Statements below show three double-stranded nucleotide sequencq0z1 n;indv+gex 9h* tes. Which of these s9v0zn1ide tx * ;hqn+gequences 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 the structure based on the tetranucleotide hypoau, +8 cuhf8a6o wu.xk zp5ii2thesis 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 dati c68+2k 5 h8o,zafwupauu.ixa 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 hrk wgjp81,(da:nk7vvl 5 l8ksomes labelled in the micrograph?

  A strand of nucleotides reads CCUAGAGCUUACCG. Which type of pe669y )s j(3d tjuyokdeke:6kmntose sugar could be found in the nucleoeou3 kk6 :y6)tj(s jde6y d9mktides in this strand?

  Which of the following processes is moslixnd e+c0l6qy): z;xt directly involved in the formation of nucleiy0ilne6x:xqcl )z+; dc acids such as DNA?

  What distinguishes uracil from2 -tmue4nh kp) thymine?

  Which statements are cjdx ev0)rs.h-h*o;h o haracteristics 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 sequence and genome size (o (lio*cq9s90pku q-wnumber of base pairs, bp) for differeci(l- 09q9uk *os oqpwnt species.

Which conclusion can be drawn, based on the table?

  How does the genetic code provide evidencpvd 92)z wdj(me of universal common ancestry?

  The diagram depicts nuc wejuf 8uini:6u+ 3mv6leosomes.

Gel electrophoresis is a technique often usez jjud)t7 c,o am13y6rzwi-(n d to analyse DNA molecules. It includes a gel and an electric field. The diagram below shows tra iy-untmw1z 7oz j)jcd63,(he 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-mRNA and three mature mRNA transcripts whe0hx ajr(n,0s*rbtom0s t x(x-re the introns have bee btha xr t*x((0s sx-0,rjnm0on removed.



What is an advantage of the above process?

  Which of the following is a similarity between transcrhda i(vp28:d:zy, px,6pwegy iption and translation?

  The diagram shows th sp3 poki/g+eph) 5s4je structure of a DNA fragment. Which bonds easily break and spjgs/e3i5h p+)p4o kreform?

  What would make one DNA molecule ja7*ssbox)5 e 2 gwg.e 5ylv9lmore stable 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 co y2i5 pqq+zxm i(7nsh+nducted an experiment to investigate whether DNA or protein serves as the genetic material. They cultured 2 batches of viruses, one in a mediu psmq(i+yqhxi+n5z27 m 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 je ;nys++z2tbep7t.+ rp(j my in the table below?

  Which statement highlights the importance of nucleosomes in D:hjjl*n7 (cwqqt1e7 hNA supercoiling ?

  The image shows many ribosomes on a mRNA moleculeg w.-6-ws rqupri2p2c . How many unique polypeptide chains ares2u.p-2rwqg 6pw ir-c being translated?

  Which of the labelled structures shows the corrqn: 2pgrygh+ og1d th05z8,hfect directionality of the DNA molecuz fh y1q 8p:gh+h2 ggn05trd,ole?

The diagram below shows the structure ofg,- di:/xx(h6i vnmn6scqy w) 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 yev)e9r*va jsjf: .i92eak1dinvolved cultured viruses that were radioactively labelled with eithervy9)9:2 r1s a.fe daev*eijj k 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, anct-24j+nwl: fj wtpj chu:q;*d R if S is a pyrimidine?

  How did radioisotopehy:*-ig1i ls/;s iv qss help make the investigations by Hershey and Chase possible?siy-hsv1qi:g;si l/*

  What feature of the DNA molecule was utilised by Hers6s))t u5,gk mqq7temp hey and Chase in order to identify that viral DNA is ame6gqm5t u, st)7kqp )ble to enter host cells, but most of their protein is not?

.

The image below shows a0/gr3 c4xzc:d cfix*4a4zlsl 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 following shows the correct com u*0 dt4 ftwn3dq.yzb*ponents of one nucleosome?

  Hershey and Chase conducted experiments using the radioact8+kbytf+m3cd ive 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 experimeny/9.7lgvf:-wcsyx cy- skq:t t conducted by a team of researchers investigating the relationship between the composition and melting point of different DNA samples. At the melting point:-y:gsyvl/sc q7t.yc-9x f kw, 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 esjcd ug bs1n-e 83bfr,5sential 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 they :d 1ohteif+iwe:gl/n( c4jf:s; 0nl8 0 pyrk 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.