The graph below shows the relationwvol6bi32 gm9n.t 6h hship between maternal age and the incidence of non-disjunction. What relationship is suggest n h .639lw6mvhob2igted by the data in the graph?

  Which stage of meiosis is represented in2oqswz cdq077w;ktm -kq-xy) the diagram below?

  The diagram below shows chromxq1e9b.)15zh wjoltk( uh z x0osomes during meiosis.


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 stal/a-g s8osug3 qr, 0kktes the number of alleles of a single gene which would be present in the nucleus of a cell as a result of8ua0 -os/k l 3grks,qg each process?

  Which keyword is matched to th q:+pu 40i,jjb 6xsh2)b;eksb*gp bfhe correct definition?

  Which statement(s) about mitosis isg a+hst:: 9qxz-uzz uaoc5x*9/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 belw;( 56bc1(l8 uvij+ 8 ngeewthgikbq *ow, which letter points to a cell in anaphase?

  During which stage of mitosis does the nuclear envelope break mul5ncu n x2(tq793 gndown?

  Which one of the following transport proteins only ca shx7f.syk 0 -olil70irries out active transport?l hxk .7oii00-fs7 yls

  Which process does not hauhuq(wj o:(0ippen in the shoot apex?

  Which type/s of membrane transport do/does not requ amve4(-u*2bh-qme-v y 1jia rire energy expenditure?
I. Facilitated diffusion
II. Active transport
III. Osmosis

  The diagram below represents a cell with a diploid number of 4. Which sta;ow-frol,t -uge of cell divisio;rfuw t o-,o-ln is the cell currently undergoing?

  The photomicrograph below shows a root tip meristem. Which ku;f;bp su+5d of the following sentences correctly defines a merisp+bu ;5k fsd;utem?

  When does the random orientation of homoix .dg7(c; r;wakji g7logous chromosome pairs occur?

  Which process does not occur during e6he4(/yk**fg4 hcvk mk 0aeemeiosis?

  If a cell with a diploid number of 36 ufvwct3 (pa-8 hl81 rkundergoes mitosis, how many chromosomes will be present in each daughter cell afterh8p8-f t(3uwcl v1kar cytokinesis?

  The image shows a microgdyqktro(c1 hz j) 6f-9raph of a cell.


What explains the appearance of the cell in the micrograph?

  Which statement(s) about homologous chromosomes is/are not :py (qg)c7ibhtrue?
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 individual with Down syndrom)-c ,qrlk2 psze.

Which statement is not correct?

  In the cells of a hor7(ku/coq wow7se (E. caballus) during prophase I of meiosis I there are 64 chromosomes. What is the7/q( w wcuook7 haploid number of chromosomes?

  Which arrow is pointb0bfbe /1ulma)) :p0p h sxfy-ing to a chiasma?

  The diagram below represents the d0p.k i )hyfsf n/(.9rufxn y:structure of a shoot apical meristem. Which row in the table correctly id9/:nisfrf.(0y fxp y.)hdk nuentifies the processes occuring in the structures labeled in the diagram?

  How does meiosis promote variatiobjf.k v s(ebqlsh2(ab;eu + .2n?

  Which of the following statements i3oll -c*lx 2e owgc+s7s/are correct for meiosis?
I. It is a reduction division
II. It involves random orientation
III. It produces genetically identical cells

  The diagram shows gau1 o/ gao2:bnymetes 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 form5;j:pl.a axd07 djfifation of secondary tumours from primary tumours as a ;0lia5jfjadf x.p: d7result of the movement of cells?

  How many chiasmata are present in the diagrartw,t(uo f vse+26x3 km?

  Which statement is a similarity between cytokinesis in animal and plant cells?9 ql ir9y a6wq 0yz-kj4 6q)ghd.0gmv/6jwt xo

  Which stage of meiosis is matched to the c i3fq. :o9c(9zyiy0 +hfbdmjvorrect description?

  Which statement(s) are tru1qiiiv1y v:n,e of meiosis I but not meiosis 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 first me eh5)v3js2xg1klhp 0siotic division. This results in the formation of one large cell and one small cell. What is the fate of tp g0 2v)lj51ehsk3hxs he large cell?

  Which row correctly des;z ra5 6*w3wnz9ojg nzcribes diploid and haploid cells in humans?

  The following table shows the diploid chromosome number of a range o.jo* o8g *o tg: e+ny0-mjkpylf species.


Which of these statements is correct?

  What conclusion can be drawn from the k3m24jueap xbgjep42 ,aryogram below?

  Which of the following processes is characteristic of the meiotic and not thbc xy:jl-.8 :blenbq+e mitotic cebcb q+l8n yxl:e-.bj: ll cycle?

  The diagram represen+ z v4qc; eftvl(zjv.;ts a bud 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 troglodytes) is 48. Which rowvvoyaxdh6 cw 6hv-;*8wq4uu 6 shows the correct chromosome number for diffe6yxhv auoqwuwh668 -*4c;v dvrent cell types and cell division stages?.

