Statements below show t;0+ etuns9q5* kk houg m/iqe4hree double-stranded nucleotide sequences. Which of these sequences of base pairs is possible in a DNA molechi9; qk utog e+0qes*/4nku5 mule?

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 tetranh gjnl2g+yd4 w-a1r.4e0rkn ebp)o*l ucleotide 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 onkn4)ggd*o n 1e2yw0 eb 4.llhapjr +r- 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 micrograph?c1gep*9m 5hf s

  A strand of nucleotides reads CCUAGAGCUUACCG. Whic zot1i/ g1,da wtj6v bob0r*g7h type of pentose sugar could be foroo *i bbg0t/gtz7116a wvdj, und in the nucleotides in this strand?

  Which of the following processes is most directly involved in thet4na,- dj.qkt formation of nucleic acids such as DNAd.atjk ntq ,-4?

  What distinguishes uracil from ths .17gk/jvhcynm+ b,jymine?

  Which statements are charactii+winn/+yk5*v c exnm7:+ e+ciej o9eristics 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 seqdfi3q-i 9 1hrm vtx.9 k ux/o;5ny*dy9 egd*nxuence and genome size (number of base pairs, v;fdg-h*qdi5 3* .xxk 99 runmoet9y dx/y i1nbp) for different species.

Which conclusion can be drawn, based on the table?

  How does the genetic code provide evidence of universal commo9pk hihfo2 :-ejcp(ylzbk )0.n ancestry?

  The diagram depicts nucleozz5; fe ez06rld4kxz o7an p+;somes.

Gel electrophoresis is a iw5 xk7ax-lj.or7:q q technique often used to analyse DNA molecules. It includes a gel and an electric field. The diagram below shows the outcome of gel electr:kj x7qwi .5qxl -7oarophoresis.


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 r v63,ia a8g,.g dqe9-st uw 0yfk g1uh+sg.mamRNA transcripts where the introns h+mvyfa .h .q9a1g6asue8u is ,3 g0g-g kdrwt,ave been removed.



What is an advantage of the above process?

  Which of the following is a similarity between z p04jt:v3vnp transcription and translation?

  The diagram shows the structure of a DNA fragment. Which 3hfe a p/9kylbd(/k 0rbonds easily break and r3b( e yhak9d plf0r/k/eform?

  What would make one DNA molecule more stable than another DNA molecul*ia/)gip8v mle?
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 inves tvkxcf+4gqrs 1) r-,atigate whether DNA or protein serves as the genetic material. They cultured 2 batches of viruses, one in a medium containing radcf-)x+t,k 4r s1qg ravioactive $^{35}S$ 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 c6c lrcxufimhz (e3em.k35 6p8orrectly matched in the table below?

  Which statement highlights tf -)pdccs2eopm 5e etplfv,6)d/llez6j ;6 z*he importance of nucleosomes in DNA supercoiling ?

  The image shows many ribosomes on a mRNA molecule. How ok42omkupsqrla.qm 8,/ fw:(many unique polypeptide chains ar/k a4oqol( qmkws2 8,mp:.fu re being translated?

  Which of the labelled structures shows the correct 5y3-or7or j vo:hvm (wdirectionality of the DNA molecul -( joyowhrr3mvo7 :v5e?

The diagram below shows thepw*2bkhbyt )+ 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 experiment in 1952 involved cx)5odc :. -gpsjs5 .tfmz i4uhultured viruses that were radioactively labelle p5fhs. u:-4xmot ) z.isjd5cgd 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 pyrimioio/oinl 4kvpv )8q5(dine?

  How did radioisotopes help make the investigatioei ca;7f7 q qcj8;q.cd z+cnv*ns by Hershey and Chase possible?+7 c8dqc;iz;*j f nq7cvea.qc

  What feature of the DNA molecule was utilised by Hershey and Chase in order j50zedzt j l4+to identif0tzld4 je5+zjy that viral DNA is able to enter host cells, but most of their protein is not?

.

The image below shows a short fragment of the DNA v8*c -lod.zcjn jh 1(dmolecule.



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 of one3l0lx nmd s-bc 7.sy2i nucleosome?

  Hershey and Chase conducted b - yh*9 g+fj;yg7ytclexperiments 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 thewf :trru9 oc01 results of an experiment conducted by a team of researchers investigating the relationship between the composition and melting point of different DNA samples. At the 9wotfrc:0r1 u 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 essentialkcd:p.35o13hm oon kc 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 moleculeasw dn) ;.z-bmpn;dbi3ez1 b2 .


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.