The graph below shows the relationship between )3y z3xyrxwls(ko1 u*maternal age and the incidence of non-disjunction. What relationship is suggesteyu* zk31x lr) (wyoxs3d by the data in the graph?

  Which stage of meiosis is represented in th(4 sec/ib d7hwe diagram below?

  The diagram below shows chra ;u0v ;h6ljti0hv0n domosomes 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 gene wn +1anol piz-tdldh5fu6+ eqm+ 1:m,uhich would be present in the nucleus of a cell asi -l,h d+umun1pl 6dtamo+1:n5 e+zfq a result of each process?

  Which keyword is match+3l 9al tpy/qged to the correct definition?

  Which statement(s) about mit**6y)a)kr uof 4 ug.q d +:nhhqitbqi)osis is/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 cellkhq( a(fman2f5 jh qu)k :ad/: in anaphase?

  During which stage of mitosis dk 5s)1vtqcf,c oes the nuclear envelope break down?

  Which one of the following transport proteins only carries wf3w mv/ 54 6j-b/xz.tavthor out active transport?/ orvxvt35 ./f-aw4 zh6mtj wb

  Which process does nos ,r c,l3 kcuvmaro869t happen in the shoot apex?

  Which type/s of membrane transport do/does not require energy exx0t :5 y: jo4xggl8 rp8kefe*tpenditure?
I. Facilitated diffusion
II. Active transport
III. Osmosis

  The diagram below represents a cell with a diploid number of 4. Which sta35 wnt/jx/gqi aydfrc a8bmsu i0,*1:ge of cell division is the ce5g *rf/iw3ai:dcm8t0 x1n q,s /bayujll currently undergoing?

  The photomicrograph below+lg o y(-4qpoj shows a root tip meristem. Which of the following sentences corlgyq+(j po-o 4rectly defines a meristem?

  When does the random orientation of homologous.uo,hu 9:oc9ar-vu a o chromosome pairs occur?

  Which process does not occur vbb5f,y -ldz. fpkc :6during meiosis?

  If a cell with a diploid number of 36 + x13i4t8rmj5rn*i) hazut ygundergoes mitosis, how many chromosomes will be present in each daughter cell after cy+81) ijiy3 4gmr h uzxtar*n5ttokinesis?

  The image shows a micrograph of a c 2jytxdb1v ;mf/wv7+ tell.


What explains the appearance of the cell in the micrograph?

  Which statement(s) about 0 qp4 gyzpmd8 798ntgn3dle(j 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 with Do j3xxp wk79o1fwn syndrome.

Which statement is not correct?

  In the cells of a horse (E. caballus) during prophase I of meiosis I t vt0tj+tnl x43here are 64 chromosomes. What is the haploid number of chromo+lx0 4tvt nj3tsomes?

  Which arrow is pointing to a cu(ls0f( yb;p(x3hfkvn1kk l1 )rw3lnhiasma?

  The diagram below represents the structure of a shoot api zw(f8sqpg bxajiu u 1-5.x;1ku4kd1ical meristem. Which row in the table correctly identifies the processes occuring in the structures labeup8wd(ik .jzu;x1ug5ba1ksf1x- iq 4led in the diagram?

  How does meiosis promote varyl 7zaq0yu7zb7 r66bj iation?

  Which of the following -e5(qastx4zt 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 chromosomes. m9arjmddd434zdd;f*x3f.o n


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( i5l0sp dv.rr formation of secondary tumours from primary tumours as a result of the movement of c0(dvlrisp5. r ells?

  How many chiasmata ar2rx5eyk5ea2fh;/.goa5eth ie present in the diagram?

  Which statement is a similarity betweenxl*eduw+h :6, cckb. l cytokinesis in animal and plant cells?

  Which stage of meiosis is matched to the correct descripunp(ur)y 3n mr ol )ip)xa066stion?

  Which statement(s) are true of meiosis I but note1xxdc2/s.q j1 y ix+l 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 thqdgcj5c 9s(8dx d1/aee first meiotic division. This results in the formation of one large cell and one small cell5(cc ejx /gd98qsad1d . What is the fate of the large cell?

  Which row correctly describes diploid and haploid;fj g bxmzchqfo efn 6re6,4;2q,u* m+ cells in humans?

  The following table shows the diploid chromosome number of a ra cn3j)9bb0 umynge of species.


Which of these statements is correct?

  What conclusion can be drawn from the karyogram belon1y,c ,im qr5y3n4a gxw?

  Which of the following processes is characteristic of the medr(o2gv,u y:zn.ie ;qiotic and not the mitor uv.(q: ng z;,d2eiyotic cell cycle?

  The diagram represents a bud with a shoot apical meristemz 7og-di4s72tcgvw* z.

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 trog m,qur gi rt,y6i( 6-ud:mfdw2lodytes) is 48. Which row shows the correct chromosome number for different cell types and cell division stage:-m i,,dmrtu6r(q dw2 y fug6is?.