  At the end of which phase of meiosis I does crossing over occur, and what is f y,c.z l+ max(hw;c j2-yrmo0the outcome of crossing oz 0;y(a l-2.+hwcrymm,cjxfover?

  Which of the following statements does not describe a step in the sodiaofduinr3)8t;m ob7 xm q(/ie( yb.3rum-potassium pump cycle imx).3e u/fr3io7bari;b8q dmo(n( tyn the neuronal cells?

  Which row in the table below is true ofj*-d:vl m dg2f meiosis?

Membrane transport is important for allowing particles to move across the cell rhfcc+wicc/nq95w1x g y *r/5 membrane and respond to changes in the chemical composition of the extracellular f9f+5q h/y/c*xcc w1gwncr5ri luid.

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(jjs k+ntu; pt0msr2, cells.

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 the concentrations of different cyclins during ,-fvzb,.nwuhv7ut, ks:x4g)xej 5n j the cell cycle. Which cyclin kfvu) ,ns4wvxxh bzuj-gn: ,j, .75t eis involved in preparing for DNA replication?

The diagram below shows chromosomu; fa pr,-qh (5sj/rvles during 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 invol s/6ul 35rxb8 p(frqmeves the separation of homologous chromosomes?

  The mitotic index of throat tissues taken from 4 different patients is shown,z6 vbbsc u,:nxs: i 3g+jijn( below. Which patient is z,+njj s3bivb6 c ,(un:isx: gmost likely to have cancerous throat tissue?

1.Draw a labelled diagram to represent the process of crossing over. zgunh5lrlq5 6 4t2 m/ q-jb4db

2.Compare and contrast random orientation and crossing over.

3.Outline the stages of meiosis.

  The image shows an abnormal humanyue*;6zium 69.;e peo7 p-zoxoemv c8 karyotype.


What is the abnormality in this karyotype and its cause?

The graph below shows y0vw;kq;pb*t+ wy )d ;ggq db7the relative amount of DNA in one cell during one complete cel0g)wdb ;+q 7;p*wykdybvg; qtl cycle. Each letter represents one stage of 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 a crosskppb,b r+ yeyb:*0l;i between a male cat that is homozygous for brown, long hair and a female cat that has black,bpplir k:b0, *+yye;b short hair.


Which of the offspring has a recombinant genotype?

1.Outline how polygenic traits can show o a9*mzfq :0g+r fujzeag391ea 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-m g+5zz3pl7 nvsister chromatids shown in the diagram below?3 zgl+7 n5pvzm

  The photomicrograph showszf0vj dxcpg7b+ofwn t73 qx :/1x 5z:p a pollen grain from L. candidum (Lily). Which stage of meiosis is sd0vpx: fj+q/p7b1x5ztg7 zxno cf: w3 hown?

1.Outline the events which would lead to an individual being bornv,ql(e.z 8k *7hhsmhu.jqk)c with Down syndrome, which is characterised by the presence of three copies je87kvlu)(hm.zq s. h h*,qkcof chromosome 21.

2.Explain how meiosis increases variation.

3.Outline the stages of meiosis.

The mitotic index is aly8p2 ,zbm; ,taa/gu hn indirect way of measuring plant growth. A study was conducted on white onions (Allium cepa), / z,;82uplhtgam, bayunder controlled conditions in a lab, to investigate the effect of soil 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 are2uyqn oe3 pw.g- cpu;0 two ways in which cells can divide. The diagrams below show two cells fn w-e ;y.cu2p3ugq0porom an organism with a diploid number (2n) of 8.


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 expr nsygis4 i,zps 1 r:;my33sxwu hqxi f:1j9*/lession 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 ofbftz re4db+*4.s)t 2dc,pg2d+piis x 8, in different stages of meiosis. Which row dz*4 ,22+ttr.epsbd4sxbi pfc g)i+dcorrectly names each stage?

  The micrographs show four phases of meiosis I in a plant. In whatdjs,rjha prris7z- 1w6 2w.wl4cgf2. order do these phases occurj, ia-.1w2hsfdgw r.rw6 p lsrz247cj?

Mitochondria are responsible for supp* r53nttwqcl qct10b 1lying metabolic 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 the wcltr tb01n* c53qt 1qcase 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 a c dkqq5-vk:32 ymv9 zr)*kyenumber of cells in different stages of the cell cycle in four sd qrq)zay-e5 v*2ky3: cvkkm9amples of lung tissue from four patients. Which tissue has the lowest mitotic index?

  The diagram shows the dominant cyclin/CDK v2e g nfp8u(q,complexes at different time points in the cell cyc,(8efnpug v q2le. Which cyclin/CDK complex activates DNA replication machinery?

  Studies have shown that genes such as 0 ls mb5vm0db:rs9s/2ta q( bbCyclin Dependent Kinase 3 (CDKN3) are highly overexpressed in b29q0ssm 5rblv :ta0/b d(mb scervical 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 wyg7,,m 5ffp,me: prnhighest during the cell cycle ?