The graph below shows the relationship between maternal age and the incidence umo 7-ooaryxc,dy8v) . q .l+kof non-disj,v xr.c.yqy-dk8aol+7 o)m ouunction. What relationship is suggested by the data in the graph?

  Which stage of meiosis is represented in the di 3czmi-sm11h4b ee dd326bp qwagram below?

  The diagram below shows chromosom;f fl s+f2, ;h zswnbqo+8nxw7es 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 gene j - tthfg4fa:5 p(4xdgwhich would be present in the nucleus of a cell as a result x-gjad4p5ftth(: f4g of each process?

  Which keyword is matched to the correct de 9/+ vsqvbnq f(u-k )2d2wgestfinition?

  Which statement(s) about mitosis is/a.d-w k etpz(h0yw0rg 2re 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 v17y p4g4l ea3e27n cc4xalkvcell in anaphase?

  During which stage of mitosis does the nuclear enve* n-z -mfw-1d gifu: xffguevrl8/82 elope break down?

  Which one of the following transport proteinssr* 2*/v6 zkcfmr cpc* only carries out active transport? *r/*m kcrsv6c2f*pzc

  Which process does not happen in the shootli iip/1i-n, n ;m8ck4zjkxg o c/f.whvp 5+p: apex?

  Which type/s of membrane transport do/does not require encpf3b3+ ia 7vwergy expenditure?
I. Facilitated diffusion
II. Active transport
III. Osmosis

  The diagram below repre9 tuxx w bt2w2nz;* g9.m8vd/k wizw,esents a cell with a diploid number of 4. Which stage of cell division is the cell cgxz*vt2e;z 89wbtxd,iwku29 wm /.wnurrently undergoing?

  The photomicrograph belowkp+qg td 0zbay7m 4c ja+.aua(;ruccrn518 o7 shows a root tip meristem. Which of the following sentences coa qaab c7 az+t. ;urcu4no0g(pkd m85jyrc7+1rrectly defines a meristem?

  When does the random orientation of homologzx p46ngnogqum79/ p 2wn) +zwous chromosome pairs occur?

  Which process does not occur during ipd p0(aoolw. 7;z0g ca16gh rmeiosis?

  If a cell with a diploid number of 36 undergoes mitosis, how /te.sydu u.l -geuyl*8s:v*nmany chromosomes will be present in each daughter cell after cytoksgt*ue e-: .yd ln*.v uu8sy/linesis?

  The image shows a micrographk0,sjfec y9 v6df/q.veb,ey 3 of a cell.


What explains the appearance of the cell in the micrograph?

  Which statement(s) about homologous chromosomes irt4aa xdq wo/s(4nf+ )s/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 bgpzz8cp c 8e4d/i //usyndrome.

Which statement is not correct?

  In the cells of a horse (E. caballus) during prophase I of meiosis I there are pe b5s-kx +3dnrlm;nz07fr7z 64 chromosomes. What is the haplo;0bl3r7n 7 fkx-5r zmzdsp+n eid number of chromosomes?

  Which arrow is pointing to a chiasm c5t3ep,i4l idg2:o nma?

  The diagram below reprv8v lb5 738ufkvo i9g0i:i1/qiuv e vtesents the structure of a shoot apical meristem. Which row in the table correctly identifies the 0evqilk8 i978u:vuiv1tg/f 5ovbi3v processes occuring in the structures labeled in the diagram?

  How does meiosis promote v6b--hs xxa* efz,dzrg z*o/;wariation?

  Which of the following statements i(57fmw ,dfu xem lk:b(vzep85s/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 ch0 fah(pym-.t) a4mbc6:nlu ghromosomes.


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 f(7vvn u-3xorg4s 5ou hormation of secondary tumours from primary tumours as a result of the movementhuvv g5 4uono(rs-3x7 of cells?

  How many chiasmata ar4qq2w. pl7v cwe present in the diagram?

  Which statement is a similarity between cytokinesis in animal and plant c c,o7,d2smhdp ells?

  Which stage of meiosis is matched to tbdb,fj71g *)xe 9kzgg,w.lrj he correct description?

  Which statement(s) are true of meiosis I but nodj iov qp(/ k89u(g9n iusuk.*t 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 f hplkdi:p mbzatp5v:n8 9-9e9 irst meiotic division. This results in the formation of on5imaedp h9p:: 9b -zn8tlv kp9e large cell and one small cell. What is the fate of the large cell?

  Which row correctly describvcf y, d.ara .hy)8rh9es diploid and haploid cells in humans?

  The following table shows the dip6t j. k,:enawoloid chromosome number of a range of species.


Which of these statements is correct?

  What conclusion can be drawn18z wesg6ujq8 from the karyogram below?

  Which of the following processes is characteristmw bylh(jut(:g d57 c7 .v 5-x)kysdstic of the meiotic and not the mitotic7cyl5gy th:bd - (vwu x j5s(7skmdt). cell cycle?

