Statements below show three double-straa x*- . 2er/a1r.xbl t2dmymyv ;qofl1nded nucleotide sequences. Which of these d.y/ mbr2;1ox1e y*- a.xtrlqv mafl2sequences 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 tit;z ,d-vjx 5vhe structure based on the tetranucleotide 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 of the structure, leading to the falsification of the in zt-d,xv5iv; jitial hypothesis.

  What is the main role of the ribosomes labelb9y, n3 kght)nled in the micrograph?

  A strand of nucleotides reads CCUAGAGCUUACCG. Which type of pentose su,w aud+ m;azf-438c nfprd -bqgar could be found in the numn z;,ub wd84r +dff-a3- aqpccleotides in this strand?

  Which of the following processes is most directly involved in the formation 97kq54x)spv 4urgm +tndwq:dof nucleic acids such as DN s9+w vn)r um4d7xqg4 :pd5tqkA?

  What distinguishes uracil from thymdp1w hg5.h68d8 vqq qoine?

  Which statements are char)8tef (k-gsde+ w:hw*bs ar(bacteristics 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 sequenczh n6b: zf78cre and genome size (number of base pairs, bp) for z6hb78: rczfndifferent species.

Which conclusion can be drawn, based on the table?

  How does the genetic code provide evidence of uu3 ix,p9jtodj s/g,.d:t tx -oniversal common ancestry?

  The diagram depicts ,9 ubbjy;/ljc9 sclji2ukm7 (nucleosomes.

Gel electrophoresis is a tecv5/2 m *pflg er5slws(hnique often used to analyse DNA molecules. It includes a gel and an electric field. The d*wf5s5 l g2mse/( plvriagram 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 p9+jan u4t*tuj ht w. ni2yz+n8re-mRNA and three mature mRNA transcripts where the introns have been removed.h2*+t j uu4ytazw.n+j 9n8ti n



What is an advantage of the above process?

  Which of the following is a similarity between t5.i 7fb yygq. olsw*0qranscription and translation?

  The diagram shows the structure of a DNA fragment. Which bonds easily break and h nc )4ktrmzzwt t)t; i)i/lxg5;c3d 4reform? d4gc));cw/ 5ttn m);thtzizik l43x r

  What would make one DNA moleculep+welv4 x:rr0 8 fx/v jq9r8in 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 whe( jjnhdbj- 5ci7 v;mc1ther DNA or protein serves as t1jn ;c5 dbj7hvmc -ji(he 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 correctly matched in the table w8;euv( z+zxn y;do3ebelow?

  Which statement highlights the importance of nucleosomes in DNA sup.cp+ hztb/ dk-ercoiling ?

  The image shows many ribosomes on a mRNA.f :7w o 9nmgfjc7oce1 molecule. How many unique polypeptide ch7ofc: gj7mn1f .9 ecwoains are being translated?

  Which of the labelled structures shows the correct direct+r6a /cx ab+dgionality of the DNA moleca arg c/6b++xdule?

The diagram below shows the struce 8czcg fl390;vp hp),w;mauk 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 exuhl8wy v2 p)x/periment in 1952 involved cultured viruses that were radioactively labelled lu)v/8y 2xhwp 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 pyrimh +r7 cy wfr51zezsk/9idine?

  How did radioisotopes help make the investigax;d fldc(sexjs;+s) 1tions by Hershey and Chase possible?d xs;e1;sjx(slf+) dc

  What feature of the DNA molecule was utilised by Hershey and Cha*qi2+ eaeect7y0id.c se in order to identify that viral DNA is able to eneie a*i7c e2dq0c+.t yter host cells, but most of their protein is not?

.

The image below show: ntujtkh -a 4ebaii ,84zl1;bs 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 shows5gxvu5q-q,: 6z2* lvzvjjpv- hwuf9e the correct components of one nucleosome?

  Hershey and Chase conducted expn / 40adz,etgyd1zy. neriments 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 result u31rypv)0/mvu q3hy 5nvhea8 s of an experiment conducted by a team of researchers investigating the relationship between the composition and 3vypq hu83nrvumav 5ey/)10hmelting 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 e6xh05 l zsmvsw8wfc ;;ssential 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)c qeojbz; y4uz.2y( u:*b 1rzjso8 zn fragment 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.