Statements below show three double-stra hdthkn c5*dsac7 m+.8nded nucleotide sequences. Which of these sequences of base pairs is possible in a DNA molecul 5*7cths. dkacnhmd +8e?

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 t:om 5 ctnj x:8egot/c4eyi1i (he 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 compo(y:e:iex1nic jg/4mtot 85 clex and accurate understanding of the structure, leading to the falsification of the initial hypothesis.

  What is the main role of t x,p/s+*xbbrxhm (y.k he ribosomes labelled in the micrograph?

  A strand of nucleotides reads CCUAGAGqp/rfv- f4d 3wCUUACCG. Which type of pentose sugar could be found in the nucleotidd f/3f wpqr4-ves in this strand?

  Which of the following processes is most directly involved in the s1 (5rgbnm p p7pv4g+jformation of nucleic acids suppg 4r sb1p7nvgj 5(m+ch as DNA?

  What distinguishes uracil from thhnw4 oeo4yt +ls2lv;6ymine?

  Which statements are characterist1x kwbnhy6b+:oqb 1 u;ics 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 ow 4rrt4fhdaht ee 2ps9y*j 5-,f base pairs, bp) for r -taf de5p,e 4y*hhwrsj924tdifferent species.

Which conclusion can be drawn, based on the table?

  How does the genetic code provide evidence of univera) x z(8vt ts:l2x ,tx,dww)-tfa y*mgsal common ancestry?

  The diagram depicts nucleos) cd8u+j9si ufomes.

Gel electrophoresis is a:ith;mi,w qf 5)w:imz0vub1m technique often used to analyse DNA molecules. It includwi:i 01mit) wh;:f5uqzmvb,mes 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 w/yzcl06e0ztr7y syhm g me 9,0s,5 uovhere the introns have been ru 6se/eh5gz y0y 9 ctmo ,70slvy,rm0zemoved.



What is an advantage of the above process?

  Which of the following is a similarity betwesl (pd1td yi9.en transcription and translation?

  The diagram shows the structure of a DNA fragpwc qc u ;45dykky-b5+ment. Which bonds easily break and refor4y uccky+55w d;p bk-qm?

  What would make one DNA moleq6z2 0b*1xm 7xnadzhn cule 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 DNA1,qkgp6 )n /qda)d6d)eg r usv or protein serves as the genetic material. They cultured 2 batches of vq6s) 1g qndkeur)p)avg dd/ 6,iruses, 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 ar cef2f.1b 1*wfh jx.gy7wk2z3u(hh qte correctly matched in the table below?

  Which statement highlights the importance of nucleosomes 4kzrsr *0 pg1din DNA supercoiling ?

  The image shows many ribosomes on a mRNA molecule. How many uwyya 2bcv7 ppg 9qwm8o 1g+o)9nique polypeptide chains are beiyocm agp2v9 w+ 9y1q)bgwo 8p7ng translated?

  Which of the labelled structures shows 98g/d gs, kw dv:ga9bythe correct directionality of the DNA moles9,8v/dgakygd:9bwg cule?

The diagram below shows the structure of DNA nucleotides.mc2 u9pd lim(;h4l z(j

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 viruses that ws+lj30 lb/j jq: jeg+4r8 elomere radioactively labelled witjj g jesql3 o+l/ermj048:bl+ h 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 ish(t2ae q9 zecx;ym,t*.b3xl i a pyrimidine?

  How did radioisotopes help make the investigations by Hersh q3xnq1mdsjg 3 zr wjf2ij+m.d0.ny4)ey and Chase possible24 dw .minj.g3+nsjy)dqqzj3mxfr0 1?

  What feature of the DNA molecule was utilised by Hers0moudevp*yvb / u+ 9v*hey and Chase in order to identify that viral DNA is able to enter host cells, but most of their pbp u*eyu/0mdvo v *v9+rotein is not?

.

The image below shows a short fragment o: by2fz +dekao ptl x3);;4sb0i6:o ejk (iajcf 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 i8ge uw0:-b(zba red ;the correct components of one nucleosome?

  Hershey and Chase conducted experiments using the radioactive1y7zval ,ap0neq+r.) e fo4yn 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 experiment condujt3wi prnm2i (ya m5y(2zww0g ):p i4ycted 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 separates i2 05nw4pwgyip2 :3wm)(i trzim y(ja ynto 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 km3vwthixqn/g: ew 2e6 o3.u-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 fragcxx2n*g m a f1ey)1bn8ment 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.