Statements below show three double-st v3q scg; . a(9c2c-ifwnwi (.yp,uisaranded nucleotide sequences. Which of these sequences of base pan(u.3fig (c qy i. c;c,psvwa a-wsi92irs 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 0 mls+7qbvb2qthe 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 l2bq+ qs 70mbvit 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 ribosomest*y5p zb8d y /ap8u6bo labelled in the micrograph?

  A strand of nucleotides reads CCUAGAGCUUACCG. Which txti su(75:b7 shb8fjp ype of pentose sugar could be found ixf: bp bti5s87(u7jsh n the nucleotides in this strand?

  Which of the following processes is most directly involved in thwz3hjev - 7y/ue formation of nucleic acids such a3 7zu/y-vjw ehs DNA?

  What distinguishes uracil frc8ps4(j-+bil1k ukzo om thymine?

  Which statements are characteristics of a DNAk kijbph13blyp.0j7 53xm n8r 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 gep3il)vm9:ili b ebg d. t+/6cfnome size (number of base pairs, bp) for dilmdf+bc/b6). :eilv p 3gi ti9fferent species.

Which conclusion can be drawn, based on the table?

  How does the genetic code provide evidence of universal common ancestry renk62k2(+ifpum mc7l zs. q+?

  The diagram depicts nucleosomestb46ig3v p7l( lc (lcd.

Gel electrophoresis is a69tgugjf/xx azdp./* technique often used to analyse DNA molecules. It includes a xg g/d/.f9z tx6apju *gel and 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 and three mature mRNA transcripts where the tkl yg 2 8* mk6)/kd6v1kuintrintrons have been rm8u *)r1vntkigkt6 ly/d2k6 k emoved.



What is an advantage of the above process?

  Which of the following is a similarity between transcriptionx8qfo4j5i.9 d jivyn , and translation?

  The diagram shows the structure of a DNA fragment. Which bonds easily breakpqrieud kf j -ap 917jw5;tj+- and r pej+ jpikq5wd9;1tja-u r7f -eform?

  What would make one DNA molecule more stable than anomtk wfi+/a9x 7ther 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 exp no mveo4r7gs2 xj-(n-eriment to investigate whether DNA or protein serves as the genetisen o24x (7ogjr-vm-nc 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 b ;vdpc, dodqw49k+z8f (rmh;-2vjnca elow?

  Which statement highlights the importance of nucleosomes in 3 bxm9w6hqh eb2mpb9;DNA supercoiling ?

  The image shows many ribosomes on a mRNA molecule. -xohwht jy o0( 6z17+mnc2 klz02 s6xwusr)lzHow many unique polypeptide chains are being translac1(0z k)yl6t72x jh olz 0u xsonhwwz6s+-m2rted?

  Which of the labelled structures shownh 7h-i 1,stggs the correct directionality of the DNA molecul,nsgig1t- 7h he?

The diagram below shows the sox+c yf5 40sdm fa,i.ktructure 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 1952 involved cultured viruses that were rawb -n8 o8inaa7dioactively labelled with either sulfur i8w- 7b8an aon($^{35}$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 aw 5u8y.kq4r qhh:*ns)f mlrv83g9x l pyrimidine?

  How did radioisotopes help make the investigations gtt7yb;fi;d mb: n s/2d1vsm)by Hershey and Chase possible?gty1s:imb2/t;;f )smbndvd7

  What feature of the DNA molecule was utilised by Hershey and Cc3ij0 7zj bz5 -fkwjuwr/u.bh)-y; dc hase in order to identify that viral DNA is able to enter host cells, but mo7h; ujcu)f5-yz3w/- jjdkwbcirzb 0. st of their protein is not?

.

The image below shows a short fragment of the Do )a4dxl02c quehm c26NA 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 nucleosommk)kfanc5*er*uy a (u)gu .z3e?

  Hershey and Chase conductetp/q ;i ffn2gr1+d /fvd 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 results of an experiment conducted by a team of6 (iita2n 8rj v)6)bm. oizqgf researchers investigating the relationship between the composition and melting point of different DNA samples. At the melting point, the DNA double helix separatesa8o) v(i)i .ztb6rn2mgji q6 f 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:u(.rz fb0(ppv-c p*a cy9lz c acids 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 molemc(xd f;b1kq7r9x 6 (h/pzeiccule.


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.