The graph below shows the relationshm. n8 *5zboohl2ymc/t ip between maternal age and the incidence of nmh2c/tnyl .5 o*8zmob on-disjunction. What relationship is suggested by the data in the graph?

  Which stage of meiosis is rep th *kms;y05h au; 1mw)volc-wresented in the diagram below?

  The diagram below shom5;g2a8c*m n1mf wqufws chromosomes 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 states the number of alleles of a singlkyb g fzpoxsp )5;i2)4i -vnf8e gene which would be present in the xv n5- i;kyp)gif fo)sp8z4b2nucleus of a cell as a result of each process?

  Which keyword is matched to the correctfl3suqqz:j) : zkcs la0536 ,yfyx,plfg.bn. definition?

  Which statement(s) about mitosis is/are tru amry:ris+4wc8 t4ptn6-y3mw e?
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 cell in ana t ua+1b5h(ebd5yud+w phase?

  During which stage of mitosis does the nucol,u )+vp4xw ywilp.:lear envelope break down?

  Which one of the following traphj9 ;(q cn9 phwukz17nsport proteins only carries out active transport?7qj(h9uzk9pnw;cp 1 h

  Which process does not happen inor;m. ivog *v23d-;;jc jnc+bzb+df )ptgp(n the shoot apex?

  Which type/s of membrane transport do/does any,7hd dj10n not require energy expenditure?
I. Facilitated diffusion
II. Active transport
III. Osmosis

  The diagram below reprr3bz4g xn g1.c6k6*f ampv9 suesents a cell with a diploid number of 4. Which stage of cell g39n* c1 4.a zbgx6sfmrvk6pudivision is the cell currently undergoing?

  The photomicrograph below shows a roo3yfpgde:i6v et +j6gqj65y w/t tip meristem. Which of the following sent/fvg5q63iy+jpge : wye6dj6tences correctly defines a meristem?

  When does the random orientation of homologous chromost,o(pgu-z :gq7ql st b(ktf2s-+kxx4ome pairs occur?

  Which process does not occur durinsnmn4kei k3w /hzn38 )g meiosis?

  If a cell with a diploid number of 36 undergoes mitosis, how m*+sh9-4 s0h1 lwe mt ppwn9mscany chromosomes will be pre1nlp9h epwms0sw csh-*t9 4+msent in each daughter cell after cytokinesis?

  The image shows a micrograph of a cell7ja9m)mauj6 p .


What explains the appearance of the cell in the micrograph?

  Which statement(s) about homologous chromosome*p ko(n3.* 8hoqbzj/+ mdkgt hs is/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 individu1l3y,ij,7+kv beriusvr7 n :mal with Down syndrome.

Which statement is not correct?

  In the cells of a horse (E. caballus) during prophase yz 1qg (rvb;+yI of meiosis I there are 64 chromosomes. What is the haploid number of chrom1+yvgqb ;z(r yosomes?

  Which arrow is pointing kc/yv+ e*z:9zz1(h kp69bqbeg8 eogm to a chiasma?

  The diagram below represents the structure of a shoot apical meristem. Wd d*;qaow10hd zbbdwe33mc60 nox6 1 zhich row in the table correctly identifies the processes occuri66ox b 300w3d ddwhe1omz1;aq*bnd zcng in the structures labeled in the diagram?

  How does meiosis prohxtm2/ ;,9zsjsdn ng(-5xj)9yt wdagmote variation?

  Which of the following statements is/are cojz)wtx yz :k qw;hgl42mo8k** rrect for meiosis?
I. It is a reduction division
II. It involves random orientation
III. It produces genetically identical cells

  The diagram shows gametes produsd wp3u6vo z36drr+3aced 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 fzwe 3d* hh4dqrrc.; -:fg+wxfrom primary tumours as a result of the movement 3qgh rhffwed4w+ c.zxr*-d:; of cells?

  How many chiasmata are pr e f9tmav e3.g/o9oyq0esent in the diagram?

  Which statement is a similarity between cytokinesis in an0s7 jr*iqylzwcc8 27 br b+1xmimal and plant cells?

  Which stage of meiosis is matched to the correct d(a n7:dlf dq.de+-orm escription?

  Which statement(s) are true of meiosis I but not meiosis II?alnwufmf.)u8 a2f,mx(v ev 9 7
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 fpk9-+ ge- a z. apy :l:ekl1ikj1ckn(nirst meiotic division. This results in the formation of one large cell and one small cep-a1kkl91 ynek:e.la-c + g kzni:(pj ll. What is the fate of the large cell?

  Which row correctly describes diploid and haploid cells in humans s*q/ zrkiju*7 dz0t7geahmtv 9;9 r.k?

  The following table shows the diploid chromosome number ow 3 ljx4n/tqxo4) +kxdn8-: f1 )citn2llarmdf a range of species.


Which of these statements is correct?

  What conclusion can be d)axk2t gx/b+ rrawn from the karyogram below?

  Which of the followingiy c 9ohehkl*+ 8)pt/u processes is characteristic of the meiotic and not the mi9oi yktchl)8/ *e+uhptotic cell cycle?

