The graph below shows the relatxrbc/r+5z-35 wuk 2neml.worionship between maternal age and the incidence of non-disrck5l -/rnbm 3 u5+woxr2ez .wjunction. What relationship is suggested by the data in the graph?

  Which stage of meiosis is represented in the dilo *n/ ilkbs*ztx6gw,f5d12 lagram below?

  The diagram below sh)o48(bf o eydyows chromosomes 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 d rr1ac0h *n*;kk,z1 q5eyc kegene which would be present in the nucleus of a cell as a resu, ekz hq*ea 1*cdk5y0r;1rcknlt of each process?

  Which keyword is matched to the correc-+kalv) littai3p6 s/ t definition?

  Which statement(s) about mitosis nb;8x-w 2bercgfgy*r svw 2j..x uv/7 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 lettemx0s z)//*f 1p, zz qgty4nlsceo4ga* r points to a cell in anaphase?

  During which stage of mitosis does the nuclear envelope bxsw cn fadszb 8995hq*)9)lnci ) :yfureak down?

  Which one of the following transport proteins n -bzfzz+ xi-4-,enl tfi9l,idhe7 ,bonly carries out active transport?,ix 7--fi49h,lznfedn+z t- il,be bz

  Which process does not happen in the sh4xo wus dd dm0;/5n3 6dkfx.uwoot apex?

  Which type/s of membranw0e sfx2 e cn)jm9s23ge transport do/does not require energy expenditure?
I. Facilitated diffusion
II. Active transport
III. Osmosis

  The diagram below reprpkwrsq; 1k8j+ui s(4 oesents a cell with a diploid number of 4. Which stage of cell division is the cell currently ur 8qpoij(k 4ks+ uws1;ndergoing?

  The photomicrograph below shod8e;woq5dr c.z/jkmzmx-y *ieiqr.9/ n) a, ews a root tip meristem. Which of the following sentences correctly define.,yd./jkc;q8m aqi)i zmrdx9w-e re*oe nz5/s a meristem?

  When does the random orientation of homologous chromosox2m ,b t5o40j1 ife.cq kcr(h:8emrudme pairs occur?

  Which process does not occuradzkm;k g5:8 2zpq6yw during meiosis?

  If a cell with a diploid number of 36 undergoes mit7;m1 znx,)ti 5tjzpq wosis, how many chromosomes will be present i15;zq p wm tzij)7,xtnn each daughter cell after cytokinesis?

  The image shows a micrograph of a cell. ,iacq orz75x:d :hmw3


What explains the appearance of the cell in the micrograph?

  Which statement(s) about homologous chromosomes is/7 uh/49*o7chvanm t7rsg)acuare 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 orwzo75ve dcd/7)b.io b83gu with Down syndrome.

Which statement is not correct?

  In the cells of a horse (E. caballus) dztp85 yoab4-hwu 2c 8furing prophase I of meiosis I there are 64 chromosomes. What is the haploid nz88yp chua2f-5 wo 4tbumber of chromosomes?

  Which arrow is pointing to a chias h0(a btwmn+nrkq478sma?

  The diagram below represents the structure of a shoot 4vjj0ar i hr;)tk(p0+y+n ruh apical meristem. Which row in the table correctly identifies the processt r+r0h4ihu)vpjk+n0 ay( rj;es occuring in the structures labeled in the diagram?

  How does meiosis promote varoyu s/h1k/gq;iation?

  Which of the following state3 8 cb96decbmw)d4zuuments 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 -)c c 1glk/+auzpm b-mhomologous 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 second*uu5 t;f:ezfg ary tumours from primary tumours as a result off *eu;g5fztu: the movement of cells?

  How many chiasmata are present in the diagram, sq-.quvx7cn ?

  Which statement is a similarity between cytokinesis in a-v nn2k/2ygf4w *ccpa nimal and plant cells?

  Which stage of meiosis is maty xg.pqb0r f.6ched to the correct description?

  Which statement(s) akk dnzzfl3u1 m (ii.7/2qciz -re 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 meiotic division. This rm.fxay i403 mqesults in the ffq3aim. 4xym0ormation of one large cell and one small cell. What is the fate of the large cell?

  Which row correctly describes diploid and haploid cells in humans?dgh na 25e81mg

  The following table shows the diploid)ap2-mlccdpdvh+o .a2t7i g0 chromosome number of a range of species.


Which of these statements is correct?

  What conclusion can be drawn from the ii7;)ejl kzc/ karyogram below?

  Which of the following processes is characteristic of 7xn68k t .px9htmf5mz ,nwrg. the meiotic and not the mi8r nmz9xg ,..nh t pmtk6wf75xtotic cell cycle?

