The graph below shows the relationship between maternal age and the incidence 3ro0swi6m:ipnzi ( vm98+tjl of non-disjunction. What relationship is suggested by the data rmin : 63izjlmvotswi9 0(8+ pin the graph?

  Which stage of meiosis is represented t(gwaaf 1g9c 2g:yu7 9(e)kba3iejh bin the diagram below?

  The diagram below shows ckrlgdz-); c. i gt9s;vhromosomes 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 states5 7ht .*.(ti ch7sdpdfett6 ee the number of alleles of a single gene which would be present in the nucleus of a cell as a rd d.hth(t7t57eips fe *ct 6e.esult of each process?

  Which keyword is matched to the corrik/ 1u6f, e.3qzt (0 ffn2nmx7qmtxsuect definition?

  Which statement(s) about mitosis is1edfe3 2vsf 1a/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 cell in an78cb7c a-ykx baphase?

  During which stage of mitosis does the nuclear envelope break down?6.p , ax1ndubh 4v(cfe

  Which one of the following transport proteins only carries out active transportd6+jyk ahs 65d?dsjahy+ 5k66d

  Which process does not .vvfink*6o * uhappen in the shoot apex?

  Which type/s of membrane transport do/does not require energy expendi1lnd/zin2cfd:x +j( br) .synture?
I. Facilitated diffusion
II. Active transport
III. Osmosis

  The diagram below represents a cell with a diploid number of 4. m1e,p.n1f;xfdfhm:r . d hvo0Which stage of cell diviev fp x11 r:dmnmd0h.f;h,.fo sion is the cell currently undergoing?

  The photomicrograph below shows a root tip meristem. Which ol*2bd2wqy) , xpj0h wld)d2 rdf the following sentences correryxwwj22*qd, )2dpl )d 0hlbd ctly defines a meristem?

  When does the random orientation of homologous chroe15lqy9c; lbpmosome pairs occur?

  Which process does not occur)w81m epc.pt+1frf3jiaw8q z during meiosis?

  If a cell with a diploid number of 36 un)hi rgx k/s-g2dergoes mitosis, how many chromosomes will be present in each daughter cell after cytokinesi xri/2h)kgs-g s?

  The image shows a miyoekgr3s 8l l2m02vwx; *nlu3crograph of a cell.


What explains the appearance of the cell in the micrograph?

  Which statement(s) about homologous chromosomes is/are not truu 6n3k bl tjl;-3gqavdymj)gb/a-. *17aehb ve?
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 iitla,o;tzsv4mo ; 8t8ndividual with Down syndrome.

Which statement is not correct?

  In the cells of a horsex-nmru.j0 z:g (E. caballus) during prophase I of meiosis I there are 64 chrom-gj.r z0nxm:uosomes. What is the haploid number of chromosomes?

  Which arrow is pointing to a chias6 paw iiv;ff,m06le+k:gpnj 8ma?

  The diagram below represents the tb2 2st3hfc 3/)2sk 2fwojocx structure of a shoot apical meristem. Which row in the table correctly identifies the processes occuring in the structures labeled in the diagra2k3c fsht 3jx2sowt2 o2f b/)cm?

  How does meiosis prom:3ovnm(v:jlo4.;+uw 6 fqraf(g qjzuote variation?

  Which of the followin0mvm1a;yp a:x pgq;4u g statements is/are correct for meiosis?
I. It is a reduction division
II. It involves random orientation
III. It produces genetically identical cells

  The diagram shows gametes produced from two homologous chromosox)*atp.l+zver 8q n7vmes.


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 ;sljpv; gup)7tdw ,0u tumours as a result of the movemepg7 pwus)dl j;v tu0;,nt of cells?

  How many chiasmata are present in the diagramb9jx8 i-;tks g?

  Which statement is a similarity. tyk3xe 0*iet between cytokinesis in animal and plant cells?

  Which stage of meiosis is matched to the correct debkv3k:t oii3 gq2 0m-pscription?

  Which statement(s) are true of meiosis I but not meiosisp1qg )7ujz wp:c+zkp8z,cl+d 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 ;j 7jetocq6p287ezo;vt q cn* oocyte after the first meiotic division. This results in the formation of one large cell and one s7c 8*zt 6ecqvj;njq27pt oe; omall cell. What is the fate of the large cell?

  Which row correctly describes diploidh jr 0f3rowsh17fzfx a*j .y0:zponocns6. 7; and haploid cells in humans?

  The following table shows3hoqevhc.cpd/ (b;y- dc0w 5g the diploid chromosome number of a range of species.


Which of these statements is correct?

  What conclusion can be zkt:p(loxj4 b/cq )x :drawn from the karyogram below?

  Which of the followin(u u1mz0tec sa2(3p n; +2u y)qkvkdheg processes is characteristic of the meiotic and not the mitotic kv+2mt(hdua0 zc)u3yp e; nq2(su1 ke cell cycle?

