The graph below shows the relationship between mate;og 0i d l9; msfrel,uq0pb;9t-9fulornal age and the incidence of non-disjunction. What relationshi-flls qlmre;9 p ;;guu 90otbfd09,io p is suggested by the data in the graph?

  Which stage of meiosis is represented idrz4 q1hjjld 4nj(hl.e8a72 p n the diagram below?

  The diagram below shows,0 xtz ,un nfc0lli.w;e*na 2y 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 number of alleles of a single ge-yd/386spt6mlhs8 ir .iww ou14yo eone which would be present in thed.i4m oi /yw8oh3prut 8s6o1-ys6wl e nucleus of a cell as a result of each process?

  Which keyword is matched to 7hj 5 od2iky* 5z2l6qm6dohrxthe correct definition?

  Which statement(s) about mitosis i uysp1 *t(i w8bw-9xqns/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 ;e+nnq+nt le 9letter points to a cell in anaphase?

  During which stage of mitosis do,)5yjbxig k+62uxbq v,g lhy8es the nuclear envelope break down?

  Which one of the following transporj :2w-y3ehh l6ypw9sdl3y.1 wsv.y ypt proteins only carries out active transport? ehwy-lpy ..j1w:s3dl 6hwysp2 93yvy

  Which process does not ha4+e*u 9ibkzv yppen in the shoot apex?

  Which type/s of membrane transport do/does not require energy pkls .sx5hess;/2.jfyr* o,l expenditure?
I. Facilitated diffusion
II. Active transport
III. Osmosis

  The diagram below represents a cell with a diploid numbv4d t h7tah;9ap8lae6 er of 4. Which stage of cell division is the cell;6aht98l4v te d7aa hp currently undergoing?

  The photomicrograph below shows a root tip meristemo ez+2v+ija)yophr 4vt)r,, v7bv*a9 qgt 3hj. Which of the following sentences correctly defines a meristem? vvtqh)t ,+ar ep9 rj7o)i4h jgb*2av,y+3zvo

  When does the random orientation of homologous n8qxjo-d): bort3f p06km-wd chromosome pairs occur?

  Which process does not occur ducyzl)as p29h -ring meiosis?

  If a cell with a diploid number of 36 undergoes mir.iaf c rj1a+t3f5vv /tosis, how many chromosomes will be present in each daughter cell after cytovj1 ri+ vt5. fa/ra3cfkinesis?

  The image shows a micrograph of a cell ja lvjq4x. -w/kxrb1t.n 3jt*.


What explains the appearance of the cell in the micrograph?

  Which statement(s) abe6 )vlgtcw+z-n :c e26xt-zoiout homologous 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 withan d ;1;z1lsk-v0xjfr Down syndrome.

Which statement is not correct?

  In the cells of a horse (E. caballus) dufa4 p /-go5j.uugl3mk ring prophase I of meiosis I there are 64 chromosomes. What is the haploid number of chromosom3jam k5f4gu -/ogpul.es?

  Which arrow is pointingmop 5inm/xe8* etqe63i , *8zoe qksyd- (i1yi to a chiasma?

  The diagram below represents the structur;v 7;voyxphg3 e of a shoot apical meristem. Which row in the tablpv ;;yv37 oghxe correctly identifies the processes occuring in the structures labeled in the diagram?

  How does meiosis promote variatat1m7g4yr (q9dw c.mmion?

  Which of the following sta l53njmwzsss;,8t r 3ftements 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 prhvu/an fpgs)8k a7v m .*ij*9koduced 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/d/x 5,w6kcngsn* i sj from primary tumours as a result of the movenj,s6xnc /5*kiw/ gds ment of cells?

  How many chiasmata are preffpb2cw 4p1o ;o 01u afpy0n(usent in the diagram?

  Which statement is a similarity between cytokinesis in animal and plant ceyjzi /62 z-8fqv3skoh lls?

  Which stage of meiosis is matched to the correct descriptioqat 5ltu-8ja2n?

  Which statement(s) are true of meiosis I but not meiosis II? jxy9z67 7f5 poz:cgeb (ix ,tw
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. This resl8)3 xyn /;:exbj aytnii+33ia yy 0mjults in the formation of one large cell and one small cy+a3n3xjb0/ j )m8: ti;xyinaiyely 3ell. What is the fate of the large cell?

  Which row correctly describes diploid and haploid cec rrga0-b 7s-olls in humans?

  The following table shows the diploid chromosome number ts 2m0oib*fk.of a range of species.


Which of these statements is correct?

  What conclusion can be dranx8gdf;vgw(51w ;ul) w3ls2r a/aj grwn from the karyogram below?

  Which of the followinsz57ue.: cmq;v/ln q cg processes is characteristic of the meiotic and not the mitotic cell cymv7: .su;e/nqc lzc5 qcle?

