The graph below shows the relationship b)(bq.oo ydn ptpi*:.xc 5p ky7rua s+,etween maternal age and the incidence of non-disjunction. What relationship is suggested by the data in p:(.kd) *t5 x i.qraoy7cbn+y us po,pthe graph?

  Which stage of meiosis is represented in the diagr7mjw bvq z /99:isi8slam below?

  The diagram below shows chromosomes during meio81 lf v xtm;do n 2ddt6he;.)(da.zdsl3j(tmmsis.


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 thu .;z7+qm5 d m;ztqu+ giv2aqpe number of alleles of a single gene which would be present in the nucleus of a cell as a result of each pi a;uqtu2+q g d5vm+mqp .7;zzrocess?

  Which keyword is matcheg9pd.) qrxil/k vq( (t m/(exhd to the correct definition?

  Which statement(s) about mitosis is/are (o. do w8o )/27seytivo5n wodtrue?
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 cell in anap;.;kmvi5 c m*hpla, yrhase?

  During which stage of qil:pmy an8h7am2rp/ vq69lm o) c4:cmitosis does the nuclear envelope break down?

  Which one of the following transport proteins only carries out active transport?s8 s3ujolo59 a s laoj3os9u58

  Which process does not happen in the shoo- dkei9a+v e;-t /ielot apex?

  Which type/s of membrane transport do/does not require energy expendboj tn5al- 2,uiture?
I. Facilitated diffusion
II. Active transport
III. Osmosis

  The diagram below repree*w .q 2ehu;tzsents a cell with a diploid number of 4. Which stage of cell division i.;e*uewqzt2 h s the cell currently undergoing?

  The photomicrograph below shows a root tip meristem. Wh )fi- 2.ptra4+p up:ih;uhy46 usds y36wd mjtich of the following sentences correctly defines a me -42p h3+);sparttdiw m .j :u6si fd4y6hpuyuristem?

  When does the random orienta 05/tk hq;vutvtion of homologous chromosome pairs occur?

  Which process does not occur during meij0+copfa;f h f,oa(rx .q 7gcfp fg8.:osis?

  If a cell with a diploid number of 36 undergoes mitos6v,4 9 6 ,2l9b;*anat j3idhgzl oaeei uue3dais, how many chromosomes will be present in each daughter cell after cytl66,dgeli3z3dn 9u*o;4ve 9iaa,eju2aah btokinesis?

  The image shows a microgc n 9ke/*phgvip+kl ee m:dv;(e/2g2oy z,t+wraph of a cell.


What explains the appearance of the cell in the micrograph?

  Which statement(s) about homol,)avhjt5wxt ,4;trbiehiw 7 )ogous chromosomes 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 nhq26+x1ruibw4 s7p xsyndrome.

Which statement is not correct?

  In the cells of a horse (E.6o h6;h 5 eh *6zsjhhk8coj(gl caballus) during prophase I of meiosis I there are 64 chromosomes. *lz6eh;ojhcj6o gk58h 6s(hh What is the haploid number of chromosomes?

  Which arrow is pointing to a -94pf l/4jjyhmvkgwh9 e7b4mchiasma?

  The diagram below represents the stb4e10av s+x 7qxvvt 7c6t2o aaructure of a shoot apical meristem. Which row in the table correctly identifies the processes occuring in the structures labeled in t tea+ta a1 xb6qovxv2v0c47s7he diagram?

  How does meiosis promote n7ne g(8 mtb(1zor -jrdlc (hokf d))1variation?

  Which of the followin 9w+ ;tzdu6rraz, (r7sa rzp5xg statements 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 chromosomd f4 yr:zsyh. 6*lwcddq(:e4j es.


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 swy: oauo 4wk c)dhd3;,econdary tumours from primary tumours as a result :a)h,;y odow 3dwukc4of the movement of cells?

  How many chiasmata are present in the diagramj5n (ns 0z*icpi:j;srg9 xq-r ?

  Which statement is a similarity between cytokinesis in animal and plant cells/4v l8 qu ru1kn,;.wa*hj grqh3zpv ;s?

  Which stage of meiosis is matched to the correct descrir5drd( q/):tlyqst:bl5jbl vo v:6/kption?

  Which statement(s) are true of meiosis I but +uzhx0mm0,dve l(9 gtnot 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 oocyqgr5up9c5iz 2*c ot: 52l*v2vivbto0y xbo/ vte after the first meiotic division. This results in the formation of one large cell and one small cell. What is the fate of t txobcp5*i5iyt2:vzco2l5*uo v /0q 9 rbv2v ghe large cell?

  Which row correctly describes diploid and haploi*hcd4 -x ql,q-4qtx vz(0n bqvd cells in humans?

  The following table shows t ar7i*khiu0-fvh -v83 hok8 bhhe diploid chromosome number of a range of species.


Which of these statements is correct?

  What conclusion can be drawn from the kz da0 ;bt0vfwas5*7 why sya67f( l9wzaryogram below?

