The graph below shows the relationship between maternwb;g 4u8fuznmc8 (17 e6rlhqm al age and the incidence of nonwe16;r4zq7m gc88bfmh (luu n-disjunction. What relationship is suggested by the data in the graph?

  Which stage of meiosis is represented in the diagt; )3bzn4r phnj whn6/ram below?

  The diagram below shows chromosqhd 8.2vkhx0 ,eg95np dryvlh 3j:fa:omes 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 all 06 j8hwu1qc9 k1lvd (no7tnzaigd75leles of a single gene which would be present in the nucleus of a 6lv1w9c uzkg(5tni 1d0nd7 7qa8oljhcell as a result of each process?

  Which keyword is matched to t y ssjiv+0*s6zidr2ha5fp3w4 he correct definition?

  Which statement(s) about mi1)(s1y+cw bpezb ,nux tosis 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, which letter points to a cell in anaphaswb easm9o (3v2 ty:1kje?

  During which stage of mitosis does the nuw squx*pfc9rcnj;qa312: fi-clear envelope break down?

  Which one of the following transport proteins only carries out active tm5q,c r3a (3 rx2d;(u8e)xw vvoicin oransport?i2d 5,i3wx ox r;orumv 8a3)e(qcc(vn

  Which process does not ha-vz ;uxmm) ih1ppen in the shoot apex?

  Which type/s of membrane transport do/does not require energy expenditurewbe-s9g5fkv ( ?
I. Facilitated diffusion
II. Active transport
III. Osmosis

  The diagram below represents a cell with a diploid number of4x:o enu: )i 5sjlpit8 4. Which stage of cell division ie5)nj t:p4x8ioul is: s the cell currently undergoing?

  The photomicrograph below shows ws v .e( flv;cyh3)29mdfl3 qea root tip meristem. Which of the following sentences correctly defines ay3;evls)3 hc.29ledfm( qf wv meristem?

  When does the random orientation of homologous chromosome pairs occur?co* 7 7d:sd c( xvkoo9idbngxt(6)ly 0y2jsl/

  Which process does not occur during meio i;k12fo -yepnsis?

  If a cell with a diploid nukh+;wk1 ve6 xvmber of 36 undergoes mitosis, how many chromosomes will be present in each daug+ wekkvv ;61hxhter cell after cytokinesis?

  The image shows a micrywv3s33n n:a dbl03 k,gjvgq 1ograph of a cell.


What explains the appearance of the cell in the micrograph?

  Which statement(s) about homologous chromosomes is/are not true? 9tyrcrt 4oyg.q 33rp)
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 witl7 0s8z j5jemyh Down syndrome.

Which statement is not correct?

  In the cells of a horse (E. cabe* m7o-tqj8lfeoz984 bdk z3rr2 bxe;allus) during prophase I of meiosis I there are 64 chromosomes. Whatb oz48t bxze-e7k83q jm2r 9*eol rf;d is the haploid number of chromosomes?

  Which arrow is pointing to a chik d*a1js nr+j e6g;ur.asma?

  The diagram below represents the structure of a shoot apical mer 3 up;wbfjrh93-r 1,w6hetm 7/ukvuw bistem. Which row in the table correctly identifies the procehbjkfwpu-9vw 63tm re3;b u/7hw1r,usses occuring in the structures labeled in the diagram?

  How does meiosis promote variatiu mn/j8td)td(on?

  Which of the following statemeoj7, + ; rw19 htvilf;h.jxtni (pj4expih*3 dnts 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 gametmx t3e*cs vp/q61 n,yves produced 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 vf 9e9gd itv 4*vrbsg.g7 :i9ptumours from primary tumours as a result of the movbg7gvf.d* v vip:t s rie9g499ement of cells?

  How many chiasmata are present in the 32jpcoee kvet2) q z-)2x3- dz1fd oufdiagram?

  Which statement is a similarit.fso4)wij ve wmm*x* xp836)knblt*2ux 9 owty between cytokinesis in animal and plant cells?

  Which stage of meiosis i jmjg qq8 sk-;z:d l-i3om+jkm,1dk) hs matched to the correct description?

  Which statement(s) are true of meiosis I but no j5f ygbbe)z(v xxoj gj-j2.wpk-)9 7qt 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 dc k.ik2d)ci5 pivision. This results in thedi2)5. kpkci c formation of one large cell and one small cell. What is the fate of the large cell?

  Which row correctly describes diploi;urr 47.hykc b6uhd/n5d.kodd and haploid cells in humans?

  The following table shows the diploig .st0rag2oi7ep4t+fd chromosome number of a range of species.


Which of these statements is correct?

  What conclusion can be drawn from the 1p0xsa dv 6oj2cngz66 karyogram below?

  Which of the following processes is characteristic ockj6m04kbo- v f the meiotic and not the mitotic c 6cvo-mk 0bkj4ell cycle?