  The diagram represents a bud with a s4z ;b-*9v:cv vnnt 1 nsssw0fwhoot 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) isbq ;3;9 :qcyxfjx 9ipb 48. Which row shows the correct chromosome number for different cell types and cell division 9;xq:3cypf 9;ix bjbq stages?.

  At the end of which phase waxs 35xd)o plf4ytq(/8s nl) of meiosis I does crossing over occur, and what is the outcome 5)q4alwf/ 3pdn)8lxsoxts ( yof crossing over?

  Which of the following statemea3)8tpk ahkt9y+t fwj9 h6;fynts does not describe a step in the sodium-potassium pump cycle69k y+fahjt w; t9)83y aftkph in the neuronal cells?

  Which row in the table below is trc,xn a+t6jy r*k4vql if4x u*;e .ad/yue of meiosis?

Membrane transport is important for allowing particles to move across the cell rkf/8og-.2gu y1c djsmembrane and respond to changes in the chemical composition2s jr./gdg8u -yocf1k 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 b( pf60a0s 9tewnx(q7 xgzxx/b k7cx2in 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 dxov (rhi57:lp d i9db0uring the cell cycle. Which cyclin is involved in preparing for DNA replicationdp:xb9r(odi5 0i 7v lh?

The diagram below shows chromosomes duc0xbvp(q u ;ef7 o7a0hring 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 homologous chowta 9,. 5w9aoa*e8bf: -t wrcve 6mozromosomes?

  The mitotic index of throat tissues taken from 4 different patients is shown ( u;elw e(-.w+nubh b6rinva(oryr y.g wu1(;below. Which patien+(ura(( e -(gy6 b.;w;h1nwubli yun.eor rwv t is most likely to have cancerous throat tissue?

1.Draw a labelled diagram to represenr5b qmv8zzfjax *deny a 58;42t 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 human 5r mxg;n/pr-ne ae*)o karyotype.


What is the abnormality in this karyotype and its cause?

The graph below shows the relativ*yim tdph-g0(pk n e7goz7)i8 e amount of DNA in one cell during one complete cell cycle. Each letter represents one stage of the cell cyc0 -p*do8gteyipn) zh m(igk77 le.


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 cat2xzf9(acrc 2wc( 4t 0bgvq*rs that is homozygous for brown, long hair and a female cat that has bf(w c rr9c*vqg0bc4(2 xs2zat lack, short hair.


Which of the offspring has a recombinant genotype?

1.Outline how polygenic traits can show a normal dist e5n ;lzoqnb7. shimxn+v4: bx6-mkk( ribution.

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 crossinggfxrzop 47zr: s 8 dqrp.38wm6 over of non-sister chromatids shown in the diagramdsq :r .r68gzmp43fw8r xp7z o below?

  The photomicrograph shows a +mhifjbmv .be:mo . w61xc96ppollen grain from L. candidum (Lily). Which stage of meiosis is shown? .cm e:jw96 p vf.hmoxmb1+i 6b

1.Outline the events which wvu uffu;q6x vwp0+o8(ould lead to an individual being born with Down syndrome, which is characterised by the p0xpu;wof8v f+ 6vqu(uresence 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 :mu o jp/on;o6n3b( mrof measuring plant growth. A study was conducted on whim(m oj;:r/nooup3n b6te onions (Allium cepa), 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 wi*l1ggrmbva:j .fcbx(9,7x a hich cells can divide. The diagrams below show two cells from an organism with a diploid,1 .vaf:(la*b 9 gi m7xrxjcbg 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 gcdc swhp093 j*ene 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 numbe6 eufy3tg8j d7r of 8, in different stages of t7 d6j8gy3uef meiosis. Which row correctly names each stage?

  The micrographs show four p)pfs mhru*bf8r f;yu 0n+6r. dhases of meiosis I in a plant. In what order do these phasehpm8rf0.)yf;fn *duu 6 rrb+ss occur?

Mitochondria are responsible for supplying met4vcy.fl7*kb iabolic 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 the result of sexual reproduction between two different yeast species, could be influenci .kl4b7fy v*ced 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 omfvjj+q 90xc cuh +.qdg- xd07p- )fxxf the cell cycle in four samples of lung tissue from four patients. Which 0cxxdf)jc x7qjx um9.q+ f-g -dp0h+vtissue has the lowest mitotic index?

  The diagram shows the dominant cyclin/CDK cod + 5,dmli.uz.iwnr .xmplexes at different time points in the cell cycle. Which cyclin/CDK co. ..lw5,mrdudixz in+mplex activates DNA replication machinery?

  Studies have shown that y0).ha hr g7pf+bjv8tgenes such as Cyclin Dependent Kinase 3 (CDKN3) are highly ovet hpfvgh +rb7ay8) .0jrexpressed 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 during the cellan 2i+ia5 whwso9; rcn*ow 9j) cycle ?