The graph below shows the relationship between maternal;e/ih +o oneo7ud,zxh 1(i 9bp+w-ydi age and the incidence of n z p+h+ idin/hx-wdeyooiu9;b(e17 ,oon-disjunction. What relationship is suggested by the data in the graph?

  Which stage of meiosis is represented in theq st8*h ize/6ygmh m*1d+l+bf diagram below?

  The diagram below shows chromosomefprga 1 l(-5p )tciuh6s 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 number of alleles of a single gene ksup7r,h8nyda i8h14q l3k3u which would be present in the nucleus of a cell as a result of eac1n3s8l uh4,hdkqr y7 pi8ka3 uh process?

  Which keyword is matcw q0 p9rkokxa eq3 hm)+w8*d8fhed to the correct definition?

  Which statement(s) about mitosis is/are true?vq6gdy ,7h9 x nk 1ddddx ypd7ta(t8-8
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 tv1q(7nmxlsxep ; ,u6vo a cell in anaphase?

  During which stage of mitos/ lrjh-.vsjle7aae 4+is does the nuclear envelope break down?

  Which one of the following transport proteins only carrie*3ltq8y s2qqie gn5-eziih -6 v*9 emcs out active transport?i3n 5zi9 qhg-em t6vq* eq2*-s8y cile

  Which process does not happen in the shoot apex?djz ) qk-2(ne3 pypo: k-nxc7i

  Which type/s of membrane transport do/does not require energy expenditu2* 2 nkkqnb0mkre?
I. Facilitated diffusion
II. Active transport
III. Osmosis

  The diagram below represents a cell with a diploile z-r.+2*;w )nybyqg 5jiofod number of 4. Which stage of cell division is eoi+y zoln.jfb *w-r 5g) 2yq;the cell currently undergoing?

  The photomicrograph below shows a root tip meristem. Which of the followx 2/m 0qb-x r4v6bugdking sentences correctly definvmkgbq0 4uxbx d /62-res a meristem?

  When does the random orientation of homologous ch/8ybp;xjmn 6 hromosome pairs occur?

  Which process does not occur duringw3nn hhov() iz*- l9nx meiosis?

  If a cell with a diploid number of 36 urbze(9np a dpl32(cc ,ndergoes mitosis, how many chromosomes will be present in each daughter cell after cytokinesisler az32n cbc,pd( 9p(?

  The image shows a microgjq: djzhgu;, a:7cv;n raph of a cell.


What explains the appearance of the cell in the micrograph?

  Which statement(s) about homologous chromosomes is/are not true? (d rx2how+ v:n
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 witha,jh)ixj08ek jw-emf82nk s: Down syndrome.

Which statement is not correct?

  In the cells of a hors /tr-wcqk91 o0yeq o*orh4b5ze (E. caballus) during prophase I of meiosis I there are 64 chromosomes. What is the haploid9hwyoocqz k-1br e*q04t/5r o number of chromosomes?

  Which arrow is pointing to a ch h 2ah/5n3 vgwv vxi+ ;a4hun22cje)koiasma?

  The diagram below represents the structure of h; mgzlz.m(2 ehc8o+z a shoot apical meristem. Which row in the table correctly identifies the processes o;zzme(oh gc+2ml. z8h ccuring in the structures labeled in the diagram?

  How does meiosis prom/kch4(vp5jtzu7,tg,ry rl g +ote variation?

  Which of the following statements is/are correct fqvp azd269/ (aot;enpor meiosis?
I. It is a reduction division
II. It involves random orientation
III. It produces genetically identical cells

  The diagram shows gametes produced from 8 5nhi z61x01gzx num/v 9fcehtwo 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 x0amfy.1y 0kk ah:(ca of secondary tumours from primary tumours as a rcm0:. ay f0k y1(xakahesult of the movement of cells?

  How many chiasmata are present in th1 l.y+mt* lr4b1 vujkve diagram?

  Which statement is a similarity between cytokinesis in animal an0 h)o2qvq0tr/u-cc vod plant cells?

