The graph below shows the relationship between maternal age and the i1 q:*3cyrvrxc a. t7ouncidence of non-disjunction. What rer. * 3y v7cua:rq1cotxlationship is suggested by the data in the graph?

  Which stage of meiosis is represented is9ym)n-ync) *rm yqm,j 4pr:nn the diagram below?

  The diagram below shows chromosomes during 1oo:wd pxf7dcn5) (kw 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 numbqerwhs/s 0 d9.er of alleles of a single gene which would be present in the nucleus of a cell as a rehwsds9qr. /0 esult of each process?

  Which keyword is matched to the correct . xoipqy. wuv(cb 2w; e79zl2kr2k 3h;qc,mtddefinition?

  Which statement(s) abozqobvmps : 01az***wu ut mitosis 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, whichr5.np)4hzi6mk;nzwb* o cg , a letter points to a cell in anaphase?

  During which stage of mitosis does thhktpso++ (+ ;k3. g7bjy bzuyxqvv ak.dqg1 /9e nuclear envelope break down?

  Which one of the following transport proteins only carries out active tran) snn3c,mbk -jktx6(hsport? hk)s-x(3nnc ,j m6ktb

  Which process does n(s:st j(w-h ju9ugb c,ot happen in the shoot apex?

  Which type/s of membrane transport do/does not require energycbuq-hy s s9i,)bf 23k expenditure?
I. Facilitated diffusion
II. Active transport
III. Osmosis

  The diagram below represents a cell with a diploid number p q mm 6+:5anxj9jy.edof 4. Which stage of cell division is the cell currently undergoim:d eaj+qmpx.5j6 ny9 ng?

  The photomicrograph below shows a root tip meristem. Which of thzdw,v nwk31nxacw4xmt7 -j5 7e following sentences correctly defines a meristz,w71 ktn v5jx-7wd xmacwn3 4em?

  When does the random orientation of homol ll(z+i(5qpud ogous chromosome pairs occur?

  Which process does not occur durin(xl/4 7sklj btg meiosis?

  If a cell with a diploid number of 36 undergoes mitosis, ho q58q , ubv**/l2qp nqcl6ngejw many chromosomes will be present il vn5qql6b pq/u, c**qje2g8nn each daughter cell after cytokinesis?

  The image shows a microgldqc-- -c .n:ic dk*mhraph of a cell.


What explains the appearance of the cell in the micrograph?

  Which statement(s) about homologous chromosomes is/are not tru i+8yhlnd12dpdoq***vj5tahs9 e l) ne?
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 individual81 i-p npnhf-qyx1 6ae with Down syndrome.

Which statement is not correct?

  In the cells of a horse (E. caballus) during prophase I of meiosis I there a lxcvk7v2t1 b:re 64 chromosomes. What is vlvc2t k1x:7b the haploid number of chromosomes?

  Which arrow is pointing t-b7u z)hi juu bicv.nf) tgs -de b)qef*32f62o a chiasma?

  The diagram below represents the structure of a shoot apical meristem. q 56 *b,a4pfsud2 xifslk79i lWhich row in the s5dbp f, 2s4llqkui*7 6x fa9itable correctly identifies the processes occuring in the structures labeled in the diagram?

  How does meiosis promote varia9 at-ugxr x* )o+d1usction?

  Which of the following statements is/ar39w2l6 -qb s7y wmlv.x( rkeuh4dmfh +e 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. re3 y-87o6 xzh8bb ubf


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 zjmaou2.o 8 yci;ds( m z7:bh)of secondary tumours from primary tumours as a result of the movement of cells?8:maou;7zsoih mzb djy()2c .

  How many chiasmata are pkq0 ksh472(,ek.su2iswq*tp c -l kw nuz8x7oresent in the diagram?

  Which statement is a similarity between cytokinesis in dnkc,4wp/dm/:63qnr ow nu)i7rgci)w 95kiu animal and plant cells?

  Which stage of meiosise lij* *xrme5(qo/)wz is matched to the correct description?

  Which statement(s) are true of mei nfz:/fjbt 5/josis I 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 a jlo7fbx0x3,p fter the first meiotic division. This results in the formation of one large cell and ofxx7,03 oj lbpne small cell. What is the fate of the large cell?

  Which row correctly describes5nj*8 w +(g llwlnxt2y diploid and haploid cells in humans?

  The following table shows the diploidg7; yjkvi; rf uhwk4)7 chromosome number of a range of species.


Which of these statements is correct?

  What conclusion can be drawn from the kr5: 6ykoj*13fapc /yszflu bk.c.l g;aryogram below?

