The graph below shows the relationship between m63k xkn(/hav.tfio ;;6 aygf xaternal age and the incidence of non-disjunction. What relationshipyx;6khto 3a af x ig(6.vn;fk/ is suggested by the data in the graph?

  Which stage of meiosis is represented in th +49qf/tq epsw+cvla :e diagram below?

  The diagram below shows chromosomes during m* h t86.rpxd7ahsx 4vueiosis.


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:g .2y/y c:1zkx puzqs gene which would be present in the nucleusgkzy :sz/. q2:1yxcu p of a cell as a result of each process?

  Which keyword is matched to the corre1 38ggv xs.3f kk8 uo4ws/mdqp3 i 2pp6ihc8ydct definition?

  Which statement(s) about mitosis is/are fje w9;uiy91a 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 cell in anaphasr 8h0xfm7va c1e?

  During which stage of mitosis does the nuclee6jnwg 4l8 tpit6 (s5sv-ca-kar envelope break down?

  Which one of the following tr2 mn3 e,vjz 05ewlih4xansport proteins only carries out active transport?3ejm5n 20xw,zhli v e4

  Which process does not happen in the k8vnn, sr2qpo u2o(0q shoot apex?

  Which type/s of membrane transport do/does no/ i(e4: *xvc.rxenx rat require energy expenditure?
I. Facilitated diffusion
II. Active transport
III. Osmosis

  The diagram below represents a cell with a diploiikj//:- yqhukt y4.w rd number of 4. Which stage of cell division is the cell currently unqu. wj/k h4y/ ykt-i:rdergoing?

  The photomicrograph be 4 eqz-umi5ah4low shows a root tip meristem. Which of the following sentences correctly defines a 5z-ihu 4eamq4meristem?

  When does the random orientation of homologous chromosome pairs on9meb10rci*b r6qq 4tccur?

  Which process does not occur during mei,p(-fohc *l mgp)7xk+ x2ms otosis?

  If a cell with a diploid number of 36 undergoes mj-/1 zoy a8gdbitosis, how many chromosomes will be present in each daughter cell after ob8j1/ gdzy- acytokinesis?

  The image shows a micrograph (jcor/4 2hrgezpi)t ) of a cell.


What explains the appearance of the cell in the micrograph?

  Which statement(s) about homologous chromosomes is/are not tree l29l:qq mqcw3nhq8us-8+oue?
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 nh5)p y5pw0hisyndrome.

Which statement is not correct?

  In the cells of a horse (E. caballus) during prophase I of meiosis I the43)nuvt v. jp se,nwm-re are 64 chromosomes. What is the hapl -v)v ,4spmjn.wue3tn oid number of chromosomes?

  Which arrow is pointinvs/weq15imn6w sm/, k g to a chiasma?

  The diagram below represents the structure of a shooy*u00q 09 l1nrtkqwkia(nzp7 t apical meristem. Which row in the table correctly identifies the processes occuring in the structures labeled in z0kyiw0( lan r*07pnt9uk qq1the diagram?

  How does meiosis promote) n-ixm3+ tocw variation?

  Which of the following statements is/are correct fodzt dmf1you56q3v+( b r meiosis?
I. It is a reduction division
II. It involves random orientation
III. It produces genetically identical cells

  The diagram shows gametes producwkthhmg 9n:u rt45q7, ed from two 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 tumours fjw)hvxmuu(m v636ap -rom primary tumours as a result of the movement of cellj3(aw)6m-pmuvx hv u6s?

  How many chiasmata are present in the diagram?1pt *ez.z0 so g6bsuzuo8w zfl9 e11)h

  Which statement is a rixh.a n0rzn6i/xyas 4b8h d4p8 /n+esimilarity between cytokinesis in animal and plant cells?

  Which stage of meiosis is matched to the correct descriptc, daxu 3y5/unwv 4 1zgzn(+doion?

  Which statement(s) a:5 rk7i :(9wth vqks5g*r onefre true 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 meiotic division. This8wp4 vb3z,y mtmr 7g1pv+oqv* blg8u- results in the formation of one large cell and one small cell. What is the fate of thevv8lzg741b,y 3p*o+rqvm- mb gtwu p8 large cell?

  Which row correctly describec6mv*x x bn( hxnpoo 1,b7g.et9h9m j*s diploid and haploid cells in humans?

  The following table shows the diploid chromosome number of a range of species+ 1p fbon.;cnf.


Which of these statements is correct?

  What conclusion can be drawn from the karyogram bec/eiw h237vq myds 9r,low?

  Which of the following processes is characteristic of the meiotic and not the dd(/0yj+.f, p hj exkcmitotic celxej.ch ,ddpy/(f+ 0kj l cycle?

