Statements below show three double-stranded nucleotide se1p*to-7jr5n*4ok3vdt lty 8 is a n*pvquences. Which of these5njt v81p7di*r 3*4nkyptv oto s*la- sequences 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 structure based on the tet4+ax 82v 6kb;wwwncaofde.l0 ranucleotide hypothesis proposed by Levene that DNA was made up wva2;fno wk8x wd06.a+eb4cl 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 hypothesis.

  What is the main role of the ribosomes labelled i raxgq5 *s,rl2n the micrograph?

  A strand of nucleotides reads CCUAGAGCUUACCG. Whsy*.j+u*j,/lcugz bb ich type of pentose sugar could be found in the nucleotides in this stra*j*ly/gujcs,b . b+zu nd?

  Which of the following pro:wk8*,(de( fj lnkm sscesses is most directly involved in the formation of nuclnkd( (j:k*l 8w,ssf meeic acids such as DNA?

  What distinguishes uracil from th:ggiwy2.m-xtm* s( az ymine?

  Which statements are characteristics oo;sv8 gb(yqw/ f 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 of k;,nv c,u5p tj9ugqi/base pairs, bp) for diffe 5jg;uut/vi,p ,c qkn9rent species.

Which conclusion can be drawn, based on the table?

  How does the genetic code provide evidence of universv/m+ 8k8cr1b n4 g b.otae ss,76s g6fgq*wrcwal common ancestry?

  The diagram depicts nucleosomes..6rz : ;b ahw/rfi;qxj

Gel electrophoresis is a technique often used to analyse DNA moco pw je ,(oa n9*zl1scd6*t.llecules. It includes a gel and an electric fiel9 6*dlcjsoepznw*l a.1c,o (td. 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 /yu wu:h +:2z2lnsfyt7 z xn1utranscripts where the intu2u/:u2nh fwl+ ysynzz7 x1 t:rons have been removed.



What is an advantage of the above process?

  Which of the following is a similarity between v1m;7z m9hhjr transcription and translation?

  The diagram shows the su(h)2yc q*,cm 3cwvxhd 79tke+vv2 uctructure of a DNA fragment. Which bonds easily break and refqc, 73dh) (*2cv+ckyxue cuh v2tvmw9 orm?

  What would make one DNA molehfb3c g3zeu0 ww01b gr,pj 4v4cule 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 invkwqrf 0l b(ge,(;dha5 dw:tr8estigate whether DNA or protein serves as the genetic material. They cultured 2 batches of viruses, one in a medium containg;lrafd:wbk(0e, rhdq(5tw 8 ing 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 a )bscg u7q4/d9b7 cv z+zpqgw)re correctly matched in the table below?

  Which statement highlights the importance of nucleosomesn(z).umu9u 5bi .nint in DNA supercoiling ?

  The image shows many ribosomes on a mRNA molecule. How maruih3gji;)/ 2 5whchw ny unique polypeptide chains are being translateiiw ;/rw)u 23hhj g5hcd?

  Which of the labelled structures shlu 2.:srfcu( fewdoiqw8,* k1ows the correct directionality of the DNA molecul wdo8*ff(e.ksilcu2u wq1r, :e?

The diagram below shows the structurer s9:e65dj mcb 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 expe-r(naku:5n68xwqy; ne v snv7 riment in 1952 involved cultured viruses that were radioactively labelled with eith:kves- ( rqxnnnavu w8y;5 76ner 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 isiqyz9,3g af;z*gtt 5e,5c tpf a pyrimidine?

  How did radioisotopes help make the4tro91nl f0k n investigations by Hershey and Chase possible?l1t 0 f9nkrn4o

  What feature of the DNA rp8m8x5 h.vmovc+o 1jmolecule was utilised by Hershey and Chase in order to identify that viral DNA is able to en8r+1vp8moj .xchm vo 5ter host cells, but most of their protein is not?

.

The image below shows a short fragment of the DNA molecul jgo v)y,q3g6df/(mcce.



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 ofmvrsk46 9jhq 4 bd)+ndsid9/o one nucleosome?

  Hershey and Chase conducted experim3*0tot .h1r kqkpam0 )bogh2cents 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 de5i;erft/(x conducted by a team of researchers investigating the reladefx; 5iet( /rtionship 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 organisms. i6g9oiitmm:ga+: 4nv
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 fragm83 xtn j(4tvfkent 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.