Statements below shos2;h/f ltmh(j w three double-stranded nucleotide sequences. Which of these sequences of base pairs /jtms(f l2;hhis 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 strupzyuak f3 rfkh -0/./ccture based on the tetranucleotide hypothesis proposed by Levene that DNA was made up of equal amounts of adenine, guanine, cytosine and thymine. This hypohy3-zk a.fp0/ ufcr/ kthesis 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 in the micrograph?b6fnvm*v3y cv8.3v tf

  A strand of nucleotides reaig9;kqncd -1i;vl7m hds CCUAGAGCUUACCG. Which type of pentose sugar could be found in the hv1dg7 kncm -q;i;i9lnucleotides in this strand?

  Which of the following processes is most directly involvu g+fv(;3 zid) kmjg5med in the formation of nuclei+j u)gkmfi;5 v 3(mdzgc acids such as DNA?

  What distinguishes uracil from d qqx v3eo5ryn;s86nta,1l/u,u j a*hthymine?

  Which statements are characte( 1fxujsq)ye3 ristics 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 bas+ :,d-mcihy1zze njwezq 9;-se sequence and genome size (number of base pairs-ew,+cde q ns; mh-z9yj:1iz z, bp) for different species.

Which conclusion can be drawn, based on the table?

  How does the genetic code provide evidence of universal common ancesyd5eugnx- 58umi7 g0 rtry?

  The diagram depicts nucleosomes,ozcc p,o**a4iwx4ia .

Gel electrophoresis is a technique often used to analyse DNA molecar i.o6-czaltf+96bm/5ce ff ules. It includes a gel and a ze6lfi/ a5bac-o6m+ f9.ft rcn 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 thrt/, 3h- wrebeiee mature mRNA transcripts where the introns ha 3- e,r/twbehive been removed.



What is an advantage of the above process?

  Which of the following is a similar4g+4 ,6tfwno y* yfmo1vyf/ kwity between transcription and translation?

  The diagram shows the structure of a DNA fragmendy g0qnw1m)a (t. Which bonds easily break and refogqn0da ( )1mwyrm?

  What would make one DNA .6p1tsq :c3zo p bwqu/ tz(9scmolecule 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 whethmrae666jy qy6u 8ho90qx vr8m er DNA or protein serves as the genetic material. They cultured 2 batches6 mhye9ryvrxo 6qjq0u6a88 6m 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 correctly matchedyak0 c*6 ,hr k;(utmgw*ww u4k in the table below?

  Which statement highlights tpt 7nq vf) y*m lv)s8p54krgh/he importance of nucleosomes in DNA supercoiling ?

  The image shows many (27 wv mwg0p*p wf6htoribosomes on a mRNA molecule. How many unique polypeptide c0 mww2h*6tg7wvpo f (phains are being translated?

  Which of the labelled structures shows the correct directionality of the DNu-m+v vti*nj v qqs0a78a5pm1 A molecule?*05num v+iajs 7avv-1mtqq8p

The diagram below shows the structure a)1zv l/szd 1fes obk7( xq58k 7(qigsof 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 * zchis+ p x(lhh: +n4qj1)rcginvolved cultured viruses that were radioactively labelled with either sulfurgx hh chp1(*+)z ilcs:r4jqn+ ($^{35}$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 iwji+ydcl:mp ,)1 9y1c7zvyeR if S is a pyrimidine?

  How did radioisotopes help make the investigations by Herp c 1g)krc64(qwyw hp*shey and Chase possible?qk1c6wg ry*()p 4wphc

  What feature of the DNA molecule( k o,w;,ju(y islua)y was utilised by Hershey and Chase in order to identify that vir( w(k,isl,ujyao uy );al DNA is able to enter host cells, but most of their protein is not?

.

The image below shows a short fr5b;aq4j 2 ke yq8spb1pagment 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 corru rl1 24-lootp2 ijmn -wsu7;yect components of one nucleosome?

  Hershey and Chase conducted experiments usingjh.v z:lp)p ;utoy-qr, o ;zl+ 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 showsmxezb8 n1 7hv n:k3o(p the results of an experiment conducted by a team of researchers investigating the relationship between the 1 hoekmn:( pz7bvn38x 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 tha0p):sgi lb,envujyn5n6 cq9 4 t 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 shows a sho)5vlcihb7d)jdw6gbkm3rzr 26yz1 8c rt 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.