Statements below show three double-stranded nucleotide sequences. Which of th952jw*b 1e 9sdsylyb h2:y ygnese sequences of base pairs is possible in a DNA molecy: e dj99 sybn5yg2slh1by* 2wule?

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 twapt w q0k9*+3c0u yxj1s bero:26hze he 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 jkeo1 0waw +rs9h*uc :zeqbt632 0ypx of the structure, leading to the falsification of the initial hypothesis.

  What is the main role of the ribosomes labelled in the micrograpi v1rbj2/z 0txh?

  A strand of nucleotides reads CCUAGAGCUUACCG. Whrovvj) n23s vc+o.ux 9;ali7a ich type of pentose sugar could be found in the nucleotides in this stro n)uj9a;rc.ix2o 7av +3lvsvand?

  Which of the following process c u:8lm5aykk/--sbi68o nt,tv5knmr es is most directly involved in the formation of nucleic ansl/mn68k :ui mkc85r k--tt5vab, yocids such as DNA?

  What distinguishes uracil frwrle1 dj0 )n o9mk4 )riu79jiqom thymine?

  Which statements are characteristics of a :8zx a/-xvkyb 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 genomeka3-5ff), 1edow, jkibqzdn7 size (number of base pairs, bp f31a bdzen7 w5,)dk-jqo,i fk) for different species.

Which conclusion can be drawn, based on the table?

  How does the genetic code provide evidence of universajjzlfb41.tl1 jl6n1 hl common ancestry?

  The diagram depicts nucleos uwr)cd7;rxxj,+i9n s1q8nsu omes.

Gel electrophoresis is a technique often used to analysnpw bt8eezm-)c: n)a:e DNA molecules. It includes a gel and an electric field. The diagawte))en:n-pcm b z8 :ram 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 intr.alvu14l xh;rons havehlav. ;1 xlru4 been removed.



What is an advantage of the above process?

  Which of the following is a similarity between transcription and translati lx110ifr30 e ai h+cm(sgt,bcon?

  The diagram shows the structure of up4 0ogb 52orta DNA fragment. Which bonds easily break and refor025rtpbg4u oo m?

  What would make one DNA molecullnlkh(v3.r k .e 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 gf (q yg.gbb6 /,5uochwhether DNA or protein serves as tc(hg obyg q.,bfu56 g/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 procesi1(qnb* ur f9epniw +2s are correctly matched in the table below?

  Which statement highlights the importance of nucleosomes in DNA suj t 8tn/pliq((percoiling ?

  The image shows many ribosomes on a mRNA moleukdif7v7 c44ccule. How many unique polypeptide chains arv47ik f4d7ccu e being translated?

  Which of the labelled structures shows the correct directionatb(6chox lbu5j) ut3gk3q3n4lity of the DNA moleutbb5h n4ucg3 oq l(j6t3x 3k)cule?

The diagram below shows the zezj)bqx9s f**,u ha0structure 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 vy 0cg a p.+;ax3 53ho l4: w-gzbpnhdixt:qt4kiruses that were radioacthxt3d hppni- y ;w5:a +.4b4xlg03gzk t oc:aqively 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 is a pyr 5k*+qsr+ck,4 gb 7ba tcfknj4imidine?

  How did radioisotopes help make the investigations by Herswe )2w m/+khws 1p:gskhey and Chase possiblesw:1k 2w)ghs+p m/ ekw?

  What feature of the DNA moleculexjfh n q/m2mz4 povqx p62)h75un:kh* was utilised by Hershey and Chase in order to identify thaxh26 h vzm4hqonjp2q:*)x5 u k7/ nfpmt viral DNA is able to enter host cells, but most of their protein is not?

.

The image below shows a short fragment of the/ f7ipkx(z9+0(pvo vhjr; pnu 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 compk,k(uzfzc 1p(p8d+3/d2cp1j t b cfkvonents of one nucleosome?

  Hershey and Chase conducted experimentsr5k. dnebzg, 1 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 thg0qgnbiyep36j d,w++f)o* n be results of an experiment conducted by a team of researchers 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 g60 *)wq3pyji+nfdgeb no ,b+.

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 all8wxcfvew +0+o98u l mu 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 the1x ,*hk kvlthg k4mxm-2 qh+;u 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.