Statements below show three double-stranded nucleotide sequences. Which of thes,,axbm bu1/g9h pkc m2y)bud:e sequences of base pairs is possible in a DNAgdk),byhcu 9 :1,m a pbbxm/2u 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 showd9 qzk(t. avv w:xe5 zoth+e00s 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 und0a0dqtx.9v: hv5zezt + ok(e werstanding of the structure, leading to the falsification of the initial hypothesis.

  What is the main role of the ribosomes labelled in the microgjno* 8y ovoim8w(nm ; (vzj(:araph?

  A strand of nucleotides reads CCzfgn+sxu1(f *ty y9:aUAGAGCUUACCG. Which type of pentose sugar could be found in the nu*t(gnuzsy f9:+yx 1afcleotides in this strand?

  Which of the following processes is most directly involved in9w 2a /zqkwiq8p 3(j;j ksxk)f the formation of nucleic aj 8wk w9q xq3kip(zj;fks /a2)cids such as DNA?

  What distinguishes uracil from tr(irit /c *k8lhymine?

  Which statements are characteristic amy +xr*r82fzs 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 j+t9juq nct0g2. 2btwof base pairs, bp) for different sjnqtg.2u+t ctw2j09 bpecies.

Which conclusion can be drawn, based on the table?

  How does the genetic code provide evidence of unioq h.brcu*(z 1versal common ancestry?

  The diagram depicts nucleosomesh2+jt c2o 6(jr38my3/ozutxq: fegw x.

Gel electrophoresis is a tu (:pjw 86ojm 8a)zogqenf )i 5n6g9eaechnique often used to analyse DNA molecules. It includes a gel and an electric fie)zo): ge8nm8f 6ujqaiao69g(wn ej5pld. 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 shows6skvu l19 mxk, pre-mRNA and three mature mRNA transcripts where the introns k 1lsu 6vmkx,9have been removed.



What is an advantage of the above process?

  Which of the following is a similarity between transcription and /tx1v: w4ros 9x qdsgj1nb;6ztranslation?

  The diagram shows the structure of a DNA fragment. Which bonds easily b*z x* cl7uuhg3e9uyl+reak and reform? *9l yzu hle+ xcg*73uu

  What would make one DNA molecule more stabl1eowuuk7 2m99pgp9v d*dryh0 e 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 iqmmy;-wr:f z4 nvestigate whether DNA or protein serves as the genetic material. They cultured;z:m4-qw yfrm 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 tabyqw xf j0 zp+ kb8savf3-z.6b:le below?

  Which statement highlights the importancv)iz7gudnjsw /9l 0dcqyv:ca u8v .83e of nucleosomes in DNA supercoiling ?

  The image shows many ribosomes on a mqcj q-r+92zxejbsv, 9s +g u0dRNA molecule. How many unique polypeptide chains are being translated? -2xjs+d gucj,90q zb r9 ve+qs

  Which of the labelled structures shows the correct directionalit 6xvdd-.c,ru hy of the DNA molecule? dxvd 6-h ur.,c

The diagram below shows the structure of DNA lci1l uhp9 b+/v(a *(b; eyru:c;cswo 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 involved cultured viruses 5mf kk0z8cn0ro /l 9hdthat were radioactively labelled with either sulfur 0rh/o0lkz cf5 nmdk98($^{35}$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 .*ba+vs ddv/tif S is a pyrimidine?

  How did radioisotopes help make the investigations by Hershey and Chase possiblw.(f8x3ame7 a28vq n7vt xy 3fstt *cne?fx7nvte(832tc7my*.ax saw f tv8q n3

  What feature of the DNA morkbdw ej;q0,8p tym13 lecule was utilised by Hershey and Chase in order to identify that vi3ymrd0b8ekj tw p;1,qral DNA is able to enter host cells, but most of their protein is not?

.

The image below show-lm o*g-l7 a.o+eiadz s a short fragment 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 the correct components of one n*y;d .tvv2cl hyv: w7bucleosome?

  Hershey and Chase conducted experiments u3 h /bc(pmdm;fsing 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 oszxr+(bc7p g6,s- liyeec :7,foe*ue f an experiment conducted by a team of researchers investigating the relationship between the composition and melting point of 6rc :esyfsbx-*o z7ue i+7,pg, le(ecdifferent 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 liviynf3 q h.rl)2j02 we:eq y(hhpng 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 molecuo:mnsn 4(j3 kble.


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.