Statements below show three double-p 4/4e a m6oe9on m.qmu/v43xzcuso8tstranded nucleotide sequences. Which of these sequences of base pairs is possible in a DNA mol 6.xq m/p 3 m4mez8 nu4ooateso94u/vcecule?

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 thei3) xvvpw)-)z 2gbcbj tetranucleotide hypothesis proposed by Levene that DNA was made up of equal amounts of adenine, guanine, cy)gw bvbc)xp-)i2zvj 3tosine 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 initial hypothesis.

  What is the main role of the rimwq i5 .w3yjd4+hve/ abosomes labelled in the micrograph?

  A strand of nucleotides reads CCUk/fgs 7j 6cf+fAGAGCUUACCG. Which type of pentose sugar could be found jf/ fgfk7+c6s in the nucleotides in this strand?

  Which of the following processevb4g5x1r(qihn nhem k ez/ 5(;s is most directly involved in the formation of nucleic acids such as zq(g14 xn( 5;/hvnb5m ie rhkeDNA?

  What distinguishes uracil from thymineo ;d lvu;;g664jvg linxympm se27d55 ?

  Which statements are characteristics of a DNjacz: -(w w d,cq*yuc.yyk6)yA 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 seque* ,b kwckcd9g zx texj6;u(0vzl(-)alnce and genome size (number of base pairs, bp) for diffe6u0bade( ;(lg -j wzckzx klx9)tc*v,rent species.

Which conclusion can be drawn, based on the table?

  How does the geneticwq5; uq:/yghc code provide evidence of universal common ancestry?

  The diagram depicts nucleosome/ j9s3y4te as l)s+gz ; p6ezsh47vqljs.

Gel electrophoresis is a tec khf 2tmo*/3q rayf)z6 5*lljdhnique often used to analyse DNA molecules. It includes a gel and an electric fflyjo ht **flrq6mk5 a/z) d32ield. 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 shonict . o zog438z;dn;l mtsf;9ws pre-mRNA and three mature mRNA transcripts where the introns have bl og i tz8ct.nz;n4df39om;;s een removed.



What is an advantage of the above process?

  Which of the following is a similarity between transcription and translatiofo2swduadfwr+b s8 a8 :skz*+6i( xa- n?

  The diagram shows the structure of 4)q+pmi6p3f mj 9fyrkch9vp 0 a DNA fragment. Which bonds easily break and refof0rpkfmq9j3y)p6 hv9 pi+ 4cm rm?

  What would make one DNA moleculy)etc- 508pw1u qn rmn zz6r*ee 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 experime,f3uhimky ( o rvj851nnt to investigate whether DNA or protein serves as the genetic material. They cultured 2 batches of fu5,r 3mv81( nojyikh 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 0. khnycvnwm*8x j:-nthe table below?

  Which statement highlights the importan fv r 5ne0udzs1a2nwi4 psp-3qm83z.hce of nucleosomes in DNA supercoiling ?

  The image shows many ribosomes on a mRNA molecule. How many unique pe/-9sdumptmwi j 33en*j, ,pzolypeptide chaini,3en/wuz -*jpmt p9,s3 ejmds are being translated?

  Which of the labelled structur x xbibhpvdr2dw.d8n 4437g5aes shows the correct directionality of the DNA molecule angrd5447phw8x3bddi2 .bxv?

The diagram below shxo4v6d+a * x)i-msw brows the structure 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.m ylrznhk-3 . viruses that were radioactively labelled with either hn.rlkz3y -m .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 pa*ebqliw m a(du21)2 pyrimidine?

  How did radioisotopes hel,1nixmu2oal64 m g,cw ,b tay1p make the investigations by Hershey and Chase possiblel1yau,6imcg axbn,2t41 ,mow ?

  What feature of the DNA molecule was utilised by Hershey and Chase in :p 5qf li / of1ltnkbs3ttan2m 8f(:5border to identify that viral DNA is able to enter host1k:3nff b8t(5:lt lso5f pq/aintm2 b cells, but most of their protein is not?

.

The image below showsw;3 2 uh1jfkqkwu2k *l 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 shot9pdc r-1;diic(k 1 iaws the correct components of one nucleosome?

  Hershey and Chase conducted experiments using the radioac.df pi s biq8ob:q7lr. gh*.a/tive 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 colh ad9 *+nnka2y28kefnducted by a team of researchers investigating the relationship between the composition and melting point of di *e22n9 anky8k+f adlhfferent 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 orgw p:;k:1: vn :acdr(xlgzgek)anisms.
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 fragmbluee0d,g65 k. +qwnc ent 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.