The graph below shows thepo x b a/2np)cw1x4zx, relationship between maternal age and the incidence ofa pxzxx1,n o4/c )bp2w non-disjunction. What relationship is suggested by the data in the graph?

  Which stage of meiosis is repre0qfe7y * qga x;h36jzrsented in the diagram below?

  The diagram below shows chromosj+f+vv hyg ;j6omes 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 single gene whic9ji q75o (vfflh would be present in the nucleuv9(5 o7fi fljqs of a cell as a result of each process?

  Which keyword is matched to tfk qxlpkp9 : :adetz e2,9sp5;he correct definition?

  Which statement(s) about mitfcaua , i8)o6ha:6h xzosis 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 cell in anaphaseq+ dicf jx/+g +w)n4bn?

  During which stage of mqof3.;vrqvv8,s-x 0f). appx/aqci fitosis does the nuclear envelope break down?

  Which one of the following transport proteins only carries x;wit: :x5vg47kfir-p rb. o mout active transport?; -x45w.mfi ot:gb vr :pkx7ir

  Which process does not happe*8 (q ou ov1y-zm3*nwgt*guahn in the shoot apex?

  Which type/s of membrane transport do/does not require energy expen9* x 8iklf+emwditure?
I. Facilitated diffusion
II. Active transport
III. Osmosis

  The diagram below represents a cell with a diploid number of re2; wrgwj f4b+ i6wnib1yi6. 4. Which stage of cell division is the cell currentlyig;y iw4 b2r6ij1bf +w6er. wn undergoing?

  The photomicrograph below shows a root tip meristem. Which of the followc-/gnt.v w jjo(zi a (+fcox b9d7:a7rna. z1wing sentences va j7o:c (dixr anz.zo+nw7bc9g.j/t (w-a1fcorrectly defines a meristem?

  When does the random ori w/80ollmyw5 c0t r8dgentation of homologous chromosome pairs occur?

  Which process does not occur during meiycr enlq+ 32d)osis?

  If a cell with a diploid number ofz (e:o9s;-hmy r7i9 py -dn c7oqn5exj 36 undergoes mitosis, how many chromosomes will be present in each daughter c -n cy7qm 9y-djzo(o;ieex9 7ns:5rh pell after cytokinesis?

  The image shows a micu z,0i15h sh( i c3h1hisjm:kyrograph of a cell.


What explains the appearance of the cell in the micrograph?

  Which statement(s) about homologous chromosomes i/z*zwe/b*g;w aao7i hdxphbry-0 mvm+n3m +2 s/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 individual withl fg j -;duf8nxf9npkkz10.ls7 y4,zr Down syndrome.

Which statement is not correct?

  In the cells of a horse (E. caballuse*: bz4u:-9nsc h oozy) during prophase I of meiosis I there are 64 chromosomes. What is the haploid number of chromosomz- 4onco 9hz*ebu :ys:es?

  Which arrow is pointing to a chiasma? 3yc8kry )gv q2 6r l qwscdsx7qrbnwk)01u*. 5

  The diagram below represents the structure of a shoot apical meristem. Which d12a yp 2wh(dtrow in the table correctly identd(yta 2d h21pwifies the processes occuring in the structures labeled in the diagram?

  How does meiosis promote varian9hy 0+c g5dhetion?

  Which of the following statementsd, yo,v* +5mzo0pr*ou ou(efn 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.h i4vfyiab.c)i+ qo4 ,r0u at 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 l.)t c-qjz;00 voln) pejl5cbtumours as a result of 0co0lj)cle-nz .pvj5;bq )ltthe movement of cells?

  How many chiasmata ar t;-8erbs,sy0(p lsoq*e .xoqe present in the diagram?

  Which statement is a similarity between csu dpy(+ .i9fnytokinesis in animal and plant cells?

  Which stage of meiosi 6f fr,e9n9hmfs is matched to the correct description?

  Which statement(s) are truex+nz i t+8soe 6rgdi-. 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 meiotic division. Tiz ha x(k;wy94his results in the formation of one large cell and one x k9ziw;y4h (asmall cell. What is the fate of the large cell?

  Which row correctly describes diploid an3aeqdue aby *np+))2 l* qwi 3aq/zmth2f7+xtd haploid cells in humans?

  The following table showsb3pv n ,9gaq3d the diploid chromosome number of a range of species.


Which of these statements is correct?

  What conclusion can be drawn from the kar:izz8ynr hb /t6x;g,jyogram below?

  Which of the following processes is characteristic of the meiot) (o ;vjj;iwg9(bjou i piv gwrt390nff6g52xic and not the mivx(o93f j)i96w2in ug(gjt;p0w v frg5; jboitotic cell cycle?

  The diagram represents a bud with a shoot apical meris)0:v/ j4pn l l1suzjretem.

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 row shows v df.vv1qqo0 c q/.:5os, r3wotmec 2ethe correct chromosome number for different cell types and cell division stag.:ovf0t 3 1esv ecw/qo .md2rq vq,oc5es?.

