The graph below shows the relationship between matql 4*3f5 xqgrmsrg 3)xernal age and the incidence of non-disjunction. What relationship is suggested by the data in the graph rfqgxmrxgs) q3l354 *?

  Which stage of meiosis is repres .vyzker* m0.cented in the diagram below?

  The diagram below shows chromosomes du2c f.2dr u;dvm 9i0,jp*l nugcring 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 singleif/uq4n l:rd). ta-yub n-j wzm)c:*u gene which would be present in the nucleusn:.q) ic4 bfld-n *j/um)w:urut-yza of a cell as a result of each process?

  Which keyword is matched to thiwj t.* vj/3zjizj;qk .oylz7: *d/dt e correct definition?

  Which statement(s) about mitzu,0m ex63e feosis 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 anaphasouenzp3 5y)lm)ntc-9 k:1ke:w ujkd(e?

  During which stage of mitosis does the nuclear envelopoxhz95*f un,0 9x.fgxjnn87n d uugv:e break down?

  Which one of the following transpor90 oy7l ki99lvemao z(t proteins only carries out active transport? eya97 oi(v lm0o9klz9

  Which process does not happen imz)yz z)- ;q(x5tgscsn the shoot apex?

  Which type/s of membrane transport do/does not req vehb1c40l, ; f)z)d0ovywpmouire energy expenditure?
I. Facilitated diffusion
II. Active transport
III. Osmosis

  The diagram below represents a cell wi s ((l/m7v rc/iu,bjhu:zcws:th a diploid number of 4. Which stage of cell division is the cell currently undergoing? bl7r( (zijvm/shws: cc /uu,:

  The photomicrograph below shows a root tip u4kf y3:wg7kimeristem. Which of the following sentences correctly defines a meristemu4i7yw:3kfk g ?

  When does the random orientation of homologo:bq8p+b ny-dz3g1yt rb6ja: nus chromosome pairs occur?

  Which process does not occur zgr nortm3q,o1 : 8cp1during meiosis?

  If a cell with a diploid number of 36 undergoes mitosis, dffu;3n78g7 s h9drbh how many chromosomes will be dfn rh;f38ds 9u7bg 7hpresent in each daughter cell after cytokinesis?

  The image shows a micrograph of ad+ uph:dq z1x0u /byh8 cell.


What explains the appearance of the cell in the micrograph?

  Which statement(s) about homologous chr;vhsq a-qlsk/i4 7 ag8omosomes 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 Down syndr( 6z /xf8augnzruks1(ome.

Which statement is not correct?

  In the cells of a horse (E. caballus) during prophase I of meiosji4nnq 0. ebi8is I there are 64 chromosomes. What is the haplo4i ib8nj0 n.eqid number of chromosomes?

  Which arrow is pointing1az 15j slt(aji zz0d8 to a chiasma?

  The diagram below represents the structurenlqj-)dya-o i2p,mx 6 f nvx+5 of a shoot apical meristem. Which row in the table correctly identifies the processes occuring in the structures lab-n, fmn+jo)2-ypi5aqxxvl6 d eled in the diagram?

  How does meiosis promote za8psj7v iiv:e 7h* s1variation?

  Which of the followingt-qjf ket:i-ca7xd- 8 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 homologkm/d /bpsv24 gfu.5 tgous 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 from primary tumoursve)xw:nb)s ymqjp-hi, ( fc 79 as a result of the movement of cell97 bpey- x)h: jw mn)ivc,(fqss?

  How many chiasmata are present in the diagp8)tn *xaad6*oyfyz.:x rw 6b ram?

  Which statement is a sn281mpabk9 wj e 1fgm: a+q4mueq.z0gimilarity between cytokinesis in animal and plant cells?

  Which stage of meiosis is matched j(s+n*q+s .i-) abdh/sms/ /ma kfxa mto the correct description?

  Which statement(s) are true of meiosis I3h1d yam).s0pehjc f) 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 th.2ojrh+mg ro *mh/bl -e first meiotic division. This results in the formation of one large cell and one small cell. What is the fate of /.-*rg2 m+m rjblohohthe large cell?

  Which row correctly describes diploid and haploid cells in huguu trn1w7,tf*g8wq 5 mans?

  The following table shows the diploihal*t)s k x,bhd*f7 /6r33u ohssvss*d chromosome number of a range of species.


Which of these statements is correct?

  What conclusion can be drawn from the karyogrsubr03 (aka( wam below?

  Which of the following processes (89 w9lkpx fqr7m9lpcis characteristic of the meiotic and not the mitotfrx k9 mw9 p8(lp9q7clic cell cycle?

  The diagram represents a bud with a sho g3me2 r: r53yin)8 sxggun*atot 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) is 48. Which row showu v)pn8b y*l :yappo4)jp0hbl45t ,kls the correct chromosome number for different cell typell ,:5yhj4to8)pb *)yl0kupvn p ab4 ps and cell division stages?.

