The graph below shows the relationshi psz +huc+zyx2 9bc4e-p between maternal age and the incidence of non-disjunction. What relationship is suggested by ts24uxyc9p ez -++ bhczhe data in the graph?

  Which stage of meiosis is represented in the vjq)xvyr/ 4q;diagram below?

  The diagram below shows chromosomes during meioa n3gm68oa r o2.ed.bssis.


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 ge n(n:.nzep0ftn kwx/; ne which would be present in the nucleus of a cell ;0/wxn:fnn pn .k (eztas a result of each process?

  Which keyword is matched to thecu, r(j en6n:w d+ox/w correct definition?

  Which statement(s) about mitosis is/are tryn8y2l: lyu1i1 hs rpqr )yo(5ue?
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 c /t6;ce te,qlir)iv r5ell in anaphase?

  During which stage of mitosis doesm+2t x1lvr a3o the nuclear envelope break down?

  Which one of the following transport ljm-( np u4 8 wwn,8sie;86zhxvw4q jxproteins only carries out active transport? 4m ius8xnqjevz(, w8 h8w46j;x l-npw

  Which process does not 5i*3.cvvn tze +up2-d7c fgav happen in the shoot apex?

  Which type/s of membrane transporoo5qa +2:w aib(blwf6t do/does not require energy expenditure?
I. Facilitated diffusion
II. Active transport
III. Osmosis

  The diagram below represents a cell with a diploid numb )dn1ihp 2uh014 uzqaber of 4. Which stage of cell division is the celh4i 2uq1nadu) 1hpz0b l currently undergoing?

  The photomicrograph below shows a root tip meristem. Which of the follozv51pii3 3nfd wing sentences correctly defines a mz3 f3inv15pideristem?

  When does the random orazqbtc039e (r/r.asn ientation of homologous chromosome pairs occur?

  Which process does not occur during mef43ce g j4v.rgiosis?

  If a cell with a diploid numbera 7( bl0sh/i kzn*0her of 36 undergoes mitosis, how many chromosomes will be present in each daughter cell aftsai0 *herbzl/ 7kh n0(er cytokinesis?

  The image shows a microgra1es8)n5p7djcns5jh) ,n ond v ph of a cell.


What explains the appearance of the cell in the micrograph?

  Which statement(s) about homologous chromosomes im0ax x1iv.* vep28gxds/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 syq xf x*4159rk1gu-3vna0vhqw0pasb,d5 f kay ndrome.

Which statement is not correct?

  In the cells of a horse (E. caballus) duri ch60:l*znw,md 0wnz r0fcmre/77umz ng prophase I of meiosis I there are 64 chromosomes. What is nrm 7enc:0*dcw/zmhw70 fm0 rzu zl6,the haploid number of chromosomes?

  Which arrow is pointing to a chiasma?dz x3ymmc v /wz4t+e/kgr j6h6iq5mr4 /40llt

  The diagram below represents the structure of a shoot apiv+l3;9b3tz9 ap6u(s3z zwa s:ow coyy cal meristem. Which row in the table correctly identifies the processes occuring in the structures labelw 39+v3swb zaozytu 3sc:6yza; 9pl (oed in the diagram?

  How does meiosis pro(dgokj tn9 p*4uygijy3 ab:t 7zf27w8mote variation?

  Which of the following statements-2a yd abr.(81kjta ct 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 from two homologous chromosomes1jm u9rz5jt 0f.


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 se(acfzukiyy,; h pm-+dq60o/rcondary tumours from primary tumours as a result of t/hy r,pci 0(ku +aq-zm6f;odyhe movement of cells?

  How many chiasmata are present in r1k3zc9;5na xadoi ;sthe diagram?

  Which statement is a similarity between cytokinesis in animal and plant cells?*xl 8ll2;3 -mazjdgt z1v )gy8anuuq4

  Which stage of meiosis is2o,oqw/y zi u5 matched to the correct description?

  Which statement(s) are true of meiosis I butttzo ;ndjpn0-9-job)0d q)yw 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 the first meiotic division. Thi(*b 7 m)udyt )uuo:ajms results in ( bomu7tjyuu) dam:*)the formation of one large cell and one small cell. What is the fate of the large cell?

  Which row correctly describes h8 ow 67 y5mg9cy7dd7bap ,rnd)0wuiddiploid and haploid cells in humans?

  The following table shows the dipl9bls 9g6;c dzxoid chromosome number of a range of species.


Which of these statements is correct?

  What conclusion can be drawn from th251gus0zx rn wtfs0 .hrio,+de karyogram below?

  Which of the following processes is characteristic of the meiotic and no( d); /x6qfkakic.r ms 4e.eu7(uiam mwpg-q 0t the mitotikq6r).g(ui ;ie/.e sda(macxf-mkw0m 47u p qc cell cycle?

