The graph below shows the relationship between maternal age a wlm f90uzix5vx (/k+cnd the incidence of non-disjunction. What fz/0xxl9 i vk+c5m( uwrelationship is suggested by the data in the graph?

  Which stage of meiosis is represented in the diagramd a -.tvuly8qcqoxf6 ;d s,x65wc x:(t below?

  The diagram below shows chromompn/)9q l0bsp)n-t*oz h8dwlsomes 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 singlez)edk*4 +ju7om 3ezqe gene which would be present d4k+ezq7) mo*ee uzj3in the nucleus of a cell as a result of each process?

  Which keyword is matk8vr/h -n oata5mz+ph ,9lm7te; l tls+.ph5xched to the correct definition?

  Which statement(s) about mitosis is/are toy m 5pg)3,m9fwhgzh ,rue?
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 letter points to a cell in anaph;fz/zlrm-,: snwxkg.2a 8ume ase?

  During which stage of mitosis does the nuclear envelop, kx,j) w0x e*fzp/uuwe break down?

  Which one of the following transport proteins only carries out active tru8ce t4hom-+ic ue+2yansport?i-h2muc4u 8 tyoc+ee +

  Which process does not happen in the sfja/a kj(9 r -+ 8,5wy,vjg,trtggdu fhoot apex?

  Which type/s of membrane transport do/does ffka.8*t p 3hsnot require energy expenditure?
I. Facilitated diffusion
II. Active transport
III. Osmosis

  The diagram below represents a cell with a diploidsqsx5us dd0m ns;zgdu 9ipr,2*9a;m 2 number of 4. Which stage of cell division is the cel 5 09dd*du smxpgz2 ;q;,nasm9i2ru ssl currently undergoing?

  The photomicrograph below shows a root tip meristem. Wh tqiwfu/ kg27guci9t2 l-+s4 zich of the following sentenc /gu4ct+wz7lf 2qi gikus-29tes correctly defines a meristem?

  When does the random ok r ytxj97x-5fr( 5uferientation of homologous chromosome pairs occur?

  Which process does not occur jo(qh5)5 rpcvpe/x 6a during meiosis?

  If a cell with a diploixabmhwww7/ a 9xqw ,mns2w;6-6n6zk ud number of 36 undergoes mitosis, how many chromosomes will be present in each daughtew xsh7w6 9 u wkzqx26mww -,m6abn/a;nr cell after cytokinesis?

  The image shows a micr:4m7-pox: papkb6 v* p7agn clograph of a cell.


What explains the appearance of the cell in the micrograph?

  Which statement(s) about homologous chromosomej0.bhy:mxp b1 z2.ngks 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 ind4z mfny;, 9c;c(hbol qividual with Down syndrome.

Which statement is not correct?

  In the cells of a horse (E. caballus) during prophasesb in86jpu: dfr04u8q I of meiosis I there are 64 chromosomes. What is the haploid64:pi8 udjq 8 sunbf0r number of chromosomes?

  Which arrow is pointing to a cozj8r0*h pxbv: *vx)tctvr+29 ga8 arhiasma?

  The diagram below represents the structure of a exdzg *7 x93ixy8e/ o6mhm,z zshoot apical meristem. Which row in the table correctly iden e xzegmz6hzm,37o *89x /xdiytifies the processes occuring in the structures labeled in the diagram?

  How does meiosis promote varie2om+ f vfltq o4,e5/0 tbjzr8zu qe/( eh6+ywation?

  Which of the following statementsr0fc /mhu)sis 2om,;q 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 hd/40d2 y5v3qftpo wsp omologous 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 tumours from primarh/ hh sfc,-e))cocx 4p ffv5ff-te (3wy tumours as a result of the movement of cell -we5-f 4sf(fh vcc)off 3h )xpe/h,cts?

  How many chiasmata ares vawd-j*mxxy7*a 0 4e present in the diagram?

  Which statement is a similarity between cyto1p oa5pw 5bt0nkinesis in animal and plant cells?

  Which stage of meiosis is matched toll3l7 4qnw(ws 7t*key the correct description?

  Which statement(s) are true of meiosis I d4wb3ubm c(k./98i yyc -y o k):kratnbut 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 fire-- d68uz*0 vtpobi- p,lqualst meiotic division. This results in the formation of one large cell and one small cell. What is the fate of the large c-o0*ilb zla,vq-t6 8 p dupe-uell?

  Which row correctly describes diploz..s*2g jizihz +c9yz id and haploid cells in humans?

  The following table shows the dywvx 9 6*x *4fqiq8y; zfiq;sjiploid chromosome number of a range of species.


Which of these statements is correct?

  What conclusion can be drawhapx.a c0r hp-e 5-7hun from the karyogram below?

  Which of the following processes is characteristic of the meiotic and not the miyjd(5r1esu ugf:)mg ( totic(g( j:15ed m usyfru)g cell cycle?