  At the end of which phase of meiosis I ,ga-a*k vwk/s (t e42n muq/ntdoes crossing over occur, and what is the outcome of crmn-awg/ksv /q ,et 4ut nk2a*(ossing over?

  Which of the following statements do3mvytb6k:w5i px+xv4 es not describe a step in the sodium-potassium pump +k64t5bx3wvm: p iyvx cycle in the neuronal cells?

  Which row in the table below is true of mmj 77/()p 1ucwakjsldeiosis?

Membrane transport is important for allowing particles dmkd vdhfqt56koa./7gt2i. bwe)qpl. m (3y; to move across the cell membrane and respond to changes in the chemical composition of the extracellulao 5/.)mhpf (.vtbt; 6gd7a 2kkqed3mldiy. wqr 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 regulacxqhk. ;pax2;si/y vcd uxua0l/r4uxf 3.k25ted 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 during t ,ksbrx,w+dz vuv y5b*zejo 5y**5yy9he cell cycle. Which cyclin is involved in preparing for DNA reyv 5w z,**b v5yb9 dz *,+5ykrsoeujxyplication?

The diagram below sho)jyip1 qfv 4k.fybt a3-31psgnzxk 41ws chromosomes 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 separation of bueyk1l9ks 64 l- mc*phomologous chromosomes?

  The mitotic index of throat tissues taken from 4 different patientlov8u eu +d9eod5,vu3 s is shown below. Which patient is most likely to have cved u9u3 evd l,5oou+8ancerous throat tissue?

1.Draw a labelled diagram to represent the :s h7z.1xyt+pmbi5 kzprocess of crossing over.

2.Compare and contrast random orientation and crossing over.

3.Outline the stages of meiosis.

  The image shows an abnormal human karyotype. qt +/j;iq w:e/gqlg3 k


What is the abnormality in this karyotype and its cause?

The graph below shows the relative amount of DNA in one cw 4jj+qoq4w0zo g86txell during one complete cell cycle. Each letter represents one stage of the c 446tj+q jw0xo qzwg8oell 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 di kjc3.q g*w;s 45tuncross between a male cat that is homozygous for brown, long hair and a female cat that c5j;qw d .s*tkng4u3i has black, short hair.


Which of the offspring has a recombinant genotype?

1.Outline how polygenic traits can show anb) ,s t/kzfltsac0o5 p0e5 ;e 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 ofbhg sn2(x2j (f non-sister chromatids shown in the diagram below?b(gx2jh( fs2n

  The photomicrograph shows a pollen grain from L. candidum (Lily). Which wollsk*r6s 0:stage of mew0o6sskl: lr* iosis is shown?

1.Outline the events which would lead to an ind; ih4mu7smqmolmni .0n3i3d3ividual being born with Down syndrome, which is charactm7mdnq3uh4m0nl3.3m s i o;i ierised by 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 osqpz.w. bicl5fo 5t*)f measuring plant growth. A study was conducted on white onions (Allium cepa), under controlled conditions in a lab, to investigate the effect of soil pH on the mitotic in5 )q.5.otbzcwil * spfdex 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 wb;qnx t mpl245-5mv xwhich cells can divide. The diagrams below show two cells from an organism wi nb;-l45w5 txqmmpvx2th 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 g zsxev; aqjy)6.6d/)w x-t dnzrowth.

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 s --i0c1 swp w2*hk+cvp)x sqeatages of meiosis. Which 2vsea0 qsk1+)p wiwh*- p-cxcrow correctly names each stage?

  The micrographs show four phases ofpmby- -v*z34 n ptpy1b meiosis I in a plant. In what order do these p p*ptzp m 3nbb41-yvy-hases occur?

Mitochondria are responsible for supp 5ucyb7pj8j v-lying 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 suggestc87 p5-vj jyubed 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 ctc1t.n2rxqu *g.9kcz ell cycle in four samples of lung tissue from four patients. Which tissue has thq .1tgru c*tckxn2 .9ze lowest mitotic index?

  The diagram shows the dominant cyclin/CDK complexes at different 1zt *h(q/f(cc;qdc dg,bn vw/time points in the cel hc1 (/ t;z vnqdc/gw,dfqb*(cl cycle. Which cyclin/CDK complex activates DNA replication machinery?

  Studies have shown that genr vuug d1b) kg*7)j6efv oqo52es such as Cyclin Dependent Kinase 3 (CDKN3) are highly overexpressed in cervical tumoursu2vv6duqb e7)o) gojr *gkf5 1.


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 concentrationm0fmkx.zs ( o;kw9b;*c53 dwcq4nnfz of cyclin E the highest during the cell cycle ?