Statements below show three doublejl( bwk309v:ecw8w qx-stranded nucleotide sequences. Which of these sequences of base pairs is possible in a D8wkel 0cwvj(9 bqw:3 xNA 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 hypothesis prifr+3zm9 yslx jz.*l/c)a ek. oposed 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 accurk. 9+cfx.rlzis)yej/la m*3z ate understanding of the structure, leading to the falsification of the initial hypothesis.

  What is the main role of the ribosomes labelled in th,m 2mrqg:v;ro b 9 6mu01,64u rrssxzxcaxdo/e micrograph?

  A strand of nucleotides reads CCUAGAGCUUACCG. Wh.g 9tk(hh0p 7:nncbllich type of pentose sugar could be fop 0:l.g lntcb9h(k7nhund in the nucleotides in this strand?

  Which of the following processes is mos n( 7w1q+v1z n3yjjwhvt directly involved in the formation of nucleic acids such as Dhvqy+(w17 nzjvjw n31NA?

  What distinguishes uracc4tv35poc q:xn i m22 vqq+nd8be,k e nn6ls62il from thymine?

  Which statements are characteru)lo0*, clkkcb 8t2mvliv 9t /istics 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 an -1hva u(51yqyotf)w cd genome size (number of base pairs, bp) for different s)u15afv1qo y w(c th-ypecies.

Which conclusion can be drawn, based on the table?

  How does the genetic code provide evidence of unive rl.n*u7+1 wpn zei4sjrsal common ancestry?

  The diagram depicts nu urhunox ;4/-h*is-u3wal e7ncleosomes.

Gel electrophoresis is a technique often used toxt 9 j2gv 9-aj3 we-(rlu;byap analyse DNA molecules. It includes a gel and an electric fieldy 9bpwj --e93xul;aa(jv rt2g. 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 shown , la.o(w04v0 pgpsbus pre-mRNA and three mature mRNA transcripts where the intron appu(lo .v 4b,sn00wgs have been removed.



What is an advantage of the above process?

  Which of the following is a similaritv40zyu *, qlxilua6v8y between transcription and translation?

  The diagram shows thnx:e6e.re 2 gve structure of a DNA fragment. Which bonds easily break and reergn v:2ee.x6 form?

  What would make one DNA molecu 2 slupky)yy1e7g7*od le 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 inveg,c, gwcujjjz ;/os73stigate whether DNA or protein serves as the genetic material. They cultured 2 batches of viruses, one in a medium containing radioactiog7gj u,c;czw j3,s/j ve $^{35}S$ 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 corrm 1- ,4fb bajqp;)rue7 oxu: l/wh:gjkectly matched in the table below?

  Which statement highlights the im0frf mc;6ja 7mportance of nucleosomes in DNA supercoiling ?

  The image shows many ribosomes on a mRNA molecule. How many unique polypeptide cwar /nf 3;yzjt-:av -yhains are being t:yf tn/3jr-vzwa y;a- ranslated?

  Which of the labelled structures shows the correct directionality of theuvq 16r6mlmbcm:uxww o92s */ DNA molecule*2vrqc6/ 1 womlxu sbw9u6:mm?

The diagram below shows the st w+* 13f)pcwg rhxiod8ructure 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 qb n)to) crj5 *)ev2*h7udgcx8on2 ju1952 involved cultured viruses that were radioactively labelled with either sulfur (g5ohu)n r27co cjxtj)bed 2q)*n *u8v$^{35}$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 pc rphr0m:,hb2j(cl p4yrimidine?

  How did radioisotopes help make the investigati.3a8,rjjppd) bs on 3bons by Hershey and Chase possible3 jno .)ps8d,3pajrbb?

  What feature of the DNA molecule was utilised by Hershey and Chastj52r .dqqc3 we in order to identify that viral DNA is able to enter host cells, but most of t25j3 qtq .rcdwheir protein is not?

.

The image below shows a; .*aseau;70) w u zpiejfu /vleo2n-r 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 o80 soyv3tn w6 jd0s5f;s :lsqgf one nucleosome?

  Hershey and Chase conducted experiments using the radioactiveup 8a bpik xg691ss*y2(jv1ym 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 cond2 +y7s8vkbu4- nrghov ucted by a team of researchers investigating the relationship between the composition and melting point of different DNA samples. At the melting point, the DNA double helix sr+ nuyhgs72-4 vv8obkeparates 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 tha,w- /*xzj/tbgx0b wdy k+op;pt 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 D3f fvbp.) b.qf hvbi/+NA 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.