The graph below shows the relationship between matoshd;uz7q14 jmt0 yf;ernal age and the incidence of non-disjunction. What relationship is suggested by the data in the graphd;mhq; stj7 o1f0z yu4?

  Which stage of meiosis is rtg3pd. .marh,u0 kuldi n x51:epresented in the diagram below?

  The diagram below showsr ui9q 9wp7tmoqi -w47 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 numw mul eyr7l6(ryr*f3i76 dr)c741hk sb gkb/aber of alleles of a single gene which would be present in thrm46 c/7u 1bli7 lsk7 *rw b )(fyya3kreg6drhe nucleus of a cell as a result of each process?

  Which keyword is matchw0f5iivjnvxlv , lcv*.- 89q oed to the correct definition?

  Which statement(s) about mitosis is/are trwoqvj/ nsh, 4 g*zso2o/ot81 vue?
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 anaphasj/41tvcl2v8inrj4+ qq8+ ewb e gb.rve?

  During which stage of mitosis does the nuclear envelopj3ls.98rog lp f7 +yuze break down?

  Which one of the following transport proteins only carries out bt 7/p,ll(lj0jr*av f active transport?v7p*b,(ltjr0 /fa jl l

  Which process does not happen in the shoot ape5;bi ;j;f ojktx?

  Which type/s of membrane transport do/does not require energy: q4qdofj6g b8yh/ 3vfqj0g7db. tg,y expenditure?
I. Facilitated diffusion
II. Active transport
III. Osmosis

  The diagram below represents a cell with a diploiue:4e r et:dz 9vl2vv+hp 4pl1d number of 4. Which stage of cell division is thete evv2u:hlp+1z dpr9l: 4e4v cell currently undergoing?

  The photomicrograph below shows a ron7 x.4ys5.x tr:jmzza wg4(erot tip meristem. Which of the following sentences correctly defines a meristem?.z:.xeygxt s4w5(jn7 am 4rzr

  When does the random orientation of homologous chrob-0lefk/ yiov*nz7 ,mmosome pairs occur?

  Which process does not occx;yxu: ub3/9lfp;,3lt5ykhps; cc pnur during meiosis?

  If a cell with a diploid number of 325 r:gppb//ztiav 3 lc6 undergoes mitosis, how many chromosomes will be pp:z52gtp/ vlb i/c ar3resent in each daughter cell after cytokinesis?

  The image shows a mic due,,e5i:nrdbkw )0l rograph of a cell.


What explains the appearance of the cell in the micrograph?

  Which statement(s) about homologous chromosomes is/are by +:yspvr)7k9mh v+lnot 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 ;i :-i*sojxq3/a gbplindividual with Down syndrome.

Which statement is not correct?

  In the cells of a horse (E. caballus) d 5*8tye3hkrhqi sj83wuring prophase I of meiosis I there are 64 chro*i 5he w hk8j8yr3t3qsmosomes. What is the haploid number of chromosomes?

  Which arrow is pointing to a ch8 b;9 e2kro dk*0sey/k cee -1/segtcniasma?

  The diagram below represents the structk yq7se0by)c v9e8i7xure of a shoot apical meristem. Which row 8ycx0)qebi7ks 9vy7ein the table correctly identifies the processes occuring in the structures labeled in the diagram?

  How does meiosis promote variation?y)saoe. 6 8v )qsc*nat

  Which of the following sta*9vffa y-g qx z6 v*ah9 yjsj3mz97te0tements 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 chromoqids20khnn(g,8 4+ kupo buy(somes.


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 ,c9c4s8i2egn fp2e x0i jj +ucthe formation of secondary tumours from primary tumours as a result of the movement of cells2j4x9nie c0 c8ip2j gecus,+f?

  How many chiasmata are present iiu(km,b)6l v xn the diagram?

  Which statement is a similaritxqrahcsr- g+u.1o6i q+py5,yy between cytokinesis in animal and plant cells?

  Which stage of meiosis is matched to the correct cvc yn)e fy1k: g83lb11w knv)description?

  Which statement(s) are t +t zjkf*.iw-vrue of meiosis I but 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 meiotis932i1 /pvxjdp.a zl (0yfcdnc division. This results in the formation of one large cell and one small cell. What is thez2i1na(f9j3vc0p l sxd/ yp.d fate of the large cell?

  Which row correctly describes diploid and haploid cellsvr6tq vy28 y7v in humans?

  The following table shows the diploid clvl dq cx9;ut75io 1d.hromosome number of a range of species.


Which of these statements is correct?

  What conclusion can be drawn from the karyogram 8sbkxy(2, l mp24jelibelow?

  Which of the following processes is characteristic of the meiotic and not 7 1ks hs2u.hzk 7ceqy5the mitotic cell c hszq.2c hk7u7e 5sy1kycle?

