The graph below shows the relationship between maternal age and rc8 hv.hp1o5u.hv/ ec the incidence of non-disjunction. What relationship is suggested by tr. 5 e/h1hvcohuc. 8vphe data in the graph?

  Which stage of meiosis ivl yf 6t8bj**fs represented in the diagram below?

  The diagram below shows chromosomes during me+ zaxv e8+f7hhiosis.


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 number8gs1y0r w7xw;qp jvf61vf w kjbb19 k- of alleles of a single gene which would be present in the nucleus of a cell as a rebqg 71kf xwj -0 6j8rwbywvsf; k9v11psult of each process?

  Which keyword is matdv )k9io2tznly.2: us m4 ;wziched to the correct definition?

  Which statement(s) about mitosi1--u+bj lrlixk3q (xg s 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, whi(iu(s,pekrid65a i9vf,r1v p ch letter points to a cell in anaphase?

  During which stage of mitosis does the n2 jtqwfuzm2(4g j) keg:x;(mh uclear envelope break down?

  Which one of the following transport proteins only carred01tge3/o q xqk 2afj5 t(r4iies out active transport?x 1qf/j5e2 o kgd(0 iat4q3ter

  Which process does n5 )eu)pa:ifpcw3 er 8cnuc(e6ot happen in the shoot apex?

  Which type/s of membrane transport do/does not rew uv.b 1xi4qawh,n k,)quire energy expenditure?
I. Facilitated diffusion
II. Active transport
III. Osmosis

  The diagram below represents a cell with a diploid number fvnkxl0a0 )oi2 yi,x7yb 2j6gof 4. Which stage of cell division is the cell curre, 0oi)0g x iflyxa6vn272jy bkntly undergoing?

  The photomicrograph below shows a ro-m84sjuu7-h vj d(croot tip meristem. Which of the following sentences corre87 u- jhc4u(s-movr djctly defines a meristem?

  When does the random orientation of homologous chromosome pair2 1p0s rqftb65i b6 rk,,xpizbs occur?

  Which process does notg2mw )o* 8y-rmnxl7u shwd:.y occur during meiosis?

  If a cell with a diploid number of 36 undergoes mitosi .gl0,v/bzk yys, how many chromosomes will be present in0bv.,zyy/kl g each daughter cell after cytokinesis?

  The image shows a micr5:tqnzi,r:2h6di kc ew-2i xtograph of a cell.


What explains the appearance of the cell in the micrograph?

  Which statement(s) about ho- bwfoyp6ix0; vt w.+emologous chromosomes 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 iny221(c 2nf*tzdjgssk dividual with Down syndrome.

Which statement is not correct?

  In the cells of a horse (E. caballus) during p0dhj9f )fsufm 4;2)lzcke:mp hfm6+z rophase I of meiosis I there are 64 chromosomes. What is the haploid number of chromosome ujhm:cd260+)m9elf;m)pz4fs f fzkhs?

  Which arrow is pointing to y:x 1f 2gthr*za chiasma?

  The diagram below represents the structure of a shoot apical meristey)j/*dmu pv pnh95 6vyuz8azv qffs (05x0 li)m. Which row in the table 90/yzp)j5dxf(avv)650 8uq l iyfph*smvznu correctly identifies the processes occuring in the structures labeled in the diagram?

  How does meiosis promote variation?q116.mqh6xc p2th;5xg os zot

  Which of the following statements is/are correct ff g+bdyig3kvhpz8gh+*n4 2 6bor 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 ho:o r;9aqwk c 9ic4uhr,mologous 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 txtvbdh/1s* aei cj://o 9a un7he formation of secondary tumours from primary tumours as a result of the movemch7xuaa/:sen o ijv//*t9d b1ent of cells?

  How many chiasmata are pres,nt tv.crm8bo* w4(fcent in the diagram?

  Which statement is a similarity between cytokinesis in cwi o07yqkg2fl dm07: animal and plant cells?

  Which stage of meiosis i3n4fm+pc9:z*h m ,zxzo- buk rs matched to the correct description?

  Which statement(s) arem*ke3v+i62 lcat0mt f true 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 meog x6 -/r*gjvnt r ((dirm)*nbiotic division. This results in the formation of one large cell and one small cell. What is the fate of thertgg6xr i(m-j)(bn**dv no /r large cell?

  Which row correctly ipf.010 ad bodj 0wwbzu1( *i1gz vhm5describes diploid and haploid cells in humans?

  The following table shows the dip 7pwpeu)bi,9bo2 m 0b:sj7hu qloid chromosome number of a range of species.


Which of these statements is correct?

  What conclusion can be drawn from the karyogramel/1 t/qfaw;b below?

  Which of the following proc0pr uf.tbx+i c -3q2smesses is characteristic of the meiotic and not the mit.imr f-30buq2pcx+s totic cell cycle?

