Statements below show-;d385ov eauf13s:fi cbjl hh three double-stranded nucleotide sequences. Which of these sequences of base pairs is possible in a DNA molecule? hf5abulo:e j3 c1i-f3sh8;vd

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 strucd1ul p2k (tbq)ture based on the tetranucleotide hypothesis proposed by Levene that DNA was made up of equal amounts of adenine, guanine, cytosine and thymine. This hypothesuld1pqt ) kb2(is 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 labeqekhuz6 w p:+3mbca;q qj0cw08rb)mnj-t q0,lled in the micrograph?

  A strand of nucleotides reads CCUAGAGCUUACCG. Which type of penf4 r8p4xfb7ox- no /bntose sugar could be founfnon/f8xx7p44- bb o rd in the nucleotides in this strand?

  Which of the following processes is most directly involved in the formation of nzehj+2n i+t 0b6g.fpn 1yvq r/ucleic acids sucq/ fgn. jrb+v 0y6hz ipe21n+th as DNA?

  What distinguishes uhqi+o + nqrp o2jb6:8n yb2lm2racil from thymine?

  Which statements are characteristics of a*l5fz3wi +526dafssm0 0xda) rm ny xz 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 ba)(vdzr ry epg*b9 3)uzse pairs, bp) for different specidvyz9 geb*rr(upz3)) es.

Which conclusion can be drawn, based on the table?

  How does the genetic code 4sq tiobu66nvy6:t; e provide evidence of universal common ancestry?

  The diagram depicts nucg(1(ccw0 uu4vr4t17nrdzl1lt vlj o(l p 8cu0leosomes.

Gel electrophoresis is a technique often used to analyse DNA molecules+vg b(79 geykk. It includes a gekb9kg ve (+7ygl 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 mR/sa3**fdm (t2psk ntj NA transcripts where the introns have bees(2 jdmfk np 3tsat/**n removed.



What is an advantage of the above process?

  Which of the following is a similarity between .lrw;lplb,p53n0s eseh, xf 6transcription and translation?

  The diagram shows the structure of a DNA fragment. Whr:zxs4k0wt6m jw5 a+/oa* jmcich bonds easily break and rk5*cmw0x a : az4/tjsom+w6j reform?

  What would make one DNA molecule more stable than another DNA molecule3zecw, *r)os v?
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 DN dgkeu(q,. lq84dbv 3jA or protein serves as the genetic material. They cultu.gk3 8bjv,q(uleqdd4 red 2 batches 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 p6tx +r+ak-btoz .or 7p k4/gofrocess are correctly matched in the table below?

  Which statement highlights the importance of nucleos-dqat pvj x+9+akmt.6c hfl)5 omes in DNA supercoiling ?

  The image shows many ribosomes on a mRNA molecule. Hse8/k flt- 7uhl2ed+m ow many unique polypeptide chains are being tr72eu/l kslt+e-dm hf8anslated?

  Which of the labelled structuresmwr8001boz9 vnta2z9aump0 y shows the correct directionality of the DNA molz pa80o 9mmtyb awz20n09vur 1ecule?

The diagram below shows the structure of DNA nuclk9x8 zyl2vwf7lw(oa. y/gz e29om xi9eotides.

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 involved cultured viruses that wcrfgu (ay3*f363xuo zere radioactively lr*x zu(cgy3 3uf3aof6 abelled with either 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, andwqk /qya40s y:+nwa:l R if S is a pyrimidine?

  How did radioisotopes hl)lyesz)1awn. x 3tbe *(k*hk elp make the investigations by Hershey and Chase possible?a*(x ew3.kt) el n)yzlkh1s* b

  What feature of the DNA molecule was utilised bq)c c;6vw l2vxy Hershey and Chase in order to identify that viral DNA is able to en)2w; cvqxc6vlter host cells, but most of their protein is not?

.

The image below shows a short fragment of the DN:9u4b 41btdwmy j+uh iA 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 nucleosome?wo *d3s4jon( y/ogjb3

  Hershey and Chase conducted experiments us8 ro mp8hx/gg u,8jj6iing 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 team of re6 g1/hh4n ed9zgr) fcgsearchers investigating the relation 6zhd1g9 /4c)nhggr efship 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 t-gu6 666 0m:vsg ovn+zqed kdxhat 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 short f((gu jzr/ b)uphz 27;lpazpw;ragment 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.