The graph below shows the relationship between maternal a9vf s+ za2wp4f y dcnysm6sl75 9i;pk*ge and the incidence of non-disjunction. What relationship is suggested by the data in ifs4lc 7+ak6wp9fms* 52vy zn 9ps;ydthe graph?

  Which stage of meiosis is represented in the lue l, lunk q/t t*5dqo0e):)vdiagram below?

  The diagram below shows c5)qhy42kx ,d d0qjza vhromosomes 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 gene w f1c 8-ry)mwathich would be present in the nucleus of a cell as a result of eachfa 1t-cm8 )rwy process?

  Which keyword is matched to the correct -uk8eyer-j ty29p8qd definition?

  Which statement(s) ab itf coi1f -uoqsmfc88p 2*z25out 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) 2bzsl,hfm6n)z c21wejn4f qzhk)8z, which letter points to a cell in anaphase?

  During which stage of mitosis does the nuclear envelope break4i4itz , acbd6qq2ct3 down?

  Which one of the following transport w ljcc+ yfq: io,,rjab )be/oo5 sk,xx-hi(17proteins only carries out active transport?5o +,yj lrbik co ow/xb7 ,1i,hjca: qxe)s-f(

  Which process does not happawrw emq /qhta,*0l( )4gdi2fen in the shoot apex?

  Which type/s of membrane transport do/does 6 *tpv+pv-zzanot require energy expenditure?
I. Facilitated diffusion
II. Active transport
III. Osmosis

  The diagram below represents hbgxm4(b6)q y/pxka6w9 2rev3o d(ah a cell with a diploid number of 4. Which stage of cell dg /xhb92q 6bak xo6vwd(y(4m3)pr eha ivision is the cell currently undergoing?

  The photomicrograph beloiyua d,qu 5i.h6sd 9o t3-ab,uw shows a root tip meristem. Which of the following sentences cor.d9ado,uq usu,hb36ti- ay5i rectly defines a meristem?

  When does the random orientation of homologous chromosome pai3l (5c, tt fzjszs0(mdrs occur?

  Which process does not occur during mejgg )duz:12 xys:.ro* aroz1me tu- f5iosis?

  If a cell with a diploid number of 36 undergoes mitosis, how many chromosomes wk8(e )+htsjm:/f qwtbe7d,pi, h5 ec aill be 5md8, p,hfq7) ah:/ ewe+itjtbc(esk present in each daughter cell after cytokinesis?

  The image shows a micrograph mab 9ertn4:z5q3x0ra of a cell.


What explains the appearance of the cell in the micrograph?

  Which statement(s) about homologous chromospor.u+a (cz 6aomes 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 s 9: h cd6p wnrd(ae/43nenbf4xyndrome.

Which statement is not correct?

  In the cells of a horse (E. caballus) during prophaseqyhp7i(df8 ,vebpx+) I of meiosis I there are 64 chromosomes. What is thxqpbdp yh +87)f(v,ie e haploid number of chromosomes?

  Which arrow is point9d5oez. tgi( uing to a chiasma?

  The diagram below represents the structure of a shoot apical meristem. Whichnf ezn7/7xm: e row in the tablx7n m7ezef :/ne correctly identifies the processes occuring in the structures labeled in the diagram?

  How does meiosis promote -rezm 2 rby;/kyl7)c c-7 jsjfvariation?

  Which of the following statements is/are corr gcz e ewt180nnby):t/ect 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 chromosomes. 6is cyiatop4k;a lret3k- -a3s9tn10


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 formati0nm 8sa x-jz.jon of secondary tumours from primary tumours as a result of the m -8sax0mjn. jzovement of cells?

  How many chiasmata are pres+*3w a*vil,o: ot*ni 4b wtrceent in the diagram?

  Which statement is a similarit o mx;g;1*wpcstzdz ej2r6d4 /y between cytokinesis in animal and plant cells?

  Which stage of meiosis ipjh7nj 1rp ccp:f7z-, s matched to the correct description?

  Which statement(s) are true of meiosi*x 8no(a muiudny7,8r s 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. Thic(6ibhlu4+0 oh. qurxs results in the formation of one large cell aurh .loi+6 4qb0xcu (hnd one small cell. What is the fate of the large cell?

  Which row correctly describes diploid and :ihb whk8*usaxk+ 3kp8s; uw 6haploid cells in humans?

  The following table shows the diploid chromosome number of a raw)wbs c;bqm,;nge of species.


Which of these statements is correct?

  What conclusion can be drawn from ttohbj 91e5 bh9b. 4pgjhe karyogram below?

  Which of the following processet w b 7y)a4;9.n,om:dknlkrdr)l / 82tintahes is characteristic of the meiotic and not the mitd4ek,:;)lytrn7ba/nol t9i28n dma h)kr tw. otic cell cycle?