  The diagram represents a bud witd5 yhx)3)di(rvktz*0s y ebe 3h 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 t7ta/rzq2 vfus4 pf(b 59-tw rjhe chimpanzee (Pan troglodytes) is 48. Which row shows the correct chromosome number for diffe varffpbq-( r/zts9u45wjt27 rent cell types and cell division stages?.

  At the end of which phase of meiosis I does crossing over occur, and what is th*rzy 6tk1 e (r:nig(lye outcome of(lk:zy 1 n*itg6(r rey crossing over?

  Which of the following n 3jf1 botg23z9hg1 sqstatements does not describe a step in the sodium-potassium pump cycle in the neuronal cells?t31shn2bozf g1qj 3 9g

  Which row in the table below is true b1pvbfj;yyi8)d: ;tuof meiosis?

Membrane transport is important for allowing particles to move acrosf;vh lepr 6dek;20kkv6nk 9i2s the cell membranef0vle2k6;e hki d; n92kr kvp6 and respond to 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 in wb6c;sxsl )n t5u6 ij9cells.

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 d-jt ,dv35hcfyn nu-c4ifferent cyclins during the cell cycle. c,3vtcn5 d4-ufny hj-Which cyclin is involved in preparing for DNA replication?

The diagram below shows chromosomes during meionw9o2jtnhh3s6 7y9 fh6r3ddksis.

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 chromz0ig1 hcj 4b7hbn-m otl35-. if kt)lxosomes?

  The mitotic index of throat tissues taken from 4 different patients is shux :e3eh fh6p*10(o c)yjglzdown below. Which patient is most likely to have pjdgec3h 0hx*(lzu6f) :y oe1cancerous throat tissue?

1.Draw a labelled diagram to represent the process of crossie0*6y.mbh kyd mc1/ qtng over.

2.Compare and contrast random orientation and crossing over.

3.Outline the stages of meiosis.

  The image shows an abnor6s,zbo*rx 7ddmal human karyotype.


What is the abnormality in this karyotype and its cause?

The graph below shows the relative amount ofg 1 qc hz,(zbyxnh1 ,)*siezx0 DNA in one cell during one complete celnh b)*(h0gi1 qz1,xczyxze,s l 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 cross between a male cat that is homozygous for brownasiinh* brpgo1qr:5:to :/b ; , long hair and a female cat that has black, short: bhoa:: trp;1 o/ib5giqsrn* hair.


Which of the offspring has a recombinant genotype?

1.Outline how polygenew(2( 3g jz xaryzbz0d)( ;erdic traits can 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 chromatids sho 7i ,z0k pc,abic/,) nex ccf)hzx)t3awn in the diagramknp c7,zebix3az/ c)0ih,x a fc,))ct below?

  The photomicrograph shows a pollen grai wv.c 2tj20dvk))0kdvib6 tgl n from L. candidum (Lily). Which stage of meiosis is sho0.0dkbivcgkld2 tjt w6 2) vv)wn?

1.Outline the events which would lead to e5brx5xgb0+wq / ujh3rh-yf-b+bo 5s an individual being born with Down syndrome, which is characterised by the presence of three bj0- efbr5w5h5 -+xsrbboygh x+/3qucopies of chromosome 21.

2.Explain how meiosis increases variation.

3.Outline the stages of meiosis.

The mitotic index is an indirect way of measum/veu8f4ey )e*thr;1xmcyre *5s q9iring plant growth. A study was conducted on white onions (Allium cepa), under com4 r;9s5)i*u feqvy* e rxhey8/t1mcentrolled 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 wayse yidvme;euwzj;3dus:j,a(:2 jf 6 : k in which cells can divide. The diagrams below show two cells from an organism with a diploid 3ki(ve awudyz:dujsjfe6 ;,2:jm;e: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 gr0:2kjual8 f tsw;+ ri4w*cygfw 3da-powth.

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, wi yx.n7c ;8,gi0 fsqy33kfhas hth a diploid number of 8, in different stages of meiosis. Which row correctqys8n; c3fa xgi7fk hsh0. ,3yly names each stage?

  The micrographs show four phases of meiosis I in a plant. In what order do the( mja8sk:syy(se p(k jmssy8a(y:hases occur?

Mitochondria are responsible for supplying metabolic energy sq.z) r lpe3idi8 6g6min 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 by th zm)is3.68rp gi6 qldee 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 o/ jg vcpy2vx*2:j7wynumber of cells in different stages of the cell cycle in four samples of lung tiwj* p/v 7jg2xcoy:v2y ssue from four patients. Which tissue has the lowest mitotic index?

  The diagram shows the dominant cyclin/CDK c 9au3*li;y u-d8uwfwcomplexes at different time points in the cell cycle. fi u9a8c-w3wyu;*uld Which cyclin/CDK complex activates DNA replication machinery?

  Studies have shown that genes such as Cyclin Dependent Kin.,p6;f jaodns 4t oa,.wmu zx,,n8dknase 3 (CDKN3) are highly overexpressed in cedm,j;afxt n,w8 zs.,6n oo. pdu ,a4knrvical 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 cellvhhy ir 6or26;h1hr;f cycle ?