  The diagram represents a bud ajfp 0z 3.qk 8zdxnf(,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 thcd ;1k/cy0 kx- 8ubm0* xoogace chimpanzee (Pan troglodytes) is 48. Which row shows the correct chromosome number for different cell types and cell division stages?cx ko-c8adcugm/*1x0 ;y0 bok.

  At the end of which phase of meiosis vmp vlk+6j4oz h,72qqI does crossing over occur, and what is the outcome of crohk 46p,qzolqmv2+v 7jssing over?

  Which of the following statements does not describe a step in the sodiuejfi/;l05swk 3p) k:ojep qt:m-potassium pump cycle in ;tsl:p:fw iejej 3 o/5pq)k0k the neuronal cells?

  Which row in the table below is true ofztt -+p0ps;:z4h hwfl meiosis?

Membrane transport is importf4hjgn 0+8p8lxa0wkic vm;5f7a 3odqant for allowing particles to move across the cell membrane and respond to changx j03 q;87f45 +p0ko i8cdnhfmvawagles 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 regu oarlnz*(d3u8 lated 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 cyclins during tw534a7ccs ug5cr j)lskr,2i l he cell cycle. Which cyclin is involved in preparing for DNA replicatis5c,j5lli )u2kcc47 graw 3sron?

The diagram below shows chb(.a5) jdod mmw4 wa-g9hf1 horomosomes 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 thkvgmv5czy aw8*m7fit dy9s/a1z i a:t8 -21tce separation of homologous chromosomes?

  The mitotic index of m2a vj;b l*bu3a-;acvthroat tissues taken from 4 different patients is shown below. Which patient is most likely to have cancerous throat tissue 3 ;2acmbabla*uj;vv -?

1.Draw a labelled diagram to represent the process of 74unkuc3 ) )uzo:c k,:lfuznj;sjt. t w13xue crossing over.

2.Compare and contrast random orientation and crossing over.

3.Outline the stages of meiosis.

  The image shows an abnormal human karyoty q2/i veveb6b7tr ek2/m-kx.fpe.


What is the abnormality in this karyotype and its cause?

The graph below shows the relas8f/h5wm4khwts s 4 nhlqb-y,ovm,6j -a d,l:tive amount of DNA in one cell during one complete cell cycle. Each letter represents one stage of the cell cyclm,l o/s5ht, y-fls6nk8hsvqd-h, 4 ja4w :bmw e.


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 homozygous for brown,8omx:gx 03nhw63 fyug long hair and a female cat tha:yx3gwh0m68g nxfou3 t has black, short hair.


Which of the offspring has a recombinant genotype?

1.Outline how polygenic traits can show a normal dishhssw 82j6)x*+z lb kgtribution.

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 chromatijb-iqkpu4y sx32pgz4+hz i4b)z ( 1mkds shown in the diagram below? 1ju+ib )m4pq 2z3k-hyzs4bkxg4(z p i

  The photomicrograph shows a pollen grain from L. candik( flc0djk 6j ky7w7e5dum (Lily). Which stage of meiosis is jd0(7kjkfe6k 7 wycl5shown?

1.Outline the events which would wa mr0lf y9dc*uz/o44lead to an individual being born with Down syndrome, which is characterised by theurmz*0aofwc yd4/ 9l4 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 ce99y/ pu*ohdg cj qglzv2 6*cg006o kof measuring plant growth. A study was conducted on white onions (Allium cepa), under controlled conditions in a lab, to investiq6cepj y*v2go0h 9oc9kud/*g z06gclgate 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 cells can divide. The diagrams below1:(ms;nl1t l opza ad:giy/.gd0o+ne show two cellsang+li:1 satp/ dlznoy (d1; m 0ge.:o 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 expression in stem sutzj9.evxb 3*,hd0jgrowth.

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 numbe.hit7v i;: bk+ls(i tor of 8, in different stages of meiosis. Which row correctly names each st:l i vh t;+i(b.iotks7age?

  The micrographs show four7aht9j-vuh1 8/s 14wga-db fbsfcc6 h phases of meiosis I in a plant. In what order do these phases occur/b ahs6uch9-wbg7d j 1s41a-8v fftch?

Mitochondria are responsible for supplyini3q2s* gcjf s6g 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 mtDNAsf6 32gc s*jqi 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 differen blvbb0 y8cz/ur,tgn /e04ye)t stages of the cell cycle in four samples of lung tissue from four patients. Which tissue has the lowest my/0)e z0c gulb/ter 4y8bvnb,itotic index?

  The diagram shows the dominant cyclin/CDK complexes at drig (j54qy x/cifferent time points in the cell cycle.i4qgr5cy j/(x Which cyclin/CDK complex activates DNA replication machinery?

  Studies have shown that genes such as Cyclin Dependent Kinase 3 (mixf.w1nmydpyovf: ): 7( + nmCDKN3) are highly overexnv xpy: .im1 f +):(fym7domwnpressed 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 di6hl)(9 4hx::qhp1tnoxe(3 mnk u m iyuring the cell cycle ?