The graph below shows the relationship between mater4aggg q2/2ktp k0+2 c/nva xyenal age and the incidence of non-disjunction. What relationship is suggested by 0 ck//4k2g2ga+ qn vexpygat2the data in the graph?

  Which stage of meiosis d 93 vej ;8vy.h1o+dapnwcp2uis represented in the diagram below?

  The diagram below shows chromosomes during meiosis. l4vsrfuug5:95kpvmzmgmf gb69o4 05


1.Identify the stage of meiosis from the diagram.It is    I

2.State one process, other than the one shown in the diagram that promotes variation during meiosis.

3.State when the process you named in part (i) occurs in meiosis.It is    I

  Which row correctly states the number of alleles of a sl eszq6dr*j :8 9ci:gbingle gene which would be present in the nucleusbl9 6gd8s:jq e:c ir*z of a cell as a result of each process?

  Which keyword is matched to the correct r n/l0blw 7ruxr16e+ddefinition?

  Which statement(s) about mi*x9sdg;o6g 5l3yc2wom3 z cr mtosis is/are true?
I. Sister chromatids are pulled apart during metaphase.
II. The nuclear envelope reforms during telophase.
III. Chromosomes supercoil and become visible during prophase.

  In the micrograph below, which letter points to a cem mt2: a1-dlx unyaio)d)v8i rt.n-)mll in anaphase?

  During which stage of mitosis does the nuclear envelope break ; r/o1+ degxgvdown?

  Which one of the followi5 1y8 bhm7t(yholns ,ing transport proteins only carries out active transport? 7o,ybnyshit l m(851h

  Which process does not h z klk4(zm+3tj2l;vziappen in the shoot apex?

  Which type/s of membrane transpox9 /kms)by eo;rt do/does not require energy expenditure?
I. Facilitated diffusion
II. Active transport
III. Osmosis

  The diagram below represents a cel z f-;;ftnfn-r1kz4pc l with a diploid number of 4. Which stage of cell division is the pf-tz1;zn f 4k-frcn; cell currently undergoing?

  The photomicrograph below shows a rfg4ws2 rxea67p+m3wzobd8pe a l2 w 1)oot tip meristem. Which of the following sentences correctly 2p ep w o 7ma4f6 gdwxasb2r381)e+wzldefines a meristem?

  When does the random orientation of homologous chromosome pairhi:) xic/brmg3c(hh9 t.l h)os occur?

  Which process does no:l0v9debgw : fg6kq6it occur during meiosis?

  If a cell with a diploid number of 36 undergoe4qnw/*zq xwp /m dxbw25tr 787jxo 3fls mitosis, how many chromosomes will be present in exnd7oq mp /q wbf24l3x7zjw*5rtx/8wach daughter cell after cytokinesis?

  The image shows a micrograph13)48b ncag af ;tt)fpp* huqur*lzz- of a cell.


What explains the appearance of the cell in the micrograph?

  Which statement(s) about homologous chromosomes h-,x csq2noyhpe m x:qif.9 24is/are not true?
I. Homologous chromosomes have the same centromere position.
II. Homologous chromosomes have genes with the same loci.
III. Homologous chromosomes are identical to each other.

  This karyogram is for an indivi 53z3nuz 3erkni yv;ikg07 +bidual with Down syndrome.

Which statement is not correct?

  In the cells of a horse (E. calqitttnjpoo0p t ,, dn*:/7 +aballus) during prophase I of meiosis I there are 64 chromdt+,j 7qt, itpo0 /o:la*ntpnosomes. What is the haploid number of chromosomes?

  Which arrow is pointing to esg +nq594km3p7mz1gbcw2 r qa chiasma?

  The diagram below represents the structure of a shoot apical meristwgba6kd xb-o 6nsa u7y0i+0 w3em. Which row in the table correctly identifies the processes occuri bb-xs+awg7 00ikd6u3 wn6 oayng in the structures labeled in the diagram?

  How does meiosis promote va;p;9ydmsh1mb yvv i l,3a094984imxikx ujzfriation?

  Which of the following statements is/are correct for meiosis? k1emnd + o+(x*k-aeqpxqmaj1*9)vj y
I. It is a reduction division
II. It involves random orientation
III. It produces genetically identical cells

  The diagram shows ga3 u1 ipa)aqu.tmetes produced from two homologous chromosomes.


What single crossover event could have occurred to produce the gametes?
I. Crossover between Gene A and B
II. Crossover between Gene B and C
III. Crossover between Gene C and D

  Which word describes the formation of secondary tumours from primary tumo o:txvp+9b, mgurs as a result of the movement oxg+p 9bmv:o, tf cells?

