The graph below shows the relationship between maternal age and the inciden69hl0cpuum )a m-xbjuc9( x3u ce of non-b06umxp- x 3ulc9 umj(hua9)cdisjunction. What relationship is suggested by the data in the graph?

  Which stage of meiosis nueq h u c;vd35ok0 a*pyfbu-y cn46.-is represented in the diagram below?

  The diagram below shows 2q.lpl0p5 59qct :uozvxe ht cnsr160chromosomes 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 allechx1 t p(b sz90.7:unop9nutrles of a single gene which would be present in the nucleus of a cell ts909potchr 7n( z:x n1b.uup as a result of each process?

  Which keyword is matched to the a7+xs-s zt6tpf+1moicorrect definition?

  Which statement(s) aboutp wo-ho5 /qr:l 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, which lettei+ ns+dkob9m)qc 9bk +r points to a cell in anaphase?

  During which stage of n b8*9qep g7jt3tw;z qz7rup8mitosis does the nuclear envelope break down?

  Which one of the following transport proteins )e8w(-fwuie pt w3xg: only carries out active transport?w:egtw(83fx-p )eiwu

  Which process does not happen7qdm1r0f k1m/c/ lkzx in the shoot apex?

  Which type/s of membrane transport do/does h9p g,s7l :6jnwbics*not require energy expenditure?
I. Facilitated diffusion
II. Active transport
III. Osmosis

  The diagram below represe; vl uycsqtr7up,947cx*tb h(nts a cell with a diploid number of 4. Which stage of cell division is the cell currently un,cts7vhc lyb; x94puur 7* (tqdergoing?

  The photomicrograph below shows a root tip meristem. Which of thecti*w5/p7 f wd following sentencwwdp7 5ct/ *fies correctly defines a meristem?

  When does the random orientation of homologouspg7xsv33p1zn+ t ess5 chromosome pairs occur?

  Which process does not occur duri.yha0msg bi 2)ng meiosis?

  If a cell with a dip*zdl/c da:t/dxc0 gc s k(u+z8loid number of 36 undergoes mitosis, how many chromosomes will be presentlgsd/ z(dc *8uz+x:ccd/a0k t in each daughter cell after cytokinesis?

  The image shows a microgrwht-ex)r77dh e )y8zjaph of a cell.


What explains the appearance of the cell in the micrograph?

  Which statement(s) about homologous chromosomes is/aro15f m+ibcfzk5 *ya0be 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 fow,f9zx qdsr0 -r an individual with Down syndrome.

Which statement is not correct?

  In the cells of a horse (E. caballus) during pro)5zaslf j7f .y t;ojt4phase I of meiosis I there are 64 chromosomes. What is the haploi z.jjf)7t syltof5 4;ad number of chromosomes?

  Which arrow is pointingq.dfjf jrg:3 5 to a chiasma?

  The diagram below represents the s0btejmeijnt,0k:7w,xw -t hk:),bwntructure of a shoot apical meristem. Which row in the table correctly it etm,w0:wjxtkb0 - kj, )bn,i 7whne:dentifies the processes occuring in the structures labeled in the diagram?

  How does meiosis promote variation? .o8gmxodt5v v fc)b:.5i uqw-

  Which of the following statement;x0pc -sbzd01pcc-u7 7pajhh s 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 game+jlh i+q66y n;aq0ymn tes 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 secondarymqfc m71,phgj, 7+gsc tumours from primary tumours as a rehj c1+,mgp 7mgf7cs,qsult of the movement of cells?

  How many chiasmata are present in rjf 9gj-2x2 x.t7 vfs.ge.el qthe diagram?

  Which statement is a similarity between cytokinesis y7b mjyi8v 3-x-l2xqzin animal and plant cells?

  Which stage of meiosis5v 35.eg5azu btk ufh0 is matched to the correct description?

  Which statement(s) are true of md 9.0y -wxv a:bwk1yuneiosis 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 abu n:iclpn.x03/rc *pn oocyte after the first meiotic division. This results in the formation of one large cell and one small cell. Whxnl*pci p0r/:c 3unb .at is the fate of the large cell?

  Which row correctly describes dip0 cjdr:u2 dfjgx35 uk(loid and haploid cells in humans?

  The following table shows the diploid chromosome numbe,rabe5e8c bh 6xiu30h r of a range of species.


Which of these statements is correct?

  What conclusion can be ipsfov5oizq s)), a0,thrj-; drawn from the karyogram below?

  Which of the following processes is characteristic of the meiotic and not tnl0n m ixy3 ma8, oytp5z*rcy./h n4z6he mi mty ,i65yp0l.hzo3cxz8rann ym 4n*/totic cell cycle?

