Statements below show thr 3zixw*l4v)n uee double-stranded nucleotide sequences. Which of these sequences of bni3zv )*xl4wu ase pairs is 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 teg. j*xi)vye6alvi2 f/6raj; v tranucleotide hypothesis proposed by Levene that DNA was made up of equal amounts of adenine, guanine, cytosine and thymineyfj6v i 6xe;g*2lrija /v)av .. 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 role of the ribosomes labexfuk/1fp )5zn+r,h5 e6aymcd lled in the micrograph?

  A strand of nucleotides reads CCUAG7 cgu d4+5xgipkf r.f4AGCUUACCG. Which type of pentose sugar could be found in the nucle7kf cpx +4 .fu5grg4idotides in this strand?

  Which of the following prbv8tj cn1 :lvv.3ugb (ocesses is most directly involved in the formation of nucleg 1:v(l8vb n.j3vtbcu ic acids such as DNA?

  What distinguishes uracil froi :gi,nn7 qjk3 *hmud3m thymine?

  Which statements are chavm 5eew 38f5nhracteristics 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 (nu1 rip5oh+ rq9dlr:1asmber of base pairsrir qls:+51 rpdoa9 1h, bp) for different species.

Which conclusion can be drawn, based on the table?

  How does the genetic code provide evidence of universal common avgn2nji8v df7w6c d;o )dmk-*ncestry?

  The diagram depicts n8q r(q-8 5tc)haiabn kucleosomes.

Gel electrophoresis is a technique ofte0jr;x o2 aj l3e0qlhn6n used to analyse DNA molecules. It includes a gel and an electric field.a oqj 26e 0;j3rllxnh0 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 yohvce 9,dodfo 8, *2trx1at9d three mature mRNA transcripts where the introns have be9d 89oyde,2h, cor t *1xftaoven removed.



What is an advantage of the above process?

  Which of the following is a similarity between transcription a 4blgoxs fr+p32zw-8m nd translation?

  The diagram shows the structure of a DNA flgkesq 47/tr il3c7);vfzxg :ragment. Which bonds easily break and refo37tel cq4fvz);7sklir/ g xg :rm?

  What would make one DNA msv: r 9oq1n4gz*m62 oklxb/nt tbp05tolecule 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 whetheriaqd0s8c n 6.w DNA or protein serves as the genetic material. cq8dwn6.0ia s 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 correctly matched in the table belowh)ah .rk* 1vct?

  Which statement highlights the importance of nucleosomes in ds+d7w4yxwt :0k zj, m09rca hDNA supercoiling ?

  The image shows many ribosomes on a mRNA molecule. How man)qph v),/)sxmta ,dl8 t0ghpfy unique polypeptide chains are being translat/x)ldtt)q0hs ppva ,f8, g h)med?

  Which of the labelled structures shows the correct f: mc suhsuis,ogp7m-9 lhq6h c-k92) directionality of the DNA moleum kupc)lq:9 9s2 o6c-hshif -hsm 7,gcule?

The diagram below shows the structure of DNA nucleotides.+nwv f3w+eaxol ;0w5e

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 inv4ki;jza9l u .r(dx2d nolved cultured viruses that were radioactizx (nad4;. 9ir2 lujkdvely labelled 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 i,r9bf -o j;s2 8d9l jqner7m .0zlnqvrs a pyrimidine?

  How did radioisotopes help make the investigations by Hershey 7,i3zfn4gsfwjum5k nz0 i .9r and Chase possiblei ,w.9kngff5ju m0nz7rz s34i?

  What feature of the DNA molecule was utilised by Hershey and mxfc1-s n5 (wmx1h q7iChase in order to identify that viral DNA is able to enter host cells, bu751f1m nsc hqx i-wmx(t most of their protein is not?

.

The image below shows a short fragment7+kfgln*5i,cz w ov q: 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 ssm6i rsq)8/q cuq83 zthe correct components of one nucleosome?

  Hershey and Chase conducted experiments using the radioactive isotopes lkb 79i3kvn+s$^{35}$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 peyf9fg+4 / wrt9f2 *bfzllr6 an experiment conducted by a team of researchers investigating the relationship between the comebpfw* +f6l 4lg9ztyrrf2 /f9 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 are essential to o 5 u6 er-7avx3v1cvtqall 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 molecule. whvrlln:*0twem, +qg 1(k u n0


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.