The graph below shows the relationship between maternal age and the inckn6tk c lv,y347sivt:3n :w wisy 2j3oy yd27jidence of non-disjunction. What relationship is suggested by the data incyio 3kty ,2t3yji2s76 ys7 v::3w vnl4knw dj the graph?

  Which stage of meiosis is represented in the diagram b5fhf;bxtprqd - -x +6celow?

  The diagram below shows chromosomes sv4io zisx):; 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 gen r 2zqytzftf*g4b,c2f3 itc* :e which would be present in z3,tz2ffg42q c*yi ct b*ftr:the nucleus of a cell as a result of each process?

  Which keyword is matched to the correct definition? rd;nji fzo;/0

  Which statement(s) about mitosis is h 1wan6-muxnu1dk*2 o/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 letter points to a cell in anapbl3ms4 k l*ww7hase?

  During which stage of mito,byf lt:90ki xsis does the nuclear envelope break down?

  Which one of the following transport proteins only carries out active transport68,4 rc./avl0fff hl xplmtb-zu1g u.?h l/.z 0fbualp4tg. m6cf ,u-l8xrv 1f

  Which process does not happen in the shoot apex-9 van: ambye/?

  Which type/s of membrane transport do/does not require energy expenditur5.vg s7mxl sl x,,pre/e?
I. Facilitated diffusion
II. Active transport
III. Osmosis

  The diagram below represents a cell with a diploid number 7 dwnszice50; of 4. Which stage of cell division is the cell currentlycn5dsw iz ;e70 undergoing?

  The photomicrograph below shows a root tip meristem. Which 9xmhq( m0db 2)9lnn pbof the following sentences correc9 ( ml2)n9hm npbbx0qdtly defines a meristem?

  When does the random orientativh d2c19zsft4 0igek-on of homologous chromosome pairs occur?

  Which process does not occur during meios:at8(edtqo/ 5ed;t*m9wm01u y pr tfvis?

  If a cell with a diploid number of 36 undergoes mitosis,-)o0s o.,knnuek sl 2e how many chromosomes will be pkoo2k )l-0se uen.sn ,resent in each daughter cell after cytokinesis?

  The image shows a micrograph of a )yj9 ix* mv)9guhjw)fcell.


What explains the appearance of the cell in the micrograph?

  Which statement(s) about homologol r, qhdt+ b hbu)10d.-un-gwcus 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 individualk di9xnt:3el+ with Down syndrome.

Which statement is not correct?

  In the cells of a horsel(u7x0 3:c ;c(x zts2a mdlz*ebtcz5e (E. caballus) during prophase I of meiosis I there are 64 chromosomes. What is the haploid number of chromoztexe(cmc u(l7*3l5;xa b s zczd2t0 :somes?

  Which arrow is pointing to.h4azfdv) 65 wau-ar b a chiasma?

  The diagram below represents tz.zh tua)9( dche structure of a shoot apical meristem. Which row in c9a.z t()dhzuthe table correctly identifies the processes occuring in the structures labeled in the diagram?

  How does meiosis promo9l8 qj bj)jzm/te variation?

  Which of the following statim5t x9; ,v; zjlzh, l+/bfwxhements 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 homologous cnm w4b7r;z4ap hromosomes.


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 t 0xw0 z n4wls-*r dxm8og3rnwuaw0f9.umours from primary tumours as a result of the movemenw04 afznxw0m0o du93.w8-n*slw gxrrt of cells?

  How many chiasmata are present in them5t9 kh*va j r e2u: eanjncby2j767/i diagram?

  Which statement is a similarity bzfc4o5l:5 vqm p3dfd1fr+ cu 5etween cytokinesis in animal and plant cells?

  Which stage of meiosis is matched to the correct descl 4+ ig+ckdr+f r-qmpi 5w*u1lription?

  Which statement(s) are tru0gd * -hphq7ume 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 ml rn3d,fg:pui. e g,1e(( dza/csp9 vheiotic division. This results inpepa .(gi:d9rchdz, e3g1,fls/n uv( the formation 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 jv r0 emf-4as1humans?

  The following table shows the diploid chromosome number of a r;*kl5l1 8ckb(rb3 n(*pfyzk y,kfierange of species.


Which of these statements is correct?

  What conclusion can be drawn fromtfu /.qg7oz50i.v aam the karyogram below?

  Which of the following procv,lo fx nxk.)+esses is characteristic of the meiotic and not the mitotic ceo. ,xl)kvx nf+ll cycle?

