The graph below shows the relationtdz (,e(o jvbeu;:e c;izy58;otd+ h uship between maternal age and the incidence of non-disjunction. What relationship is suggested by tei ;tz to( jc:h5(d+eeuz;o 8 ;,bvudyhe data in the graph?

  Which stage of meiosis is v pwi3rian+ it;6 3dhv ue3 x*;8s,ytorepresented in the diagram below?

  The diagram below shows chromosomes dursz jg f98poc(-ing 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 alx*lxa 4tef5 3-gqr dfb 8l-3tdleles of a single gene which would be present in the nucleus of a cell as a result of 3r*d b-e a-4tfl8ltqxxf g3d5each process?

  Which keyword is matched to the correct 2ccd5(h9szeldefinition?

  Which statement(s) about mit v:ehk1z-yr.t 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 cell in ahuwb,ku d jzcfw uyhpmz3*:.x qy(c/d*5+(x0naphase?

  During which stage of mitosis does the ns ojmp11 f:n2duclear envelope break down?

  Which one of the following transport proteins csag- 9 j1w)-il opxd6only carries out active transport?-lsgjaop)6 1w c9-xid

  Which process does not happen in the shoot api: sa202 y nrbtxt0xm/*9m j7ddhdy6mex?

  Which type/s of membrane transport do/does not requireo6pzln(v 4mr9:py *ln energy expenditure?
I. Facilitated diffusion
II. Active transport
III. Osmosis

  The diagram below represents a cell with a diploid number of 4. Which sn8oc0 c-r xv)7.cbya c)yk 9wutage of cell division is the wxc90yuvcr c) y.nbkc8-)a7o cell currently undergoing?

  The photomicrograph below s:3vpe pn(hg /lj kea5t47rasgy3 xp9 4hows a root tip meristem. Which of the following sentences g3axy5pvt4pj7:pla h/9kge4r(ns3e correctly defines a meristem?

  When does the random orientation of hohf **4;kvopp mmologous chromosome pairs occur?

  Which process does not occur durin7j4fkivm h+.c9p r d/kg meiosis?

  If a cell with a diploid number of 36 un ) 0wl;j rpicd *xmk5-.amcs2gdergoes mitosis, how many chromosomes will be present in -pijsraw;m)5m.d 2lxc k*cg 0each daughter cell after cytokinesis?

  The image shows a micrograph of a cell w::8;( kaev mqsf)spcd0*msw.


What explains the appearance of the cell in the micrograph?

  Which statement(s) about homologousaf )u,pxhkmfic /+4ys54t 5m; yrti2*q+ imz r 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 Dow5 xc,hfcsi1f /pmj8ahc c8 ;d(ow*:gtn syndrome.

Which statement is not correct?

  In the cells of a horse (E. caballusb mcb34n3 jreejw33 d)) during prophase I of meiosis I there are 64 chromosomes.33 n jbbdec 334je)rwm What is the haploid number of chromosomes?

  Which arrow is pointing to a chia/jvmxgf /kf )6sma?

  The diagram below re: jkazt( r(f.rpresents the structure of a shoot apical meristem. Which row in the table correctly identifies th r(.tr(a kzjf:e processes occuring in the structures labeled in the diagram?

  How does meiosis promote variation?zo;ccui(x iw prh(* 96

  Which of the following statements isghrylva;ib7rl ;1s,d 1sk0 4 j/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:9b 1r /trmm/bh6thul 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 )9tlt8c0 whj-9kwph y tumours from primary tumours as a res9)9yk 0jh hp-w8 ltwctult of the movement of cells?

  How many chiasmata are pre4im u dpdv u.7n51pci8sent in the diagram?

  Which statement is a similarity between cytokinesis in animakv-3 v4pxz 1o ;nrfa(gl g*ym3l and plant cells?

  Which stage of meiosis is matched to the correct descr dk .i0,yf6a1crw9fsn iption?

  Which statement(s) are true of meiosis I but not meiosis pf).w,wyv ql9 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 oocyt 92y ; 1+beai-qbqdvkse after the first meiotic division. This results in the f+ev1qb q b92d;k syai-ormation of one large cell and one small cell. What is the fate of the large cell?

  Which row correctly describes diploi c5g-xchs9k *ed and haploid cells in humans?

  The following table shows the diploid chromosome number of a range of specie mph(4 / sz c2 (8abdzmxq*su3yj*y:nts.


Which of these statements is correct?

  What conclusion can be drawn from the karyon1.d xv+g.;pndjg n.p gram below?

  Which of the following prevb-4 -h157hrujyghq ocesses is characteristic of the meiotic and not the mitotic cell cycle?hyve b u4h5rq--g1j7h

  The diagram represents a bud with su :sxbtgm au o4642(rb1k:cja 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 (Pan troglodytes) is196g xd6c *d ioht4lvq 48. Which row shows the correct chromosome number for di1q6dvg6lc4*o dth x 9ifferent cell types and cell division stages?.