  At the end of which phase of meiosis yl,-cc 0(cplx I does crossing over occur, and what is the outcome of cross (cxlc -y0,pcling over?

  Which of the following statements does nox7(/kibc +vo 3 hqqja(t describe a step in the sodium-potassium pump cycqok v((h3 /+ci7ab jxqle in the neuronal cells?

  Which row in the table below is true of m ock2+h*cjis, eiosis?

Membrane transport is important s2 f,d7dry( tuoq+*c);pj sde: x.g qzfor allowing particles to move across the cell membrane and respond tou(7*op e+c dqsz)y,jtg xr 2f;q.:dsd changes 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 wyn;-j, )k kb4rkz np u83s,loin 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 diffev.(jzns2egn)w mh aat.w*8r6rent cyclins during the cell cycle. Which cyclin is involved in preparing for DNA rtwzs.()e w.62vjr8m*g ahanneplication?

The diagram below shows chromosomes during meiosis.r;kg wkw5s07d

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 xeg v6a r64*9b v wmiv((xx c mxz3pv7x613moochromosomes?

  The mitotic index of throat tissues taken fromb)g8gbpfan 4 ) 4 different patients is shown below. Which patient is most likely to have cancerous throat tissg )48np fgbb)aue?

1.Draw a labelled diagram to represent the process og9/i+3ey)7gvnb we a dyuf z-6f crossing over.

2.Compare and contrast random orientation and crossing over.

3.Outline the stages of meiosis.

  The image shows an abnormal human karyoq-baq1l 3qxu:b 6d xcs -nco p2u3:y(ltype.


What is the abnormality in this karyotype and its cause?

The graph below shows the relative amount ofzpw wdp v3re.x8+a;rt y; 8xzyf(f)m1 DNA in one cell during one complete cell cycle. Ea.ay1 y z;dm3 twxfx 8v(; zepp+f8rw)rch 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 cross b sej )hr1ufn;jpq5r(9etween a male cat that is homozygous for brown, long hair and a female cat tha)9 rs5h(er1jp;ufq jnt has black, short hair.


Which of the offspring has a recombinant genotype?

1.Outline how polygenic traits can show a kgy d9o.3 ebf3normal 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 showkv x*+7 * ; bfd/3f;tjfjbidssn in the d3 fbt*jj/;s;7*fd sb+iv fxkdiagram below?

  The photomicrograph sh( pd0cjmkc *ktl88 pvg:0yr6 kows a pollen grain from L. candidum (Lily). Which stage ofdmctkjry80plv :*ckk p06g 8 ( meiosis is shown?

1.Outline the events which would lead q.9 uu2pex hxi 7hp+ um48d(wqto an individual being born with Down syndrome, which is characterised by the presence of three copies of chromosome pue8wx2i 7h4qx.m hqp(u d+u921.

2.Explain how meiosis increases variation.

3.Outline the stages of meiosis.

The mitotic index is an indirect way of measuring plant grow .m ar,yeun7slf q)v zzm7:p27th. A study was conducted on white onions (Allium cepa), under controlled conditions in a lab, to investigate the effect of soil pH on the mitotic index of thy2)7mufns7 z. :qm7lz,rape v e 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 belo.5k-*bihqa 1yhy/hx 3kxfh1usm , hnrc4u. v-w show two cells from an organism 5s n -mchv*bh .-xhyy/x3fh u1k.ui q14,arhk 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 expressi02)lg1liugdp6l 9 1gclsh sn2x5p gh )on 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 diffe16uldotx xg5 +2ixe7 arent stages of meiosi d7i g1x+e2l6oxxu 5ats. Which row correctly names each stage?

  The micrographs show four phases of8rqy pcp:- u3qs3ej( ,pgi9up meiosis I in a plant. In what order do these phases ocg-yiu8,p9u3jq p(p3: rqc se pcur?

Mitochondria are responsible for supplying metabolic energ0:yfc ha5 n()oh/iebzy 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 hy (a hn :iybo5ez0fc/)hbrid 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 cell dak3y0uce x5to6+2d rs in different stages of the cell cycle in four samples of lung tissue fxrdu +eao0d6 5yk3tc2rom four patients. Which tissue has the lowest mitotic index?

  The diagram shows thez r ;qvgp18*p2 fo7;n zunw3fd dominant cyclin/CDK complexes at different time points in the cell cycle. Which cyclin/CDK complex 8wnf p1;z;o vd72fzn3 rp*ugqactivates DNA replication machinery?

  Studies have shown that genes such am ;fm9 /ej8cxl:b5v6ivino. cru 7zj 3vwa, 6ds Cyclin Dependent Kinase 3 (CDKN3) are highly overexpressed in cervical tumojnb,zc:vdf/u; 3m6w m9.5 evr 8ci6j7 ailxovurs.


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 j,dm 4-isxu xn *),: f )wf5nbbmmgny0E the highest during the cell cycle ?