Statements below show three double-stranded nucleotide sequences. Which of theske djo23sak le*,kgj q 668y.7q6 )oo f+kamyje sequences of base pairs is possi k62j3jj qam)q f 6gldkyeoks.oo7yea8*+,6k ble 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 structura/xahl1d /dqf,z oih xvwe8r3 ,,)p-w hb:ir:e 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 ah-hh ,pd,/:dr,)oi8f 1qiwba/3r:l avw ex x znd accurate understanding of the structure, leading to the falsification of the initial hypothesis.

  What is the main role e ro/9e/y;j+ ggzm ,drof the ribosomes labelled in the micrograph?

  A strand of nucleotides reads7r v 66v9-xnb.j2skhs hca cyb-z64nepf 5hc, CCUAGAGCUUACCG. Which type of pentose sugar could be found in the nuhbhscs2nc 6cz7,rhpx4y bf- nv.v5ke-6 aj69 cleotides in this strand?

  Which of the following processes is most directly involved in the fo ,jy+n3a4swdlrmation of nucleic acia y3 l+w,4dnjsds such as DNA?

  What distinguishes uracil from ttmx vvl:)i/5 khymine?

  Which statements are c-e 0vkv9 mpz-nharacteristics 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 nucleotidk1ur;wofh 0 :gr)d*0ve-huvje base sequence and genome size (number of base pairs, bp) for differ10vr wej* -huvor0;)hfgd :uk ent species.

Which conclusion can be drawn, based on the table?

  How does the genetic code provide evidence of universal commozrj(;ii6un u 0n ancestry?

  The diagram depicts nuc ny2la:xn/ek i72dyu ;leosomes.

Gel electrophoresis is a technique oxgb9gjg 5v6 w 7g;aa6,p4say dften used to analyse DNA molecules. It includes a gel and an electric field. The diagram below shows the ou6g;xp wy4s5 v b6a 7gadg9ga,jtcome 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-me7zm op7)68k 6 eyrv3ju w-3rml( rstfRNA and three mature mRNA transcripts where the introns have been removed.tlk-smpeouwr 6y)r(z vfrm36j7 378e



What is an advantage of the above process?

  Which of the following is a similarity between trabr v5a jfmmj +g+,r.g+g-d/ jfnscription and translation?

  The diagram shows the structure of a DNA frag)pdv hg0jyw9h:h/ng- ment. Which bonds easily break and reform? gg )nw9 :h0vyh-p/hdj

  What would make one DNA molecule mor8zt-pz1 r4bdqe 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 experiment5ws61t/mnzv 3b. ;de, 5t+yotzaovrq to investigate whether DNA or protein serves as the genetic material. They cultured 2 batches of viruses, one in a medium cont31; y 65,tqo+5ad sezto. vnvtbmw/rzaining 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 0moy)i gzu/z.m uvw r fo :oi4y+m+q30the table below?

  Which statement highlights the importance of nu 7byoyep ye9dto s qbb1up/ 7::xw/:3ucleosomes in DNA supercoiling ?

  The image shows many ribosomes on a mRNA molecule. How many unique polypepm i+7zqpce 47 5iprsxz*p/eg/tide chains are being transq/pez r +mpszgx 4i*5e/ ip7c7lated?

  Which of the labelled structures shows the correct directionality of theo/v66 fl6mcc o,fg; mh DNA molecule?6 vocm 6;c/o6gl,fhfm

The diagram below shows the sr ycp 6+vs7bc+m,xh8n ejsh,5tructure 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 experime):rpc7g:xa d mbsf9qn+ z7cp*syk5:k nt in 1952 involved cultured viruses that were radioactively labelled with *ra)c:cfgd: yx s 7pzsbm n5k:p q7+9keither 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 ib ;4:c7)evaj ysilqd +s a pyrimidine?

  How did radioisotopes help make the investigations by Hershey and 4pyj jrb:- se-Chase possible-rjb-j4e :py s?

  What feature of the DNA molecule was utilised by Hershey and Chase in wfyr skcw. )e mb26v:bpe y3o(w+7, wzorder to identify that viral DNA is able to enter host cells, but most of tv(z7 f we. 2:6 byr3seokmwp+)ywc,wbheir protein is not?

.

The image below shows a short fragment of th*cll 0rlqy3 pyx0:fh yx6au( 5e qm7o:e 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 nucleos8r(wbts ej( 5h9au( irn o50hkome?

  Hershey and Chase conducted experiments using the radiog*uck33d7mxsw-7i chh n k 6)ntk3i /vactive 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 vl y)ff/*az f6 )lq4copp0y0wan experiment conducted by a team of researchers investigating the relationship between 0vfqop0w)a6y cfl)y/l *zfp4 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 living organism t drqsp0x. qyb:-(-bas.
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 molecu.; v1hwwj(, tzxer3o ble.


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.