The graph below shows the relationship between maternal age and the .d hblb70gw4iincidence of non-b 4h7wd0 .lbigdisjunction. What relationship is suggested by the data in the graph?

  Which stage of meiosis is represented in ng0asws,tz5( the diagram below?

  The diagram below shows chroos, rb.-cql4xmosomes 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 stat3/v uga7q b7zdb(7epees the number of alleles of a single gene which would be present in the nucleus of a cell as a resa7 de up7/e(7gbqbz 3vult of each process?

  Which keyword is matched to the cb5:-vjul+e cg m*pw.e *4bhx lorrect definition?

  Which statement(s) about mitosis is/areb(bp.7 ;n o)9-akad;dhl1bktuy-ov oel x/1d 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,q m4vab.g ksi/29bvn3 which letter points to a cell in anaphase?

  During which stage of mitosis does the nuclear envelope break down?0f f 82-sw(qxf 5xvugl

  Which one of the following transport proteins only carriesv,x29tl* f wrlbz i9q8oixu57: ioh5b out active transport?2 vw bqhx5b8,57t*zri : ollu9i fx9io

  Which process does not happen in the shh9j ;,l:/m doych+pngoot apex?

  Which type/s of membrane transport do/does not require energy expend82*o 4icr xa 2pdovzz+iture?
I. Facilitated diffusion
II. Active transport
III. Osmosis

  The diagram below represents a cell with a diploid numbexufcw3w3rt g+mi89 n5 r of 4. Which stage of cell division is the cell currently 9w5 8mgn3f+w3u rxictundergoing?

  The photomicrograph be6xvpay93q7 c7 )v xq (akncyt*low shows a root tip meristem. Which of the following senteny 9q3 y(*ccx77)nta xkavpvq6 ces correctly defines a meristem?

  When does the random orientat7rc pmlbs88m1 /zbnxjn4( ; w v*bq:gxion of homologous chromosome pairs occur?

  Which process does nohouy) n)n uwy* u:3b3qt occur during meiosis?

  If a cell with a diploid number of 36 undergoes mitosis, how many chromosoml/niyg+ 9uzo32w7yu xes will be present in each daughter cell af/u9oxw+gyy i7u n z2l3ter cytokinesis?

  The image shows a miuap a8 -(qs0kbm ff)wcudo5 17crograph of a cell.


What explains the appearance of the cell in the micrograph?

  Which statement(s) about homologous chromosomes is/f(vsi bf nbor4t( ;oriem)h7z: 8)c,k 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 indivi v3o)w qy9+amgdual with Down syndrome.

Which statement is not correct?

  In the cells of a horse (E. caballus; +sr0gci r2wq ub:t8u) during prophase I of meiosis I there are 64irc;bgsw2 : q u80+utr chromosomes. What is the haploid number of chromosomes?

  Which arrow is pointing to a chiasd7/*ao yxj5d cy/wf(yma?

  The diagram below represuh96 a,ej.gwa 7bgxq( )+pbx mzq+dz5 ents the structure of a shoot apical meristem. Which row in the table correctly identifies the proc+q7hgp edm ,6wbbx5za g(.uq+ajzx )9esses occuring in the structures labeled in the diagram?

  How does meiosis promo a3t(n 4fhzq3mte variation?

  Which of the following statements is/are corry/xor +31 amvzect for meiosis?
I. It is a reduction division
II. It involves random orientation
III. It produces genetically identical cells

  The diagram shows ga6n5gsefyx f)y:fp )1ncrca/ou/ 8k 6umetes 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 ofr v/,d r:, rwtbwn-* exty2wq/ secondary tumours from primary tumours as a result of the movement of cell:v,r t rbwr, -tnd e2*wx//ywqs?

  How many chiasmata are present in the dia,h7;f) 3rqv8djtmtr dgram?

  Which statement is a similariz/it7j0itr) 4 qg n3gqty between cytokinesis in animal and plant cells?

  Which stage of meiosis is matchepm:6-( 1lh xqdtea*c 3sv/qhc t3(xrr d to the correct description?

  Which statement(s) are true of meiosis aeca0k2di22gt11v wp 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 thef hrcetlu)*jdkl 135 , first meiotic division. This results in the formation of one large cell and one sm*l 1ulhrek,dcj5)t f3all cell. What is the fate of the large cell?

  Which row correctly describes diploid q/82(ll v:o m.chln lband haploid cells in humans?

  The following table shows the diploid chromosome number of a rangsxwrd1k+t,6)0l:c kt8vv zewchn ; 7be of species.


Which of these statements is correct?

  What conclusion can be drawn from the karyogr jm;l5qidkv,6m 3s) jcam below?

  Which of the following processes is characteristic of the meiotidsuary+9gf 8z,fj .(wc and not the mitotic cell cycleg fu9fy.a, z(r+8wjd s?

