The graph below shows the relationship between maternal age and the incide zut7q. 3r7rxcnce of non-disjunction. Wcuxtr7 3r.7qzhat relationship is suggested by the data in the graph?

  Which stage of meiosis is represented in1lql(9nb4vq:avgb dv8 kc98a the diagram below?

  The diagram below shows chromosomes during mp d0-cf p33etwf3w)rf j) (/xbu4 fzpteiosis.


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 allc uv7i,l y *,ddu v mx.vl/gih6x1f(87xocx2deles of a single gene which would be present in the nucleus of a cell as a result of each procev dhx1/ 6 (v,xicx8lg2dyivu ml *fd7.x7ouc, ss?

  Which keyword is matched to the correct zmz.0g w(mynm) oa8b1f;(f bsdefinition?

  Which statement(s) abdqk4 3e0su9 zna2jqkoc1;u9 xout 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, whisqo y gfm) 2.wtah-47gch letter points to a cell in anaphase?

  During which stage of mitok5, :wd y:77sqx rgxejsis does the nuclear envelope break down?

  Which one of the followro3 3wjd983bscyb8 m uing transport proteins only carries out active transport?ob83d9 bur3w y 8csjm3

  Which process does not happen in the+z2fky/tum k 0 shoot apex?

  Which type/s of membraw11esi2hp 9e ane transport do/does not require energy expenditure?
I. Facilitated diffusion
II. Active transport
III. Osmosis

  The diagram below represents a cell with a d*9yaugouh .4 liploid number of 4. Which stage of cell divisul.g o y*u9ha4ion is the cell currently undergoing?

  The photomicrograph below sho1cs nkh(i8f,l2x-y ddn2 n 8ti:s *vkzws a root tip meristem. Which of the following sentences correctly -2i( d*zlxdscvk 8 ikt, :2hs81yfnnn defines a meristem?

  When does the random orientation of homologous chromosome p6) v0 1dt atf,-nrv2w sl5zbdfairs occur?

  Which process does not occur, x0 3pshp+ 81f/qxlm/ogxape during meiosis?

  If a cell with a diploid number of 36 undergoes mitosis, emgp,r9- eoa, how many chromosomes will be,, g9-reoa epm present in each daughter cell after cytokinesis?

  The image shows a mi(wocao3-d)1 f :yffeee 94chf crograph of a cell.


What explains the appearance of the cell in the micrograph?

  Which statement(s) about homologous chromoz f/u 1yu r oo7mxqof+0k8x9o*somes 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 individual with Down syndrome. /ik+kx-tv9g,. ms 7dnhv rd irg.7)cr

Which statement is not correct?

  In the cells of a horse (E. caballus) during prophase I of meiosis I there a9 nyp1neyf3k, re 6nny1ke,f py 394 chromosomes. What is the haploid number of chromosomes?

  Which arrow is pointingel6n5 bi/m; eh to a chiasma?

  The diagram below represents the structure of a shoot apical meristem. Whjbcv/ 3p )x75b* uztncich row in the table correctly identifies the processes occuring in the s 5vp7*3tzxbc ucnjb/)tructures labeled in the diagram?

  How does meiosis promot9ws-t u aeo(v)e variation?

  Which of the following statements is/aliee. : h-m2cure 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 chrx2zdn6ln:os3s pd :*comosomes.


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 primaryppd8+.bqfk6zg d +tz9 tumours as ab6.8 kz9tz + g+pddfqp result of the movement of cells?

  How many chiasmata are preswm/w qe9,3zd (n6pu nsent in the diagram?

  Which statement is a sidryc )am/,dv sif6d( (milarity between cytokinesis in animal and plant cells?

  Which stage of meiosis is matched to the correct d:kqs7zs )abz:escription?

  Which statement(s) are true of meiosis I butxo)(i f +d;mm2-qw fibhm 0pisikb;15 ,h4bck 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 divi 6p9px3mm b4fim+sg0ysion. This results in the formation of one large cell and one small cell. What is the fate of0x9s gb+ 4yif63m mpmp the large cell?

  Which row correctly describes diploid and haploid cells in nq6mts7cr)hou2 c -+ uhumans?

  The following table shows the diploid chh/ csw*;9zjx mjmy )fa65(wmn romosome number of a range of species.


Which of these statements is correct?

  What conclusion can be drawn from the karyoga523mk ozttrykp(7h q0 07ywhram below?

  Which of the following processes is characteristic of the meiotic and not the m 1lwkorr)zvh srs3;96itotic celllsr r;v9o 1kr6)hz3w s cycle?