  How many chiasmata are present in the diagram? y wmq91uooib0x.fb;f.f/ h*qa ir(kf 3u)o5z

  Which statement is a similarity betwer67b5o0 gep/zb yfedy:/s*bt en cytokinesis in animal and plant cells?

  Which stage of meiosis is matchls otim/bm 8+ifttqa/wifg* 7x e8-/2ed to the correct description?

  Which statement(s) are true of meiosis I but not meiosir a+nqyg 68x ez*+/jtas II?
I. Crossing over occurs during prophase
II. Sister chromatids are pulled apart during anaphase
III. Chromosomes supercoil and become visible during prophase

  The micrograph shows an oocyte after the fir;9(; jsgfr; y efr4wfjst meiotic division. This results in the formation of one ly( ;we; 49rfgrsj ffj;arge cell and one small cell. What is the fate of the large cell?

  Which row correctly describes diploid arwhrg or. xnv*y1-)u 8nd haploid cells in humans?

  The following table shows the diploid chromosome number o j*uwv:n6o3j jf a range of species.


Which of these statements is correct?

  What conclusion can be drawn from t,7)2g kyji5x )xh n3 /bcgpd 2ucatte*he karyogram below?

  Which of the following processes is characteristic of the meiotic and n/ze/kxm c:x 0dc aakdo/)l9d;ot the mitotic cell cycle;0d k c/9:l/okdaax) /zxecmd ?

  The diagram represents a budr 8atlez72 we; with a shoot apical meristem.

1.State the type of cell division that occurs in the shoot apical meristem.
   is the type of cell division which occurs in the stem tip.
2.Outline what happens to the cells produced in the shoot apical meristem.

3.State two types of tissue that are produced by the differentiation of cells found at the shoot apical meristem

  The diploid number of the chimpanzee (Pan trc-o*.z(ll nt71k1oe: xj4rnwm*l jj n3lw9o soglodytes) is 48. Which row shows the correct chromosome number for different cell1* sjnwt-lnk4joo el* 3.nlzw:xl17 c j9 (mro types and cell division stages?.

  At the end of which phase of k7yv*a 77c jvaq6xyj7meiosis I does crossing over occur, and what is the outcome of crossingj ykq7vyjv7 *7 ca6ax7 over?

  Which of the following statements does naf eux7j mll-. os94:tgt2je :ot describe a step in the sodium-potassium pump cycle ino7 msl.jx :je9ta4g fu:te2l- the neuronal cells?

  Which row in the table vm;kcy ydhx 70m.;wq67*qv mz6ucy 1a below is true of meiosis?

Membrane transport is important for allowing particles to move across the cellzkudc7 5q * c-fnz;plhn; mumr 5k54c: membrane and respond to 4nlrkcq-;cpzu 5 czn fm5 ;7 duh5k:*mchanges in the chemical composition of the extracellular fluid.

1.Outline the effects of placing a liver cell in a hypotonic solution.

2.Outline how the fluidity of membranes allows materials to be taken into cells or to be released from cells.

3.Compare and contrast four types of membrane transport. Include an example of each.

1.Explain how mitosis is regulated in cells.w9swma31ayh*5z9*cf d /bfc a

2.Describe the stages of interphase and their importance to the process of mitosis.

3.Discuss the importance of mitosis to living organisms using named examples.

  The diagram below shows of0 5lyi+9w xfthe concentrations of different cyclins during the cell cycle. Which cyclin is invox iy0o9flf+ 5wlved in preparing for DNA replication?

The diagram below shows chromosomes du xqri7kgt/ 7)cring meiosis.

1.1.On the diagram above, label chiasma with the letter R.

1.2.On the diagram above, label a chromatid with the letter Q.

2.Describe the process of crossing over.

3.Explain how crossing over results in the formation of genetically unique nuclei.

  Which stage of meiosis involves ut1h 69pdqofn f-/b.sthe separation of homologous chromosomes?

  The mitotic index of throat tissues taken from 4 different patieebh7n-5q b iha3qf eo44 (r8dxnts is shown below. Which patient is most likely to have cancerous4f3h4o(dq -iqx hne5babe 8r7 throat tissue?

1.Draw a labelled diagram to represent the process14fo /e u-) wqgvqn)tzhfs+ n) of crossing over.

2.Compare and contrast random orientation and crossing over.

3.Outline the stages of meiosis.

  The image shows an abnormal human karyotype. l*c ta)xqgobw 8(hnp29 zg wv)yom2)6


What is the abnormality in this karyotype and its cause?

The graph below shows the relative amount of 5opnina 064 inj1h5owx;+ wr t6ady6aDNA in one cell during one complete cell cycle. Each letter represents one stage of n6xpo;654y nd aw nj 1i 6a5woaitrh0+the cell cycle.


