Statements below show three double-sv(f6a v gxowb-d)m88ltranded nucleotide sequences. Which of these sequences of base pairs is possible in a DNA molecul(w g8vvxbo)ml- fd6 8ae?

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 hypothegf e c-j5: a6xkcmpc(5sis proposed by Levene that DNA was made up of equal amounts of adenineccpckax-56 fe5gm: (j, 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 utto,0(5ifule w t;4e of the ribosomes labelled in the micrograph?

  A strand of nucleotides reads CCUAGAGCUyq ;dc**, wwpi c:psy7UACCG. Which type of pentose sugar could be found in the d,q7py* iwcps*ycw ;:nucleotides in this strand?

  Which of the following processes is most direcxg io3(2n(t/l xc-e dbtly involved in the formation of nucl(x-l( 32gxc/ned btoieic acids such as DNA?

  What distinguishes uracijten6m16d,k peuk(b3 l from thymine?

  Which statements are characteristics of agl(iv wz-1/cl41s 8atnl dxw( 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 lj9t4msm(iwjl- +xr - genome size (number of base paisl+( wj- m4itjlm-9x rrs, bp) for different species.

Which conclusion can be drawn, based on the table?

  How does the genetic code provide evidence of universal c/ 5shj rzg06xvommon ancestry?

  The diagram depicts nucleosomes. oyeaq (h+o:;g(yi1kbu- 8mre

Gel electrophoresis cv:eddwui. cm t/+kez*h9r09is a technique often used to analyse DNA molecules. It includes a gel and an electric field. The diagram b i/m9rhectz+uk0dc9.:d *ewvelow 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 trjd(izmaz(0q h8ynf ;am9+kxi3) g 5njanscripts where the intron3(nq8z mai+x;9jm diz)afn(k0h 5jgys have been removed.



What is an advantage of the above process?

  Which of the following is a similarity betwez ,d,ucovia3 er6qz24 en transcription and translation?

  The diagram shows the st 12kpv8)rjlq p;/qaox ructure of a DNA fragment. Which bonds easily break and reform?; aq pklqoj1/8) rvpx2

  What would make one DNA molecule more stable thanm/w,ga 2hjq s-2hlxf/ *4mbob+v j : iby4o4zc 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 condudx4ung9ygr3t0.t ubh2:nc 8c cted an experiment to investigate whether DNA or protein serves as the genetic material. They cultured 2 batches of viruses, onh2gccu dn8b ut rnty .94:0gx3e 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 table belo8 m/q vx:fw g5nyd*-njqb: sh+w?

  Which statement highlights the importance of nucleosomes in DNA faw7d6cy8 3vv supercoiling ?

  The image shows many ribosomes on a mRNA molecule. How many unw-0is nh7ei.f2m 4u. osr9ze yique polypeptide chains are being fesi0 r72zyo. wu .h4n9im- setranslated?

  Which of the labelled structures shows the correct directionality of the91;utsq5 thco1b/ec n DNA molecul95/uett 1hnb;1c socq e?

The diagram below shows the structure of DNA nu pn6o735 -3vtkh-f2zi)i pjrozeti2zcleotides.

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 expe rqmcvksjd*f4t0 /)2xriment in 1952 involved cultured viruses that were radioactively labelled with f2m v)* sxd0kj4 rcq/teither 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 pyrimidine?ppw7c.a(avw ews7 j t:,0;eul

  How did radioisotopes help make the investigations by Henm;;r ztyu ;zp+5r;bhrshey and Chase possible?;r+ mt;r zzb;yu;hp5n

  What feature of the DNA molecule was utilised by Hershey fk,m / avx db q;;xl1mp/3jwcl kp07m5and Chase in order to identifyda0x1wplmm3cp//v k; l kx7bq5f,; mj that viral DNA is able to enter host cells, but most of their protein is not?

.

The image below shows a short fragmenv w1d2r0sqm .lt 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 followiuh ii 1vx .j.my bh1tvx 2+8+p7htrwy7ng shows the correct components of one nucleosome?

  Hershey and Chase conductm 3h4h: kdcgi 3c3y,sced 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 y eo 04fo,eak::- g4xo-hcgz iu,m(olof an experiment conducted by a team of researchers investigat :o4-0 f(y: umog xhlizce e,-oo,ga4king 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 nucledds le y- dxs9k;+mk2;ic acids 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 4exryng gwox,)st )e (d3p1oh/n+ 3kja short fragment 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.