  The diagram represents a bud with a shoot apical m2 ejnulzhx5 lc9)b-jpf1 9xi3 eristem.

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 row qrcli aexl sv. ,p*5:p(;nup(shows the correci (l ,n ;r:pe cx5psqau.v*pl(t 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 ejjspa3g gtq*4p-g 32is the e3g saj*tg2qg3j -4ppoutcome of crossing over?

  Which of the following statements does not describe a step in the sodium-po3bz)f .4jr)i;gx-c7lgapay atassium pump cycle in the n) c a)7rijap4fggl3 -z .bax;yeuronal cells?

  Which row in the table below is true obg,zn/) zbcjkq9wsmmn1:rl vm *hm -m0k81 z -f meiosis?

Membrane transport is important for allowing particles to m4)hvjq 3(jszw ove across the cell membrane and respond to changes in the chshqvz4j3 w() jemical 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 rer)u sg -a(o4ljgulated 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 conyms 5i7 6oqjivowv mitkt(4wbr7: 3z h68 3-sicentrations of different cyclins during the cell cycle. Which cyclin is involvevhowi7m5vjo4-s7 it zk6q3( trwy68 s im :3bid in preparing for DNA replication?

The diagram below shows chromosomes dsyxt5c /w 7 6:mywql-vuring 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 of homologous(i,jt j8oua,r* jvw1f chromosomes?

  The mitotic index of throat tissues taken from 4 differexu;9unxp 9wjx1f1 0 8oi:idcqq16 lllnt patients is shown below. Which patient is most :jlf dcupi w 1;1u 1xq 8i960nllxqxo9likely to have cancerous throat tissue?

1.Draw a labelled diagram to represent the process of crjpe xy1 f7sl tfu w.c8.qe1e.d 6r6r7vossing over.

2.Compare and contrast random orientation and crossing over.

3.Outline the stages of meiosis.

  The image shows an aat3eo njl lph7u4+esbq,/ :w1bnormal human karyotype.


What is the abnormality in this karyotype and its cause?

The graph below shows the rela4q1nkuvg:)7/wezna u tive amount of DNA in one cell during one complete cell cycle. Each letter represents one z w)ge un/v:1knu47aqstage 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 homozyq-yxljpmib bu89; y1d3 0du ,fgous for brown, long dp9 f,3-yqdu1juxbyml8i ;b0 hair and a female cat that has black, short hair.


Which of the offspring has a recombinant genotype?

1.Outline how polygenic traits can show a :nba) njab7+koz8w r 9normal 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 chromatids sho* g+ x+(kh1gxjfbr 8mj9q r-yhwn in the diagram below? r(g *j+fyhm+jk9 xg1brqxh8 -

  The photomicrograph shows a pollen grain am lm .ab,7zn r.0/wbxfrom L. candidum (Lily). Which stage of meiosis is shown? ,lmbr7.w/.xna0a mb z

1.Outline the events which would lead to an individual being bor trpm jj/+m qyt6/i6/zn with Down syndrome, which is characterised by the ptm//qpyt6j+ 6z/rj imresence 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 measuriz ophirzj 576:ng 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 mi56 zipr7zj h:ototic 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 wht9b, yagbe.p/boqp l4 (1d )gfpef52xich cells can divide. The diagrams below show two cells from an organpfppeg52egx ty 9.l )ob/d4, fqba(1 bism with a diploid 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 exprez or.eieq(+.1bkzy4 gsa(/vjwp +n1n04b pig ssion 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 show a ce eji0b2l: c.0/ zwzgojll, with a diploid number of 8, in different stages of meiosw 0b ./zeco zjigl2:j0is. Which row correctly names each stage?

  The micrographs show four phases of meiosjv9d)unz vdm2 wh qxe2-;* (zhis I in a plant. In what order do these phases oc;uezm*z)w22h (n9 vhd-q dxjvcur?

Mitochondria are responsible for supplying metabolic energy in em-dve(mx:cr3c5/ sv ,:cg hjhukaryotic cells. In most eukaryotes, which reproduce by sexual reproductihgjecv,5-/ vh: :m c 3(xdsmcron, 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 different stages of the cell cyclem0fdii)0j6 r n in four samples of lung tissue from four 0dnmif)r6 0ijpatients. Which tissue has the lowest mitotic index?

  The diagram shows the dominant cyclin/CDK complexesg9 o+u 9j(yk5)p6ex e8xx8k4qv vueqn at different time points in the cell cycle. Which cyclin/CDK complex activates DNA rxvu ue 4e x) nk9v(95jkxy8qo+g68p qeeplication machinery?

  Studies have shown that genes such as Cyclin Dependent Kinase 3 (CDKN3q3l*/n wnwhf dq. jd41) are highly overexpressed h1ql f4wj*n ./ddq w3nin 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 cyc:e f viw tovd5b905ohyx rt3g sz-4n)/le ?