1.1.State which stage of mitosis or interphase is represented by stage B in the graph.

1.2.Explain your answer to part (i).

1.3.Bortezomib is an anticancer medication and arrests cells in the G$_2$ phase. If a cell shown in this graph began the cell cycle at A with 3 relative units of DNA, and Bortezomib was applied to the cell culture at stage A as well, estimate the relative amount of DNA in the cell at the end of C.

2.Explain why the amount of DNA in one cell remains the same in stages C and D.


3.The diagram above shows cells in different stages of mitosis. Label one cell that is in prophase and one cell that is in anaphase.

  The diagram below shows *guxct15bt g7 a cross between a male cat that is homozygous for brown, long 7u*t txgb1cg 5hair and a female cat that has black, short hair.


Which of the offspring has a recombinant genotype?

1.Outline how polygenic traits can scu8 .d1jxij g3how a normal distribution.

2.Outline the differences and similarities between homologous chromosomes.

3.Explain why expected and observed Mendelian ratios may differ.

  Which gamete can result from the crossing over of non-sister chromatids shownwr8)4pib 7zte in thrb7ep8 iz )t4we diagram below?

  The photomicrograph shows a p * .*+(rbsgeib8iz v:s jsnbd.ollen grain from L. candidum (Lily). Which stage of meiosis isbs*sbid. * ni+r seb.:j8vg z( shown?

1.Outline the events which would lead to an individual being born with Down syno6e9o9t gdhxdw2 6uz sudlf6,s:4 3qodrome, which is characterised by the preud oh3o 2wo:xlsu6s99dtd6 qg , 46zefsence of three copies of chromosome 21.

2.Explain how meiosis increases variation.

3.Outline the stages of meiosis.

The mitotic index is an indirect way of measuring plant grozsc e0yqvv* a,*1.visl w 8ff4wth. A study was conducted on white onions (Allium cepa), under controlled conditions in a lab, to investigate the effect of soil81lz y* fi4wca qsvf*,.evvs 0 pH on the mitotic index of the roots.


1.Describe the trends shown in the graph.

2.Outline how the mitotic index is calculated.

3.Discuss whether the data support the hypothesis that onion plants should be grown in soil with a pH of 5.5.

4.Suggest how a pH of 9 affects the process of mitosis.

5.1.Explain why measuring the mitotic index in the root is an indirect way of measuring the overall growth rate of the onion plant.

5.2.Suggest another method, apart from measuring mitotic index, that could be used to measure plant growth.

6.State one of the variables that must be controlled to make this experiment valid.

Mitosis and meiosis are two ways in which cells can divide. The diagrams below sdgyt *y+kaoth7i)s47m. q2 yr how two cells from an organism with a diploid number (2n) of 8. i) 7 .2mg4ay s7khqyydr*to+ t


1.Deduce if Cell A is a gamete or a somatic cell. Justify your answer.

2.Identify the stage of meiosis represented in Cell B. Justify your answer.

3.1.Draw a diagram which represents Cell A during metaphase I.

3.2.Draw a diagram which represents Cell A during prophase II.

4.Compare and contrast meiosis and mitosis.

1.Outline the role of gene expres/dvadjxwg39yq6g8h(yf ej, : sion in stem growth.

2.Outline how growth is controlled in the shoot apex of plants.

3.Explain the process and applications of micropropagation.

  The diagrams below show a cell, with a diploid number of 8, in different a4: mtugn2rxdc:+ 6 xzstages of meiosis. Which row correctly names ea x6 marxnu: 4tgc+z:2dch stage?

  The micrographs show four phases of meiosis I in a plant. In what ordeo +ne lh/e96xm i1(urkr do these phas+mix6 kul 9o/ en(r1ehes occur?

Mitochondria are responsible for supplying metabol2w (icfe3pi3 pic energy in eukaryotic cells. In most eukaryotes, which reproduce by sexual reproduction, mitochondrial DNA (mtDNA) is inherited from only one of the parents: the mother in thpef3(2i 3ciwp e case of humans. This is in contrast to nuclear DNA which is inherited from both parents. It has been suggested that, in some eukaryotic organisms, inheritance patterns of mtDNA found in hybrid cells, which are the result of sexual reproduction between two different yeast species, could be influenced by the parent’s genetic background.

In an experiment, scientists investigated if environmental factors could influence the inheritance of mtDNA in hybrid cells resulting from the sexual reproduction between two closely related species S. cerevisiae and S. paradoxus.

The first step in the experiment was to produce hybrid cells, which were then grown on different agar plates, each providing different growing conditions, which simulated different environmental stresses. Cultures were then taken from each agar plate and grown in a liquid medium, with the same respective environmental conditions. The procedure is outlined in the diagram below.


