The graph below shows the relationship between maternal age and the incide e/te a(7 7c7t;x;xfgxlexmy- nce of non-disjunction. Whxexx7 t;fxlc-(g/e7;yem a 7 tat relationship is suggested by the data in the graph?

  Which stage of meiosis is represented in the /i qc ljb*(ro.diagram below?

  The diagram below showsran 026)wk brk chromosomes 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 u;ooor m ct6 ./7jqlx7o)zlu)a single gene which would be present in the nucleus of a c; t )m.co776 /olrqlzo)o juxuell as a result of each process?

  Which keyword is matchhq18p 3ntevk7ed to the correct definition?

  Which statement(s) about mitosis zeinh gvq si +:s:6(d3is/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 below2zwp c0h,)t5gwytxo 2ya aj ;0, which letter points to a cell in anaphase?

  During which stage of mitosis does the nuclear envelope br6qqwza /g1k2heak down?

  Which one of the following transport proteins only carries out active llyw3gk99a8atransport?g39 kaal yl89w

  Which process does not happen in the ,ad10*frh etu shoot apex?

  Which type/s of membrane transpor404 2k-hgm .bpp;knqea* zuq irvk76xt do/does not require energy expenditure?
I. Facilitated diffusion
II. Active transport
III. Osmosis

  The diagram below represents a cell with a diploid number of 4. Which stsemgieuz0d605-v fega r1y() age of cell division is the cell efruei1) 6em z(0s g5d- vyga0currently undergoing?

  The photomicrograph below s hql+nbe3d:-u l08vq shows a root tip meristem. Which of the following sentences correctly defines a meribhelnvsqdlu 8 +- :0q3stem?

  When does the random orientatiewvqus kc42,zo ,f8-s on of homologous chromosome pairs occur?

  Which process does not occur durinnhi4:hxhtkh3/kz lkwg* .6+ 8 (psazqg meiosis?

  If a cell with a diploid number of 36 undergoes mitosis,-9i6iykr73htgi g w xp+p o42x how many chromosomes will be prggh4+3i9p 6ikxxoirwp 7-2 tyesent in each daughter cell after cytokinesis?

  The image shows a micrograph of b.zae79hj7b+zn iy 4ua cell.


What explains the appearance of the cell in the micrograph?

  Which statement(s) about homologous chromosome( k73v6 nevob2d6rp+w*l zyhds 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 individual with Down syndrome. w .p9*j67p qpmov(eom

Which statement is not correct?

  In the cells of a horse (E. caballus) during prophase I of meiosis I there ar)zn5w yg4k 0hre 64 chromosomes. What is the haploid number of chromosoz wyg54 k0rh)nmes?

  Which arrow is pointi,tt-xrdrp.hzu :ukc l+((ma8w rsh )a8dbp 4,ng to a chiasma?

  The diagram below represents the structure of a shoot apical meristem.;cc+0lyq q *k o+,xtui Which row in the table correctly identifies the processes occuring in the structures labeled in thkc*oq c;tx0 iquy++ ,le diagram?

  How does meiosis promote 4+ vx6qukqm9otfmfyj:(m,2 qvariation?

  Which of the following statement0/0)s jd,dc.le i5p,vez wqi es 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 f dx4 day(x;fow4t4s*+;dmwu zrom 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 tumours from primary tumoudg0u wsg br,+d cfy8/.5de:pirs as a result od/ewf8y ,cd.+grb :d gipu5s0f the movement of cells?

  How many chiasmata are present in thmcq5)- qbamd7z7;trqe diagram?

  Which statement is ag;-r)(o qt -scmkjpo5jtuzhfh24j 84 similarity between cytokinesis in animal and plant cells?

  Which stage of meiosis is matched to the correct dh piuxb:o w.ok1xk( (9escription?

  Which statement(s) are true of meiosis I but not m-/7puuw2ym3 4jjy mjnib 6tg(7s sh +qeiosis 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 adur90c::iyb v fter the first meiotic division. This results in the formation of b y90vi :ucrd:one large cell and one small cell. What is the fate of the large cell?

  Which row correctly describes diploid and haploid cells in7e 5glbr 0u4wx6yzh. e humans?

  The following table shows the dipl5tmdnok6 60 wzoid chromosome number of a range of species.


Which of these statements is correct?

  What conclusion can be drawn from the nao7+qv :q :au)lnf4 zkaryogram below?

  Which of the following processes is characteristic of the me3p s 43/ga:pe0qzbuswiotic and not the mitotic cell cyc: 3sbuap qeg/3 zp40wsle?

