Statements below shoyq) u6c //vfn ,uwb4gzw three double-stranded nucleotide sequences. Which of these sequences of base pairs i4/vy/ubncwfu ,6 )qgzs possible 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 te:8 4lz)eiqrj/tqm- k)am o+n itranucleotide hypothesis proposed by Levene that DNA was made up of equal arz4:i-aie ) k)m/q mnlj8q+tomounts 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 understanding of the structure, leading to the falsification of the initial hypothesis.

  What is the main rol bvpkx/ y*59jhe of the ribosomes labelled in the micrograph?

  A strand of nucleotides reads CCUAGAGCUUACCG. Which type of dj + /gmg)lctkzfn b;-v3 i/4tpentose sugar could be found in the nucleotides in b g;v/jn d+)ltzi 4fg3tc/mk -this strand?

  Which of the following processes is most bl8.suoo0y: ay61q1 6rgbxxr directly involved in the formation of nucleic acids such as DNA?axg0q6xl yo1yb 6 u:8r1rsb.o

  What distinguishes uf 3qe gi(7m+curacil from thymine?

  Which statements are characteristv+ua3dx6t u 1zics 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 seq)q)nzu p6;9dhnzpv l a j.4xy7uence and genome size (number of base pairs, bp) for dxq .4j)7un)n p 6zazl;p9vhy different species.

Which conclusion can be drawn, based on the table?

  How does the genetic code provide 3(uwi9rr zw8o ;p kt o/zrv)k6evidence of universal common ancestry?

  The diagram depicts nucleohmi 5 ( ,geb)(utevwo2somes.

Gel electrophoresis is a mr yk7gptr9;.z/fc1ejk 3xm9 technique often used to analyse DNA molecules. It includes a g/pk7 91m;r.mj k3z9ryetgc fxel 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 .c/f joe,f g)rwhere the introns have been remogce,o jr./f)fved.



What is an advantage of the above process?

  Which of the following idlu7 nc q4stiau-i/urwe(.43 s a similarity between transcription and translation?

  The diagram shows the strnule,j/37f s gucture of a DNA fragment. Which bonds easily break and je,7ug fls3 n/reform?

  What would make one DNA molecule more stable 9b+2ixhectwz 47 zce 3j ;zn-vthan 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 whethe 5fm,e 79q).o vxukvqkre:0ybr DNA or protein serves as the genetic material. They cultured 2 batches of viruses, one in a medium cont emv.)9 x5byke7q r,kq: u0fovaining 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 xs2m8w k wps4fwm,s2*1o4 maz correctly matched in the table below?

  Which statement highligv- ,p0og9t*(xny pq;*lcqm:xc ld7 bohts the importance of nucleosomes in DNA supercoiling ?

  The image shows many ribosomes on a mRNA molecux .ildx+ocueh2ja3s ,wmh2+ 3le. How many unique polypeptide chains are being3eh2hc a.o w uj ix2dl3s,+xm+ translated?

  Which of the labelled structures shows the correct directionality of the DNA roz* ze8o5o 7bmoleculob7zoz 5r8*o ee?

The diagram below shows the structure of DNA nucleowwddg7q tv3vldxq 6 6oa1 0:s9tides.

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 ;b/lk;qx.syk*y /1nr c,aozein 1952 involved cultured viruses that were radioactively labelled withzscr,n/e bx ;1ly.koa ;yk/q * 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 r5m n -hb53s5ld+2 xrysq*v diis a pyrimidine?

  How did radioisotopes9o:6; sqyhl7t /qzopx k hwb50 help make the investigations by Hershey and Chase possibleqh;k5p7yz96boq 0lt:xh so/w?

  What feature of the DNA molecule was utilised by Hershey and Chase in ord olp3w6ig44;4vj o .jcdxir w6er to identify that viral DNA is able to enter host cells, but most of their protein is g rio j6ivo4p6w;w d.43 4xcjlnot?

.

The image below shows a short fragment of the DNA molecule. wm+d+5 fyrc6rzicvjg5 f8gt1c:4 4 aa



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 nucft- r fv3cup dq8c/-5nleosome?

  Hershey and Chase conducted experiments using the v99g1ek svmt59ay7 fa 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 of an experiment conducted b s90uj/j(n zjry a team of researchers investigating the relajs ( rj90unj/ztionship between the composition 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 are essential to all living o3z,ch vdpt*j ,rganisms.
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 fragmen4nj*ih2sn qmvt ; 8ff9rxm: 1mt 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.