  The diagram represents wnehe;9 t/j6r0 vi7rca bud with 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 xoz.y 0pen24vl4ubf3 row shows the correct chromosome number for4bl4.u2y0oz 3xnvpe f different cell types and cell division stages?.

  At the end of which phase of meiosis I does crossing over occur, and what r3x/batbv7h) is the outcome of chab 7)t3xv r/brossing over?

  Which of the following state-kwmea uer* 2k.b6(elments does not describe a step in the sodium-potassium pump cycle in the neue*(bk6- u r.weame2lkronal cells?

  Which row in the table below is true of meiv1n i7 erko.tv:w,n- zbma5 ;xosis?

Membrane transport is important for allowing particles to move across a8hh4fwu; ut+u3k jk0 the cell membrane and r; a8wt3kuhk +u uj4h0fespond 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 mitosisqsic yfb. (f87 is 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- gq9/3cyz+nq wnf.7ywbs tkt--c aytct(:p8 concentrations of different cyclins during the cell cycle. Which cyclin is involved in prepar-s: -./bc9wty8gtzn(ccpn+yyq a k f-qtw 73t ing for DNA replication?

The diagram below shows chromosomes during medof7g u1t*/7u hl75ogo cqhd *iosis.

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 involvep bq;8nr(w2 bhs the separation of homologous chromosomes?

  The mitotic index of throat tissues taken from 4 differentuu dv 1(9lyd/w patients is shown below. Whichlwu1d u(d /v9y patient is most likely to have cancerous throat tissue?

1.Draw a labelled diagram to represent the process of crossing ony +xpwzph 94:ver.

2.Compare and contrast random orientation and crossing over.

3.Outline the stages of meiosis.

  The image shows an abnormal humang fl6qoow4-xf0j :c6y karyotype.


What is the abnormality in this karyotype and its cause?

The graph below shows the relative amountqp5 tedd0wopo97x k26 of DNA in one cell during one complete cell cycle. Each letter represents one st odp5xpoe 29qdt0 kw67age 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 a7(zz s7u v,wxw cross between a male cat that is homozygous for brown, long hair a v7su,zw( zwx7nd a female cat that has black, short hair.


Which of the offspring has a recombinant genotype?

1.Outline how polygenic traits can show a normal distribution.5 6wbh. ,ql iynbte:p3

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 crossi,4a)lb q0iztwr6bkm, u)db * zng over of non-sister chromatids shown in the diagram below z)qkbzi6)m4 0t , wa,brbdu*l?

  The photomicrograph shows a pollen grain from L. candidum (Lily). Which sasn. 7uimk5ur81; utsky9hb 3ewontt ( rh5 9)tage of meiosis is ws)5n u5hk3r91(ui k.t8he 7an ;tr yob9utsm shown?

1.Outline the events which would lead to an individual being born with Dow98fm6 d h,6t)fnxfps n u2-t9vomtm9xn syndrofn8f 9n69dmom 6 pxt9hxfvm,2 -sut)tme, which 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 jferz t:n8m o q8wz,34i9 g2);dfltrw plant growth. A study was conducted on white onions (Allium cepa), under controlled conditions in a lab, to investigate zt29fj8m z;t4r8 ,) fldq3io:wrew gnthe 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 tv wz 86 h6yhsa-kfa5uj,)l uk;wo ways in which cells can divide. The diagrams below show two cells from an organism withs6)hh ,-ju6kylufaw 8 ;z5akv 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 expression in stem grow /egtr8;n2odb th.

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 dip3qnrcm b8t+mdqg*0 nvj8p.rwzg ah 6 m(7n1 k.loid number of 8, in different stages of me8jq6k(.g 87gv qp. +hna*nrrwncm 1dmzt m0b 3iosis. Which row correctly names each stage?

  The micrographs show four pha 8fu5hop ju(f4ses of meiosis I in a plant. In what order do these phases ochfuuoj (485p fcur?

Mitochondria are responsible for supplying metabolic energy in o/g5 mpiqog7, 8j1t( v(4 hj9dmyroif 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 1dri(yom/ g7mfqp 5,ojo89jv 4ihtg (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 cycle in bco gz )n,riqta)45q9 four samples of lung tissue from four patients. Which tissue has the lowest mci)groq, 9zaqbtn )45 itotic index?

  The diagram shows the cst;:v+ u+pv u)m xe0odominant cyclin/CDK complexes at different time points in the cell cycle. Which cyclin/CDK complex activates DNA replication machimcxtvu+v;: +)u pos0e nery?

  Studies have shown that genes s *vbrsa(k,u+(9b h2rvmpsqd- uch as Cyclin Dependent Kinase 3 (CDKN3) are highly overexpressed in cervical tum -a*brvupsk+2b msh (dqr,v9( ours.


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 hig of+nqwz0f) vm :fk+z,hest during the cell cycle ?