The graph below shows the relationship betwe: fmc-wtzrs(w (zj ugpg:sn24g0j;9 uen maternal age and the incidence of non-d2 fc:ws-0g uj(jt: grn p(9s4 wuz;mzgisjunction. What relationship is suggested by the data in the graph?

  Which stage of meiosis is represented in the diagram bep qw ah-dseerg 5t98cx*u3( f7low?

  The diagram below shows chromosomes during .4tql8vd19hst im)cl 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 nevjb j bex+7lfn/j;2 /umber of alleles of a single gene which would be present in b2l/ +j/x je;bn7fjev the nucleus of a cell as a result of each process?

  Which keyword is matched to the ci 5 6j9vc uv/jbb4m4ilorrect definition?

  Which statement(s) about mitosis is/are tr8 u3o.u 0q-nzp.y lgvy.p3iybb9y9mtue?
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 besvy9:x2ohh l0)v r- nolow, which letter points to a cell in anaphase?

  During which stage of mitosis does tk.rksysb fi, 2bbx91 6he nuclear envelope break down?

  Which one of the following transport proteins only carries out active transport i(n k.xm9ldt/ (cfk0hn8+swl?k.if(+9 0hskwnldn(t /xm l c8

  Which process does not kmm8g i)+md kpfm,rl-mrg9 72happen in the shoot apex?

  Which type/s of membrane transport do/does not require e.(ms:lkiclph+ 3z w 1anergy expenditure?
I. Facilitated diffusion
II. Active transport
III. Osmosis

  The diagram below represents a cell with a diploid number of 4. Which i 95yqsnk9 wqi93zreb.a/ly2stage of cell division is the cell curren /q9kbyyel 9a9.iwr5s 2i qz3ntly undergoing?

  The photomicrograph b jo 9)hffp)*(wb*dt2ezfub 0 eelow shows a root tip meristem. Which of the following sentences correctly d9t)ezo dh*bwbp)f f2 *fjeu 0(efines a meristem?

  When does the random orientation of homo r/0 qvl+0 x*p2 wfdranvrlc7(g+,gxwlogous chromosome pairs occur?

  Which process does not occur durin4tdgwc9 p5 la0g meiosis?

  If a cell with a diploid number 3y5teu9 m*rnuh2*t;bq7jf *rn q o w/wof 36 undergoes mitosis, how many chromosomes will be pr9wt/ nno*2 tfm57bru re*jhqw;u*q 3y esent in each daughter cell after cytokinesis?

  The image shows a microgrs1sl.sq9)erc.x5e i4qq 1hob aph of a cell.


What explains the appearance of the cell in the micrograph?

  Which statement(s) about homolaid2m+zaardw 2r2 6)e ogous 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 individual with Down-eozikn2at/mjalp w 8+fw;d1a. z9 4d syndrome.

Which statement is not correct?

  In the cells of a horse (E. caballus) during prophase I ofe jwu/9. w/x mkh lb9zh.;nf vc1te87i meiosis I there are 6e uck j/hb1; /7f.8.mhnvtlx9ze i9ww4 chromosomes. What is the haploid number of chromosomes?

  Which arrow is pointing to a chiasma? ( vdq np,i27llwe1tq:

  The diagram below represents the structure of a *; u7uflfumpo53vbs 3f4) qse shoot apical meristem. Which row in the table correctly identifies the processes occuring in the structures labeled in the diagram?pb)*;ufso 37muv le45s3 fufq

  How does meiosis promote variation?/h(9nxb*hj8ka b r ,kb

  Which of the following statements is/are correct for meiosie38u1kzn t/ fpj,q gq4s?
I. It is a reduction division
II. It involves random orientation
III. It produces genetically identical cells

  The diagram shows gametes pn jc6 c4ek3oy6roduced 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 tumoutpv +hrn5/mf 9rs from primary tumours as a result of thvhnrmp9+/ f 5te movement of cells?

  How many chiasmata arb4z sjfq xd6r++1.ed/ ncd78subrgq; e present in the diagram?

  Which statement is a similarity between cytokid,*b0dnsknx(;ys 2zu nesis in animal and plant cells?

  Which stage of meiosis is matched to the corre( ws-sxl w: mwgbgq 38 elf))1j3ybcr8ct description?

  Which statement(s) are true of meiosis I but not sphl ;wymr3 )u3/dghr u3uy,)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 divcz,do l6lg 9 gxq0h;1dision. This results in the formation of clz h,odg;g016q dlx9 one large cell and one small cell. What is the fate of the large cell?

  Which row correctly describes diploid and haploid cells i eg*w43 rqtvg-lpg;m;n humans?

  The following table f*fe kdzl*o:oxu u -i.8.zu3 cshows the diploid chromosome number of a range of species.


Which of these statements is correct?

  What conclusion can be drawn fro/vl/f2fgczret 2v.:s m the karyogram below?

