecule.thq 72z(r vtohw7q5t .td4lh7 How many unique polypeptide chainh4t7th 7(q5 wt2ovhq.z t7rlds are being translated?

  Which of the labelled structures shows they/v1x w 041vyqqufwhf-5q (b;oj ;jxz correct directionality of the DNA molef5o-h0uyq/w1xzj;vfwyjq 1qv( ;bx4cule?

The diagram below shows the structure(l:gg8xg )g4rpb mj k( 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 werewun (m6*t bugky7)xr + radioactively labelled with either subty w ( g6u7nux*)rm+klfur ($^{35}$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 pyrimidine?w.i 6(d3x qehoscpo9r :5gtt-

  How did radioisotopes help make the investigations by Hershey an s2bc*vddd,l/fijdkm/8 2 u5:;yiaz,(t siced Chase possible2,dk i;u zd cy52m cldivsbd8t ,esj*ai(//: f?

  What feature of the DNA moe (( ;s b)fckoarb;t6s. mhwt0lecule was utilised by Hershey and Chase in order to identify that viral DNA is able to enter hosebthab( ;(;trw6 k0o)scf.mst cells, but most of their protein is not?

.

The image below shows a swjt)2 0,g 9mnfnhr0kwhort 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 compo y6hv njsm7)+wnents of one nucleosome?

  Hershey and Chase con8mohwa 2+ 9, c3kryattducted experiments 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 resp-i)yd /ffue ipx5x25ults of an experiment 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 douid52ff- /uixxy 5e )ppble 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 livztr15 m cbn3:qp v7jg,sqlb )ry74z,5c9we o qing 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 thet1ap0ndt5 cx27o* 2 k+ vfjuyj 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.