Statements below show three double-stranded nucleotide sequencepg+wx0o i(4j tvy1cq6s. Which of these sequences of base pairs is possible in a DNA+ py4qj t 1ox(6vw0igc 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 hypothesis p;ksw 5 7 4sp+2ewfcmirroposed 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 was7sewc f +4 skr2w;5mip 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 txr) e 7g1m/yab svb.v 8+bvp7uhe ribosomes labelled in the micrograph?

  A strand of nucleotides reads CCUAGAGCUUACCG. Which type of pentose sumel(1d l2be. *mpq x+vgar could be + 2evdm. me(1pllb q*xfound in the nucleotides in this strand?

  Which of the following processes is most di b.qmtt) g 40z wou t9rn2j1leq9od52crectly involved in the formation of nuclb4r9 wc9jqun 0me2ot 2t.l t5ogqz1d)eic acids such as DNA?

  What distinguishes uracil from thyma4q+r lpcl saq4 wt;;2ine?

  Which statements are c)*2harz e e*qru ; pvgmr8ta9*haracteristics 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 of bast- *g isw*lembb4qe0x +m-w4f e pairs, bp) for diffe* xbsqem44 b+wt f-m0*ie-wglrent species.

Which conclusion can be drawn, based on the table?

  How does the genetic code provide evidenc 2iee vxu7-ub :u/f/a m0gnea1e of universal common ancestry?

  The diagram depicts nucl qqk4i+d4 c-u 4agp*weeosomes.

Gel electrophoresis is a technt9qhmyp /1aq -ique often used to analyse DNA molecules. It includes a gel and an electric fi m-t/hayq q1p9eld. 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 an qku.). suam o09zzh.dd three mature mRNA transcripts where the introns have been removedzd. o q 0kzsuau9..)mh.



What is an advantage of the above process?

  Which of the following is a similarity bey)/9 /jwbg fcy) q)coctween transcription and translation?

  The diagram shows the structure of a DNA fra )8jhiv1ux zo(gment. Which bonds easily break and reform? j8v1h) u(oxzi

  What would make one DNA molecule more stablkbaf0hyo8puu)3)j+r)s;e8 a ltlv k 3e 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 protei :raqr-w -jr2x1fr:v nn serves as the genetic matef r rj:w2:-a1-qrrxvnrial. 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 processsbb*v:vt:iu;m,r: rc are correctly matched in the table below?

  Which statement highlights the importance of nuc7rr55 htiojq )leosomes in DNA supercoiling ?

  The image shows many ribosomes on a mRNA molecule. How many unique polypeptid/)282tzzo0c rccv* xmsp z/hde chains arept)0/ 8voz2c 2m/hdzz x*crsc being translated?

  Which of the labelled structures shows the cellmrwkx85 49y) 5.y nw s4ejhorrect directionality of the DNA molecule5 smenrw5y . j4hl8y4e9l)wxk ?

The diagram below shows the structure of DNA nucleg)tyij7jn 4kgteco0j g(g ,53 otides.

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,d8n wpxd), 5rwy:fzm6 n h-jw viruses that were radioactively labelledwh r6nzfx j8pywm5,dn,:wd )- 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 pyrimidine? z,j 59oz1abwe

  How did radioisotopes he-5qe *cbae* nd(5(+: cv e3gwrzd nfhflp make the investigations by Hershey and Chase possibleaffegb:c+rnd5(hc53*z(vee nd* w q- ?

  What feature of the DNA molecule was utilised by Hjm5: 7r/zn sak8z6uozershey and Chase in order to identify t7m zjk6srn5a 8ouz/z :hat viral DNA is able to enter host cells, but most of their protein is not?

.

The image below shows a short frag0 a-a 5rdh5jk::xi oqrment 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 corrf bjnq 4;.bi/v dimhs3e,/ hl.w 1ql,cect components of one nucleosome?

  Hershey and Chase conducted experiments using the rxu)lrir ,5rcd.ec :6 aadioactive 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 experimery/ c nv::nc3.:yswlgp4t (rel(c6cknt conducted by a team of researchers investigating the relationship between the com.l yvrgc:4s6(n:le(yw3: /nc tpkccr position 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 nucleic acids that )mdgffu bms0l,p7 8-c 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 fr tz*d(+e0zwa9gmsx, gagment 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.