  The diagram represents a bud with a shoo1is* -5reqq r (stzek-t 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) i y h6m4sl2;zk zyz(t+hs 48. Which row shows the correct chromosome number fsmhyz4; hzy kzt+l(62or different cell types and cell division stages?.

  At the end of which phase of meiosis I does crossing over occur, and what y-n q ttiapwdt8 l7oyz(a+6 y*64uzk5is the outcop-towuka6atz7q8 nydi(y 65+z* t y4lme of crossing over?

  Which of the following statements does not de de dqomx *n+s2w)2hd)scribe a step in the sodium-potassium pump cycle in the neuronaldqe*+d)h2 d )2 wnsxom cells?

  Which row in the table below is tw,h sys:,sy:(tfa b- frue of meiosis?

Membrane transport is qj6jz1je6 n19 n5uzqelxm90 aimportant for allowing particles to move across the cell m 95j anze 066qqjl9jxn1 zem1uembrane and respond 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 mitosis is regulated go gqcc 5 o/)e0c3zzh+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 cyclin) x,k3z71zv* *uqbguzrl2 5y-uj)yedul(lr u s during the cell cycle. Which cyclin is involved in preparl z(v)yq u1uz7)2-z erxyk*r,du 53 ujgll*buing for DNA replication?

The diagram below shows chroacrlf06 4tiuqqltb+oq7 0:h9 mosomes 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 separation of 1 )upcn am1a.:acky8x s y: lyd-pt;1dhomologous chromosomes?

  The mitotic index of throat tissues taxaff9 hhgeq:,0gmg )j v2l9v,ken from 4 different patients is shown below. Which patient is most likely to have cancexhhva0mj) 9qgl,:g 92f v fge,rous throat tissue?

1.Draw a labelled diagram (n,pprlwi +azs7fc ), fh 7i0tto represent the process of crossing over.

2.Compare and contrast random orientation and crossing over.

3.Outline the stages of meiosis.

  The image shows an abqmv92 i kwg74znormal human karyotype.


What is the abnormality in this karyotype and its cause?

The graph below shows the relative amount hgg1hnp8jg() of DNA in one cell during one complete ce 8g hj1h)n(pggll cycle. 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 cejc2bulb7lugdhm37 ) 38 qa; bross between a male cat that is homozygous for brown, long hair and a female cat that e8 h27 mb7buq;g)3adc3bllj u has black, short hair.


Which of the offspring has a recombinant genotype?

1.Outline how polygenic t2e f *q kb-e8a*aey4vidcf ulbxqs;y.:1 (0vnraits 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 f2 n+dnnre5jz: ,j; tktrom the crossing over of non-sister chromatids shown in th+ tdz;:ej5nt2nnr , jke diagram below?

  The photomicrograph shows a pollen grain fro cwk x0hl/,w3spwe 89ym L. candidum (Lily). Which stage of mek98w3scy,he 0 wwpxl/iosis is shown?

1.Outline the events which if gw,i by+((x(n q-ftwould lead to an individual being born with Down syndrome, whichgq(+(- nfbifyx i,t(w 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 m rko3u+j**sy2ln8i h weasuring plant growth. A study was conducted on white onions (Allium cepa),uorsw8*ijln y+3 kh*2 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 n;pg18a l/flhx l.ho0cells can divide. The diagrams below show 0n hhl .l8xpl/go;1fatwo 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 o9(ae* jbgzn) hx f5j3ef 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,ee1nmsotir 6 ph1s:* , with a diploid number of 8, in different stages of meiosis. Which,s61np reith1e*:s mo row correctly names each stage?

  The micrographs show four phases of meiosis I in a plant, oqdns4n wd16hx377r+8asne ncv( u s. In what order do these phasea8o n sv nd4nu1xrse(d, snwc 6737+hqs occur?

Mitochondria are responsible for supplying metabolic ene3pht/)xk 6bc: x bxxid8w2uu-rgy in eukaryotic cells. In most eukaryotes, which reproduce by sexual reproduction, mitochondrialuxuxpxct86)d 2 hb3x/ kbwi:- 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 numbern/ ;dvr i8:cq;pff vx)id 9r2gt0s0mi of cells in different stages of the cell cycle in four s)di g;nsmvvp;9rq tf/ 20 :idif8x c0ramples of lung tissue from four patients. Which tissue has the lowest mitotic index?

  The diagram shows the dominant cyclin/CDK ia)yg2(7 ; imgn; ab1zvrm8vycomplexes at different time points in the cell cycle. Which cyclin/CDK complex activates DNA replicar(; vbymzay; 7 mingi8v1ag 2)tion machinery?

  Studies have shown that genes sdo(s.c:y0sof uch as Cyclin Dependent Kinase 3 (CDKN3) are highly overexpressed in co(oss y.c 0fd:ervical 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 r9:hzey:bhku)-aqg 7 of cyclin E the highest during the cell cycle ?