The graph below shows tly*mqkm:3 7ak he relationship between maternal age and the incidence of non-disjunction. What rel*ak7ylk qm3:m ationship is suggested by the data in the graph?

  Which stage of meiosis is represented in ; 9ejd-zkjnuq ykhj,)/ 7n +dbthe diagram below?

  The diagram below shows chromosomes durin wf u,;1b34ky 2lyp.)tq wdkd 2+khovtlvg5b9g 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 which wo6un+-ov deun7 uld be present in the noenu-d+ uv76nucleus of a cell as a result of each process?

  Which keyword is matched to the correct dheb o jimeh71 -nv(-p2efinition?

  Which statement(s) about e (ag4nxe b/9s wstn14mitosis 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, whic2pp5yj4)c6m; mx6cngd *ff o bh letter points to a cell in anaphase?

  During which stage of mitosis does the nuclear envelope break down0cco h8k5ud; n?

  Which one of the following transport proteins only oe1tlad k)2.:fsm p ,o3n qeh8carries out active transport?,a)qtns :2oe p o.1f8lh3e kdm

  Which process does not happen in sp4)nd(ek*gx the shoot apex?

  Which type/s of membrane transport do/does not require energy expenditure? qj6c5j x,ewj18 lp+wl
I. Facilitated diffusion
II. Active transport
III. Osmosis

  The diagram below represents a cell with a diploid number of 4. Which stage5vs5u4*j ;/b 5ki *wkihs mlem of cibwlkv4ss 5k/*5i5 ;ejm* humell division is the cell currently undergoing?

  The photomicrograph below shows n ,fs1i i)yinz+b )tq;a root tip meristem. Which of the following sentences correctly defines a meristem? qf1+izt )sy)nii n, ;b

  When does the random orientation of homolo/k 5ydquv4q,o ppw/-mgous chromosome pairs occur?

  Which process does not oc0qk r* ru 3d-2u5befgzcur during meiosis?

  If a cell with a diploid number of 36 undergoes mitosis, how mt +fqrhmj;27v any chromosomes willmf h+t;r27jqv be present in each daughter cell after cytokinesis?

  The image shows a micrograph of a;ao bm(m8mxem 07* 0/fqorybl cell.


What explains the appearance of the cell in the micrograph?

  Which statement(s) about homologt43.+ ggkzf jlqs7mh/ ous 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 jh97 yr6g kg)kp /-cx+7fl,(ajsbkhi individual with Down syndrome.

Which statement is not correct?

  In the cells of a horse (E. caballus) during prophase I of meiosi+ 7nry9cdds: os I there are 64 chromosomes. What is the haploid nuos9cr n y+:d7dmber of chromosomes?

  Which arrow is pointing to aw3*.v 7u9x ,jcsmr nzd chiasma?

  The diagram below represent,t4 :lsh87 +fs;bpgozhae cy,s the structure of a shoot apical meristem. Which row in the tgh;a fes s, hl7bpc :48o,ty+zable correctly identifies the processes occuring in the structures labeled in the diagram?

  How does meiosis promote vlb2-cgna b+ c2ariation?

  Which of the following st/bi d* scw,omb .4cgyibc .b43atements 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 chrom9: fs5pw l9phi8pkhxd24ur o1 osomes.


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 tvw(krb 5 bt14oumours as a result of the movement of ce5v1kow(bb4r t lls?

  How many chiasmata are present in the dizt2s krvg0y56agram?

  Which statement is a similarity between cytokinesis in animal and .3uhg qpjbwf+ 0 gb.5cplant cells?

  Which stage of meiosis + t ajds4u1z,*rk 7o/9s jf65sbqf eeois matched to the correct description?

  Which statement(s) are true of meiosis I,oso cm -ni v0;63irze 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 the first meiotic t7 d32r g7qa1rptk)or *gmjz 8division. This results in the formation of one large cell and one small cell. What is the fat2rjr)tz ggtd17 7qr3mok 8p a*e of the large cell?

  Which row correctly describe8r p.7,-cefrewr ys6os diploid and haploid cells in humans?

  The following table shows the diploid chromosf9 v,fqu fk;y7ome number of a range of species.


Which of these statements is correct?

  What conclusion can be drawn from 3lak(n8w 3tb vthe karyogram below?

  Which of the following pr:fz6 6 upfrav3z+zo,hocesses is characteristic of the meiotic and not the mitotic cell c36 v6orazz+ fpz:hf,uycle?

  The diagram represents a bud with a shoot apical meristem. + 0(l. n+ )v.wmti d yav+fuja1w7jkn3r)j ogi

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 t :b-0xgyj*+qxs 7lr uhroglodytes) is 48. Which row shows the correct chromosome number for different cell types and cell divisiru 07-gxyq+x*slj: b hon stages?.