  At the end of which phase of meiosis I does crossing over occur, zz9dp +2jdq9 (zuc yc6i60-zorj9nm yand what is the outc 9cujd0i96n+pc d(zyym2zrq z9z-6joome of crossing over?

  Which of the following statements does not describe a step in the xic+**;)ste2o6/w rz vnn z yqsodium-potassium pump cycle in th inr*/ syze c2qw)6z;tx*vn+ oe neuronal cells?

  Which row in the table gltwu ,2vvv c) h) 87;ruiy9jgju h,w.below is true of meiosis?

Membrane transport is important for allowing particles to move across the ce d/g*iiy8nip. ll membrane and respond to changes in the chemical composition of the extracellular/p g.8 idi*iny 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 regulate 6 vk+1l m//i wesgira-ene:ael 9v3-td 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 durin 4m vgf.f6 s-3h8ycyl4ezmp((d re6pqg the cell cycle. Which d m .4 ml(ep(6g-3scv pe86qyrzy f4hfcyclin is involved in preparing for DNA replication?

The diagram below shows chromosomes during px(r84ibfx: u 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 chromvhnln4owt b7*e: ) cc4osomes?

  The mitotic index of throat tissues taken from 4 different bb+ck/6- ylblpatients is shown below. Which patient is most likely to have l6klybc -b+/bcancerous throat tissue?

1.Draw a labelled diagram to represent thdr 6l v.:d mz- ct+))5gbcq/aqjdo0 cqe 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 karyotyps8zpgj* e+r uw *s06lwe.


What is the abnormality in this karyotype and its cause?

The graph below shows the relative amount of DNA in one cell during one cirrvg7cb ,145j bgeq0omplete cell cycle. Each letter re70e1b,rqvg5 ir b jgc4presents 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 an+1/s ;d:o0hc lu3cjst ,ahyb cross between a male cat that is homozygous for brown, long hair and a female ca+bdas/3cshjo h,:l 1ut0n cy ;t that has black, short hair.


Which of the offspring has a recombinant genotype?

1.Outline how polygenic tjlf(y9m9bk j p;y-y ,kraits can show a 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-z+(q)(5dug pi*w tepesister chromatids shown in the di) zp e(+(g5e d*tpquwiagram below?

  The photomicrograph shows a pollen grain from L. candidumti+;v:gqrb/jkz ;4 1i. kxkt79 )vipi2 ol wbv (Lily). Which stage of meiosi )7 4qt;vil/biz 1;jtkpv x+wkrv:b .9ok2 igis is shown?

1.Outline the events which xo-( kqq8ce*0fwl2zcvl z6 4w would lead to an individual being born with Down syndrome, which is characterised by the presence of three copies of chromosome 21.20qz-xf8c4o lk6v*e(c lz wq w

2.Explain how meiosis increases variation.

3.Outline the stages of meiosis.

The mitotic index is an indirect way of measuring plant growr.cn/bzrpbbhn5by/h2 +q m+jx x4wn05( e g (nth. A study was conducted on white onions (Allium cepa), under controlled co/nj4( mh gh/ 52 qnen5rx.c+nbp +xzbbw r(b0ynditions 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 which cells can divide. The diagrams bel**ek n4xn5w6i2 ttw,r ri)rllow show two cells f t* 2 l6r5xinnl)rtw,r4*kewirom 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 ge, 0 gu *)owqcvt fibj1ig f4k4do0vl63ne 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 cel-p6k .l9nsfl, /jeet txo +s;ll, with a diploid number of 8, in different stages of meiosis. Which row .lx,s;en6+9op-ftje s/ tk llcorrectly names each stage?

  The micrographs show four phases of meioc5je,zwg s)92u0p9 b) ggtjspsis I in a plant. In what order do these phases o gbzpw 0es) stu9j9)pcggj, 52ccur?

Mitochondria are responsible for sup ;h q+uio2bpj:plying 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 the result of sexual reproduction between two different yeast species, could be influenced ju:2;ib+h oqpby 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 v-s(m,ouu x ue4 4ny/rnumber of cells in different stages of the cell cycle in four samples of lung tissue from four patien /ur-e, u4(onu4vsx ymts. Which tissue has the lowest mitotic index?

  The diagram shows the dominant cw;8)tck z57zeiwa ,ceb8ltxenm *z 20 yclin/CDK complexes at different time points in the cell cycle. Which cyclin/CDK complex acze7mbw, nx t)c2 ;885 e*0altcizzewktivates DNA replication machinery?

  Studies have shown that genes such as 2g*p (2cu6rzr b4 ailrCyclin Dependent Kinase 3 (CDKN3) are highly overexpressedrp(cir 2*baugl46 2z r 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 cell cyccv6ffe 0dpa3 b1rb(+ a-p cgs7le ?