The graph below shows the relah53byv 0n.zw htionship between maternal age and the incidence of non-disjunction. What relationship inyz0h vw.b h53s suggested by the data in the graph?

  Which stage of meiosis is reprodx npl:asyw+ 1 e;k7g6bq9 s,h(x/ai esented in the diagram below?

  The diagram below shows chromosomes during meiosmd;u:nl r2nsw pnl) -ctk,vo/t+f c+4 is.


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 5 sjha)hjf7njaw stqs+p43/8alleles of a single gene which would be present in the nucleus of a cell as a result of each proces aft3w4 jsj hjhn sp)as75q/8+s?

  Which keyword is matched to th8 5f-8vbohj fce correct definition?

  Which statement(s) about mitosis isq/s a9smrw ,i y,uqd/ jd1*8qz o+e/ee/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 letter points to a celz qk1x8*0nm 6-hoxh ypl in anaphase?

  During which stage of miw,n/g2r.0 g)mxv7efuon mf *ctosis does the nuclear envelope break down?

  Which one of the following transport proteins only carries o.8cbc :i)4vmogi84fqdsn1k4s s m7zzut active transport?4i8g )c q c4s7m:fvbmk 4.ids8z1szon

  Which process does not happen in the sho eql18vb,p.a:a9:xch s+rmm got apex?

  Which type/s of membrane transport do/does not require energy expenditure? uusq(,stvz/ jb0kh+ 5
I. Facilitated diffusion
II. Active transport
III. Osmosis

  The diagram below represents a cell with a d 5svpf.(wfm 5ns zh*yul0d(u) iploid number of 4. Which stage of cell division is the cellsfpu)(wz y5 fsvh u(.0dm*l5n currently undergoing?

  The photomicrograph below shows a root tip meristem. Which of the fofxx;hy;yb0j /rnxk4)6w n lf0llowing sentences correctly defin4fl ; 0 j;yr)bfxky60/w hxnnxes a meristem?

  When does the random orientation of homologous chsa* 1a:qc/ 5cjl0:uczumt 2bmromosome pairs occur?

  Which process does not occur durin. pnn7l.bkwefrravl)5knq+ ) j;)i; *sbenc3g meiosis?

  If a cell with a dipcm:.hjw d, eq,wlx6jx 63 ud80j ek5qkloid number of 36 undergoes mitosis, how many chromosomes will be present in each daug6xm3:l.jd eje,c kwuqh 06,kj 5wqdx 8hter cell after cytokinesis?

  The image shows a micrograph of a cell. q; b; uhi*cqr5pd+ jut ;)af3 :0caqct


What explains the appearance of the cell in the micrograph?

  Which statement(s) about homoru. j0 /r0gflrt0 cu-+2z.a hr 3uabahlogous 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 indd.8ryp mu b;m/ividual with Down syndrome.

Which statement is not correct?

  In the cells of a horse (E.w*h.aq.y3 upl .rv;gk caballus) during prophase I of meiosis I there are 64 chromosomesk; *ygpahlr.w vq..3u . What is the haploid number of chromosomes?

  Which arrow is pointing to avu c1f00vr+dma 7ejd+ chiasma?

  The diagram below represents the structure of a shooazw2v l9yn) 8ft apical meristem. Which row in tzv8w9 fya2 nl)he table correctly identifies the processes occuring in the structures labeled in the diagram?

  How does meiosis promote va2ygrh bfch08 ldl4f3:riation?

  Which of the following statements is/are correct foc29u m*4g qu0mvg;sjoa ;: qtrr meiosis?
I. It is a reduction division
II. It involves random orientation
III. It produces genetically identical cells

  The diagram shows gametes produced from twoj*g:q llcs*n8nc,:1gfo 6olz 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 tum33 063o gld wdg.kspfxours from primary tumours as a result of the mg dgx6k0 wpslo3d. 33fovement of cells?

  How many chiasmata are present in7y (:+lafc oznc7oo2 c the diagram?

  Which statement is a-v2 mfw; klobxme.uj:qmc),8m 5qx mrwk:b ). similarity between cytokinesis in animal and plant cells?

  Which stage of meiosis is matched to the corre9q*:vncj7 ubx ct description?

  Which statement(s) are true of meiosis I but not mei k+n(w;cv*4we cx tu6p*v /gnlosis 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 oocytfw(0 k0a z.fr36 hox7 nbd+szekg ep)3lr;g 6ae after the first meiotic division. This results in the formation of one large cell and one small cell. What is the fate of (6afr7 bhk3 3 rf;0 6)x+szp zwngeoag de0kl.the large cell?

  Which row correctly describes diploid and haploid cells ij:9aaya u-b .zn humans?

  The following table shows the diploid chromosohttt(q/ :fnxot4 luv o8;q33ame number of a range of species.


Which of these statements is correct?

  What conclusion can be drawn from the karyogram belotk(.nd3lxxhsb, i 354n0,z:rsyb2ca h3b kpjw?