  The diagram represents 2 -jt+*q:en8hjajhtja bud 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 (ke:xcz)ch6hdm/ k8 w 9Pan troglodytes) is 48. Which row shows the cwckdx 6z9he hc:m/k 8)orrect chromosome number for different cell types and cell division stages?.

  At the end of which phase of meiosis I does crossing over occur, anfmcm.bl3v6y -g 8h7co bpg,:z d what is the outcome of crossingm7.cpmc8blzgy h6 f3bo,:-v g over?

  Which of the following statements does not describe a sto 5c3ty ff7f8)w3) jqvhxlh9kep in the sodium-potassium pump cycle in the neurcxl ov 9f)3jhfk7wqf)t y85 3honal cells?

  Which row in the table below is true of meiosuf+ead,n5 t /2nwlnn9is?

Membrane transport is important for allowing pa x6gpzc/z95a ts6,lr prticles to move across the cell membrane and respond to changes in the chemical cor,azztp p s 65x9l/g6cmposition 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 99ku:w3hnd/f0ksd dbin 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 concentrati mzp:zh 5s,hn,ons of different cyclins during the cell cycle. Which cyclin is involved in preparing for DNA replication? s z,n5:zh,mhp

The diagram below shows chromosomes duriqai)d2im, 8 smng 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 separat5 .lw pra+xiz+ion of homologous chromosomes?

  The mitotic index of tb 73d fcw -e1xtxv4)q 5t3jaznhroat tissues taken from 4 different patients is shown below. Which patient is most likely to h5q4 3b tx)d7at jnxzfewv -1c3ave cancerous throat tissue?

1.Draw a labelled diagram to represent the process of cros a+ahvmjpoezfy)tj1) bu,y )l1f))i7sing over.

2.Compare and contrast random orientation and crossing over.

3.Outline the stages of meiosis.

  The image shows an abnormal human karyotype.1i/j- ,saqiyi


What is the abnormality in this karyotype and its cause?

The graph below shows the relative amount of DNAnrter( sw 9)lw3o .,ul in one cell during one complete cell cycle. Each letter represents one stage of the cell cycle.rwr(, otw3 n.es)l9ul


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 homob8zay0s iawe:)* 2,un8uj knazygous for brown, long hair and a female cat thuk8zu8 yb:wa 2 )s i*jena,na0at has black, short hair.


Which of the offspring has a recombinant genotype?

1.Outline how polygenic traits can show ;z.v * dpj.zg dnakxka /(c67ma 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 from the crossing over of non-sister chromatids shown inq ; xjre/. 7wq7x-bkgfw-je6d the diaww.d 7x; qe6k-qxf g-j7r/jeb gram below?

  The photomicrograph shows a pollen grain from L.2yxqjuc k:i: *y8rog) )fo df1 candidum (Lily). Which stage of meiosis iyi doxo:j1ufq fgyk:r2 )*c)8s shown?

1.Outline the events which wouldrf fxoa ca u 872:0:j;ijivih, lead to an individual being born with Down syndrome, which is characterised by the ifj fx2 caviu0:i8;:rja ho ,7presence 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 measu w k,f4d d)rdat*9azh4ring plant growth. A study was conducted on white onions (Allium af,*9k)r zdh4 da t4wdcepa), 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 e1wdy br:f m3)in which cells can divide. The diagrams below show two cells from an organism with b:fy1)remwd3 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 growt 56ej o(oiw5*2mixcvy lx6aq5h.

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 diuki 97wd+g/h p :h-kpz-o t5zcvu4mj*ploid number of 8, in different stages of meiosis. Which row correctly names eac tmuc 9 ou5/4+--pd*g7jzhi vzwphk: kh stage?

  The micrographs show four phases of meiosis I in a plant. In what order zzds1nk (ll7qvc h9 )30wnwy: do these phases occucdz9ky70(qnn z :) s3vlhl w1wr?

Mitochondria are responsible for supplying metaboliclc) btx4s /. u3vg89u(lio arq energy in eukaryotic cells. In most eukaryotes, which reproduce by sexual reproduction, mitochondrial DNA (mtDNA) is inherited from only one of the parents: the mothe.gq a or8xu9v3t)i u/cl lb(4sr 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 of the cell cycle in hs:appc2/zm - four saz/:-pchm p 2samples of lung tissue from four patients. Which tissue has the lowest mitotic index?

  The diagram shows the dominant cycxs:6vk;aoi.kj/0 cwk lin/CDK complexes at different time points in the cell cycle. Which cyclin/CD jk6vci:s.xw a/ kko0;K complex activates DNA replication machinery?

  Studies have shown that genes such ff+ ,ti jg:mc4wp 98ylas Cyclin Dependent Kinase 3 (CDKN3) are highly overexpressed in cervical tumowc ymg+:jlpfi9 8 tf4,urs.


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 cycl ivxvc; w.. r.h2d3kmlin E the highest during the cell cycle ?