  At the end of which phrqc bd( 9i1;fm fmnv08ase of meiosis I does crossing over occur, and what is the outcome of crossing drqnmmb cfi90( f81v;over?

  Which of the following statemx 0 fh)w,uw68 zc;jiqments does not describe a step in the sodium-potassium pump cycle in the neu;6 zfjhw,iq0mxc)uw 8 ronal cells?

  Which row in the table bepn8xt f:ao p ;yjb6c6r0 x,dw8low is true of meiosis?

Membrane transport is important for allowing particles to move across the cell mjexq tgl4x0he05j k/3 embrane and respond to changes in the clgqxek5j0h/3t ej x0 4hemical 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 regpomzsc6w.b7( 0vszs ev;(af( ulated 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 differenf8mezxrz) p r hi(+ y0i+*kwdu u76wa6t cyclins during the cell cycle. Which cyclin8*6rk0e wzi+ iw hr(7p)ax u6d+umfzy is involved in preparing for DNA replication?

The diagram below shows chrorhmemnmo/7hmc 1 cg-28(e hp -mosomes 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 the separati( pw,d6a;e kbk0afz9v on of homologous chromosomes?

  The mitotic index of throat r,tweroiv4:r5mp (xsqx7 e;- tissues taken from 4 different patients is shown below. Which patient is most likele svxe- q7xim4;r,(rrt:w5 opy to have cancerous throat tissue?

1.Draw a labelled diagram to represent the process of kk9scacxq 2 1*crossing over.

2.Compare and contrast random orientation and crossing over.

3.Outline the stages of meiosis.

  The image shows an abnormal human karyotyh( o. wdzze f:6n7xh*jpe.


What is the abnormality in this karyotype and its cause?

The graph below shows the relative amount of DNA i0gatygd. 0r2ql h5rg7n one cell during one complete5l y0qg.da7h0rrt gg2 cell cycle. Each letter represents 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 aw0ak e:n0 z;iwty y7l) cross between a male cat that is homozygous for brown, loyk0z:a7)nl wt0;ewiy ng hair and a female cat that has black, short hair.


Which of the offspring has a recombinant genotype?

1.Outline how polygenic traits can show a normal dfb0s) z 0c4aeytxj7 :m6xjae) istribution.

2.Outline the differences and similarities between homologous chromosomes.

3.Explain why expected and observed Mendelian ratios may differ.

  Which gamete can result from .fev2 msi h2:-wrlyj au( v)6vthe crossing over of non-sister chromatids shown in the diagram bel(rvf6i2. mu2hew:)svy ajvl- ow?

  The photomicrograph sg z7bm.c7sg3 u*sh c:n,fd0cxhows a pollen grain from L. candidum (Lily). Which stage of meiosis is shohsf7*c,nbc:7 z0.xu s3m ggdcwn?

1.Outline the events which would leg2dyv2 /lsdn2h0m(8 mxji ow: ad to an individual being born with Down syndrome, which is characterised by td o2 jm22g( ds :mx/v08lyniwhhe 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 measuqavt93-gtv /jring plant growth. A study was conducted on white onions (Allium cepa), under controlled conditions in a lab, to investigat vatt/ v9qg-3je 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 diagh9ii /c nhqa7gl)6y6y rams below show tw 7q hahin9i6c/ 6)yylgo cells 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 exptgub---(lk 7 pm 9rchqression 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 numbe6h-f /3 jdnwlxr of 8, in different stages of meiosis. Which rhnx6j/-3wldf ow correctly names each stage?

  The micrographs show four phases of meiosi2.5mr+lnw (( uls3ur(zyll qc s I in a plant. In what order do these phases r lclwurl( lm+n2ys (5.z3 u(qoccur?

Mitochondria are respon* 2gyhr4 hzw**rghf i7sible for supplying 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 yey 4rh7r i2**fhz*ggh wast 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 differf fo3:doq +t4ith(x14 rn-ijo ent stages of the cell cycle in four samples of lung tissue from four patients. Wh1rinq:to3ho dx44 - f+(ftoj iich tissue has the lowest mitotic index?

  The diagram shows the dominant cyclin/CDK comp gez0;8zh 2 ea1vzyto*lexes at different time points in the cell cycle. Which cyclin/CDK coz2 18oeh ; z*vgeazyt0mplex activates DNA replication machinery?

  Studies have shown that genes such as Cyclin Dependent Kina:h+ddcr;s lpr3ku6m, se 3 (CDKN3) are highly overexpressed in l3,k6sr +dup;mc:hd rcervical 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 cyc. q-cw.vqq mv(lin E the highest during the cell cycle ?