  Which of the followifrflk20dc7kzv8s6 )daza,/ut pm-c ,ng processes is characteristic of the meiotic and not the mitotic cell cycle?zrc ka7szt8/vpl0, fd )dkaf u 26,c-m

  The diagram represents a bud with a shoot apical meristem. q d/l5;w7 v h9smsww)r :wzvn;

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. lpz z(o;zn4zgk;o a5 l,h1tm52gy .qoWhich row shows the correct chromosome number for different cell types anok .z5pz,4aq ; 5(nogl1gtlz y;o2mhz d cell division stages?.

  At the end of which phase (h0ahm4b6 4)q.rkcu z0cdus x of meiosis I does crossing over occur, and what is the outz( c.chr0 db4qah)46 smuk x0ucome of crossing over?

  Which of the following statements does not dhj(q y)h6tj qllg :4j,tp1 ny+escribe a step in the sodium-potassium pump cycle in the neuronal c(yl+p y6l1qjhtnjq ,)jgt4h :ells?

  Which row in the table below is true of mefew9 :+d x zfrho/;)fpn5.wqhiosis?

Membrane transport is impo,v1t9yo0cd) iekwp : ertant for allowing particles to move across the cell membrane and retewdk ,)cv pey0 i9o1:spond 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 cewz1q3y/:w8zflxp b 6 ills.

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 0qn -dvqy4zv0concentrations of different cyclins during the cell cycle. Which cyclin is involved in preparing for DNA replicatiy-vq04v q0 dnzon?

The diagram below shows ij lz+ xvx837ochromosomes 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 o9l yj-(z t3y ra3jrcu5f homologous chromosomes?

  The mitotic index of throat tissues taken from 4 different patients is s1x4;f;3 psddxlsq c7 nhown below.xdpf3; 1xls7 ;4c qdsn Which patient is most likely to have cancerous throat tissue?

1.Draw a labelled diagram to reptyd tls8g5)p /myi80 t )5keiax6(ldv resent 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 human kam 5gyur7 ()iobryotype.


What is the abnormality in this karyotype and its cause?

The graph below shows the relative amount of DNA in one cell during one c1gvn8 c9x1zju omplete cell cycle. Each letter representsc8gv1 9xj1nzu 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 homozygy p haoe a*c2k-6e,-ltous for brown, long hair and a female cat that has black, short haoal p2tae6-y ke* -c,hir.


Which of the offspring has a recombinant genotype?

1.Outline how polygenjakr :7mobtx ;.0*b ddic 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 cro 0zon. a0+vzfossing over of non-sister chromatids shown in the diagram be.00a z+nvfzoolow?

  The photomicrograph snr;fbk h: i/r2k w6jyvulatz 0jp /f.f:z6:t/hows a pollen grain from L. candidum (Lily). Which stage of meiosis is s/6zw.aik/:f2nv pu/fj0zy; l trhj k ftr::b6hown?

1.Outline the events which would lead to an individual being born with Down sye*.p(g e n xd.abgttg;v 8z7.vndrome, which is characterised by the presence of three copp tv.v d;ga*e(7 ezxn. g8.tgbies 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. A study was3cdy4z b .-fet conducted oc.4tdy- 3b zfen white 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 disi q+zejs2 a2b f6k73xvide. The diagrams below show two cells from an organism with a diploid number (2n) of 8.2xabq js 3 26sf+kei7z


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 hw 0s xmbujphu6m)723stem 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 o z/rctq7k36rd,ozvwh7c d8n3nxve2+lh / ce(f 8, in different stages of meiosis. Whhzzh3(7kx t2+/o/8 cw7cn dnc6v rdv3rqel,eich row correctly names each stage?

  The micrographs show four phases oqkhj;v 4i3+* j jnmrlteu2k-5f meiosis I in a plant. In what order do these phases 5j+r n;lu*ihkk jm 2ejq-4tv 3occur?

Mitochondria are respons7z/ize2+,2jrxjo8nv iig s 7,z tdo,dible for supplying metabolic energy in eukaryotic cells. In most eukaryotes, which reproduce by sexual reproduction, mitochondrial DNA (mtDNA) is iix dzt8+o2,njj2r,,z/7g e dsviiz 7 onherited 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 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 wsazsy. gq75(4kwf1e different stages of the cell cycle in four samples of lung tissue from four zq1way4.wsgk 7f( s5epatients. Which tissue has the lowest mitotic index?

  The diagram shows the dominant*v7q48kul1+eq gnm c r cyclin/CDK complexes at different time points in the cell cycle. Which cyclin/CDK ul rge q 87cmn41*qkv+complex activates DNA replication machinery?

  Studies have shown that genes such as Cyclin Dependent Kinase 3 (CDKzl :d:ozbz; n8mob;:odlh/,x N3) are highly ob /dobx8loo,h ;:zz:l: nm; dzverexpressed in cervical 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 during2p6kh;ocy,;);ua- ffd uedq uas yj19x go46x the cell cycle ?