Statements below show threevuufhp6 ej jo gl/6tt)9/ hb)--ttz4s double-stranded nucleotide sequences. Which of these sequences of base pairs is possh49 jotlgue6t)tbp6/z /- vus ft)-jhible 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 hypothbkjl;2wvlpxt0 7;i gxt z *x:m)n*uf *esis proposed by Levene that DNA was made up of equal amounts of adenine, guanine, cytosine and thymine. This hypothesis was a problem ofunlkl*) zxw;*mt* v0jb;txpx 27i: gf 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 of the ribosomes labelled in the micsmwnqlnp6 .:49/ bxoprograph?

  A strand of nucleotides reads CCUAGAGCUUACCGvx)bh x8mbif 3. (d0h6 +gmzuv. Which type of pentose sugar could be found in the nucleotiv+ .3 b)fdmhmhzix6xb v0g( u8des in this strand?

  Which of the following processes is most directly involved in the fof8dtw/o 2pm 0nrmation of nucleic 8tp2dmo0w f/ nacids such as DNA?

  What distinguishes uracil from th-r*edg ly z,(cymine?

  Which statements are characteristicsj:ord q1h/q. :vln5l3dkv sp 1 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 nucleotm6c/j u yq:vj p31, ecc/m9cthide base sequence and genome size (number of base pairs, bp) for different speciesm/:eccm ,vcp y jq3hctj9/1u6.

Which conclusion can be drawn, based on the table?

  How does the genetic code provide evidence of universal common ancs6uu5 dfq hez5op8 r.e 2jgc(2estry?

  The diagram depicts nuclez krw( e ; xi9(v9)(kx6nup2g e4fvrgiosomes.

Gel electrophoresis is a technique ofti ne5d4rf2fzdu )3c 6-a9iq+ )cuzx keen used to analyse DNA molecules. It includes z)fkx -i9cu edr acfin3 2dzu+46e5q) a gel and an electric 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 + c.netn5nr :iintrons in5c+n n:r et.have been removed.



What is an advantage of the above process?

  Which of the following is a similarity between transcription and trankz(xw*a+ me o()vqs5hslation?

  The diagram shows the structure of a DNA fragment. Which bi4 go3vfb7n 5xb8qv;monds easily break and reform4fq xbo;i mb7v58 gvn3?

  What would make one DNA molecule more stable than another DNA molecule ,sp26/m zt-t 36rc;8psvqf y +oci5 ndmkvmd,?
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 whett( (cnxzlz,z62zopb9her DNA or protein serves as the genetic material. They cultured 2 bz z(zctn69x2 lo(,zpb atches 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 proce+blsk9 .3aa1up 5uqxiss are correctly matched in the table below?

  Which statement highlights the importance of nucleosomes in DNA supercoiling .*06x.nz esfkd0(tza 1r eqcv.yh7xl ?

  The image shows many b8vyfu t6:/ oqribosomes on a mRNA molecule. How many unique polypeptide chains are bei 8q:oub6fvyt/ ng translated?

  Which of the labelled structures shows the correct d9i6) gz5:mkd(kisf e * tbr(zairectionality of the DNA moler6kk da(z (mtzsi):b5g*i9e fcule?

The diagram below shows the strulfy3q;zhlh;7d *te;;ou5 r h ucture 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 cultured viruses1 s0nm kcdw,ja8m9z9hw-.c lg that were radioactively lamzh80-w c1l9 9mjd.gsanwck,belled 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 py6kl6zt b,/ xpvrimidine?

  How did radioisotopes help make the investigatc 2nl ijf-+yb1ions by Hershey and Chase possible?yfcl j2-nb i1+

  What feature of the DNA molecule was utilised by Hershey and Chase in order to 5w/: uftbm ng7)-jk+;jr1sa 7s nnjvhidentify that viral DNA is able to enter host cells, but most of their protein is not?g trv u1js-7n7bjm5;afj) hnsk/wn :+

.

The image below shows a short fragis .9gikw z-n4s1j d q8+btg(.rzz2g oment 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 o3s1 6m9tqlc3t2 ktt;ytziko2 f one nucleosome?

  Hershey and Chase conducted experiments using thebpk1awyr2r 8pj 8s8 cdp17s 8p 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 resudnyt/b:,g.. xqh7w6c ul sj:hlts of an experiment conducted by a team of researchers investigating the relationship between the composition and melting point of different DNA samples. At the melting point, the :q hyxtsulh w:jd.b,n7.6 cg /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 ess1 qa7tt7rk9k jential 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 the DNA moleculehf fhq4 0y:x9zq+p s9e.


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.