Statements below show three double-stranded nucleotidp866 pm-8np cem:uafj1+ e wode sequences. Which of these sequences of base pairs is possible in a DNA cpa-1m euof:6+d8 ne6 wmjpp8molecule?

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 +*nqcvhbdemq7m ,0uf ; ;z 7ikthe structure based on the tetranucleotide hypothesis proposed by Levene that DNA was made up of equal amounts of adenine, guanine, cytosine anc+*z; k7, eb 0nqvm7uifmqhd;d 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 role of the v 6 rwhr(3px+bz6:tg 8uuqhn-ribosomes labelled in the micrograph?

  A strand of nucleotides reads CCUAGAGCUUAog2hyhv7jk/ 4bx y :iild,;+m CCG. Which type of pentose sugar could be found in th;jhk o b:mh2d74lxi, vi+ /yyge nucleotides in this strand?

  Which of the following processes is most dibv*)m 0- zr1jricr ii)rectly involved in the formation of nvb)r-r0)1zmi*i cri jucleic acids such as DNA?

  What distinguishes uracil from thymine? ;1ze;z(79 lwxfcvakr+wz q+f

  Which statements are characteristics of a DNA4 yvbkf1i9*h z 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 geno7x (;5c0 q)mf +trohqjdq4x gwme size (number of base pairs, bp) foq7 g+qx0mf5ro;(t x)q hcw4jd r different species.

Which conclusion can be drawn, based on the table?

  How does the genetic code provide evid) yd)m f3q 7hy98rabudence of universal common ancestry?

  The diagram depicts nuv**j:v)a cugucleosomes.

Gel electrophoresis is *hhj/u/9e.pca i -gja lky6py(j2ep7a technique often used to analyse DNA molecules. It includes a gel and a k7jcj- p/ j(p i9ae2y.l6g uhph/ya*en 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 e3w.v,aa rj xzh10f w.and three mature mRNA transcripts where the intr.eh0jz .afwa,3v x rw1ons have been removed.



What is an advantage of the above process?

  Which of the following is a similarity between transcription a(.rxo k qb8;q/r(m )uaie2+a tk+lwwosz+ y3 ynd translation?

  The diagram shows the structure ofz64b+ bylajw3 a DNA fragment. Which bonds easily break and refa4 6wj3lyb bz+orm?

  What would make one DNA molecule morheas lv: ( 37j hthbvdflve a5*h7;g-j a-er88e 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 DNA o)n; wybju;pg ;r protein serves as)yup; n bj;;gw 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 correct83f t-l;6gk3n-b m1ogpq gesf ly matched in the table below?

  Which statement highlights the importance of nucleosomes in DNA supercoo4 b-965 dzu(qn/gkmcxymnz :ma+p+ ziling ?

  The image shows many ribosomes on a mRNA molecule. How many uniq j-z33:0mgc.l// jcoq knclesue polypeptide cha.qgm/s j3 cnl0ckco:/j lze -3ins are being translated?

  Which of the labelled structures shows the co+ ,h,oc5eub fg ogq*9x+zlq5krrect directionality of the DNA molecule?ofg u egq 9,b++5khq5lc,*x zo

The diagram below shows the strup6vwr l0;pgpv/0t uk) cture 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 experiment in 1xj/l9gymy wnib3 rio6 ( ay4(.952 involved cultured viruses that were radioactively labelled with either sulfur /yl x9jw my.(gibry3iano(64 ($^{35}$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 isgdm8jv7wp sf i.-a(9 b a pyrimidine?

  How did radioisotopes help make the inve1nztdg xbt::hvm p 46*stigations by Hershey and Chase possible?g4d::*nxvb 6thpm 1t z

  What feature of the DNA molecule was utilised bb m:tzc)d j*fpa:5 qr7y Hershey and Chase in order to identify thtaj m:cf r5bdp*zq7 ):at viral DNA is able to enter host cells, but most of their protein is not?

.

The image below shows a short fragment o2*i/fk m400doximsyrf 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 cih-z1qg,w7p/-vq)w)ihi +k *- fvzqs 6agyztorrect components of one nucleosome?

  Hershey and Chase conj5b s 7rf g6)knvvh 7ug*5cja46hz gc1ducted 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 resultox yjx mr +9h5zv*4u7ds of an experiment conducted by a team of researchers investigating the relationship between the composition and melting point of different DNA samples. x4+5o7mzdy jru*v h9 xAt 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 a/z:+mzjzzk 4rt*i*gbll 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 molecudf4x5:j us:96lrn5gl+dsnd 0un .aicle.


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.