Statements below show three doublu cn igdwf 5.5(lv0 nw5)5rkmttwe g6,e-stranded nucleotide sequences. Which of these sequences of base pairs is possibl055( dv5.nitul k5gmfw6 ,n)wc gewtre 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 tetranucl1rr3 bobx*kdeccv xo f4e 7h*+-gj ,p4eotide hypothesis proposed by Levene that DNA was made up of equal amounts of adenine, guanine, cytosine andck gorjd vr*x+epf*413,c4bhb xoe - 7 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 rolqc8tgx 6/vn9fee 2.dde of the ribosomes labelled in the micrograph?

  A strand of nucleotides reads CCUAGAGCUUACCG. Which type ltna9k3me3 a6*md l3efu78*7hh jc pl of pentose sugar could be found in the nucleotidatj36 e7p 9a**lmmfk 37hhcle3ln d8ues in this strand?

  Which of the following processes is most directly involved in t5p2wu1tf (xdhhe formation of nucleic acids such as DN (f2xd hu5tpw1A?

  What distinguishes uracil from lm 5ehh3)y)tg thymine?

  Which statements are chardsp x udy3wh5.* lii4(acteristics 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 base sequence and genome size (numberj(+rl5t3tlbk w4i,dq ivvi 72a5tg0 j of base pairs, bp) for(iir 3a,v+v5lt k jj72it054lw qtgdb different species.

Which conclusion can be drawn, based on the table?

  How does the genetic code provides(/mcq+,f oh z evidence of universal common ancestry?

  The diagram depicts nucleosomes.hmc u-,nhydflt22 r( *

Gel electrophoresis is a technique often used to analyse DNA molecules. It inclum7a2vu 8f vg*g4nh :yhe(mjbus0 1fg6des a gel and an el8yea m(h7uf:j6vs ufv g2g0hb*1mg4nectric 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 transcripts where the int: 1k* v-)6 sln2gsr fqgshtel(rog s62 -(htlvsk:g lnqr1*esf)ns have been removed.



What is an advantage of the above process?

  Which of the following is a similarity between transcription and 549t. dam edmz9azzr7 translation?

  The diagram shows the structurexhi29z1cm3.. 6or.z:okayexb/ *j qxq+zh wd of a DNA fragment. Which bonds easily break and reformd zx/ik.yzo.:1bo3j6exqmc hh w2ar*9.+ qx z?

  What would make one DNA moleculf,q j ekg3;ph;e 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 whether DNAqf wdb*x 9*zx9z y(qk)+ vw.ek or protein serves as the genetic material. They cultured 2 batches of viruses, one in a medium containing radioactivee dz*) .vfkxxzbky(9 w*+qqw9 $^{35}S$ 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 matched in thezjz;5hl (lwxdi,jhz,d5 p6o* table below?

  Which statement highlights the importance of n4vmr:5qp* sog bzmp; 35j mo3jucleosomes in DNA supercoiling ?

  The image shows many ribosomes on a mRNsij+bk9ulh+ * A molecule. How many unique polypeptide chains ar +s9ukl+*b hjie being translated?

  Which of the labelledknrg, wnh:)0a structures shows the correct directionality of the DNA mol w),ag:0knhrnecule?

The diagram below shows the struc6chn m- 3ly.,we7s7a eyze*xj ture 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 experima3biu ,)e*j:hny2 yldent in 1952 involved cultured viruses that were radioactively labue: ln2 y 3yihdbj,*a)elled 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, and R if teb .t p42f v-(pxh;21ypuhdbS is a pyrimidine?

  How did radioisotopes help make thc3c26h ad9xz 92*dbgr hvp(wapb1n 7d e investigations by Hershey and Chase possiblehbv cpdp2 *1 3n xra2 c6z9(ad9dwgb7h?

  What feature of the DNA molecule was utilised by Hershey and Chase inoeh)j7zc1 c/a order to identify that viral DNA1/jzc) he7oac is able to enter host cells, but most of their protein is not?

.

The image below shows;c:jx8;q h d(cfu ,fyg a short 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 components of one nucleos aw/kndub r35 n89 4de r-zb-g.u1zutlome?

  Hershey and Chase conduxb7 :etriu7d (cted experiments 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 conducted by a team(.ah9ogynya :v/ o gdlg*h.q: of resear 9n:q.d(a.hghag :ylvg/o*y o chers investigating the 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 livs *rsjw:x/io8b1c kl 3ing 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 fragment of the DNA moleculeeq;c (q+g1d.sfqytq5 .


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.