The graph below shows the relationship between maternalx e r+ns*rec,6 age and the incidence of non-disjunction. What relationship is suggested by +ne*rrc6xs, e the data in the graph?

  Which stage of meiosis is represente i,:5.va..onhv:uh*up. jsbygt hrm8d in the diagram below?

  The diagram below shows chromosom.hlz hvkm2rq)ik,q9z f64 ul8es 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 )6( g tjcplxm6 8 :v9aljcf-eqnumber of alleles of a single gene which would be present in the nucleus of a cell as a result of each proce8cl( ae:qm -6fcvl9xtj6j g)pss?

  Which keyword is matched tov6w3aan u eablf0q/t6d+*a ) b the correct definition?

  Which statement(s) about mitosis is/are trj-u4xqgwo8u*: j 1jj fe3ofh;ue?
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 celn x/wiaiki60uf3cn (w6hx8t8 l in anaphase?

  During which stage of mit,l . 9wb7h )5lp wqo1ttdzj.uposis does the nuclear envelope break down?

  Which one of the following: x spzdsmy-tx qv;0w.;hp5 4i transport proteins only carries out active transport?.pdpqt5z-mw ; svx:x i0s4;hy

  Which process does not happen iniu ce,2,ht0a i5f k6xd the shoot apex?

  Which type/s of membrih8b 7-z06ps ,qvhrz uane transport do/does not require energy expenditure?
I. Facilitated diffusion
II. Active transport
III. Osmosis

  The diagram below represents a cell with a diploid number of 4. Which stabfac3ds)*f q: ge of cell division is the cell currently undergoin3dbf qs)a*f c:g?

  The photomicrograph below shows a root tip meristem. Which of the followindwoum .h. m,ygx((*dog sentences c o,mdg(dux wh(o* m.y.orrectly defines a meristem?

  When does the random orientation of homologc/m3d 6gc(;)il4tw huee9sf ,ce)50qozca ooous chromosome pairs occur?

  Which process does not occur during m: l+ cy qb-ib05uql/cb bru/:beiosis?

  If a cell with a diploid number of 36 undergoes mitosis, how many chrc4q em)fxk0f* omosomes will be present in each daughter cell after cytokinescemf0 kx fq4*)is?

  The image shows a microgr n ryv,73ec-jt4,5laozhmnv.aph of a cell.


What explains the appearance of the cell in the micrograph?

  Which statement(s) about homologous chromosomes is/are not 3v:jegdh2g6w 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 individug wu:nq x,l*o3lyp*-5bj co8yal with Down syndrome.

Which statement is not correct?

  In the cells of a horse (E. cab6j3klem 1)3nk-q.4r.o d.nxqc f rzfzallus) during prophase I of meiosis I there are 64 chromoso l1nn3 kozf r4j 3d6.e r.-.kxq)fmqczmes. What is the haploid number of chromosomes?

  Which arrow is pointing to a , xuw u*l0o04jcx*lflchiasma?

  The diagram below represents the structure of a shoot ac )bf )zx6jby;v18c5-(+w x rsbbnxjkpical meristem. Which row in the table correctly identifies the processes occuring in )jn bbywf16b c-;s ( 5rx)xzj+kcxv8bthe structures labeled in the diagram?

  How does meiosis promote varyxsx k3i)e1bsc .e c2pln2/8 siation?

  Which of the followingm 6npmuy 4;u 2jgipl40 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 gametenznxr3( ip6 bp6wp; -ls produced 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(b6xpfv s1+5-h irv gesw :qib+nz24z from primary tumours as v- 2v4 hznzbsw:6r+fix5bgisq1e+ p(a result of the movement of cells?

  How many chiasmata are nqa:b ,bn s q:kec6kr 0 w-w/4c.jrt,0sgup1o present in the diagram?

  Which statement is a similarity between cytokinesis in animj 7e0q3f)pbkq al and plant cells?

  Which stage of meiosis is matched to the correct des8btset4 1pxeo.. xuc+cription?

  Which statement(s) are true of meiosis I but not mei(swjdk ek8n djd7x1 r n+ gs r8/g0uo0ey5;.noosis 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. This resl 24*sex.p)ywufah* qults in the formation of one large cell and one small celh ylux ea)24*fqs. *pwl. What is the fate of the large cell?

  Which row correctly describes diploid and hqlo+o g,)i. wj8tqg6naploid cells in humans?

  The following table shows the d x2a3 iz3 t)3o6tqdq 4icipee3iploid chromosome number of a range of species.


Which of these statements is correct?

  What conclusion can be drawn f;m0fy pcfg,a.(mwjv)pnn :d. rom the karyogram below?

  Which of the following processes is characteristic of the meiotic anj9iqkh-d,i) ld not the mitotic cj)i i,kdq-9lh ell cycle?

