The graph below shows the relationship be/wp6l qy+klm,tween maternal age and the incidence of non-disjunction. What relationship is suggested by th6kml/w+ pyql,e data in the graph?

  Which stage of meiosis is represente3mo8h/h101 ukqthx 3mmxue 0wd in the diagram below?

  The diagram below shows chromosomes during meiosis.8h0lvr)t 14nq zi,4qdkm )xqx;3qv jn


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 p.2/bmd8r9 us bmmlp)gm. i; agene which would be present in the nucleus of a cell as a result .m)2ibgb d9m8 r pmm/u;slpa .of each process?

  Which keyword is matched to the cjb*4x 22 zb2u1+9afgc iu ikxzmu(v7 worrect definition?

  Which statement(s) abo/ ;fxe(citn;h ut mitosis 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 anaphs,ec(y(g omyf9x 7n1rz5p tr: dm:py,ase?

  During which stage of mitosis does the nuclear envelope break (qoo,-/jaf kpdown?

  Which one of the following transport proteins only carriesgaw)2d1rl0fzxs r10 os tr .b5 out active transport?w05lsr z g )odtfarrxb10s12.

  Which process does not h6q3c)o4 f.fxttm 90zby)q jhbqzt :)rappen in the shoot apex?

  Which type/s of membrane transport do/does not require energy yhuzg12r9 r6u4-5uv)eoy7 a c 2n otrjexpenditure?
I. Facilitated diffusion
II. Active transport
III. Osmosis

  The diagram below re /( hh:oy4(pctwfzn wf -w()elpresents a cell with a diploid number of 4. Which stage of cell division is the cell c/yfwhe)pzw (c: f (tlho (-4wnurrently undergoing?

  The photomicrograph below shows a root tip meristem. Which of)obasi:.ll ,zb;h8m a lt28i f the following sente. o,i)blatl zia:f8;lmh b8s 2nces correctly defines a meristem?

  When does the random orientatiou; i7 zq9ams9hn of homologous chromosome pairs occur?

  Which process does not occk orlm9+s:o f6ur during meiosis?

  If a cell with a diploid n y.:g k wwkty6kiwu(+fd862fg umber of 36 undergoes mitosis, how many chromosomes will be present in each daughter cell ay66d+w2f(wk k8g:w tiy. fkgufter cytokinesis?

  The image shows a micrograph of a cell -y)b(fg0squ -dtqa /l.


What explains the appearance of the cell in the micrograph?

  Which statement(s) about homolog wntt3eluir33.3h /py ous 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 a3s, ti/btjn r-n individual with Down syndrome.

Which statement is not correct?

  In the cells of a horse (E. caballus) during prophase I of meios n9)wuim9/ lq+svafo0 bwuv(2 is I there are 64 chromosomes. What is the haploid number of chromos unb0qwi)a+ml( 9so2u9/vf vwomes?

  Which arrow is pointiym1d*vp cx3-h ng to a chiasma?

  The diagram below represen9 lne*o5g 94cib0pwvvts the structure of a shoot apical meristem. Which row in the table correctly identifies the processvp590lenio9b gw c*v 4es occuring in the structures labeled in the diagram?

  How does meiosis promotekvuzn +j.plsz9 :t)z: variation?

  Which of the following statements is/are correcl;apyzsh 35ded6oj0 /t for meiosis?
I. It is a reduction division
II. It involves random orientation
III. It produces genetically identical cells

  The diagram shows gamet2m bul- igx 8yhn jy.90o 1corwzd5,.bes 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 formation of secondary tumours from primary tdyrn gb:3gho; ,60s mtumours as a result of the movement of celsobt 0gdm:rny h,;g63ls?

  How many chiasmata are present in tb-, bvcu 89chm-6ke oz/ac6q bhe diagram?

  Which statement is a similarity between cytokinesis in ani:dsutd +ksk/8h0/u i vmal and plant cells?

  Which stage of meiosis is matched t 5d0a29tgreh* eo3kke el3qp+md+)tmo the correct description?

  Which statement(s) are true of meifwt9(t)f0 y ngklg8l9 osis 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. Thi2r7:kwbf0ezig- 3s4x dcp9 oy sr*a5z s results in the formation of one large cell and one small cell. What is the fate of tfz zp-ac 5os ryr4xweb9k* 2is7gd0 3:he large cell?

  Which row correctly describes diploid and haploid cells in4i d+j czj9patvg,d6g tuq thj;-79q: humans?

  The following table shows the diploid chromosome numdrhx i*ckah39a-gc .5 ber of a range of species.


Which of these statements is correct?

  What conclusion can be drawn -4t bfnw3i o hc3n.g0yfrom the karyogram below?

  Which of the following process x9rqvp /e,q*ves is characteristic of the meiotic and not the mitoqv9v*q /rp ,extic cell cycle?