  The diagram represents a bud with a shoot apical meriste3dddj6 * 3-vwev6pirnm.

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 chim istd.;az /s7t73psiqve/6cf panzee (Pan troglodytes) is 48. Which row shows the correct chromosome number for different cell types and cpvt s i qd.s3zta7es;6/ifc7/ell division stages?.

  At the end of which phase of meiosis I does crp ojphg/fd -6o5o*ax.ossing over occur, and what is the outcome of crxhdoop*/ g65j afp.-oossing over?

  Which of the followinjp1fu w*t 0r.eg statements does not describe a step in the sodium-potassiep rj.0fw* t1uum pump cycle in the neuronal cells?

  Which row in the table bel(k 7foihc3 xgy ::x3pcow is true of meiosis?

Membrane transport is important for allowing particles tou u82o sng.y:i move across the cell membrane and respond to changes in the i.2s:ugonu8 ychemical 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 reqbznq xuwq2-n-ja2kx w5/h*1bf3)ml gulated in 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 concentr8tzihgn9jhh pst0iq92 xp /7k-p / fu8ations of different cyclins during the cell cycle. Which cyclin is involved in preparing foik-7hhp/2ph8np i 0 g qjsu9t8f 9/xztr DNA replication?

The diagram below shows ch ipy8tj9b/6w( viw0f yromosomes 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 involves the separation of homologous chromosora:r/-e xc.6qq qjwp;mes?

  The mitotic index of throat tissues taken fr- 95zw pc2mgxkom 4 different patients is shown below. Which patient is most likely to have cancerous throat 5 -2g m9wczxkptissue?

1.Draw a labelled diagram to represent the process of crossing overa4hi )tcyn .c8.

2.Compare and contrast random orientation and crossing over.

3.Outline the stages of meiosis.

  The image shows an abnorm5*d 7zo w6 uyj.4yxydgal human karyotype.


What is the abnormality in this karyotype and its cause?

The graph below shows the relaj iiwctb3z0sfexp(0rs; 6e s* 0xq/ (ltive amount of DNA in one cell during one complete cell cycle. Each letter represents one stage o6s*sst0clqef r3/ (0xje0w zb;xpi(i f 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 cross between a male cat that is homk06xdm1;vj jvozygous for brown, long hair and a female cat that has blackj;k m60vv j1xd, short hair.


Which of the offspring has a recombinant genotype?

1.Outline how polygenic traits can show au+ ju7 3.5l) rb:dmaxje vbkc: 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 the6.pjc0 w 8e 2qz4ptieo crossing over of non-sister chromatids shown in 6.4t28zwcp o piee0q jthe diagram below?

  The photomicrograph shows a pollen grain from L. candidum (Lil k9z2j pyhc 0la7q*y6yy). Which stage ofy kp9 z7qjyac6yh 0l*2 meiosis is shown?

1.Outline the events which would lead to an individual beingkaou 5mug8v:f-u,8m 8 suc k4t born with Down syndrome, which is characterised by the presence of three ,58k8ac-4:umum g to8uku v sfcopies of chromosome 21.

2.Explain how meiosis increases variation.

3.Outline the stages of meiosis.

The mitotic index is an indirect way of measurinmvjdv7b8pu3pg3 o(,e g plant growth. A study was conducted on white onions (Allium cepa), under controlled conditions in a lab, to invest 7( vvjge3p3d8b umo,pigate 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 are two q:iusbi*l( 4 z9 prr;von,;zqways in which cells can divide. The diagrams below show two cells from an organism with arziiblvr, 4qs *p:9u;;(nzoq 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 expression in stem growt+eu rht0b5tc 7h.

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 nubk t lxpcj74 dnhp-mj,z 1g7/4mber of 8, in different stages of meiosis. Which row correctly 7bn 4dk,pc j-zp/lxm1 gj4 7htnames each stage?

  The micrographs show four phases o22xwr9s8b 0w) i2 xucryrb2tz rpky*6 f meiosis I in a plant. In what order do these phasy2r8w062yx kt2rr2rsibx bw )p z*9u ces occur?

Mitochondria are respo 1bor-cbr-;m jnsible for supplying 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 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- br;rc m1j-ob 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 cells in different stagf;:(z:miahuabl t ;skvuwe+9/ a9h z6 es of the cell cycle in four samples of lung tissue from four patients. Wht:e zi;a6as m:bzf 9(+k uhvh9la;/uwich tissue has the lowest mitotic index?

  The diagram shows the dominah0 ci /t07kuh5 bfig6tnt cyclin/CDK complexes at different time points in the cell cycle. Which cyclin/CDK complex ag0 th c6ik5/if7th0ubctivates DNA replication machinery?

  Studies have shown that genes such as Cyclin Dependent Kinase 3 4hzx9em g +:3nxawba6ck/pd. - 0f gvr(CDKN3) are highly overexpress-9nac4e hm axxbwg+:6.k rfv 0p/3dzged in cervical 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 the zp sp7- u-hh9ex9wwt9n9sio *i,9lotcell cycle ?