  The diagram represents ag xh43 ,qwy1l7kn)zwc 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 chimpanzd y;d95whp02wx 89we vxaqm3n ee (Pan troglodytes) is 48. Which row shows the cox8q2p; dd9xwh3w9 neaw v0y5 mrrect chromosome number for different cell types and cell division stages?.

  At the end of which phase of meiosis I does crossing over occux y,(yrr2 tul;r, and what is the o r ulrx2tyy(,;utcome of crossing over?

  Which of the following statements does not describe a step in the sodiu2dm.in0wo w.b+ex; ykm-potassii x2m 0+o;.wdywne.kb um pump cycle in the neuronal cells?

  Which row in the tab,vg+c*-99 ct;oexyt aiv3tb qle below is true of meiosis?

Membrane transport is important for allowing particles to mwxi8a624scz1u4 v abh ove across the cell membrane and respond to changes in the chemical composition o6vbs4za4hi wacu8 12 xf 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 rez9r mt y(6pt4b ()jd 5p+m3o il9zhssvgulated 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 concentrations of different cycqhy.r )4w y8k*oiqqm*rz+d z8 lins during the cell cycle. Which cyclin rh8z.ro zqi+8 * yq qdk)my*w4is involved in preparing for DNA replication?

The diagram below shows chromosomes durilry ( 0km6wuf2ng 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 th; sqtoi,( lrx4m-g kjf8o7: yye separation of homologous chromosomes?

  The mitotic index of throat tissues taken from 4 different patients is s7s38xm hr4ojio vb 9 5lf/axr/hown bel xhmv olo8rr b7j/53i9xasf/ 4ow. Which patient is most likely to have cancerous throat tissue?

1.Draw a labelled diagram to represenevt+1ln)cf5s9ul a64wb jb v0gx g9-a t the process of crossing over.

2.Compare and contrast random orientation and crossing over.

3.Outline the stages of meiosis.

  The image shows an abnorm--z) sqf ):2hua0y.ps ut ttqsal human karyotype.


What is the abnormality in this karyotype and its cause?

The graph below shows the relativelg(8w ; buq-hml8qr-p+x i /ea amount of DNA in one cell during one complete cell clw /e li88g+(-q;mhpru ax-q bycle. Each 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 khio /3bw:a 4j.ju5hc0ku qt/between a male cat that is homozygous for brown, long hair an/.a jjhqwuuoi54kk:0bh c/ t 3d a female cat that has black, short hair.


Which of the offspring has a recombinant genotype?

1.Outline how polygenic traiu./ iz;zk1si 8r y)yal3vgxo,rx+d 1uts 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 o1rj5a8aim s/; m abc/dkr79kl f non-sister chromatids shown in the dm/8ad 7l9ba5 jm/1s k;ar rkiciagram below?

  The photomicrograph shows a pollen grain from L. candidum (Lily). Whichkjf)o )hnv.1f stage off 1v)jk.n)ohf meiosis is shown?

1.Outline the events which w1h+1 5kgu qgujb.jdh1r)p ,ckould lead to an individual being born with Down syndrome, which is characterised by the presence ofrup,1kh k1gbu5h c1g +j)qd.j 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 plant growth. Az) 9 )/mz42xhasx d xj0ni6wzs study was conducted on white onions (Al9wj)xzzdis/s 2mh06n x4z )a xlium cepa), under 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 which cedmy2d 021j ;bex.ladjlls can divide. The diagrams below show two cells from a.mxe 1j;dda d0yj lb22n organism 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 expression in stem gajv spheo e(4d7m ym 9v*9p*dt*j j7c.rowth.

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 of 8, in different stages jzf1;v;z:i8hy3wip a of meiosis. Which row cor 3 ziw;v 1ij8;f:hpyzarectly names each stage?

  The micrographs show four phases ss 8z 9i+8dct xh0gi:fof meiosis I in a plant. In what order do these ph+idz s0it: fxsh8c 98gases occur?

Mitochondria are responsible for supplying mei*n wd0lw1z4r *ldr 0qtabolic 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 betweeqrrlz w* 0 0dwd*li4n1n 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 c(0n. rwn p:-jad xjhabtsc 86)ell cycle in four samples of lung tissue from four patients. Which tissue has the lowest mitotic inanx60sn .:raj ) w-dth8 (jcpbdex?

  The diagram shows the dominant cyclin/CDK complexes at different time pod4a2u*tpqq.,d +bw j q1tq :goints in the ceqw 1 .tdqqub +pd:* q2ajt,o4gll cycle. Which cyclin/CDK complex activates DNA replication machinery?

  Studies have shown that genes such as Cyclin Dependent Kinase 3 (CDKN3) arenn pi*boc7j5 jc7e(4w highly nw7ce 4nci*o5b jj(p 7overexpressed 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 ceh he 8pr-ccars)*7n c7ll cycle ?