Statements below show three fp0.s;aa8wjb8dg h7 0ycj,eldouble-stranded nucleotide sequences. Which of these sepc 0j,bl8 y8.ajsf0wg7h; daequences of base 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 e x )xfu7m0a4w0 4on0rf/vjqnstructure 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 understanding of the structure, leading to the falsification of the inf)rm74v fq4/jnon0 euxx0a0witial hypothesis.

  What is the main role of the ribosomes label/r1zvs8+lt:nq pdgl (led in the micrograph?

  A strand of nucleotides reads CCUAGAGCUUACCG. Which type of pentose sugar co bv- xswv;q)o+uld be found in the nucle qovx- w);vsb+otides in this strand?

  Which of the following processes is most directly involve8jbv(mooib2 0d in the formation of nuclov20ji bo b(m8eic acids such as DNA?

  What distinguishes uracil st.u.sj)bft7 from thymine?

  Which statements aretae libq5ewaex q:6:/+:;rw t characteristics 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 seqw-e7p lcqk.xg7i3(g7sv a3b buence and genome size (number of base pairs, bp) forgxpisb e-7kb.g cv7 33 aqlw(7 different species.

Which conclusion can be drawn, based on the table?

  How does the genetic code provide evidence of universal common ancestryv3sclg)h59vxgn 1pamj:b 6 -t ?

  The diagram depicts nucu2oya *dz oxc.pe,pj5 g6*p/vleosomes.

Gel electrophoresis is a technique often used i/tol,8n + ippi/x;ut to analyse DNA molecules. It includes a gel and an electi +tptu ;xil8,n/ipo/ric 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 ,a006gftmh zcn8rky4 mature mRNA transcripts where the introns have been remz8 ,40ht yark6mf0gncoved.



What is an advantage of the above process?

  Which of the following is a similarity between transcription and transd ndz1+ s pz +dlvrt(an)g,*;flation?

  The diagram shows the structure of a DNA ftbkyblv z 8o8e m(-/z oo2ifqkqy.29ua1 (vu 0ragment. Which bonds easily break and reform8qk(y0te zz/ia v 8uv q29 my. lo2bfkou-bo(1?

  What would make one DNA molecule more stable than another DNA molechb*u ;; .2tj*klrtrg4 fz9tz bule?
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 whethea/7 gacf76 ugi 2gwam/r DNA or protein serves as the genetic material. They cultured 2 batches of viruses, one in 2ga g 7fig/ac wam/6u7a 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 cxfei-- n4edw2 orrectly matched in the table below?

  Which statement highlights the importance of nucleosomes i mzu5dj31fd7c -k6d7zg3 m: gg0 asinxb gwd/+n DNA supercoiling ?

  The image shows many ribosomes on a mR a22la;u*:njb /btlo yNA molecule. How many unique polypeptide chains are being trao n l;ybl t/2b*j:u2aanslated?

  Which of the labelled structures shows the correct directionality of the DNA mhj :aydo.pj95olecule:a ypod9j 5h.j?

The diagram below shows the structu1 0oamo hocpth: 9 wu5eiv;8e*re of 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 involved cultured viruses that were ramev fysuc 3f7gl2b4 k++.cg/)jwqy j;dioacti+bc+ uy7j .mgffg 2/)qykc;vjw 4es3lvely 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 pynp4 o;wg9q(c8plxnrbq+ 2 kq) rimidine?

  How did radioisotopes help make the investigations by Hershey and Chase possoj;u2 h kgm,hve*hv 5:ible?h*5;vug m2kvh :hjo e,

  What feature of the DNA molecule was utilr td6zspy6 ow03 e1p7xised by Hershey and Chase in order to identify that 6op7rt1x ysepdwz3 0 6viral DNA is able to enter host cells, but most of their protein is not?

.

The image below shows a short fragme68mqcqu n+mn+nt 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 nucleoso1/dylb 4ntm 0n)7j fzpme?

  Hershey and Chase conducted eznl q-2 2m-hmb g+ou0x 000ctgw * (g2oliooauxperiments using 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 of an experiment conductedi)g 1tkr8bg;ga / rv0vaxjdj i5 88vv, by a team of researchers investigating the relationship between the composition and melting point of dixj jk08gvgtria, 8;bva8/1vvr) i5 gd fferent 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 thatv rgg-og+iq x0tv w*8* are 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 shows13 9ybo/wm quj a short 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.