Statements below show three double-stranded z uu23lsb ;- 01xdnvckug ,ub;nucleotide sequences. Which of these seq3,-dl xvugkb; 0nu c21uuzs;buences 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 struj p*.g5-no3hg:y0-d h :gkvntyj(yr d cture 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 evidence and data revealed g5jygo .- (ynyd p0v g3:jthrndh:-k*a more complex and accurate understanding of the structure, leading to the falsification of the initial hypothesis.

  What is the main role of tus2r: ku11yj6r 1 qksahe ribosomes labelled in the micrograph?

  A strand of nucleotides reads CCUAGAGCUUACCG. Which type of pentose sugar c6mzsr70 fmi7uould be found in the nucleotides in this stran sufz7r67mi0md?

  Which of the following processes is m an*(bd hv3n+j a*lmtnb,e--jm )4tr lost directly involved in the formation of nucleic acids such-d)(nnl*,mnlm-ha+3 e4vbjrj*a tt b as DNA?

  What distinguishes uracilef2x) xqi; 6 u/umbygqerbu 7* 1u-7fz from thymine?

  Which statements are characteristics of2xb, hkrio+ 798 d 5zxfvfkaf- 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 of base x,b 9zixa: cb: ;lh0obc f6xw:pairs, bp) for different specxx0b; lbwhib6c :9:f ozax,c:ies.

Which conclusion can be drawn, based on the table?

  How does the genetic code provide evidence of universal common(8mm2e s5 i3-,5 ok -ik ihqvrassl7xj ancestry?

  The diagram depicts nucleosomes. x2cd km y/w( ps7b j3shuy+2w*

Gel electrophoresis is a technique often ur+loi 73culu2l zz 28tsed to analyse DNA molecules. It includes a gel and an eleci2lt+7u 8r l3ulzcz o2tric field. 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 pre-mRNA and three mature mRNA transcripts where the in lu hj-1cxw07i53yx-qerib) itrons qxlhw-urb1)jc 7 x- ie iiy305have been removed.



What is an advantage of the above process?

  Which of the following is a similarity between tran k o0uwadob3q89* tx7sscription and translation?

  The diagram shows the structure of a DNA fragmenb; hy6x.9yydyqum )p8sz ;w*et. Which bonds easily break and reform? mq9y y);ew bs;z*yy68uhx dp .

  What would make one DNA molecule more v rf26oak:;g o(fjwl*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 conducted an experiment to investigate whether DNA oqjk u8r3l -ey.r protein serves as the genetic material. They cultured 2 batches of vij -y83.klru qeruses, 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 ar8 d .d1 lptu6q0orqn5xe correctly matched in the table below?

  Which statement highlights the imporgnul5 untt)9 (bmpa375h-kd ytance of nucleosomes in DNA supercoiling ?

  The image shows many ribos: p1x5ts yawn8jvj(*oomes on a mRNA molecule. How many unique polypeptide chains ar5 *yvw( j8s 1pxtj:anoe being translated?

  Which of the labelled structule+qrt):6 dfl10ua y fres shows the correct directionality of the DNA molecule?1q:lf l6fy t)0u+edar

The diagram below sh2.u /s o;xn:, x2enzgwevt l:cows 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 expegki b.dikm7 wre70;yxu g1.q- riment in 1952 involved cultured viruses that were radioactively la;kgm1wy. 7iq ri7d -xbku.g 0ebelled 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 pyrimidinsee a4e -eai3ra gku.9v)o v,-e?

  How did radioisotopes help mak25wsr((lo um gdp ex*awmechqr ,/a14/f*- qxe the investigations by Hershey and Chase possible(u1 x2m adwoaerewl/m hfrs qp5 c,(qx*-*/4g?

  What feature of the DNA molecule was utilised by Herv9df bn 9*fc 6s(g8s(p:m ag1sdk9qfpshey and Chase in order to identify that viral DNA is able to enter hosdv c6(fk*9s1 msd9f(a8n pg:9b gsfpqt cells, but most of their protein is not?

.

The image below shows a short fragmen,qfw;wdno5a. j9; ma wt 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 oq b8l (0*k; b h cbi6:p:;ghlcs3lkgssf one nucleosome?

  Hershey and Chase conducted experd2qn9*ychq/yodh f: ;iments 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 con(pxguz.r 68 d0nlfu5rducted by a team of researchers investigating the relationship between the composition and melting point of different DNA samples. At the melting point, thepn0dul rg5frzx8.6u ( 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 ad8d 3nqx1t3jvo3ak5s cids that 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 frag ::2iv1voufyvuy9m :ument of 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.