Statements below show n*zrri gzks0j6 5-+rithree double-stranded nucleotide sequences. Which of these sequences of base pairs is por5z - r* krgi+jsn06izssible 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 the tetranucleotide hypoth 7pnan1 7 dlj+l6njgxdi6- qd4esis proposed by Levene that DNA was made up of equal amounts of+ d l77 n-dgd6j4jx6l1nip aqn 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 initial hypothesis.

  What is the main role of the ribosom3lzu ( wq w9b-w*9gnw3bixu(ses labelled in the micrograph?

  A strand of nucleotides reads CCUAGAGCUUACCG. Which type of pentose + ewfha:09;e xmwxpl (a2pfh ;sugar could be found in t x f+xapew:0 9e;lhw(mh;fap 2he nucleotides in this strand?

  Which of the following prz hk2b1oz1 4r l;kz)arocesses is most directly involved in the formation of nucleic acids sucka21zr k41zz h ;olbr)h as DNA?

  What distinguishes uracil from ufu lh6; pz0-ctf7cx4 thymine?

  Which statements are characteristics of atrf2 ) nn3cf4f 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 and genome size (number of baseu qee2ig03zl j;1s4k(b -knue pai ne02 zjeul3; qs-bekui41 gk(rs, bp) for different species.

Which conclusion can be drawn, based on the table?

  How does the genetic codefa;0ps1 tgd8pg p8 .vt** kyyw provide evidence of universal common ancestry?

  The diagram depicts nucleosomes. ) h;2;kvqkrgg

Gel electrophoresis is a technique often used to aof pg 2mt1:r ,ry978kw go.wxsnalyse DNA molecules. It includes a gel and an elspr 1.f 2o x mkgw798tw,:yorgectric 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 tj3mn8lbh0 q 9whe introns have9n 8ml0qb 3whj been removed.



What is an advantage of the above process?

  Which of the following is n8gko4/1odog 9.gq zu a similarity between transcription and translation?

  The diagram shows the structu;y)os80x5j4lyik uu :lf +l ogre of a DNA fragment. Which bonds easily break and reform) ;5ology4jy8ul:0x lf+ usk i?

  What would make one DNA molecule more stable than anothe 1*.vb53fsotvvc+tdg apmq3 6r 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 investtq,edcqdd+ (af( rld-lfl +(+l9g.np igate whether DNA or protein serves as the genetic material. They cultured 2 batches of viruse(+d+ e(clr( pqtf dn9lddf,ll a.+g-q s, 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 cjsy+ie8, )z rsorrectly matched in the table below?

  Which statement highlights the importance of nucleosomes eb v b1lyfa8pv ,5*ik0in DNA supercoiling ?

  The image shows many ribosomes*v l5qv+eg)cg+kp7ob) wp2rv on a mRNA molecule. How many unique polypeptide c +gvvke p2lcv 5p*w)o)r+ qgb7hains are being translated?

  Which of the labelled structures show3v of8n5x0-2zn zzhgzjr0i f:s the correct directionality of the DNA molec5v:g 0xnz0-f 2ho3zrjz i8znfule?

The diagram below shows the structure of DNA )q q l7eh5obxyouuh2 b,u;a-/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 radio.pr*dz*p4rb j activelrzr4jp.dpb* *y labelled 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 c jgc xl-:17osis a pyrimidine?

  How did radioisotopes help mav xwmism79//2p +uu yxke the investigations by Hershey and Chase possible?xm/up+7wmui/sxvy 9 2

  What feature of the DNA molecule was utilised by Hershey and Chase 0,a8d)ncb ft;x9db wuww 1fo:in order to identify that viral DNA is able to enter host cells, but most of their pro: b,dafbfuw 9)nxo81d0w;w tc tein is not?

.

The image below shows a short fragment of thea ovh)vtqt p7)92 z s7lixh,w1 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 compmy5vg5 yu2ms 3onents of one nucleosome?

  Hershey and Chase conducted experiments using the radioactivoz- z/ wr3 )rg7d:wiree 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 of re) 9sl1mfni39esnr1d: wa1ln esearchers investigating the relationship between the composition and melting point of different DNA samples. At the melting point, the DNA double helix separates into two individual strands. fms 1iaw9de n9sl :1 enr31l)n

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 smsk 4c y-kd0v91qwv: 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 u *c 4xbr 5 glq(zv:0o5ldv/fgfragment 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.