Statements below show three double-strandeeuj)bbeg6;n sf.9x8ho h o ;+ed nucleotide sequences. Which of these sequences of base pairs u. 9f )go;hx;e8j6benso b +ehis 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 tetzx/, ymmbmy-qo9 f y .z4rf8n/y)7tpjranucleotide 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 understandzy r8 b/ /x9o7y mtmp-yf4nzjqm,f .y)ing of the structure, leading to the falsification of the initial hypothesis.

  What is the main role of the ribosomes labelled inb;5i+.york n4 :lap jb the micrograph?

  A strand of nucleotides reads CCUAGAGCUUACCG. Which type of pentose7o xt8r g x d0h7mna4;ueudu54 sugar could be found in th; 7hdrag n x7m448 uetu50xduoe nucleotides in this strand?

  Which of the following processes is most directly involved in the formation ,ru /x)f )axo0+0vadwo zor2ubdssdd83 n2 -bof ndds z8a+2udnf osu0 -)o dxrb3r0/va)x2ob ,wucleic acids such as DNA?

  What distinguishes uracil from +d1sxw p9hzs5j ;up+y thymine?

  Which statements are characteristics of a DNA molecule?u;3sxij 7x;hh
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 (numb lw .q 9i2:n/clf/xrppiu) 2yher of base pairs 2wu/icl:nh ilx.f29qpyr) / p, bp) for different species.

Which conclusion can be drawn, based on the table?

  How does the genetic code provide evf*g u6vs(hu y)idence of universal common ancestry?

  The diagram depicts ;1 mm ixphnb49nucleosomes.

Gel electrophoresis is a techniqu94 l7r:ebwuuo ;2yt lne often used to analyse DNA molecules. It includes a gel and an electric field. The diagram below shows the outcome of gel electrophruw7 uolnt;ey9lb: 24oresis.


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 pred* i -vs(fry: -s-fmskt 3ymh2-mRNA and three mature mRNA transcripts where the intronssyk*rtm(v--hd f fs -sym2i:3 have been removed.



What is an advantage of the above process?

  Which of the following is a x ppx.qz14lie e *n(.7wwgf8g similarity between transcription and translation?

  The diagram shows the structure of a DNA fragment. Which bonds+zylck*64qz ug+df w 0 easily break and refuzl+6+y0 4wzgc f*kq dorm?

  What would make one DNA02t ik:b:ocm zc wdd( kqo*p38 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 investigate www.w mas ;hbk6q-7e u1hether DNA or protein serves as the genetic material. They cultured 2 batch ka ;mwqwe7-w .u16bhses 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 correctlyia(. ;x5zrpj x matched in the table below?

  Which statement highlights the importance of nucleosomes ini(k-lcxe tq5 94b:o* os*efal DNA supercoiling ?

  The image shows many ribosomes on a mRNA molecule. How manyrhx8x3wdk 3/a le);rx unique polypeptide chains are being transla;rxer33x)k xahw8dl /ted?

  Which of the labelled structures shows lg5z3 v5 6f:zyhkyhk -uw7k:tthe correct directionality of the DNA molec g3 kzklh6:yywz:tfk h57u 5-vule?

The diagram below shows the structure of DNy3 n+y.yot(krbcfq 9 7A 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 in4jgzbl)dlw)dj (1h fza)f4jh(ko 0 zrm (+ 1aw 1952 involved cultured viruses that were radioactively labelled with eit(z glda()1zjm1 hf4za4flw)jk 0rdj(+h)w obher 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 pyrimp ,c dh721mnriw 81g5d9nmnzgidine?

  How did radioisotopes help make the inves r+ 6 l:e.iqv8 )itjrk1dnlp2vtigations by Hershey and Chase possible?j r1i:k6 lql i.+r 8vevptdn)2

  What feature of the DNA molecule was utilised by Hershey tg8bx g9veczw9o y-bb 1if;81 and Chase in order to identify that viral DNA is able to enter host cells, but most vci8zoy19 g bf1 e9wbb ;-8gxtof their protein is not?

.

The image below shows a shox6+ycs /iw87gvz g (5oq( d(alpv1kmort 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 componen (old2gs:aqx7;3dv0tvfl 02pu0f fdkts of one nucleosome?

  Hershey and Chase conducted experiments usa*w7, k eaz-xjing 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 5;r*cskqdvx mbj8,8e by a team of researchers investigating the relationship between the composition and melting point of different DNA samples. At the melting point, the DNA double helix separa 8ecxrq* ,v mkj;8bd5stes 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 allqi w0so8 -fs6l 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 shows a short fragmen9t ifu. rj/2uj(g8csiim71eg t 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.