Statements below show thn1rl 396svexbu1.qnm;n5 u izree double-stranded nucleotide sequences. Which of these seb.xe5 vu;sq61 z9nnnm3 u 1ilrquences 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 tetranucleotide 6eeil1cwqk . +n3 qd2ji1sth :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 understanding + l icw2h1eqn tji3.e1q:skd6 of the structure, leading to the falsification of the initial hypothesis.

  What is the main role of the ri)pt o2z69ondubosomes labelled in the micrograph?

  A strand of nucleotides reads CCUAGAGCUUACC:xuz .jl dvjn i,ckf+- iwt260)u) ikqG. Which type of pentose sugar could be found in the nucleotides in tk+nij6:-z .k)x,iutqv) fu02i lw cdjhis strand?

  Which of the following processes th wv uw).40z0, rwf8gamg8h;d7 jwaa is most directly involved in the formation of nucleic acids such aswt;u8z a wf0waggh04m,8.r7) hv ajdw DNA?

  What distinguishes ur yyhexu8rvo88 rwo*21acil from thymine?

  Which statements are characteristics of a DNA molecule? dxd p pg2043gtaxbm :3
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 (ndy 7m8k/sn+)z l9 gqqfumber of base pairs, bp) for different speciyq /sl97ndk z8fg+ )mqes.

Which conclusion can be drawn, based on the table?

  How does the genetic code provide evidence of universal common ancestu16j)ha; b isdry?

  The diagram depicts nucleosdt1gv f,/3 ctbomes.

Gel electrophoresis is a technique often used to analyse DNA molecules.guvm.:yu)tc 3 7)de vu It includes a gel an:)vevu tuy7mc).3g udd 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 an te4e0s 30vbr1n 9/ajemm9 xopa*w lj*d three mature mRNA transcripts where the introns haoepwx ev*ls9j4 *am0r0 jb1 3etma /9nve been removed.



What is an advantage of the above process?

  Which of the following is a simf 0s 8ajfg4;dzilarity between transcription and translation?

  The diagram shows the structure of a DNA fragment. Which bovf;kt:q-mc0n n yux, 2nds easily break and reform? yxcqf;t0 -kvnnm u2,:

  What would make one DNA molecule more stable than an,n qrto38 v*t7qbay u5other 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 whxcs,k g1e9zxc2 m)j1m ether DNA or protein serm1x2m) c c9ek,jg1zx sves as the genetic material. They cultured 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 process are correcw4f(k3ol:g8 y mra4 l-om (nwwtly matched in the table below?

  Which statement highlights the importance of nucleosomes in DNA supercola/uab q7q-- 4 j1vunoiling ?

  The image shows many ribosomes on a mRNA molecu*.1stu8xx:l.ub(u tsid 4p nile. How many unique polypeptide chains are being tr x8idnt4txp1s i*b. uu. (usl:anslated?

  Which of the labelled 16ny- wadw2w s:cd7tzovvx9f: :q2 r dstructures shows the correct directionality of the DNA molecunt29f:ws y dcz27avw q rod6v-1x wd::le?

The diagram below shows the structure of DNA nucleotidq;3p 9e cftb,,,ry;hlrwgxk6:jf : gves.

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 cuq nrn g 1(7vzuzumnjbdvq4s3, q6: e13ltured viruses that were radioactively labelled n3 73du(smqj1r u nv1bq 6 :vzzenqg4,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 S is a pyrioscb55d+57 8fa j cnilwqe ;e8midine?

  How did radioisotopes help make the investigations by Hersh qxo 47s5gzo7gnqqwz3u11a f ;ey and Chase possiblea37xn;fgwzqq7 o51so4 u qzg 1?

  What feature of the DNA molecule was utilised by H)5g bpfxqz z65jmtx,2ershey and Chase in order to identify that viral DNA is able to enter host cells, but most of their prote),j5 6xmzx2bqz5p g tfin is not?

.

The image below shows a short fragment 7oalbz(zi6:tfd 0:jx 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 nucleo:lj)*ftf;paqj+qyzel + 60ogsome?

  Hershey and Chase conducted expj.xlacr eqk22 31q1r teriments 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 experqnnzn*b:f. 5tf 0p;g0al m81 sol+z ;r h0ieakiment conducted by a team of researchers investigating the relgn m1;a5 8k.li;bple+fz :0zrn t0hs0nfo aq*ationship 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 acfe35q4w2 kj8 zc6sjj qids that 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 fragment of the DNA mole(6ttruq af t, ca1v9n)m d07zacule.


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.