  The diagram represents a bs lxg isx63k*g7y8f1) .wnpm oud 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) is6g b1u l9w2pu9hfz s:t 48. Which row shows the correct chromosome number for different cell types and cehsf 1pzb 6g2wlt 9uu:9ll division stages?.

  At the end of which phase of meiosis I does crosswtmxsfu9v7g dw0t kt2,l : 2g(ing over occur, and what is the outcome of cros2t:fm wdwt g7g 2(9v0s,xut klsing over?

  Which of the following9yr .v3 rog,qmm8,2kul advy7 statements does not describe a step in the sodium-potassium pump cycle i ro9uk.7y,ay28m ,gml v rqd3vn the neuronal cells?

  Which row in the table below v p vkpg5t6m1;is true of meiosis?

Membrane transport is important for allowing particles to move acrosp-lnegt;d9inb(sw *l g)sz 58s the cell membrane and respond to changes in the chemical compos -wgs t;8(b9 p* 5ngsdnile)lzition 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 regulatcaywcmn5w(1-e vw g):mak- a1 ed 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 concentration6 d ax6dl)p 0*uxuiky)s of different cyclins during the cell cycle. Which cyclin is involved in preparing*p6)6klixdyuau 0) dx for DNA replication?

The diagram below shows chromoss)/v3+ p h)atkmxn+ ,bzmbb;fql9 hg.omes 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 separatywe-,,xf2 h zdion of homologous chromosomes?

  The mitotic index of 40sv6teuurj g 89iwp+throat tissues taken from 4 different patients is shown below. Which patient is mog+06r8u4ev it 9jspwust likely to have cancerous throat tissue?

1.Draw a labelled diagram to representjn.v w :yh3nqi463xx*.gyoq j the process of crossing over.

2.Compare and contrast random orientation and crossing over.

3.Outline the stages of meiosis.

  The image shows an abnor ).tlz-j;d d iyf,lsj7t5mqo7mal human karyotype.


What is the abnormality in this karyotype and its cause?

The graph below shows tha a/,laf x.r*jj)u* oy lqes.,e relative amount of DNA in one cell during one complete cell cycle. Each letter represents one stage of tjfa.u)x,q,eo /syaj* l lar.* he 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 07fp ht brly-j s*18 w7dwwi*n)1e qrethat is homozygous for brown, long hair and a female cat that has black, short*wede-l8biy0h nrf) s7p1*qt1w w 7r j hair.


Which of the offspring has a recombinant genotype?

1.Outline how polygenic traits can show a normal distribut)t2adcfo+b w laz16/oion.

2.Outline the differences and similarities between homologous chromosomes.

3.Explain why expected and observed Mendelian ratios may differ.

  Which gamete can resultpug3 ff547z(jr v0shv from the crossing over of non-sister chromatids shown in the dr4f0 zp vg v(uh7j3fs5iagram below?

  The photomicrograph shows a pollen grain from L. hr5 m;o50o;o8prf nuo candidum (Lily). Which stage of meiosis ir05oporoh8 ;5mn f;uos shown?

1.Outline the events which would lead to an n++ 3mdmzo vs*individual being born with Down syndrome, which is characterised by zmnv*+dsm+3o 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 measuuj5/yf w/,gmmauta+ *pnng/+uk5;oalzm(2q ring plant growth. A study was conducted on white onions (Allium cepa), under controlled conditions in a lab, to investigate the elm/uuaa+nwzo(kg,; f5y ua / 5 *n m/jm+2tgqpffect 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 b*v c0( thn3eclvku7:1jkrt4j elow shc:t* 7k0j1 cuv(trje h4 knv3low two cells from an 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 3g ubxci.cru ep, )(kd+2lb1p gene expression 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 cell, with a dipls -*cs nr rgt--f4*wnhoid number of 8, in different stages of meiosis. Which row corrn* -s*t-s h4r ng-cwfrectly names each stage?

  The micrographs show four phases of meiosis I in a plant. In what order do e*.8j*wmhwhb these phases occu *wemwbj*hh8.r?

Mitochondria are responsible for supplying metabolic energy in eukaryotic cklqkf 7o*0cd qyno26 (ells. In most eukaryotes, which reproduce by sexual reproduction, mitochondrial DNA (mtDNA) is in0d6kq(k*lf7 2qo ncoyherited 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 o 1ts 8zts-cj:wf the cell cycle in four samples of lung tissue from st -s:tc8j1 zwfour patients. Which tissue has the lowest mitotic index?

  The diagram shows the dominant cyclin/CDK compb szm n79i:8,rwjrwn-;jukc: 4ampe -lexes at different time points in the cell cycle. Which cyclin/CDK compw:n4n;jkm wu iz9-ra:, s8 bp7-rmcej lex activates DNA replication machinery?

  Studies have shown tha54jwv7 z 9i4zyyvbq:c t genes such as Cyclin Dependent Kinase 3 (CDKN3) are highly overexpressed in ce:y9zw44jqbyvcz5 7virvical 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 cyc*02cvntw0(m uxwgo*plk 1vh/lin E the highest during the cell cycle ?