Statements below show three double-stranded nucleotide sequences. W j,er),k/xuce. qe1ychich of these sequences of base pairs is possible in a DNA molecule? ,eq yeje)u kc1r./,xc

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 tkv2zs8vf 8kwkz6 c0e;c i+l,):opxc 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 understanding of the structure, leading to the falsification of the initial h s) zvxkkzw0i lcpt 8:,2o+ ef8vk6c;cypothesis.

  What is the main role of the oy6 npsf+d:2u*2 fts oribosomes labelled in the micrograph?

  A strand of nucleotides reads CCUAGAGCUUACCG. W ge2d,xhlyo3: hich type of pentose sugar could be found in the nucleotxg 2 y,3:lodehides in this strand?

  Which of the following processes is most directly involved in thy: ud 2ye5vhhq3+q;te6drrij- i bm41 e formation of nucleic acij2u3q16;dryy+b5vh q ei ehd:mirt4- ds such as DNA?

  What distinguishes uracil from thymine?ljcai c*t+, : vfg(mu7

  Which statements are characteristics of a Ddm mpd lo : l++skjkk(6 hbv78,rz.3gcNA 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 bao2x7v(+yrd ke dl2 x5lse sequence and genome size (number of base pairs7dlv(e+or xlxk d225y, bp) for different species.

Which conclusion can be drawn, based on the table?

  How does the genetic / dg2gaka;o-,voy68j(ap nepcode provide evidence of universal common ancestry?

  The diagram depicts nucleolcbb6)xp / oqtxvx 1x s/qnzms;:8 /k4somes.

Gel electrophoresis is /g+gr8 3klzhta technique often used to analyse DNA molecules. It includes a gel and an electric field. The diagram below shows the o l8trgzh/+g3k utcome 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 transcr80o8bvbd)h i ripts where the introns have been remov0irbbh8d )8o ved.



What is an advantage of the above process?

  Which of the following is a similarity betwe;e97i. gtd4xw:rg y6 gc ctp*qen transcription and translation?

  The diagram shows the structure of a DNA fragment. Which bonds easily break aftah.qbi.7e v q :(6* ana3gm lbks5d4nd ref hgqaf7t(d4 as*v5 6 qbmbai.nek:l .3orm?

  What would make one DNA molecule more stable than another DNAc;u *mflpqlt j i(9fr77e+gs2 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 ew21hh cdzf)q 8cfpsgf 00.ba9xperiment to investigate whether DNA or protein serves as the genetic material. They cultured 2.p h z2fccs1h)fqbwa00 98 gfd 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 corrd6 ob0sbqy 5n)y*qx.takyd 7,ectly matched in the table below?

  Which statement highlights the importance of ny1tisum3 wjc1.p 52a cucleosomes in DNA supercoiling ?

  The image shows many ribosomes on a 8x2q3c ico8k;*dqo p9ue-dr f mRNA molecule. How many unique polypeptide chains are bqxi*; 8 oec d9kf2 p8-c3odrqueing translated?

  Which of the labelled structures3bis / kzd;l+ zc bw;w.9gj9mz shows the correct directionality of the DNA moleiml gz9;.b k3jw9wd/z;zsc + bcule?

The diagram below shows the structure obmthood gws +( qn),sicas64:)q:s2 yf 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 involv8v l.t,r ,bjrved cultured viruses that were radioactivelytj., 8, rrbvvl 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 is a pyw)xtx, nxcsly i 48*7nrimidine?

  How did radioisotopes help make the investigations by Hershey and Chase possiblt opqdno:8/;xy0f6jt btgvm2r g a38-e80;6jr o y:a2v fmgt bt8odxqg-3/npt ?

  What feature of the DNA molecule was utilised by Hershey and Chase in orderdtba 51z17nlfox 3rm+ to identify that viral DNA is able to enter host cells, but most of their proteimod+zl3ab1f1 7n rt5 xn is not?

.

The image below shows a short fragment of the D8w 9u74,owdtivvz .f gNA 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 com2ssn:e, q 5ujmponents of one nucleosome?

  Hershey and Chase conducted experiments using the radioactive isot+fto+s -xn n: 0f dcpm;qlb2-vopes $^{35}$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 resq*wtfy ;hm3b3ults of an experiment conducted by a team of researchers investigating the relationship betww3hqm3* ; ftbyeen 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 aremvbg k1) 4l* .m,x73nxb oqfoe 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 shows a shortb8ociulq2pmr4dct3vb29(.rb 5g 1w z 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.