  The diagram represents a bud with a shoot apicalp l5x.d7c*h; deob qp hzm,g-m()nh+f 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 trpp2 b aq td.mt7) 6ta7oa0/svuoglodytes) is 48. Which row shows the correct chromosome number for different cell types and ce s2t 70apbamqtd6).a/7puot v ll division stages?.

  At the end of which phase of meiosis I does crossing over occur, anj-);vn:,h0ght4*k zxhtecn fd what is the outcome of crhnt4cev , hz;x0k)jg:-* nfthossing over?

  Which of the following statements does not describe a step in the sodium-6 2*ufap 6anxmpotassium pump cycle in the neu*nu 26mpaax 6fronal cells?

  Which row in the tabl8wx f5t*z :gsy;j tfr8e below is true of meiosis?

Membrane transport is important for allow:utc9b fp ag2od)6vhjn e-w2-ing particles to move across the cell membrane and respond to changes 2ednp2 bofj9-w:hcg 6uva- )tin 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 celu*z2he*:v7 qwl wj)lx ls.

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 cyc+ jlp3to1 6eptlins during the cell cycle. Which cyclin is involved1lte o63jpt+p in preparing for DNA replication?

The diagram below shows chromo,c zaa 7 l0*/ .agfs9ktvkrt6xsomes 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 h :1ntve ,axqw/omologous chromosomes?

  The mitotic index of throat tissues taken from 4 different patients is shown e4sfa f.x-3;ibi vts* below. Which patient is most likely to have ca 4sti x- e3sifaf.v;*bncerous throat tissue?

1.Draw a labelled diagram to represent the process ofaws: 7i1n94 ,qzxjfzk crossing over.

2.Compare and contrast random orientation and crossing over.

3.Outline the stages of meiosis.

  The image shows an abnormal human kary 6qfmfny czw232sp/f8otype.


What is the abnormality in this karyotype and its cause?

The graph below show(vz/g oze0h) pbot0j5s the relative amount of DNA in one cell during one complete cell cycle. Each letter represen0pt5(z zog0)oe/j hvb ts 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 c0 u1 mf6al+2;andfuk brown, long hair and a female cat that has black, s+a2 lf df6mc1uu;n0 akhort hair.


Which of the offspring has a recombinant genotype?

1.Outline how polygenic traits can sho kylzz1 w/ b*to slryd9+*r,*dw 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 qav9o pu,4 das8zq;y2 chromatids shown in the d9p2uad,qoy4 ;asz qv8iagram below?

  The photomicrograph shows a pollen grain from L. candidu; gq s;6nrz2ytm (Lily). Which stage of meiosis is shogyzs ; n6t2q;rwn?

1.Outline the events which wou aer 48 2d(oqgzvti po,fon j,cu1,z (ufip7)9ld lead to an individual being born with Down syndrome, which is characterised by the presence of thredpqj enupor2 )fv (4i18, u 7f ,z,(gtzooia9ce 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. tzj0, 7 hqk9 ke)7gcj:fq;zoeA study was conducted on wez7 q,g9:t)7kz cj q ;ehkfo0jhite onions (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 which cells can divide. The diagraz6/bo 1wx;6g t5tyrc ums below show two cells from an organism with a diplo t6twu1 6;bxz/y cgr5oid 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 inh/ zyc3d( a5xv 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 dh xshm7 sfq,h05*6w sdifferent stages of meiosis. Which row corre hsws5h7sf0,dm6h * xqctly names each stage?

  The micrographs show four phases of meiosis I in a plant.fs-; c1/42cq5cnrxxeqp 4q kd In what order do these ph;ccrpc- k142fsqeq q5x 4dx n/ases occur?

Mitochondria are responsible for supplying metabg i1e31n/cq .rgi5ln folic 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 q.cnni ggl1ef/i3r15 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 stagesukuq. o2pn b,2w zm(+ l-zjb,g - hp/w;,vsfog of the cell cycle in four samples of lung tissue from four patients. Which tiz-+uq2suw-bpjo pfzh;nv., m2 gkg,w/,lbo( ssue has the lowest mitotic index?

  The diagram shows the dominant cye b;s re/1 cs6fud;t-yclin/CDK complexes at different time points in the cell cycle. Which cycli;e /bsr1scef ; tu-dy6n/CDK complex activates DNA replication machinery?

  Studies have shown tv*ock ms149u /u3rcch hat genes such as Cyclin Dependent Kinase 3 (CDKN3) are highly overexpressed in ce/h1r omu c93*uks4cc vrvical 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 celldz9r ha:n /tos,s.n.jb v+lq 5 cycle ?