Statements below show three double-stranded nucleotide sequenceifoa, 7z s 11u,fni42j usrph3s. Which of these sequences of base pairs is possible in a DNA molecz7a1in4ff3, o2srps hju, 1i uule?

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 thet;q ;l 7 :5/f9.vxdexkmhxnwh 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 a more complex and accurate understanding of thv xx x 5 kth;nfq9mwhed./l:7;e structure, leading to the falsification of the initial hypothesis.

  What is the main role ofvkvs)i5l. kiz9 xr:p84hd- js the ribosomes labelled in the micrograph?

  A strand of nucleotides reads CCUAGAGCUUACCG. Whicwudqzx blm98u5h k59 .b +,-o0vp kjvfh type of pentose sugar could be found in the nucle u0pvbvb ox5, h899 mfjzud.lq5kw-+kotides in this strand?

  Which of the following processes is most9s(md:hrx vha a*f,l p) g6*rf directly involved in the formation of nucleic acids sa)a,vpg* dl9r*h 6(frm h:xfsuch as DNA?

  What distinguishes uracil t*iov5w6ud 3kfrom thymine?

  Which statements are characteristics of a DNA molecqi) -v4auyzzeo+ a i du-.l/9uule?
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 sh:v,ubapi0p33f ,t uk ryhi8o/l 15qpize (number of base pairs, bp) for differevpyh 0 bpau,5l h/tf13k3q pi:ou8ri, nt species.

Which conclusion can be drawn, based on the table?

  How does the genetic code provide evid 2dpfc84z lm8 g1z3wimlg :/on/.pdnnence of universal common ancestry?

  The diagram depicts nucleosomes. w4 r evt.c n2c; qet5kzbp: l+gl9ab8)

Gel electrophoresis is a technique often used to analyse DNA molestbeh81ap 9dc )6m*bbcules. It includes a gel and an electric field. The diagram below shows th1mp)b h8ta6e bbs*dc9 e 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 whi, rxn+rcy8;g ere the introns ha,ry+;r 8cigxnve been removed.



What is an advantage of the above process?

  Which of the following 3-t -y3+8mo mui,i k*f.wb+dlinrhtvis a similarity between transcription and translation?

  The diagram shows the structure of a DNA fragmentd9 3bmfu1ib ;3iybi-c . Which bonds easily break and reform? 31b idyiu;mb f9bc3- i

  What would make one 31f5) pl(d7mjj :nyxdxvtz- mDNA molecule more 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 or pshveixo 3h0 r2zz08g78(k dzsrotein serves as the genetic material. They cultv0zz2 oisk07zdre hh 8s8x3g(ured 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 in the table be f95 1hq1fmgewlow?

  Which statement highlights the importance hzsb7 c0+a6+f y ggki6.9hcfd of nucleosomes in DNA supercoiling ?

  The image shows many ribosomes on a mRNA moj dts ,4gm-gr)yq;u0q hi./v clecule. How many unique polypeptide chains are being yq0d )igm-cjgus,/tr4h q;.v translated?

  Which of the labelled structures shows the c:m,z;13wir z4uh r qsvorrect directionality of the DNA molecqiwu rr1,m;4z: vsh3zule?

The diagram below shows the structure of DNA nuclekg sm6(vjy/ +jotides.

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 experime2dvi,4rj r -yob/1mt vnt in 1952 involved cultured viruses that were radioactively la4dt-mry1 vibo,2rj/ vbelled 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 a5( 8,q qmh(w tjf:i73rvyv6 o/zajvqww0: far pyrimidine?

  How did radioisotopes help make the investigations by Herre;m c3rwl:)bzf8 *ujshey and Chase possible:ec)z3;m*r 8 jwrfl ub?

  What feature of the DNA molecule was utilised by Hershey and Chase in or0.fgn nrnv.p6h6 6omk der to identify that viral DNA gf0n6 .v6h nom kp6nr.is able to enter host cells, but most of their protein is not?

.

The image below shows a short fragment of t-f*b1ts jkbl j)rot,8-uis)che 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 tpe8i4 a,(iz( uoghnb/f:6w ey he correct components of one nucleosome?

  Hershey and Chase conducted experiments using the radioactive isotxqk0ma2 fz 4hx(hg*8zopes $^{35}$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 showb27q qi;c/el/p* lcf ys the results of an experiment conducted by a team of researchers investigating the relationship between the composition and melting point of7cc ef2 y qb//plq*il; 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 ljpt//5:sp.to o1 ww cjiving 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 -yobi /dn8 h/pof 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.