  At the end of which phase of meiosis I does e;b z a85gln:mcrossing over occur, and what is the outcome of crossing :a5ze8l mngb;over?

  Which of the following statements does not describe a step in the sodiumph- k2qxp8tt.mj)kc0-potassium pump cycle in the neurona2-t k8x )km0.qppcjhtl cells?

  Which row in the tabl :v8 vb,buzk1v zf:6s)qk-tcbe below is true of meiosis?

Membrane transport is important for allowing particles to move across the*-xds/n62q xvh5n bs i cell membrane and bx5sh nd- iv*s/nq62 xrespond to changes in the chemical 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 regulated in cz mo.j,5ml9 dq hmyo/5a 3jr/dells.

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 cu ogyz tnfw4 -0e)6ww:8f,l fryclins during the cell cycle. Which cyclin is involved in preparing for DNA replication?l6w f8 ) yewu0 n,tz4fw:r-ogf

The diagram below shows chromos k-nxs.f(*,ccynw 0 h hq1f8;qyfy7nnomes 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 separatiobti2xr1a))/ jml.tsf n of homologous chromosomes?

  The mitotic index of thrhde3vc9 70luo oat tissues taken from 4 different patients is shown below. Which patient is most likely to have canceroueo0cv 739l uhds throat tissue?

1.Draw a labelled diagram to represent the process of m (jqft0 x.+ci s:eg;wcrossing over.

2.Compare and contrast random orientation and crossing over.

3.Outline the stages of meiosis.

  The image shows an abnormal human 0l z.xay. l,dokaryotype.


What is the abnormality in this karyotype and its cause?

The graph below shows the relative amount of DNA in one cel65p1 7jymqm uql during one complete cell cycle. Each letter represents one stage of the cell qpqjm75ym 1u6 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 cat that is homozygous for bnd/ ( h2r4ujou dl3 wm8u:f2wjrown, long hair and wd 3u2l24:nwmj/ ud r(h ujof8a female cat that has black, short hair.


Which of the offspring has a recombinant genotype?

1.Outline how polygenic tragh2r/yn8d6mq6o gk z:/89im pijxvf8qmfg ). its 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-sister chromatids xqz u2k5uy)z8shown in uu5kz z2 xq)8ythe diagram below?

  The photomicrograph shows a pem38sr pm4ptwtl*/x2ollen grain from L. candidum (Lily). Which stage of meiosis is shown?pe*t43/p sl wr28xmt m

1.Outline the events which wouldd,*nc,rm d+7y.ttrjm g 2o; ej lead to an individual being born with Down syndrome, which is characterised by the prestgrm.;jj 7tn,, +*me rddocy 2ence 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 gq;7e,siu42p / d6c,cf 4nndgvi7 ivc arowth. A study was conducted on white onions (Allium cepa), under controlledp,/42c74nq;vfv gccd ndi 7ui6 ,ies a 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 way*wqx 5h;h978uzjcyrl6gj ) )qztga) ts in which cells can divide. The diagrams below show two cells from an organism with a diploid jhhy ) g8 7lgczqtu*;xzt 5wjra6)q9 )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 express5gou y je,(vh3y0p 0odv 6y ajj79,lusion 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 sho6a7s0wmo1 a8pflm h/ww a cell, with a diploid number of 8, in different stages of meihm /7a1p80wwlafos6 mosis. Which row correctly names each stage?

  The micrographs show four phases of meiosis I in a plant. In what order i dfnj:iw(c 0g h+h(1wdo these phases occur?wjidi0n:hhw ( ( 1+cgf

Mitochondria are responsible for supplying me7fpbws 3 ;vqy5tabolic 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 n7py 3f s5qvwb;uclear 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 of the13+-r h/no olpsbvtj01:0i5kr rrqw0ain p4f cell cycle in four samples of lung 0s+ 5rnh14p 3nfro r/r0wpkb-v10qaijloi t:tissue from four patients. Which tissue has the lowest mitotic index?

  The diagram shows the dominant cycxwz6o9l7w: s (i0kl)y0 da d 5krmpfn5lin/CDK complexes at different time points in the cell cycle. Whic m9 o(6p7ikw0 fwl0ndl:syxz) 5rk ad5h cyclin/CDK complex activates DNA replication machinery?

  Studies have shown that genes such as Cyclinv9yq-)iv;0 yuqrbc s*1fda f3 Dependent Kinase 3 (CDKN3) are highly over-9fyar *q 0q)yuv ifbv;1scd3expressed 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 ti4 bvzci6f //l9dde c )zlgn7/he highest during the cell cycle ?