Statements below show three double-stranded nuc g/co j.jp87nuaag(w*leotide sequences. Which of these sequences opoa nj ac.*8uj7(g /gwf 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 hypothesiz(yegowc1 - - ;la) zyij8je4is proposed by Levene thl1o e-y wzc)y8iz-(e jiag;j 4at 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 ribo xaw 6*s c4f-8e,qmyvvuukuz y: b05j9somes labelled in the micrograph?

  A strand of nucleotides reads CCUAGAGCUUA: qxz -h5dj+ i72nwedhCCG. Which type of pentose sugar could be found in the nucleotides in this str +2 dnh z7jdq5e:-wxihand?

  Which of the following processes is most directly in33kic lz eyp+ezvi/4 o7bs9d,volved in the formation of nucleic acids such as DNAd4+oezs9ik c eb,ip/3zv7yl 3?

  What distinguishes urac1 lr ;b/2rnqm qn7wq:*n3wpn ril from thymine?

  Which statements are characterist*mq4m2 8yrx) gq2kxh jics 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 .k bcl)fwc4c+sequence and genome size (number of base pairs, bp) for different speci.w4f)c ck bcl+es.

Which conclusion can be drawn, based on the table?

  How does the genetic code provide evidence of6 + r5s, ubv2simnw/ns z*wbg; universal common ancestry?

  The diagram depicts nucleosomep .0fvc2spvso m2d 5-js.

Gel electrophoresis is a technique 04- dd7xosibp often used to analyse DNA molecules. It includes a gel and an electric field. The diagram below shows the outcome of gel elesd0dxiop4b -7 ctrophoresis.


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 three mawh.xxv *u we/a:af8me34t4il ture mRNA transcripts where the intron hx4lwwa4*3 i/. mefv:a8exuts have been removed.



What is an advantage of the above process?

  Which of the following is a similarity between transcription odr bjmq wy lo/g7/vsz64.50n/4y bfzand translation?

  The diagram shows the structure of a DNA fragment. Which bonds easily break and,8me+ooz try7-umwr0 rez,-w r8eym0+m ot7oru form?

  What would make one DNA molecule more i3k+p *c ci)8 h/gjtikstable 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 conductedl. xz oqsb ,hsak ,v120wr0vc1 an experiment to investigate whether DNA or protein serves as the genetic material. They cultured 2 batches of viruses, one in a medium containing x.,qsvvz2wsok 0 110hralcb,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 cor c6se +ivsx1si c0.nm1rectly matched in the table below?

  Which statement highlights the importance of nucleosomes in DNA supercon uk*2fz2h9x hiling ?

  The image shows many ribosomes on a mRNA8n)7m a g monf0,b,dlc molecule. How many unique polypeptide chains are being )a 0no,l 7mcmbgn8d,ftranslated?

  Which of the labelled struct / 6hqye13ynmdures shows the correct directionality of the DNA mole6d3y/ yhqm en1cule?

The diagram below shows the structure ok iu( 8lsw8(jjf 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 involve se-aa/)f 9qp.g-ovbq d cultured viruses that were radioacg o)qfqs/be.9p - av-atively labelled 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 pyrimidinfx :tlmf.qveof(:a i)l1ur/l6 h( o k*e?

  How did radioisotopes help make the iny*v3d( ( y +74fwi3vixwapg zqvestigations by Hershey and Chase possible?wv4d(pa v* fxy(7iygziq 33 w+

  What feature of the DNA molecule was utilised by Hershey f)1f ),lvbj pz5i nkb6and Chase in order to identify that viral DNA is able to enter host 5)1 jf z6blbpk,f)vnicells, but most of their protein is not?

.

The image below shows a . xx8d60;ux0 tngxyppshort 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 components of one nucleos:t9nqav4:c zw6jf. qoome?

  Hershey and Chase conducte8z+i yx1y:/;cb sueqfd 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 results of an experiment conducted by a teamp f2qn *i(p3:.3ox sur9nlnq q of researchers i3npq 3xqnoln( 9q fs.p: ur*i2nvestigating 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 are essential to all livintz) (lv 5t 1m3u5,p9tvcwpu jno:4ewlg 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. y/zfj :,zu7ktt -r8ohd mc)9 f


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.