  The diagram represents a bud with a shoot apicalc yowk7 ;x7+3rbvl-ey0n9 xsu 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 4 i3*jm fj6rdvtroglodytes) is 48. Which row shows the correct chromosjf *mdi6r34jvome number for different cell types and cell division stages?.

  At the end of which phase of meiosis I does crossing over occur, anf8 . x(jdt7rphs5wlw )d what is the outcome of crossings lh. w)f 7d58w(xptrj over?

  Which of the following statemen wmyaxfx fd. -*z,;xdjj+8l-c ts does not describe a step in the sodium-potassium pumpdmx+xjf;z*-a,. d 8 l fjcxwy- cycle in the neuronal cells?

  Which row in the table below is true of meiolit43 l; /od f*urng4fsis?

Membrane transport is iim71qo c o22 q.xoikf;d76n jpmportant for allowing particles to move across the cell membrane and respond to changes in the chemical composition of th6xojnm7oqp i1k22o;f.i 7c d qe 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 is3jsuyjei*tsn* p44xu s415vi regulated 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 duringm5zmrpl 0hxmpj64cf1dg 2rtd . n;u)* the cell cycle. Which cycli ;m mhcg rx6j r1fmzu5pp.l42n)t d*0dn is involved in preparing for DNA replication?

The diagram below shows chromosomes during :ig4z 2c m)o/k +jtbytmeiosis.

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 separatio6kh ():-uzusd;tu i egn of homologous chromosomes?

  The mitotic index of throat tissues taken from 4 differ0eidnbq,m; fn h+io+gb+0o o8ent patients is shown below. Which pati , +indn+b +;oqhoofmb i8ge00ent is most likely to have cancerous throat tissue?

1.Draw a labelled diagram to represa kgtob/x,)w:ent 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 karyq21 w:p dc0 yzdl*1ejhotype.


What is the abnormality in this karyotype and its cause?

The graph below shows the relative amount of DNA in one cey3 ehy* q/eh o4tgz62oll during one complete cell cycle. Each letter represents one stage of the goqh63 ez2yo*th4ye/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 h) t2hs-atqn x;ri29vl 3f aj9momozygous for brown, long hair and a female cat that has blac)r t -ahl mxtjsv29f 2;aq3in9k, short hair.


Which of the offspring has a recombinant genotype?

1.Outline how polygenic traits can af48ebls0;uh fod;n * 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 croqn8u ni+jyf43ssing over of non-sister chromatids shown in the diagram below? ufq3n y4+i 8nj

  The photomicrograph shows a pollen grain from L. candidum (Lily1ifr6vlx8 yg-zd 4 f0edj/(zz). Which stage of me 1v0fd-ze(dz 4fx i ygjr/l86ziosis is shown?

1.Outline the events which would lead to an indim(.2i3xed/v , jgvd(zh(i giavidual being born with Down syndrome, whxv/(d3,2 g a.e( mhi(ivdgjziich is characterised by the presence 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.zm7))2b,vjn u y vy7mqrb,m x study was conducted on white onions (Allium cepa), under controlled conditions in a lab, to investigate the effect of z,x )m2q 7mvuj 7)b,rbm.yvynsoil 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 whicc 0)q:b mr 4hgjvk/x0/nzkx5pv .e+xk h cells can divide. The diagrams below show two cells from an organism with a +rmn0kbp vh /jg kqx/v.k:xcx4ze)50diploid 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 expreslx. 1qrq ngh2 wlg0d/qcf7*v9sion in 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 shrlpz x)gevn:/ly.(fd4r4 r 3q2e2lsaow a cell, with a diploid number of 8, in different stages of meiosis. Which row correctly names each stage?q( 24 efr rl /ldn lxg3esyapv:4rz)2.

  The micrographs show fysm+2n q2o 2vrour phases of meiosis I in a plant. In what order do these 2+so2yv2r nqmphases occur?

Mitochondria are responsible for supplying metabolic energy in)jl wx7xc wuuq9xg :1( 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 sexual reproduction between two different yeast species, could be influenced by the pareu7x 9 (clxgw1:u)xjqw nt’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 i l+yac*nb d j:k4gddo3q)uqz l*,e:1vn four samples of lung tissue from four due c:b,qz 4ko *vddn 3y):g1+lqlj*apatients. Which tissue has the lowest mitotic index?

  The diagram shows the*q*o2oub9ck ac: :fv y dominant cyclin/CDK complexes at different time points in the cell cycle. Which cyclq*oakfc* o2:b 9vyu:cin/CDK complex activates DNA replication machinery?

  Studies have shown t7xot 1,msz9 yohat genes such as Cyclin Dependent Kinase 3 (CDKN3) are highly over 19 zxt,m7yoosexpressed 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 higd4a 0qbq/5yjco j ca39hest during the cell cycle ?