  The diagram represents a bud wito49x/o a+wntfpgj,. jn j* .pqh a 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 of the chimpanzee (Pan troglodytes) is 48. Which row6 hvaa +sf-k 3w+d0edh shows the co0ah+ -w +vhkfae6d3 dsrrect chromosome 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 t5fjfdj /xq:y .) h8i;rja dv/hhe outcome of crossing:vyjqrfjdjh;i .8 / xahf)d5/ over?

  Which of the following statements does not describe a step in thm/7op7 7brr yle sodium-potassium pump cycle in the neuronabrp7ymlor/77 l cells?

  Which row in the table below is true3 ugd s:ez66p:)euram of meiosis?

Membrane transport is important for allowing particles to move across the ce9 oqy*cs ;4 +dinofore --0clqll membraqe co+sl9 -*qroi;yc-fdo0 n4ne 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 rehb3ku5 o l-3gp fa.0atgulated 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; m*ajjk3 p(kc concentrations of different cyclins during the cell cycle. Wj3ak(mp ;c kj*hich cyclin is involved in preparing for DNA replication?

The diagram below shows chromosomes during meiosis. h;eu ue;jq)p 7

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 homoo: ndb f0a;+rvlogous chromosomes?

  The mitotic index of throat tissuesb:wvja :js 7iv-6vl 93tcz r4m taken from 4 different patients is shown below. Which patient is most likely l9sv:w3viv4 zb acmt 6r-:j7j to have cancerous throat tissue?

1.Draw a labelled diagram to represent the procejr r8ewwo;l wi( d j-/:n;rs(mss of crossing over.

2.Compare and contrast random orientation and crossing over.

3.Outline the stages of meiosis.

  The image shows an abnorma9+ pnl: e9qckpmag./kl human karyotype.


What is the abnormality in this karyotype and its cause?

The graph below shows the relative amount of DNA in one ce-yho.ow/7nog i pby2 )ll during one complete cell cycle. Eayp -2nbhio )y.7g o/owch letter represents 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 h: aqweq4hr obfmo4 ,,n7e0-adomozygous for brown, long hair and a , 4qqaefdm bn-7oa,ow:e4h 0rfemale cat that has black, short hair.


Which of the offspring has a recombinant genotype?

1.Outline how polygenfpt-fysoweae+8+o0d - ( ptb (ic 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 3sip)e3n0zcm fu7 qp+gcj 92sh95uz b the crossing over of non-sister chromatids shown in the us ze+uz q3 gpji 9ms5b2)0f3h c9pc7ndiagram below?

  The photomicrograph shows a pollen grain from L. candidum (Lily). g189do/ggk9n q zuef 9Which stage of meiosis is shown? u/ nkgeg8q1og9 99 dfz

1.Outline the events which would lead to an individual b c1m3gn+*6o bkgwui u5tihz4 .ylt:,reing born with Down syndrome, which is characterised by the presence of three copies of chr6ytt rwl :*3m+5 4 u.onb,uz1 hgcikgiomosome 21.

2.Explain how meiosis increases variation.

3.Outline the stages of meiosis.

The mitotic index is an indirect way of me g,kes m64 ydo-+w+staasuring plant growth. A study was conducted on white onions (Allium cepa), under contros-+6ws od+g4a,etmk ylled 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 divide. The diagrams below s:p .up qk,hj5l+hx kp7how two cells from an organism with a diploxp,l:q 75phj. hpuk+k id 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 steg2j;*kduew 6* wcj*lxm 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)hiws wsrox h7 m+/5pr*rw*. s6b agn) number of 8, in different stages of meiosis. 6xs7. wrsw/p+*)rh)rnombhg si* 5 waWhich row correctly names each stage?

  The micrographs show four phases of meiosis I in a plant. Inogkg;f6m6gfk e1a +a) what order do these phases occur? a1o+gkkgf);gm6 6ea f

Mitochondria are responsib1qs 2t-0mprlx f 0t+,-kooir ule for supplying metabolic energy in eukaryotic cells. In most eukaryotes, wl,urfqt01 tk- ro 2pix- 0+osmhich 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’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 diif; q):2tnc mrwjt ,(cfferent stages of the cell cycle in four samples of lung tissue from four patients. Which tissue has the lowest mitotic i( :wjc ,mt;iq)cf tr2nndex?

  The diagram shows the domi 2;xbg :kjks4/wfkt6;)penpc nant cyclin/CDK complexes at different time points in the cell cycle. Which cyclin/CDK c 6x)tebgpcfps4 kk:;;/k w 2njomplex activates DNA replication machinery?

  Studies have shown that genes such as Cyclin Dependent Kinase 3 (CDKN3) are hig 20imwlay,o1ohly overexpreslo0ow2,y 1amised 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 ggbj c7s+z+:ii8e +afof cyclin E the highest during the cell cycle ?