  The diagram represents a bud with a shoot api41qjygbm y. l-cal 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.dii b, e.nz80ksdnllhp 43o 3( Which row shows the correct chromosome number for different cell types a son3hid(, p03n.le 8li4zbdknd cell division stages?.

  At the end of which phase of meiosis I does cromquu2- r u r l+j)g(k07k tsqkra78ie;ssing over occur, and what is the u;sg7kmqk0ei8taq-ruk+l j2 7( r) uroutcome of crossing over?

  Which of the following statements does not descri sw2kq c;nj;e,be a step in the sodium-potassium pump cycle in the neuronal cell jec,;kw;q2 sns?

  Which row in the table below 3(drk4kp0q uj is true of meiosis?

Membrane transport is important for allowing particles to move across thsi5fnrd2ns; 7rv5( tqs 0go0be cell membrane and respond to changesvsg2b; 5t00is oqn (frrsd5n 7 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 regu bkkqobkm.3 c7 w/2zql4oot /8lated 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 cycljy *lb/zjz fzrsj3* l2)zk(u9ins during the cell cycle. Which cyclin is involved in preparing for DNA rep(lfys z)j 2uzzzj 3*r9b*l/jklication?

The diagram below shows chromosomes during meiosis* c-gb q,;bil lc, e8tp9*holr.

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 involvesd.m-rg u k7q2ewm.5ty +v xy0hoch4i 3 the separation of homologous chromosomes?

  The mitotic index of throat tissues taken fcng)ukvq:a8 yl 17sc4rom 4 different patients is shown below. Which patient is most likelynacy ) :glkc 4q87vu1s to have cancerous throat tissue?

1.Draw a labelled diagram to represenc/ 86nh zecu1at 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 hum w*b qf9)mxfk/an karyotype.


What is the abnormality in this karyotype and its cause?

The graph below shows the re gnucn +iu857olative amount of DNA in one cell during one complete cell cycle. Each letter represents oni +5o8nucu7 gne 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 cro4n0m1fdh9okw7 v)m3 cp qqkx6 ss between a male cat that is homozygous for brown, long hair and a female cat that h7nqdv31 km)fpo0mw4 hqx96ck as black, short hair.


Which of the offspring has a recombinant genotype?

1.Outline how polygenic traits can show a normal distribute tyy 0v4m-w)qion.

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 shown inkyr4x9i: nuv 8wf umgvzz 5(toa-+ z8/ the diarkf5o +gxm8 9it:yzz(-avuv wn4/8zu gram below?

  The photomicrograph shows a pollen2f l.0ak ajch;:q0 muo grain from L. candidum (Lily). Which stage of meiosis is ;akjal c0moh0uq2 .f:shown?

1.Outline the events which would lp 2e e(y4g tju3z7uddq3g5x(d ead to an individual being born with Down syndrome, which is characterised by the presence of three copies of chu7g(53 d dg jye3d(uxqzp42etromosome 21.

2.Explain how meiosis increases variation.

3.Outline the stages of meiosis.

The mitotic index is an inak 1w mgdv45p8(e6xr. xq/xav s3 hp:bdirect 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 thexaawkvpq3b5ge1m/x r dx:p(8.v4h6s 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 di)han5t;h0j9 f1qwazgas. 7 frvide. The diagrams below show7)jfs g.r;a n9zaa hh01t5wf q two cells from an organism 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 expression in stem gmv8w: d7q-qs vrowth.

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 cgs;8w1-y 3gtdkz b sh+ell, with a diploid number of 8, in different stages of meiosis. Which row correct18hyt+ ;gsdzs-gkw3b ly names each stage?

  The micrographs show four phases of meiosis I in a plant. In what order do t w,v3 uvvha9(u x8u,quhese(v9,q 8uwa3 hxuvu,uv phases occur?

Mitochondria are responsible for supplying metabolic energy in euka ohuqsl53 *b4g(. erel2iyrg+ ryotic 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 diylie3eoulg.hrr25* b4 (g+ sqfferent 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 cycle in2lk; 0( 3xjqhfa p0muemc/d0 v:jr,lp four samples of lung tissue from four patients. Which tissue has the lowest mitot hf3cxr:qlp(a;l0 vkmdpj02 mjue0/,ic index?

  The diagram shows the dominant cyclin/CDK complexesi5j+ hnc9 t:m;fx oy+t at different time points in the cell cycle. Which cycliiy h+;jn5x o c:tft+m9n/CDK complex activates DNA replication machinery?

  Studies have shown that genes such as Cyclin D*pq8d dfrrax 64j 2ty.ependent Kinase 3 (CDKN3) are highly overexpressed in cervical tumoursyjad. 28r qxf46 pdrt*.


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 celquw68cq(: enx(ob: t dl cycle ?