Statements below show three double-stranded nucleotide sequences. Whicmw2 -vvof1x r1qu2c ct00m-jthw7p7kh of these sequences of basw m1vhc u-otm07t 07w2p1xjvr-ck 2fqe 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 sxkee3yt.hwaxc .;w ; 4tructure 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 accurahce.3w.;xxek ;yawt 4 te understanding of the structure, leading to the falsification of the initial hypothesis.

  What is the main role of the ribosomes labelled in the micrographpur2+ 1fsue v0m3imi ,?

  A strand of nucleotides reads CCUAGAGCUUhcu0h a t7-c,nACCG. Which type of pentose sugar could be found in the nuccac7-t , hhu0nleotides in this strand?

  Which of the following processes is most directly involved in th/swx89 (8tflu (l zsyrznr5s3e formation of nucleic a8r(ly( 5w /f3uxlrztss9n 8szcids such as DNA?

  What distinguishes uwae1 mh;e:zo. 156zxnbzpx6.yvy / avracil from thymine?

  Which statements are characteristics ofy6v,8 / 1he;yu wrvv,q 2+uo4nmyptx q 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 sequence9vc v ihrfeqn(v7/ p/4 and genome size (number of base pairs, bp) for d 7 fpcvnv/v4/(i9hq reifferent species.

Which conclusion can be drawn, based on the table?

  How does the genetic code provide evidence of univers0a i* -stnkave(e 78acal common ancestry?

  The diagram depicts nucqfic u*y /i5*jleosomes.

Gel electrophoresis is a technique often used to analyse DNA molecules. It iwdp1 c .,uqp*is.svj85er ch4ncludes a gel and an electric field. The diagram below shows the outcome of gel ele4h rqc,sp.idw8pvcj.u5s*e1ctrophoresis.


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 mRNAj(1udy k3:gqu transcripts where the introns have b( 3u:quy1j gdkeen removed.



What is an advantage of the above process?

  Which of the following is a similarid4-fvok2y 4mi ty between transcription and translation?

  The diagram shows the structure of a DNA fragment. Which bo qh; sj-08tepoy. y0dnnds easily break and re ns.- ;dphot8yj0ey 0qform?

  What would make one Dbfa* )p bnzpg4)0r ysz:d6 ki1NA molecule 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 ink fk 7e i;lyxpiu(2kd6av20 yuwq*6v9vestigate whether DNA or protein serves as the genetic material. They cultured 2 batches of viruses, one in a medium containinykki6 xqkpieu2d(lu9a6 *w v0 2;fy7vg 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 pi- 15mnhieg* trocess are correctly matched in the table below?

  Which statement highlights the importance of nucleosomes in DNA supercoilingclv: 9zfmmpvq+9/b.g ?

  The image shows many ribosomes on a mRNA molecule. How p2v0yllzk xb.qlnui s9+ +-/hn8xb /omany unique polypeptide chs0n/lll8 u+ q2+-k 9yh nvox/x.bzibpains are being translated?

  Which of the labelled structures shows the correct diz 7cz0mygf11z rectionality of the DNA molecymzf g1z107cz ule?

The diagram below shows thg;z7y,a* uv d4(sc92xkmfa dte structure 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 19t ujxt ro-kafr*614k z:-f0n c52 involved cultured viruses that were radioactively labelled with either sulf -xtrkruf0n -jcat :kz41o*6fur ($^{35}$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 pyrimidinw4xbt7.; uwt 2cu5m tte?

  How did radioisotopes help make the investigations by Hershey and Chasetulka:: w ke5epb+98c possible?8:+ btpcw5 :9aekuekl

  What feature of the DNA molecule wa4q i+fpr r( d4;k/pjg2(gucn1(kadf os utilised by Hershey and Chase in order to identify that viral DNA is able to enter host cells, but most of their protein is not4/iu(nck p ad(j+qr;f4 2 p1 frgokdg(?

.

The image below showo/y)v7iwsthox3 a34q f) 3casr awd.-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 nucleosilj/u)*/ xpjsome?

  Hershey and Chase conducted experiments * dslu-finl4x3d2e 7o 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 conducted by a tea nf20xf59r7f)juqt u ntkj k/;m of researchers investigating the relationship between the composition and melting point of different DNA samples. At the melting point, the j9juk0;rfn5t) xff7 tu/2 nqkDNA 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 organisms.;feim,d;x j7)bcutr:
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 moliki ,t 4oihe+ z f;t-8+0hivmoecule.


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.