Statements below show three docc yr;g5 ba :92dvg5f c:)wzqnuble-stranded nucleotide sequences. Which of these sequences of base pairs is possible in a DNA molecule? yg2ca :qgw9b; )f5z5nv : cdcr

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 u:*daxk5r n+u 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 liur +du*nk ax:5mited 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 labelled in the micr50jd) ra u3t :j2sxwpiograph?

  A strand of nucleotides reads CCUAGAGCUUACCG. Which type of pentoszr j)q/ u*g 9zyn-p3 ;.upvhqiq-ha5xe sugar could be found in the nucleotides in this strand?i/qyxpr.; ) -zu-q9 n h*gzpj 5qhvu3a

  Which of the following processes is most directly involved in) xr db6 yuua)vwy88+y the formation of nucleic acids u)8)yyduya r8wb 6+vx such as DNA?

  What distinguishes uracil from thyminew5 6bxpzb,s pa66w2nyj me9i4;x-l;ii ay:ji?

  Which statements are characteristics of a DNA molechxwtln4 ,m:rhmn86 za,p. m*iule?
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 of base8x;2bfg woj;ojpa2p6 pairs, bp) for differj ;pjbp 6;f8gxwoa 2o2ent species.

Which conclusion can be drawn, based on the table?

  How does the genetic code provide evidence of universal common ancdyu3upa4k4 a0 estry?

  The diagram depicts nucleosomecg/-. m yizet;s.

Gel electrophoresis ipv9y 9l7e kfy3s a technique often used to analyse DNA molecules. It includes a gelypk3y9vf9e7 l and an electric 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 mature mRNA transcripm m:w*rc(c wxg2kj /rpyk-2-uts where the introns have been removegm r:k2um/* -krwpjc-c(ywx 2 d.



What is an advantage of the above process?

  Which of the following is a similarity between transcription and /syj7/ y qxpqkq)4uxwl( 0rg4 translation?

  The diagram shows the structure of a DNA fragment. Which bonds easily break gx(9gc wtdf0oj8ipi kvj8z ++e, ,x: pand zi+k,+cog0jdxe8 gitj v 8 p f,p:(9wxreform?

  What would make one DNA molecule more stable than anothg zz8ge.0v94ignaf+s er 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 whether DNA v6/:x,c4l15rovp7lksj adb ckcmq *4or protein serves as the genetic material. They cultured 2 batches of viruses, one in a medium contais* lkj:xp5176dol v4ca/bc 4mvcqr ,kning 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 processk v gr:,kt 31ye1woc*f are correctly matched in the table below?

  Which statement highlights the importance of nubrrfb0p q 0:l3cleosomes in DNA supercoiling ?

  The image shows many riboqo6 ac .4u 5crq1+wgilsomes on a mRNA molecule. How many unique polypeptide chains are being tran1g w6o ia.r5l qu4c+qcslated?

  Which of the labelled structures shows the corre ds2f gvo8. :l1(egmoph,kt1yct directionality of the DNA molecule1p8h2,oom d1:(fk vggyet s.l?

The diagram below shows thhe0.9/6d wmak a)mdb xe 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 experime i6 i v5g4nhd1 5*fod ;x0tlij:yb:f(yop wvp3nt in 1952 involved cultured viruses that were radioactively labelled with eit 0i:jw5y(d6onh;vv3tpf 1l4 d: 5xo*iiyfgpb her 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 Rvm*dyf3t-7 y mjp7ykes 6r+v3 jbu-q 3 if S is a pyrimidine?

  How did radioisotopes help may*lvmdi v dr3az: pbik50-j*+ke the investigations by Hershey and Chase possiblez*0pvdj 5adv:+3b- *i mklyir?

  What feature of the DNA molecule was utilised by Hershey and Chase in order to x ef 1v9(h ,o)upwdvs:identify that viral DNA is able to enter host cells, but most of their proteif(v) : h9ws1e ,xodpvun is not?

.

The image below shows a oogfamd.c8lmh r;ldp.rs 45 ,gw73- eshort 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 showzzojcdf/8j:ms88z;9wp ,x jks the correct components of one nucleosome?

  Hershey and Chase conducted experimentsz1x:(6xsecs nx/ni /t 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 show4xcl;oarqgr. 7ho6+x69xcc ms the results of an experiment conducted by a team of researchers investigating toxxr9o6gc+h r.ac q 47;6cmlxhe relationship between 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 are essential to all living organismsd6ue :taw)yea )hs.-a.
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 thz,45 kd:lb sjve 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.