Statements below show three double-strande6gqn* aga/ dyt 3-;lc1 lw4ufkd nucleotide sequences. Which of thesea1qwd6*-cl gyg /f3l ka4;t nu sequences of 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 g inm +,h.uc(zr z6+.o,zj osfthe 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 data. Subsequent evidez+fno . z z,,giu.ro6hj+scm (nce 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 laz554;jtb+cf rjnf rd ;belled in the micrograph?

  A strand of nucleotides reads CCUAGAGCUUACCG. Which type of pentose sugar coul y2 i*+o1vtdg kqx7dy+d be found i+y* 2+y1x dovdikgtq 7n the nucleotides in this strand?

  Which of the following processes is most qy+wr 62 4 rz us;,a3b yz49p3rowmt3sy d8pjtdirectly involved in the formation of nucleic acirouy9z ,p8r6+ p mzdwqwyts3;r3aj32 sb44 tyds such as DNA?

  What distinguishes uracil fp7;72n5kfbbkkregg3 y,bv xz7v(pc1 rom thymine?

  Which statements are characteristics of a DNA molecule?qo6* *d/4j g0ue 2 mbl6bbyvoe
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 ac 6 1n eg0.7ew nlhj/car7hy+;gvt*gand genome size (number of base pairs, bp) for different sp* 06gh/r.j; wennyg1cct lh7a7 e+ agvecies.

Which conclusion can be drawn, based on the table?

  How does the genetic code provide evidence of unive- bjcx:et 6/h0lhc. dyrsal common ancestry?

  The diagram depicts nucleoso -mj+)25 uah+av lyzwg/ipkx:mes.

Gel electrophoresis is a technique often used to analysfq zs)er;psz qp.r +-4 mds)e9e DNA molecules. It includes a gel and an electric field. Ths+)z4pesqe ;- .9 s)rq mfzpdre 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-/(+ :r5djp xatr 2e rqgn+.uewmRNA and three mature mRNA transcripts where the introns havrd5(ejnp.agwq/:t rxe2u r+ +e been removed.



What is an advantage of the above process?

  Which of the following is a similarity between transcrip i*;q ;s)w y8 jbsusjy-kx2o1btion and translation?

  The diagram shows the structure of a DNA fragmeiv)..lgkju 2ont. Which bonds easily break and reform?k.oi)lvju.g 2

  What would make one DNA molecule more stable than another DNA molecule17kmd:+ y1*y yv9gmkt tuiiamz,/ 4b e?
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 rjvtty,m9o;:he3vfu6 -9gip whether DNA or protein serves as the genetic materhj 3 -9ft :pvuoyt,6vi emrg9;ial. 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 tai-wa6+rwps )ptvnkf .d/a7q8ble below?

  Which statement highlights the importance of nucmqruh0 mj5cs 92t(r3 qleosomes in DNA supercoiling ?

  The image shows many ribosomes on a mRNA molecule. How many unique po,pau 35v3thywlypeptide chains are being translated?3,aw3 yhpv ut5

  Which of the labelled structures ypl ;4*5 fihdashows the correct directionality of the DNA mollf4dpi*; hay5ecule?

The diagram below shows the structure of DNA nucleotides. c6)k -fgwe 6 3lzi qxrzs98uv2mrw(3 y,go*q d

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 virusevq59wpub8a p 7s that were radioactively labelled w8au5 7pqwvpb 9ith 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 ufsz1/w s8zv5 pyrimidine?

  How did radioisotopeq7dslv2bs+8g s help make the investigations by Hershey and Chase possible?8+gssvl q2d7b

  What feature of the DNA molecule 2a;p4kucsliqo 1ws-7was utilised by Hershey and Chase in order to identify that viral DNA is able to ente2qlwko4 ucas7i;p1 -s r host cells, but most of their protein is not?

.

The image below shows (wfgbj4q f0kq:u6 n4z a 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 following6ergq. wz5/lg shows the correct components of one nucleosome?

  Hershey and Chase conducted experiments using the radioactive isotopesz 6 0f1mts2t lz;rkge2 t6dn3z $^{35}$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 exp6r hwu3c/uyiy)ll 67qi.is:zb xr g ,,eriment conducted by a team of researcz il uili6sbcygq/ ,3rwr67h y)x,u:.hers investigating 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 4drqc)r5f v a oh1uol*8ih3h6 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 fragment of the DNA molecule. ) /l ol0c p6g)qcjbo-kd zl4u7


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.