  The diagram represents a bud with +,j4gkrzvuf * * tfbr w z+*wb8qa:b3ea 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 roqhbgao qqha85f7- 6 q,w shows the correct chromosome number for different q, 6q7fq b5hoa hqag8-cell types and cell division stages?.

  At the end of which phase of meiosis I does crossing over occur, and what is the7cg8ljaj:2 j8 yncea+ outcome of crace8: jjagnl +cy2j 78ossing over?

  Which of the following statements does not describe a step in the sodium-7fxgxo/- 2b 0 2s0- kxac5ttksgmx4qopotassium pump cycle in the n kkf- 0 2x o5 4osq/mb7sxx0-tgc2gatxeuronal cells?

  Which row in the table below is true o11)szxm 8 qzwff meiosis?

Membrane transport is imporz.xh hqyk; 0 6;8mmrgm8jlf8u tant for allowing particles to move across the cell membrane and respond to changes in the chemical compo8mm.8q mlk hgf;8h0yj6xzur ;sition 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 cele9 rj z(zlusw x:56s5uls.

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 the cellsajv:a dzygr60 s )ui.u -*f*m cycle. Which cyclin is involved in prepaiyuj-* 6ad* sv0saug:mr)zf.ring for DNA replication?

The diagram below shows chromobh5hob cvkulv7r)c0u4mr fsrg4 ;4 4(somes 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 homologous8 j we1n,fgiq5 chromosomes?

  The mitotic index of throat tissues taken from 4 different patients is shown bey8xv68xjfw vb 6 38eazlow. Which patient is most likely to have cancerous throat tisa8 bxe 6fj8zv8v 36yxwsue?

1.Draw a labelled diagram to refi nx*vgh(w b3 5fyt81present the process 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.r sehxz h ojdr,-)y,;9


What is the abnormality in this karyotype and its cause?

The graph below shows the relative amount of DNA in one cell during one complet/zb5( k2 )x loa8mwcgje cell cycle. Each letter represents one stage of the cell cycl/co 8jgmx)kwb25( za le.


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 crj 6vw +(p)fipgoss between a male cat that is homozygous for brown, long hair and a female cat that has black, p) if+jvg6pw(short hair.


Which of the offspring has a recombinant genotype?

1.Outline how polygenic traits c8v qou)fz-5ef an show 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 chrf *n,fcq5-)e6v pu sab,5emvw omatids shown in the diagrae5 vf6bv5awmse-cf ),qun*p , m below?

  The photomicrograph shows a pollen grain from L. candiduarxc)) g p9a reynb0,8m (Lily). Which stage of meiosis i x9y)ea8a0r ,)nrbcpgs shown?

1.Outline the events w7yt3x-kh mf a/le0 qo(.tv/cdhich would lead to an individual being born with Down syndrome, which itov c3/.lkxmda0q yf/e(h -7ts characterised by the presence 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 growth. A fn);m fad.s3j(u6i ifstudy was conducted on white 3j (fn f;mai f.6ui)dsonions (Allium cepa), under 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 are two ways in 5q b 1dda+kn01h7j9) kfsqgafwhich cells can divide. The diagrams below show two cells from an organism with a diploh qb9)ksndf gaj1ad 7fk +510qid 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 )*nmd1kx ftx;p a/zzbxcz+enb/5 5 +fgrowth.

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 differe*4f6ae+f af (cgswdy;nt stages of meiosis. Which row correctly (fcfadf*e ya+ sw6;g4names each stage?

  The micrographs show four phases of meiosis I in a planttrdw 5 .m9wo,ot/xg;x. In what order do these tdg otr 5,xwo/9 ;w.mxphases occur?

Mitochondria are responsible for supplying metabolic energy in euk5cb04v2o* n)vss mhc jaryotic cells. In most eukaryotes, which reproduce by sexual reproduction, mitochondrial DNA (mtDNA) is inherited from only sjcsm 0vc4b5o)h2n*v 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 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 stages of the cell cyclz(bbq/mp; vd .m;7y kle in four samples of lun7m kq b(.l;;zvdm p/byg tissue from four patients. Which tissue has the lowest mitotic index?

  The diagram shows the dominant cyclin/CDK complexes awu/wsjl5 )vv9uo 0f ,xt different time points in the cell cycle. Which cyclin/CDK cvs0o vu,w )ul95wfjx /omplex activates DNA replication machinery?

  Studies have shown that genes such as Cyclin Dependent Kinase 3 (CDKN3) aretq v w2s55 *j,mf*ehlt highlyvq jsl55*,t eh wtm2f* overexpressed 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 o o3r6 ,nq(/mi :dsnebqoi r02h4pwt8the highest during the cell cycle ?