Statements below show three double-stranded nucleotide sequences.lm jr5c *eb-su7 /vn4e Which of these sequences of base pairs is possib nbjve*s74uler5/c m -le 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 showrsq1 89i4f*fy0ya w -n *hivbqs the structure based on the 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 unde fv8y*w h 4rs0*n1-9 iqqyfiabrstanding of the structure, leading to the falsification of the initial hypothesis.

  What is the main role of the ribosomes labelled in36e e)p-wyyin)um- +jm5cjk a the micrograph?

  A strand of nucleotid0yn ehp; v:j6des reads CCUAGAGCUUACCG. Which type of pentose sugar could be found in the nucleotides id6jpv h ey;:0nn this strand?

  Which of the following processes is most directly involved in the formationlgs + -bfsifztpe:qk 3)k(x;t48e6 br of nucleic acids such rtbf)+f 6xe3kpsg ;t l:zq b-isk4e(8 as DNA?

  What distinguishes uracaj l .y+e7t rc8w.yo6sgp:4r)jrbjz o5 6n *ioil from thymine?

  Which statements are characteristics of a DNA molecule? uop ib,)w2)nk
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 of4 2scp -p4 un zqm+:woxc4z*eb base pairs, bp) for differx+pn- * zczs4eo cw2mp4 uq4:bent species.

Which conclusion can be drawn, based on the table?

  How does the genetic code pr98 iu)nivlpza c v6c06ovide evidence of universal common ancestry?

  The diagram depicts nucleq9v/kpd*03 tkd9drsiosomes.

Gel electrophoresis is a techniqueuqfa5yhk,q qgl:w rz5 ,+:u5s often used to analyse DNA molecules. It includes a gel and an electric field. The diagram below shows the outcome oruwqkyg h+,sf,u5 l55zq:a :q f 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 mRNAn:r,rexcgh q:uu)9v gu6jvqc)n 9 ,v * transcripts where the introns have been reqr,u j :c 9ge nc),q :xr*vnvu9hv6)gumoved.



What is an advantage of the above process?

  Which of the following is a si/ gyia7 jtwh, 2mf zkh,9sk).imilarity between transcription and translation?

  The diagram shows the strc0/g nz q8/:tkaw-x youcture of a DNA fragment. Which bonds easily break and reform?n tx0ok: /cqygaz/-8w

  What would make one ry)3umhv,4 iw DNA 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 pro6f gsu(yq8 ty1tein seu1gtyy6 8 f(qsrves as the genetic material. 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 process are cwxx18h y 94,e1iuv emkorrectly matched in the table below?

  Which statement highrwv+5 xw6j/l 9 d5yrmbzh5 ci7lights the importance of nucleosomes in DNA supercoiling ?

  The image shows many ribosomes on a mRNA molecule. How many unique polypept3tw5 jhde; )rride chains arjrw)3td 5ehr ;e being translated?

  Which of the labelled structures shows the correct directionality of the Dzizmi vgfp 8. v m3,cu5o2d.;*mop)fdNA molem2 ., v*f) 5im u8z;do fcip.odpzmv3gcule?

The diagram below shows the strj a -zbcz8uo:ro 7ll)5r10vka 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 iz1*erw8; ,we;dms i exn 1952 involved cultured viruses that were radioactively labelled with either sulfuzri se8emww;, *xe d;1r ($^{35}$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 :3sf:3q ommpd R if S is a pyrimidine?

  How did radioisotopes help make the injj4zsg,tu c a9;k d4-wvestigations by Hershey and Chase possiblek9,c j u 4tgazws;dj4-?

  What feature of the DNA molecule was utilised by Hershey and Chasehcc9ef(6me e pr) hap,t3;/ip in order to identify that viral DNA is ableit;)pp(6h amfpc ree/9,3ch e to enter host cells, but most of their protein is not?

.

The image below shows a short fragment * b7-kzu8yco(3geokx 0 qmat, .y twl9of 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 of one nucleosomexl rlldvy* (pn9) /1py?

  Hershey and Chase conducted d*h)z:u b+5h stkvwz 9experiments 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 ofyo;)-th esroxx-af4/yh0, h w 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 DNA double helix seph0/ -fy,wetoa)hs xrx 4h-;yoarates 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 acitc 4pda1qi7k* ds 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 shows3vl), w. afga(1hwgnm a 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.