  The diagram represents a bud with a shoot apical meaw*x;(n;uy maristem.

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(wfao:nc5d3z/a9hf q chimpanzee (Pan troglodytes) is 48. Which row shows the correct chromo :f9aczdanh3w qfo/ 5(some number for different cell types and cell division stages?.

  At the end of which phase of meiosis I does crossing over occur, and what is thurzx z-0r,u 8jg3uz(y e outcome of crossing ove-rx3 z yugzzuuj 08r(,r?

  Which of the following statements does not describe a sqsl8qhaq94 w 2tep in the sodium-potassium pump cycle in the neuronasal49qh2wqq8 l cells?

  Which row in the table below is tg1 (, f; i)luh:mz wqsncj+y.w9q+ ccwrue of meiosis?

Membrane transport is important for allowing parti 3j mkm5yn(4xh rcy8ew8e5e 9mhhs,k)cles to move across the cell meme mc je5mx5 49)n 88kyehs mrw(,hyhk3brane and respond 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 cellsl7x1 gwj3c/+* frompk.

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 then3e gp07dg c4s8e6qbt ug,6gj:ls f5;b ck6 ni concentrations of different cyclins during the cell cycle. Which cyclin is involved in preparnself cngt6 gieb ucj60:d3754qggbp,8s;k6 ing for DNA replication?

The diagram below shows chromosomes during meiosis. .6v)typj rt+vz 7fnt5car4v6

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 homologous chromosoa r3ls3/b/tpj ).kej;x 6j hdsmes?

  The mitotic index of throa/ud v-muc,k +l (smnp 3+.xnbdt tissues taken from 4 different patients is shown below. Which patient is most likely to have cancerous throat tisspvks-cnd(m.ux/u+ 3 nl ,dmb+ue?

1.Draw a labelled diagram to represem5 u0ygzd+:n 9icb4 lynt 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 karyotypg l9jq8mq oc7*e.


What is the abnormality in this karyotype and its cause?

The graph below shows the 66fwma ,irs z3rl90vfrelative amount of DNA in one cell during one complete cell cycle. Each letter represents one stage of the cell cyclzmri v f ,3s0wa66fr9le.


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 homozygou zc;efr4:lr ,7)xd-lu mos+hcs for brown, long hair and a female cat that has black, short h4f ,x:o;r+dz hlmrlecs 7c)u-air.


Which of the offspring has a recombinant genotype?

1.Outline how polyge/yyf; :joho u8nic 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 crossing over of non-sister chro01 3aq qnvu(c+ sdjh4kmatids shown in th3c0k4v(js1 d aqn+huqe diagram below?

  The photomicrograph shows a pollew*iv+u8iwyd)g0 c, ua n grain from L. candidum (Lily). Which stage of meiosud +*0ya,g8icu ww )viis is shown?

1.Outline the events which would lead to an individual being born with Dow qp(hlrbfz ,3:n syndrome, which is characterised by the presence of three copies of chromosome ,zq3:fl( rhpb 21.

2.Explain how meiosis increases variation.

3.Outline the stages of meiosis.

The mitotic index is a ziwmy/b( j0pv:o8 u1cn indirect 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 the mitotic index of the root:/ b(pjvoiu0 1w8 zymcs.


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 wh96b kwn)xcho+/s,p ygich cells can divide. The diagrams below show two cells from an organism with a diploi sy x6)cb9,np hgo+wk/d 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 growthc :ui1o d+v7ca.

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 it7 6wedf8co( diploid number of 8, in different stages of meiosis. Which row correctly ift w7c(ed6o8 names each stage?

  The micrographs show fo9d3;gk veah92zo.x(berm 7d 5 uai7aiu nl1 ,sur phases of meiosis I in a plant. In what order do these39 5dkglamr2(7x.s7adb h;eon,u1i aie vz 9u phases occur?

Mitochondria are responsible for supplying metabolic ene xchdtn cd+12*rgy in eukaryotic cells. In most eukaryotes, which reproduce by sexual re*htc1+n d2d xcproduction, 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’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 differqn8ymr,kse ( xh1+a0r ent stages of the cell cycle in four samples of lung tissue from four patients. Which tissue has the m(0sr yhx8 q1+,a rnkelowest mitotic index?

  The diagram shows the dominant cyclin/CDK c*i6;2xt9l x vfhpn2iqomplexes at different time points in the cell cycle. Which cyclin/CDK complex activates DNA rtx i2hf;9lvi2n x6qp *eplication machinery?

  Studies have shown that genes such as Cyclin Dependent Kinase 3 (CDKN3er ea/6xp m6 hz29n1ig) are high/29n6iee m1rxh6g zp aly overexpressed 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 during the cell cycle ? zbru:v1p3 9iy