  Which of the following processes is characteristic of:h1f sltf.4q9sfb e2r the meiotic and not the mitotic cesb qh4r1f:2l9 .fefstll cycle?

  The diagram represents a bud with a shoot apicall/kf ;/m wado1s2c; qw:v)j pu 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 trogo, zt 9olvx. nh1/ub4llodytes) is 48. Which row shows the correct chromosome n,vlzt/uo . 1boh49l nxumber for different cell types and cell division stages?.

  At the end of which phase of meiosis I does crossing over occur, and w: ucoj/; f-zah17h l/gznz: rehat is the outcome of crossing c hh/o1n ;l:7rz g /ae:uzz-fjover?

  Which of the following statements does not describe a ste2* udrp-bmsg. p in the sodium-potassium pump cycle in the neuron-m2rp b*usd.gal cells?

  Which row in the table below6pt5g( -ecv1efbv 1vy is true of meiosis?

Membrane transport is important for allop0s5rjk8 lhn79d0 jxh )tc-k nwing particles to move across the cell membrane and respond to changes in the chemical composition of the exrs )7 0hxhck-n0 lp j5jnk98tdtracellular 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 cells. /wl;ab,xswjq)vb5b v1 8vp *j

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 concentratioffu/x4+4zi th ns of different cyclins during the cell cycle. Which cyclin is involvex4fzf /+ti uh4d in preparing for DNA replication?

The diagram below shows chromjj5x(p)w78r2l dmyx y,h gn9xosomes 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 ofckys4 i 80thv/ homologous chromosomes?

  The mitotic index of throat tissues taken from 4 different patienhu8t j8:xj)zk eq .q:ots is shown below. Which patient is most likely to have cance 8eu:t8.jq jq :xh)kzorous throat tissue?

1.Draw a labelled diagram to represent the process of crossing over.txt8j79 w* jfxy3gljl,vhz. .

2.Compare and contrast random orientation and crossing over.

3.Outline the stages of meiosis.

  The image shows an abnormal human kary p d33b)mxa,*9htzux iad)g o5otype.


What is the abnormality in this karyotype and its cause?

The graph below shows the fr75 r3;pupohm0ji+trelative amount of DNA in one cell during one complete7 uhirprjt+;m 35fo0p cell 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 cross between a maljlm0l,g9ui;yh ok5igkb4 .6k e cat that is homozygous for brown, long hair and hujli4k;kk9lygg6o 5, i.m 0ba female cat that has black, short hair.


Which of the offspring has a recombinant genotype?

1.Outline how polygenic traits can show a normal distribu3sx i9fqsmo vyl 2b0;.tion.

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( okvc gn*9k3q chromatids shown in the di (gkoq3c9nvk* agram below?

  The photomicrograph k*9xwemc l3 z lb-j)p3shows a pollen grain from L. candidum (Lily). Which stage of meioskm)x- e j lzwpb39*c3lis is shown?

1.Outline the events which would lead to an individual being born wih0u)yp*c2c gjhj7m * zth Down syndrome, which is chara* h0zgc)m p7yh2j cu*jcterised 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 ana r ung:qr41*i indirect way of measuring plant growth. A study was conducted on white onions (Allium cepa), under controlled conditions in a lab, to investigate the effect of soil pH on the mitotic index of the roots.14*uia qrr ng:


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 di9)1d83mn.rj bb zwmgqvide. The diagrams below show two cellsg1)nzm.9b r3 jdbmwq8 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 gene exi y6v 79lly-ngyrrwix(a,38 k pression 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 diploid number of 8, in different stageyuwp xghf5s6.o- qn 3t3v986g- pbfu bs ofg5g tosv3bfn9pq83f u ywbx 6uhp-- 6. meiosis. Which row correctly names each stage?

  The micrographs show 2kb jby+d0s +,cyg6rbfour phases of meiosis I in a plant. In what order do these phases occuryjcrb ds2 b,6+g0 +bky?

Mitochondria are respn zm qht(nj5v 6y5c3v*onsible for supplying 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 nv5jh*n3vtzmcy56 (q 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 nu;vs4gzdnr3 v 6o in221 f.exfzmber of cells in different stages of the cell cycle in four samples of lung tissue from four patients. Which tisszx22 1v;edgn6 4zfi r3 ofsvn.ue has the lowest mitotic index?

  The diagram shows the dominant cyclin/Cj2ga*(8rxri6.jai:d bso)ua DK complexes at different time points in the cell cycle. Which cyclin/CDK complex activates DNA repligi bs.jrrdiu) o 6( a:a*2a8xjcation machinery?

  Studies have shown that genes such as Cyclin Deps(2/wl5:x pr 0yu anzhendent Kinase 3 (CDKN3) are highly overexpressed in cerviwsp 0ryz2( 5x:unhal/ cal 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 concentrasl1fw5y05sajh , 7.gasc+vih tion of cyclin E the highest during the cell cycle ?