  The diagram represents a bud with a shoot apical mea7m6 w;ocyei .ristem.

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) is 48. Which row shows t;e no); zp+ :,hyixczshe correct chromosome number for differy)cz;zh s:,xipn e;o+ ent cell types and cell division stages?.

  At the end of which phase of meiosis I does crossing over occur, and what is tjjh t.0oq*5qo2vuq m+er 5l1uhe outcome ou1qj5r+ jo0vuqqt*h 2.lme 5of crossing over?

  Which of the following statements does not describe a step in the sozpz8f jt;,eu41v2xcane8k ) huv9q a/dium-potassium pump cycle in the neuronal cecueaauz v),; kt21nz p8/vx8j h9qfe4lls?

  Which row in the tab,qp rz+;v1orl zyw*/i -mr+uele below is true of meiosis?

Membrane transport is important for allowing ccre89j;dhc g dm ,t36wiegs 04mih3,particles to move across the cell membrane and respond to changes in the chemical composition of the extracellular fluid. i93drg; h ee,jt,8i6mccg wmcd3s0 h4

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 ef . h3v(od/: rulgq4pyf8xa),zg yg6 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 t8 rw lr3zoo:ao aiss e..d966lhe concentrations of different cyclins during the cell cycle. Which cycel 6riwao.r8o:doa3 s .69zlslin is involved in preparing for DNA replication?

The diagram below shows chromosskf4s*ocm9dd *b- t5 lb7qr:6ahd6/gq kiv a(omes 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 invwwx.r b)0.gdk olves the separation of homologous chromosomes?

  The mitotic index of throat tissues taken from 4 different patie2qubmf(:adcb2 w r ;q-nts is shown below. Which patient is most likely to have cancerous throat tissue?abm qwc 2u:-;qr(bd2f

1.Draw a labelled diagram to repre9o8lvl3qzy u2sent 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 karyo .si-7hgm3b a3gnh az.type.


What is the abnormality in this karyotype and its cause?

The graph below shows the relative amount of DNA in one cell durin iv7aogp3a .6;7cpaanf 7fmx ;g one complete cell cycle. Each letter represents one stage of t;mgnxfa7 v ;63i7a7f. capaophe 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 a cross between a male ca srdj8ou *v*7h v4g6c9 4nezbmt that is homozygous for brown, long hair andmedh sv8g9vbz4co 4r*j un 6*7 a female cat that has black, short hair.


Which of the offspring has a recombinant genotype?

1.Outline how polygenic traipg55lb5bcnm.po wp0zc/) 2j lts 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 oveaew ;8s93jso z (qpvn)r of non-sister chromatids shown in the diags j8;q)9avonsp(wz e3ram below?

  The photomicrograph shows a pollen grain from L. candidu n)fj:ou2o2wq m (Lily). Which stage of 2oo2f u :wqnj)meiosis is shown?

1.Outline the events which would lead to an individual being born wivo0;jz z j a:k-rbg:f,th Down syndrome, which is characterised byg:ofkzv br0-:z ,;j aj 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 measuring plant growth. A study q-6vpco d3 +kv0g 9joswas cond v0 copo6dsq+jv9k- 3gucted on white 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 which cells can divide. The diagrams lpjpy dx e(1, sc7a+ 4ojbezo1h*q()ybelow show two cells from an organism with a diploid nuhjy 4)l1ap (e*c ysxo qbe( ,j+7poz1dmber (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 +nyi9sfy(hv0 7 sake; 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, in different sti f4:3xgz w 4t(p(aqivages of meiosis. Which row correctly names each stage? v zt4:f(w3q ip(ai4xg

  The micrographs show four phases of meiosisx,oq+ z3 kru4ioew aw;:2r+ps I in a plant. In what order do these phases occurer sr+2k 4 ; woo:pxwu3+ai,qz?

Mitochondria are responsible for supplying metabolic energy in eukhi3 iwlwd9 tmt4/1n6w aryotic 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 contr4l1 wiwdt9 wn63t/ imhast 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 /k p. ki e4k4kw-l7-wl rfc4eqof the cell cycle in four samples of -7 f 4p4il. lwekr/kk4e-ckwqlung tissue from four patients. Which tissue has the lowest mitotic index?

  The diagram shows the dominant cyclin/CDK csb8s+,qkrsd ux-h2 i+omplexes at different time points in the cell cycle. Wh,++usdr- b2q8ksh ixsich cyclin/CDK complex activates DNA replication machinery?

  Studies have shown that genes lpbgky-3ah7.;u5k v x)e idyy0q,.ho such as Cyclin Dependent Kinase 3 (CDKN3) are highly overexpressed in celqgkh7;v)p hby-d.x5y, uai oye3k0 .rvical 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 cyclet vi q5a/arum2-(, uvd ?