  The diagram represents a bud with a shoot apicy qxwwh/okz lw 0/c1)3al 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 chimps+;qcwn(9jl h anzee (Pan troglodytes) is 48. Which row shows the correct chromosomq; j(w9nlch+s e number for different cell types and cell division stages?.

  At the end of which phase of meiosis I d2z:-xy d3uux66jxxrm: q+ ak does crossing over occur, and what is the outcome 2d:rk:u6 xadmx-jq6z +xx3yu of crossing over?

  Which of the following statements doesx oc560lq1x0pq kd1jd not describe a step in the sodium-potassium 0 5lcj1qqd1o6 pkxdx0pump cycle in the neuronal cells?

  Which row in the table below is true of me8 pt2d20vxo6i8rpz cuiosis?

Membrane transport is important for allowing particles to move across the cell f1lrx pi+s14rw)u *urmembrane and respond to changes in the chemical composition or+4f)xp r 11lws* uruif 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 lx9bu j )dvc4)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 concentrations of different cyclins during the + h b+ptuil1a;cell cycle. Which cyclin is i;+p1b iula th+nvolved in preparing for DNA replication?

The diagram below shows chromosomes *rkurbs: 552e 6qqpms fk;9lxduring 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 thew: wg)aq6r1blr4k2 9 y gatp4o6z .ehy separation of homologous chromosomes?

  The mitotic index of throat tissues taken from 4 different patients is sho7duq /yt +lb7hj yw05ewn below. Which patient is most likely to have cancerous throat tissue?eulb j70wyt /q5yh+ d7

1.Draw a labelled diagram to represent the process of crossing over ol;yh :jpx60i.

2.Compare and contrast random orientation and crossing over.

3.Outline the stages of meiosis.

  The image shows an abnormal human karyox 1jf rlvs ;zu0f0+qf.kl .m+ (wmkx3ytype.


What is the abnormality in this karyotype and its cause?

The graph below shows the relative amount of DNA ep8va1yzkc7, x/pemy/h6g 3u 9 gxm 1oin one cell during one complete cell cycle. E 7x3gm ee//cy1pkuo8gx6yp,m za 1vh9ach 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 bro.hv ah,c2dyl j5 t1ew4wn, long hair and a female cat that has black, v lh 1dtay2wh5 ,4ej.cshort hair.


Which of the offspring has a recombinant genotype?

1.Outline how polygenic traits can s4.,j w sy01tu drr(; jf5/iz typ/0zfqnsa1xp how 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 resulcc /3w.jnko1rt from the crossing over of non-sister chromatids shown in the djkr.o 1wn/3c ciagram below?

  The photomicrograph shows a pollen grain frsz/4vu-y)uadf7z m a9 b:avcj:z(8qr om L. candidum (Lily). Which stage of meiosi)/v fm(: s8jau4qavr9c-bzady7 z:u zs is shown?

1.Outline the events which would lead tpsh khu,vn:w/iewn/ 9 55ui3go an individual being born with Down syndrome, which is characterised by the presence of three copies of chromosome 21. 5 hwi:5/phke ni 3sngvwu,/9u

2.Explain how meiosis increases variation.

3.Outline the stages of meiosis.

The mitotic index is amkgzw+g3:a6arj 3 l jo/+wb:lv(hx / dn indirect way of measuring plant growth. A study was conducted on white onions (Allium cepa), under controlled conditions in a lab, to investigate the effect of soil pH on thel:ghdl+wwb m+ v:go3jx 6zr3aj/(k /a 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 which cells can divi3wtup lft.j +x-6 /mlmde. The diagrams below show two cells from an organism w3lt/ fl xup6 .m-tjmw+ith 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 expression in ste81o xxm)crld7 m 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 d2m-w4 xdikq -+enkd6wiploid number of 8, in different stages ofq-dxi2 wknw e-4+d km6 meiosis. Which row correctly names each stage?

  The micrographs show 27; kx*evm*.npemffq four phases of meiosis I in a plant. In what order do these nf qm;2ep*kvx7*fm . ephases occur?

Mitochondria are responsible for supplying m choasd5eco406q6a . ietabolic energy in eukaryotic cells. In most eukaryotes, which reproduce by sexual reproduction, mitochondrial DNA (mtDNA) is inherited from on o4s.c aaiocqhed0665 ly 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 differazw bed v6r*u29- m0uyent stages of the cell cycle in four samples of lung tissue from four patients. Which tissue has the lowest mitotic wuz 9 6bv2my-*ae0udrindex?

  The diagram shows the dominant cyciwd;v+z):a9 -t0 k,ydbeot erlin/CDK complexes at different time points in the cell cycle. Which cyclin/CDK comp; dyak:t9-od0ew+tv,ezr ib ) lex activates DNA replication machinery?

  Studies have shown that genes such as Cyclin Dependent Kinase 3 (CDKN3) are higfz+ tezr1**chhly overexpressed in cervical tumo +zz*1*c ehrtfurs.


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 tns fy9a3sa ,d /qitv//qxf+,vhe cell cycle ?