Statements below show three double-strandex8-6ihb2mql, n6wvv 5lk sl9kd nucleotide sequences. Which of these sequences lv6v8bw5k2 qlklm9s ,6ni-hxof base pairs 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 strn c2pb *1(oqntucture based on the tetranucleotide hypothesis proposed by Levene that DNA was made up of equal amo(1ncp*2tn bqounts 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 of the structure, leading to the falsification of the initial hypothesis.

  What is the main role of the ribosomes labelled injg/olapycbaw 7jf uq76 b5x otq*2:4: the micrograph?

  A strand of nucleotides reads CCUAGAGCUUACCG. W78 4jtiqa.lfi- :ztllhich type of pentose sugar could be found in the nf 7tqit4lzaj8.- i ll:ucleotides in this strand?

  Which of the following processes is most directly involved 4v /hmmb,y4c0 :aaf xp+cui,bin the formation of nucleic acids such as DNAh,y4 bv,im4 +px ac/b0ma :cfu?

  What distinguishes uracil from thymine?)ovx cui7-aenu:(m/ t

  Which statements are chao5k bp;wxqr/r. yhr: yy7q8g:8a6wt fracteristics 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 nucleotuvb3 n58uj5 qok1a-g kide base sequence and genome size (number of base pairs, bp) for different spu5vn153k- a kjgoub 8qecies.

Which conclusion can be drawn, based on the table?

  How does the genetic code prob ;bdm+wfu6 v:v9g-jdvide evidence of universal common ancestry?

  The diagram depicts nucleosomesrvr1 ckg +-+hy, h 5jbp+jyhh-.

Gel electrophoresis is a technique often used to analyse DNA mo u)po 2 33/y*hn/pklpcalx qc0lecules. It includes a gel and an electric field. The diagram below shows the outcome of//)lpq h y k3anlc* 3o02pucpx 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-b1gl chphkvd 3cm7-0n.u k1k,mRNA and three mature mRNA transcripts where the introns l3nu.7 k1vmb01g,ckpdhhck- have been removed.



What is an advantage of the above process?

  Which of the following is a similarigxfy*of +3wex,*z zk3 ty between transcription and translation?

  The diagram shows the structure of a DNA kz:sb7s m:qn:k :hbu ;fragment. Which bonds easily break and re7:mzk;ubq: kbn:sh s: form?

  What would make one DNAa yq6qa1kbe:ssu3 hs0;gne) 2 molecule 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 whethepp kkct5 4tw;svp9 9 9zu9y7ezr DNA or protein ser7 yw9e5k kp tu;pzcz99v4t9ps ves as the 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 process are correctly matched in the tabl*ts;mj0:wi x)ar;mh kceold 4)m ;ql8e below?

  Which statement highlights the importance of nucleosomes in DNA u5v)5hipw 1yg*vs j w:supercoiling ?

  The image shows many ribosomes onpyvy; (l 5wib. a mRNA molecule. How many unique polypeptide chains are beini( y;ylv 5w.bpg translated?

  Which of the labelled structures shows the correct directionality of the DNAzs) l;nd(lrbt+ -1j v ckq6da5 molet-1sn z6l qbd5v rj)kc+(la;dcule?

The diagram below shows the structure of DNA nuc ru dg8upou0j390q f3yleotides.

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 1952kng0352ka k sc involved cultured viruses that were radioactively labelled with either sk2 gsakk53c0n ulfur ($^{35}$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 pyrimidinekv euylb:bxkrx,x4(7 hg / t+4?

  How did radioisotopes help make the investigations by Hershey and:z,c(:twbao d4x cc*6 tk1ifk Chase possible?6cfxz4c akd * i ,tw(tb:o:k1c

  What feature of the DNA molnccjwo03o- y(ni o:- kecule was utilised by Hershey and Chase in order to id-jko c-n 3yic0n(w: ooentify that viral DNA is able to enter host cells, but most of their protein is not?

.

The image below shows a short fr,kyw3ws7b7b3a78+xp zp a bb essj8s, agment 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 shows the correct components of one nucleov5a 8y81zn cobsome?

  Hershey and Chase conducted experiafq (nz5j 7xsqw.r;9tments 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 exs z8+c*-atjxjperiment conducted by a team of researchers investigating the relationship between the composition and melting point of different DNA samples. At the tj* z -xsajc8+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 e).e, xfabo / ew5qkx.sssential 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 showsp: 2efdtcew3* a short fragment 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.