Statements below show three double-stranded nucleotide sequences. W hl jt9:3xc3fuhich of these sequences of base pairs is possiblf3u9c: hxl 3jte 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 bjr ,e1qui:w1s-w lz 6fased 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- lw6reis1wf j: zq,1u, 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 ribosomes labelled in th; yy cyazic(/ nvi/)ts+t*qg 3e micrograph?

  A strand of nucleotides reads CCUAGAGCUUACCG. Which type obrq3e3 nu(.* aojiu8 hf pentose sugar could be found in the nucleotides i oie3*q h.jub3un(r8an this strand?

  Which of the followingv6 o.j.i8sls4su 1 ,fiz yo4wv processes is most directly involved in the formation of nucleic acids sucoj.lv8v4ws4f1, si6y i uo.zsh as DNA?

  What distinguishes uracil from thymine kob)u.xj 3f3kzf (w6v?

  Which statements are characteri 3:y/g-usrsro stics 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 (number o(.2 cng*zp7ttn i y;bzf base pairs, bp) for n. *tn ycg(i7btz2pz; different species.

Which conclusion can be drawn, based on the table?

  How does the genetic code provide evidence of universal common )0 :xsc g0xu6hm s.aqbancestry?

  The diagram depicts nucle uz iq5:y3 jb5lrg cc8:u+e/hjosomes.

Gel electrophoresis is a technique often used to anqz 4f2 nnn khoa8m69ez.ze o-7ve0z6 valyse DNA molecules. It includes a gel and an electric z9eazom86z 7q v k204nfovz ehn.n -e6field. The 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 prer bt (si(*;xkq-mRNA and three mature mRNA transcripts where the introns xtq k*(r i(bs;have been removed.



What is an advantage of the above process?

  Which of the following is a similarity between transcraq wjph9 *mpbr3(5q4siq3v /h ,v(efjiption and translation?

  The diagram shows th63-bmt2vc y mqe structure of a DNA fragment. Which bonds easily break and reform?tv 2byc3mm -q6

  What would make one DNA molecule more stable than anothec/vjndkw4 +-er 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 experiment2x 1f u4 .hy 3a*pj)2skpdggu3hqbq9f to investigate whether DNA or protein serves as the geng2s hjbu a)p f32fku4 1yhq3 gd*x9qp.etic 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 matched i a0b:i :*nex,mqab1w)rh xs r8n the table below?

  Which statement highlights the importance of nucleosomes in ypa6ur h ieue):/uk,7*c) rsxDNA supercoiling ?

  The image shows many ribosomes on a mRNA molecule. How many uniq7co d ek/+/w ab-pq d*dm1:uxcue polypeptide chains are being translatwb cuk/o*+da 17q e:-pm/cxdded?

  Which of the labelled structures*x o(t5x/zp to shows the correct directionality of the DNA molecule5xz tp *o/t(xo?

The diagram below sh1+0jel9 6ufuv 0l4qps,f ctojows the structure 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 c(wim d(t9 +n1 d7oi nf0b5ln t0y0inkyultured viruses that were radioactively labelled with td9n i+mb i1t0 07kdnyl wi05yno(fn( 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, anpa 7ijr//l+/qnttuh/x ,h2fz d R if S is a pyrimidine?

  How did radioisotopes help make the investigations by H6xyz6a7 wqd2 uershey and Chase possible?26d7x6w yu zaq

  What feature of the DNA molecule was utilised by Hersl idgfh( wd6omzyl7 9o+1 p4k;hey and Chase in order to identify that viral DNA is able to e ohd+;lm( wol1g9 z67y ifkp4dnter host cells, but most of their protein is not?

.

The image below shows a short fragment of the DNt- hkfg:8zl.aufb t61A 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 compony *w56av inampn hn5)t3 k-n*gents of one nucleosome?

  Hershey and Chase conducia .celthd* 0;3j 8re o(f8fwtz7kg:l ted 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 conducted4bfz1najc0 b .mk x+h;rf5)2ma l+xmh by a team of researchers investigating the relationship between the composition and melting point of differ0chnmf. m a2lk+x+hbz1 a)br4m5jx; fent 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 ac bf 4a1bz)w9jre 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 o dvg9a5z;:)s 6zxyefwf the 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.