  Which of the following processes is character/4i * mc*cde lg0(pfcyistic of the meiotic and not the mitotic cell cypcgl**fymi0d4 cc/e( cle?

  The diagram represents a bud with a shoot apical meri;xb xz sh55 h*uh 2rs)4qb+wnjstem.

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 troglosb)57od.cgw z zit6 9cdytes) is 48. Which row shows the correct chromosome number for different cell types and cell divisic7).gw9t obzc 6zsd5 ion stages?.

  At the end of which phase of meiosis I does crossing over occur, and what ish/btrqa64qg bapr22: the outcom/ ta6rg4 2bqqa:b2rph e of crossing over?

  Which of the following statements does not describe a ste3pqfhtgx +-6w p in the sodium-potassium pump cycle in the hf+- 6pqt3xwgneuronal cells?

  Which row in the table below isx .g/jbba*/xfp,ed 7d true of meiosis?

Membrane transport is important for allowing particles to move across the cell w uk4kf ;mtt83membrane and respond to c;m4 uktfwk38t hanges 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 cee c,xg j5y4.ydlls.

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 differj), 7 a- gfcdf8gg2mbwent cyclins during the cell cycle. Which cyclin is img2 )cf, b-8ga7fgjdw nvolved in preparing for DNA replication?

The diagram below shows chromosom(yaf/ nk9kgzb q6b:4o i wu;g9es 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 hop.hhs 7tcku6 8mologous chromosomes?

  The mitotic index of throat tissues taken frox+o0g31* rfh4 bjccbfm 4 different patients is shown below. Which patient is most likely to havexh31 0 cgrf*bc+oj bf4 cancerous throat tissue?

1.Draw a labelled diag37v) 4k4i: uxs9dxd a0vjrlgbst e*i +ram to represent 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 karyotype. j* :o gtsfy,z3+sp/ki


What is the abnormality in this karyotype and its cause?

The graph below shows the relative amount of DNA in one zt7 grl -ee9rsi6(p36du u3n ncell during one complete cell cycle. Each letter 3r(s-r n63p 6tnue9 ul dgzei7represents 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 sh +wf9k8aa/p(bhq5zeh gzf2m: ows a cross between a male cat that is homozygous for brown, long bz 5kha8h2+zp9qgw (ea : fm/fhair 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 distri)8dc o1tq +z-g8e d29awwwnt kg-sq)wbution.

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 shownm8htgk3r/ 5s9 n/nusyu3tkv - in the dr//5ys 3 s8nn9hkuug 3m ttkv-iagram below?

  The photomicrograph shows a pollen grain from L. candiduy7 k0 drbi;v2zm (Lily). Which stage of meiosis yd 2;0k bvrz7iis shown?

1.Outline the events which would lead to an individual *gvri+rsd; 0c being born with Down syndrome, which is character+;r*isc 0 gvrdised 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 of measuring plant grj8,;wn(* tpcrv n8d thowth. A study was conducted on white onions (Allium cepa) rctw8;t ph n(v,jd*n8, 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 dia3c82wg3 p7s aktd j/gkgrams below show two cells from an organism with a diploid num3gcasd3 82k/ jpw7kgtber (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 expre4:jmldgwrb xnm/9ore - 5x6 (yug cr37ssion 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 number of 8, in different stag xj+inax7/rg)es of meiosixa7)n/jxig +rs. Which row correctly names each stage?

  The micrographs show four phases of meiosis *8/umxal.vq o I in a plant. In what order do these phasesma .8xuov /lq* occur?

Mitochondria are responsible fo9hv 3ve ;cy*r4,f* t;bcuqlexr 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 pattern;r*h4qbu;yvv tcec93f* lxe ,s 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 stagiq;ot tncz7+m3x.ftzij v.98- sn ( mges of the cell cycle in four samqn o f.i(9;z 8.t c-tsvix7 tj3znmgm+ples of lung tissue from four patients. Which tissue has the lowest mitotic index?

  The diagram shows th.ja* sp2 hpl.ae dominant cyclin/CDK complexes at different time points in the cell cycle. Which cyclin/CDK complex activateh ps.2*pajl.a s DNA replication machinery?

  Studies have shown that genes such as Cyclin De u r-q7: gd)z*afdqqzvm +pk21pendent Kinase 3 (CDKN3) are highly overexpressed in cervical qmq zuv z )1+krf2d:pd 7-g*aqtumours.


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 h19p-yqm 5lqy vt.t h.qighest during the cell cycle ?