The graph below shows the relationship between maternal age and the inciden;h7e1vfm t)pcce of non-disjunction. What relationship is suggested by the data in the graphevf;)7 mch tp1?

  Which stage of meiosis is represented in the diag enqwkm6-7:idram below?

  The diagram below shows +fc 1nflxg5h7chromosomes 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 j;wm qer roxio.,: 5:kalleles of a single gene which would be present in the nucleus of a cellw;ije r 5ko::.oq, rmx as a result of each process?

  Which keyword is matched to the correct derd,zb(66ub ;ypgh g x z r;xd0;nnu:3tfinition?

  Which statement(s) about mitosis is*tmupa6 a;n8ax(1;urlk ( ue j/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 le/x+gqkx3q qt4s1 kj(etter points to a cell in anaphase?

  During which stage of mitosis do i9qugv (9cuvajn;v26es the nuclear envelope break down?

  Which one of the following transport proteins only carries out active z t:l:mttpbn4:7) kiou1l5wm transport?7b:t:pwo4i5t1t kl n ) lu:zmm

  Which process does not happen in the s0iiks ku.u wj7ujz*f+z 78 b+thoot apex?

  Which type/s of membrane transport do/does not require energy expenditurl8rqm) f ,d fag3c86gs,ore0re?
I. Facilitated diffusion
II. Active transport
III. Osmosis

  The diagram below represents a cell with a diploid number oow)v+ e,a e9 weq cntqvfuz57(z6pu- 9axkz9- f 4. Which stage of cell division is the cell currentl)uwt7+(ce, w zqa6xeq9 z-5kpfno 9 e-uz9 avvy undergoing?

  The photomicrograph below shows a root tip meristem. Which of the follo/*z kwqh ai5jx5/u w1vwing sentences correctly defines a meristem?k 5/*vihu1/5qwjz xaw

  When does the random orientation of homologous chromosome e;ei.4p)f s8 yheype+rspt ( 1pairs occur?

  Which process does not occur during m)l ;/xc(yjh m3u)esdx eiosis?

  If a cell with a diploid number of 36 unu1jw;gd+56ti0b 5fw*c pe v uodergoes mitosis, how many chromosomes will be prese;ujwb5toigw0 u ve* cp1df+ 65nt in each daughter cell after cytokinesis?

  The image shows a micrograph of rt(lihqa+3u3a cell.


What explains the appearance of the cell in the micrograph?

  Which statement(s) about homologous chry:)z 3llonrn6pyp1d vs m/-9 2lfx8wqomosomes 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 withnb9vyt . .pj/mbembc9 u1s(n1 Down syndrome.

Which statement is not correct?

  In the cells of a horse (E. caballus) during prophase I oo pk)/a4o6ync,ffj/7f q /vnw f meiosis I there are 64 chromosomes. What is yof6v7cj,4nnwkf //afpo/) q the haploid number of chromosomes?

  Which arrow is pointing to a -ob ef- p; onzka(1 c6+tzukpmg-)+oz chiasma?

  The diagram below represents the structure of a shoot api ;9 v(zsbn-uazcal meristem. Which row in the table correctly identifies the processes occuring in the structures labeled in t9 (azu-nb;zvshe diagram?

  How does meiosis promote variationr.yewfb6ryp+ 5)p+ cg?

  Which of the following statements is/are correct for meiosie1oe(b fq6n1gcp- xx :s?
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 chromosomesvpiu z2rs2 v7tg.b 6l7.


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 formatiock-6 db)lce s(n,/u*j rvv2f,*bwy ven of secondary tumours from primary tumours as a re cd vr-v eebn*b)cw/s*j,ufvy2l(k6,sult of the movement of cells?

  How many chiasmata are present in the diagragq-5.a p .cye )t3pfevz+m:))e gqftfm?

  Which statement is a similarity between cytokinesis in animal and plant cel j js52yu*0g,y mezo ll2bm 3x;hq):yxls?

  Which stage of meiosis is matched tyvnm4 ) 7u/jneo the correct description?

  Which statement(s) are t5ed. u n 1581eojmrrq9dk2 fierue 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 , k+gzz 2fyugymj-+ 7gan oocyte after the first meiotic division. This results in the formation of one large cell and one smalluyk2,g g+m7 j-+zzfyg cell. What is the fate of the large cell?

  Which row correctly describeso;ry l1:hhx b* diploid and haploid cells in humans?

  The following table shows the diploid chromosome number of af f1j;4v 2bprym tdf07 range of species.


Which of these statements is correct?

  What conclusion can be drawp w(b 9sv1c9jwpy: d-kat0ni( n from the karyogram below?

  Which of the following processes is characteric9u2 m5beyz 3nstic of the meiotic and not the mitotic cell cycl52bn39 uz ymece?

  The diagram represents a bud with rohdd2tcx2h rz ()ghe23j4/pa 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 ofv *x8 )c,t)ct/ t sba3wdlhwl+ the chimpanzee (Pan troglodytes) is 48. Which row shows the correct chromosome num,* tvadslw ht)c+lb3w x/tc8)ber for different cell types and cell division stages?.