The mtDNA genotypes of the resulting hybrid cells were then identified and compared to that of the original parents.


1.Describe how the pattern of inheritance of mtDNA in the hybrid cells is affected by the different conditions.

2.Identify the liquid medium which resulted in the greatest AND smallest difference in number between hybrid cells with mtDNA from S.cerevisiae W303 and S paradoxus YDG197.

3.Calculate, for the 2% glucose condition, the percentage of hybrid cells which contained mtDNA genotypes of both S. cerevisiae and S. paradoxus.

4.Compare and contrast the results from the first and second experiments for the 2% glucose condition.

5.Identify the liquid medium condition which resulted in the greatest difference in the number of hybrid cells with mtDNA genotype from both parents between experiments 1 and 2.

In a final experiment, the team of scientists wanted to examine the activity of mitochondria, as indicated by respiratory competency, in the hybrid cells grown under each of the aforementioned growing conditions.
Respiratory competence was measured by using a stain, which stains respiratory competent cells red. The absorbance of cells was then measured, with higher absorbances indicating higher levels of respiratory competency.
Note that hybrid cells which contained both parents' mtDNA were excluded from this experiment.


6.State the growing condition and strain which resulted in the highest levels of mitochondrial activity.

7.Discuss the hypothesis that hybrid cells inherit the mtDNA from parents who are best adapted to their environment.

8.Evaluate the use of S. cerevisiae and related strains in the study of mtDNA inheritance in humans.

  The table shows the number of ceb0 m* uon ;mp:l:9wjcglls in different stages of the cell cycle in four samples of lung tissue from four patients. Which tissue ham ljbwcn*::m;pg o09 us the lowest mitotic index?

  The diagram shows the dominant cyclin/CDK c+n6+z5; adr u/h pcoqhomplexes at different time points in the cell cycle. Which cycl/qd56c; u+ahr+ozhn pin/CDK complex activates DNA replication machinery?

  Studies have shown that genes such as Cyclin D q9uypf lgig1x8 1,;naependent Kinase 3 (CDKN3) are highly overexpressed in ce;1x,np qfg ug98yi 1larvical tumours.


1.Calculate the percentage increase of CDKN3 gene expression in cancerous cervical tissue compared to healthy cervical tissue. Make sure you show your working.The number is   %.

Overexpression of CDKN3 in cervical tumours has been associated with decreased survival rates in cervical cancer patients and has been shown to trigger cells to exit mitosis and begin cytokinesis.


2.A hypothesis has been proposed that overexpression of CDKN3 in cervical tumours results in an increased chance of patient death. Evaluate the evidence for this using the data given.

3.Overexpression of CDKN3 results in increased levels of cell division. Describe how CDKs and cyclins are involved in the cell cycle.

4.CDKN3 has been identified as an oncogene. State the definition of an oncogene.

c-REL is another gene that has been linked to cervical cancer and its expression is correlated with the expression of CDKN3. Using CRISPR technology, cervical cancer cells have been created that do not express c-REL (c-REL -/-). Expression levels of c-REL were checked using protein analysis.


When c-REL is overexpressed in cervical epithelial cells it results in greater proliferation of cells and the cells spend less time in prometaphase (the phase between prophase and metaphase) compared to healthy cervical cells.


5.1.Looking at the photomicrograph above, identify the stage of mitosis that most of the cells are in.

5.2.Based on the evidence provided, suggest, with a reason, which of the labelled cells would be present in the highest numbers in c-REL -/- cervical cancer cells.

cREL-/- cervical cancer cells and cervical cancer cells with high expression levels of c-REL were treated with the chemotherapeutic drug, cisplatin. Both types of cells were exposed to different concentrations of cisplatin over a 21-hour period, and the effects on cell number were analysed.


6.Using the graph above, compare the response of cervical cancer cells that express c-REL and the cells that do not express c-REL (c-REL -/-) in response to exposure to different concentrations of cisplatin.

7.Suggest a reason for the different effects that cisplatin has on cervical cancer cells expressing c-REL and those that do not express c-REL (c-REL -/- ).

8.Suggest why some c-REL -/- cervical cancer cells have a similar level of cell death to those cervical cancer cells expressing c-REL.

9.Deduce whether cervical cancer cells expressing high levels of c-REL and CDKN3 will have a higher mitotic index than those with lower levels of c-REL and CDKN3..
Cervical cancer cells with a high expression of both genes will have a  ----待选择----higherlower  mitotic index, as they are dividing more rapidly.

  When is the concentration of cyclin E the highest during they pr vw;ku,.uua8kg,bc*j50t cell cycle ?