  Which of the following processes is characteristic of the meiotic an6m)izt1fb 7xc oi:g z;d not the mitotic celi1z;)fcgz7xo : tbm6i l cycle?

  The diagram represents a bud with a shoot apibvck mx*g tq*3vk6 q 8o3m*+bpcal 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 chimpa4h p-oafx(ov /nzee (Pan troglodytes) is 48. Which row shows the correct chromosome number for differenpaoxf 4h(v/-ot cell types and cell division stages?.

  At the end of which phase o,w+ 2r e3jqpvluo8w1v-(w adef meiosis I does crossing over occur, and what is the outr(2-8uva3v j1 wwlopeeqw,+dcome of crossing over?

  Which of the following statements does notac 37e, ofm-5/haknij describe a step in the sodium-potassium pump cycle in the neuronal cellskno3/5afim,jae hc - 7?

  Which row in the table below is true3x) -q+v4 pih9avamth of meiosis?

Membrane transport is important fo/.b6) mqmnmuyr allowing particles to move across the cell membrane and respond tmb ./m6mqn)yu o 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 f wftq14wcp-u1 p2 22feqsxy* 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 concentrations of different ye i )xnu1)sf,cyclins during the cell cycle. Which cyclin is 1fn)xi syue,) involved in preparing for DNA replication?

The diagram below shows chromoso wgk9,4cs3q sn5*wfc j7vw7li-it5nxmes 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 sepacv ji:o4x(p j zlq0tbjz p-b( b+aa2):ration of homologous chromosomes?

  The mitotic index of throat tissues tak ,gip oonve5 //rzjllc*2k3)den from 4 different patients is shown below. Which patient is most likely to have canlc 3zvronl 2g/ko)j5 id/,p* ecerous throat tissue?

1.Draw a labelled diagram to represlh z6igeln+; 3ent the process of crossing over.

2.Compare and contrast random orientation and crossing over.

3.Outline the stages of meiosis.

  The image shows an abnormal,e g+y( deb 3i4rj;dzlrs:0 kn human karyotype.


What is the abnormality in this karyotype and its cause?

The graph below shows the relative amount of DN-n g8.h4g+i+kk,j0khucpkm u gv2p3 tA in one cell during one complete cell cycle. Each letter represents one stage of the cell cyclemp 8vhkk.k++- 2ukgtc04ngp u3j,gih.


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 that is homozygl0gs9i8/a vjet7i gc;ous for brown, long hair and a female cat tha;gea9ji0/ t 8ic lsvg7t has black, short hair.


Which of the offspring has a recombinant genotype?

1.Outline how polygenic traits can show a normal disa9(dz,xg ;b ;wtlo0secw3fe9tq j8; itribution.

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 croq w79tcro q*fc0 x)0tissing over of non-sister chromatids shown in the diagram below0fx09oq irwtc)c qt*7 ?

  The photomicrograph shows a pollen grain from L. candidum (Lilykpptkzv2 etj6bu*4l;zif /64). Which stage of meiosis is6vk4pt4tzl2j6ie / fkzpbu ;* shown?

1.Outline the events which would lead to an individual being born with Dg.ca )wd83 q. njm4;eacxrp+xown syndrome, which isxe4pdr. aw mcncagj. 8q)3;x + 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 meas hs/b6 zi78ck wec:z:quring plant growth. A study was conducted on white onions (Allium cepa), under controlled conditions in a lab, to investigate6bkw 78i qch:sz/ez:c 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 zh; zarb9;9ha ; q:h2w8mbl jwig(r-ctwo ways in which cells can divide. The diagrams below show two cells from an organ:mr;a h2i(rzz9; bhcj9q;8wba g-hwl ism 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 o cd0esq rs0jiz(2b +h7f 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 diploid number of 8, i1rr upo orw;j6d76 :len different stages of meiosis. Which row correw:e;67 lp1 6rr joudroctly names each stage?

  The micrographs show four phases of meiosis I in a plant. In what order do thes8a.dr o7 fa.l0 bovs 5z*ne:ipe ph5sza: d.er*8oo7nifp. v ab l0ases occur?

Mitochondria are responsible for supplying metabolic energy in eukqhy5k 79s5na taryotic cells. In most eukaryotes, which reproduce by sexual reproductionk7ytash 5q95 n, 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 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 sott;i :p utzkv l+u .;5.py-kin different stages of the cell cycle in four samples of lung tissue from four patients. Which tipvt+k; piu5ku:zs -o.y lt t;.ssue has the lowest mitotic index?

  The diagram shows the dominant *rcn6dhl.; zqn 2y /c4;sga xily4d-g cyclin/CDK complexes at different time points in the cell cycle. Which cyclin/CDK complex activatesaynddxlilnr.z s4c gy6qgh 2;-c ;4/* DNA replication machinery?

  Studies have shown that genes such as Cyclin Dependent3h4mj (a. rafk Kinase 3 (CDKN3) are highly overexpressed in cerv k(.hjr4af3maical 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 concentr7 62ni0v uzmj)a 7rixyation of cyclin E the highest during the cell cycle ?