  At the end of which phase of meiosis I does croc3iag u4to50cz qx0ja 5;u5)jdgx6 mhssing over occur, and what is the outcome of cro05ac ju;5c jxug6g5 xa03i)4m hod qztssing over?

  Which of the following s vqflc t /nuqz9wf-6,4tatements does not describe a step in the sodium-potassium pump cycle in the neuronal-fql9uq6n wct 4vfz/, cells?

  Which row in the table below i9wkmmk* kmij3 h.k;; js true of meiosis?

Membrane transport is important for allowing particles to move across the 1f ektxx1,l3x(y l cs*ago /zpzc. ze3/rj*w7cell membrane and respond to changes in the chemical composition of the ext//,( zlxx1 * 1ty cs.r3g ol3*7wfkzzexjap ceracellular 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 .r;ns6:ets-n/ bt7n0 kdk wn zregulated 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 concentratnuib8).zl tu0 hxl0zn11 (w2y0nqwtjions of different cyclins during the cell cycle. Which cyclin is involved innzx qlwz(bn0tu0y h01li8 1u) .njw2t preparing for DNA replication?

The diagram below showw7 *x hgcv *q(wi hj:.t1 cfw55/ovqfls chromosomes 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 separati62obpc l; ;j1;lu btj5uagq7 xon of homologous chromosomes?

  The mitotic index of throat tissues taken from 4 different patients is shogxg7gy2hz6wjo7f ui1pg c.0 1wn below. Which patient is most likely 07gcfy g i2z7ggwp.11huj6ox to have cancerous throat tissue?

1.Draw a labelled diagram to represent thers jz)pwutgh0 th 0:v/dc , 90pvp(8ao 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-;ls0cgb* ba(6 gvelian karyotype.


What is the abnormality in this karyotype and its cause?

The graph below shows the relative amount of DNA in one cell during japthq +t+x/x9f- 6 :jf,ej grone complete cell cycle. Each letter represents one stage of the cell cyclepxrh :6f -/q+e fjxtt gj+a9,j.


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 3 fl./9 383tlaucnkmks rmqr7male cat that is homozygous for brown, long hair and a female cat that has blts/n.rmm3 3kq lkar93lf8u c7 ack, short hair.


Which of the offspring has a recombinant genotype?

1.Outline how polygenic traits can show a +; id3me : -gxajwsem.v g,vu-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 froltqrlk+zfwvij3z+s.sy72hk c96 n ;/ m the crossing over of non-sister chromatids shown in the di+ hyvlrks7 tz3+nkj 62/ ilscw9;zq.f agram below?

  The photomicrograph shows a pjuitpxot9 /4tjqje 0n(b+:4qollen grain from L. candidum (Lily). Which stage of meiosis is sh jup ti:nj bt( qte9x4/qj4+o0own?

1.Outline the eventsaqcz.2 n9u oldpo ga4wk*2 (h6 which would lead to an individual being born with Down syndrome, which is characterised by the pres2qudl9 a6(4.og nc ohzk2*wpaence of three 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. A s3i8(fu ).anrydmc om;tudy was conducted on white onions (Allium cepa), under controlled conditions in a lab, to a m3y)i o unc(d;.r8mfinvestigate 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. ;d 8*cm5yrn drThe diagrams below show two cells from an organism with a diploid number (2n) of5rcm 8 *r;ydnd 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 growt*fm*k0f n m+lmwe: k6zc(pw-gnv1+ ro h.

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 numbeq6c:a)erkjj ;( - cxhfr of 8, in different stages of meiosis. Which row correctly names each:cq ce jxr(a-)fj6 k;h stage?

  The micrographs show four phases of meiosis I in a plant. In what ordec oy 7 yyzsze4w sp-hhh;z.0,3b+*c gur do these phasesw yyzsz, hcos*h+03u- 7.bpcy z;ge 4h occur?

Mitochondria are responsible for supplying metabolic energy in eue 8hrciut1*6jvf s; 8nkaryotic 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 the parent’stje sfrhin1*8cu;86v 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 in g-dm;ev fwf6; eazoec1xbf(,9zd/d n g6 )0 xjfour samples of lung tissue from four patientj/(1wv e6xd0d9xeb ffzd;cf;,)n gm6 eoz-ga s. Which tissue has the lowest mitotic index?

  The diagram shows the dominant cyclin/CDK complexes at sv yi9 2lu sl;a;c2bz1different time points in the cell cycle. Which cyclin/CDK complex activl2v;92uy ab1zl ss c;iates DNA replication machinery?

  Studies have shown that genes such as Cyclin Depe13 ce; wqh3cizndent Kinase 3 (CDKN3) are highly cw33hc;e 1q zioverexpressed 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 cy j4/l(aom/iam6iz ,declin E the highest during the cell cycle ?