  The diagram represents a bud with a shoot apical meristem. x jx4r. kuqp:qt, 7w5y

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 reb6;aa fq. nf,ow shows the correct chromosome number fabea, f6nf.;q or different cell types and cell division stages?.

  At the end of which phase of meiosis I does crossing over occur, and whatzgt-cvwyixht0w 7o dopf3 5(;)e- h v6 is the outcome -p ;v -yv5 dxcw0(7f ohw ig3ehtot)z6of crossing over?

  Which of the following statements does not describe 02 . wi*s5tqr3e0apx/ c5dovhel 5lbua step in the sodium-potassium pump cycle in the neurona5c t2 53p/0svoailuqdb 5 *hrex.0well cells?

  Which row in the table below is true kxt/v;f*k yn-of meiosis?

Membrane transport is important for allowing particles to move acros/sfu sr2 w +0+buyddj0s the cell membrane and respond to changes in the chemical composition off u sb/jdus 0y+02r+wd 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 cellkmvc07 g y dkki5-q5z,s.

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 difrv:g;nd)k7i o f*v3k*re8.pq + z lcrmferent cyclins during the cell cycle. Which cyclinp3v)dg kermlc *oizr+kv*8;:fnq .r7 is involved in preparing for DNA replication?

The diagram below shows chvhc637 bkhs65h5yr xe romosomes 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 separatinnbg7u5g5u;pa 35 0wed iy.y)8unu edon of homologous chromosomes?

  The mitotic index of ggt)9.i k.mbwthroat tissues taken from 4 different patients is shown below. Which pattgw.bi) k.9gmient is most likely to have cancerous throat tissue?

1.Draw a labelled diagram to represent the process of c(e ae2;ncbs 9ea,3 tgrrossing over.

2.Compare and contrast random orientation and crossing over.

3.Outline the stages of meiosis.

  The image shows an abnormal humanz*di9mosn1e c; 3 ;jhta( ro*+p gu6tu karyotype.


What is the abnormality in this karyotype and its cause?

The graph below shows the relative amount ofm(s0f,y.9f8+t jkan pdq7)cvp9z-eugc r )bv DNA in one cell during one complete cell cycle. Each letter represents one stage of tv8(f.djft9u)rbn 0q9,zgpckcp) ey-7a + vm she 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 ho18 wa+wwmme1o v7 /kcfmozygous for brown, long hair and a female cat that has black, shorokw81v+/awf wmcme 7 1t hair.


Which of the offspring has a recombinant genotype?

1.Outline how polygenic traits can irrx k ax274mh f)us.z48 ve+tshow 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 chromatids shown i*b92yx) /qc7xpet ndf n the diagram bexx t)c p y*2fqebd/79nlow?

  The photomicrograph shows a pollen grain from L. c g:x js.bk/mwdmi-s7 e 4kiqe0(bg80qandidum (Lily). Which stage of meiosb d8qe:.iiq m4g/bxejmksk w70g0s- ( is is shown?

1.Outline the events which would lead to an individual being born with fn0lrwsn +54 iDown syndrome, which is characterised by the presence of t lnrnwsi4f +05hree 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 stud5vb*nuhw3 w n2y was conducted on white onions (Allium cepa), unden35b*uwh wvn2 r controlled 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 whic0i9;66ixovzbp (3o b tie 7kboh cells can divide. The diagrams below show two cells from an organism with a diploid number (2n) 9i t3iio;(ob pze 67o0bkx bv6of 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 growth.t0w3qy3l ;bkn

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 number ofrw9ug.v1hvi1(xc z0k 8, in different stages of meiosis. Which rovi9c 1gkzxh0 vr1uw.( w correctly names each stage?

  The micrographs show four phases of meiosis I in a plant. In what order do the 9pf4 )v7gzv-82 lmrxzv (rpvo:uuo)tse phasu xrz7 ) 2 pl9rf-o)vu8pg ov:4z(vmvtes occur?

Mitochondria are responsible for su2 qf23ooett h4pplying metabolic energy in 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 dihq4ofo2 t23etfferent 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 numbq.;kp/ r+ikjvw/ 1w 3nsc i-ider of cells in different stages of the cell cycle in four samples of lung tissue from four patients. Which tissue has the lowest mitotic ind i cij/w1 s k+i-r3dvq/;.nkwpex?

  The diagram shows the dominant cyclin/CDK complexes at different time poiud6nhrx:/ e ;0z8 nkcints in the cell cycle. Which cyclin/CDK complex activates DNA 6kr h0ne;/dicnzu8:x replication machinery?

  Studies have shown that genes such as Cyclin Dependent Kinase 3 (CDKN3) are hidkro d48qyiv td5+6 8gghly overexpress8d4vk+5 6ri8qdydotged 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 highiyh87 lmrbg7ik 4/ nsnaxqb510bs, 8gest during the cell cycle ?