  Which stage of meiosibx k6:fl, th+ wh *qmf:q:vt.qs is matched to the correct description?

  Which statement(s) are true of meiosis I but not meirlt6uwxj6g-;7a e tl;fnx .gx7/0)ofma:t nlosis 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 fbr/w 4d8e r+-fu 4psdpirst meiotic division. This results in dr bp44few8-dsurp +/the formation of one large cell and one small cell. What is the fate of the large cell?

  Which row correctly describes diploid and haploid cells in idoz;jbo+ :.e rfrs8v,g.t/x humans?

  The following table shows the diploid chromosome number of a range of specs 7m d .8zonv/rl bdobx1 kr+;endh1;/ies.


Which of these statements is correct?

  What conclusion can be drawn from the karyogrte1 kn 0zb++9-dfvuf lam below?

  Which of the following processes is characteribc yri,w gdqckb 7m8)b*.hz8.stic of the meiotic and not the mitotic cell cyclb87dih.c*k qwrbm g)8.,cb zye?

  The diagram represents a bud wi qvq*.6l gqj: wfo42rith a 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 troglodytn4cds etek.z2wz x.2 1es) is 48. Which row shows the correct chromosome number for different cell types and cell division stages?.nz .tws2z1c 2.kex4ed

  At the end of which phase of meiosisvssdzq). sp-/ I does crossing over occur, and what is the outcome of crossi) sq-s./pdzv sng over?

  Which of the following stwf co)hd. h.:watements does not describe a step in the sodium-potassium pump cy c.:w).o hhfdwcle in the neuronal cells?

  Which row in the table below is true of meiosismz 33(;u , xj32rn6wqvtvwsnb?

Membrane transport is important for allowing particles to move across the cell sebz2fi23 v zm(g: m.hmembrane and respond to changes in the chemical compositie(m.3 mfs:gzbhz2iv2on 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;:2vy dr k8qcsbcr3r* 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 shv,giy.97 xualjeg:as( bd :z+ows the concentrations of different cyclins during the cell cycle. gidx le(a.,u+ga: 9s7vbyzj: Which cyclin is involved in preparing for DNA replication?

The diagram below shows chrok.v9j wo3w4++bct qsumosomes 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 involg d (lw.xio,0b(t)j+(p,7ulewqb m d vves the separation of homologous chromosomes?

  The mitotic index of throat tissues tn-: n riry+5ezaken from 4 different patients is shown below. Which patient is most likely to have cancerous throat tissuenyn5-r + :eirz?

1.Draw a labelled diagram to represent the proc u73hyvw8ym676* bvo cjz xm6fess of crossing over.

2.Compare and contrast random orientation and crossing over.

3.Outline the stages of meiosis.

  The image shows an axoi*13 bi,e(3 nvdasj 3p2xvybnormal human karyotype.


What is the abnormality in this karyotype and its cause?

The graph below shows the relative amount of DNA in one cell duri d1+k-nic,32,wdh c d5 7h8f (yjvpcz uurq5ucng one complete cell h, c1d(h3 ccj +7i-u u25f5v,nru pqdczywd8kcycle. 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 a cp 9iv58e,wyo h8 jwx c7gj+l;cross between a male cat that is homozygous for brown, long hair and a female cat that ,e+hi 8jo7wwxp c8 cgl;jvy95 has black, short hair.


Which of the offspring has a recombinant genotype?

1.Outline how polygenic traits can show a normal distributiyu8n77.cld sif(ot 5u*ohag,o .9kedon.

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 qz(:it: jnuh 1of non-sister chromatids shown in the diagrami:hznju( q:t1 below?

  The photomicrograph shows a pollen grain from L. +*gohw0u gh/ wo zvz*4candidum (Lily). Which stage of meiosis is showngv+w/*huzo 4 wz0hg *o?

1.Outline the events which would lead to anv fm yvrlfw h..d 8t*2bl+m(a7 individual being born with Down syndrome, which id7wy2m v+ll 8h..(b*ftvmaf r s characterised 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 isx pd -:oxn n721an5qxndirect way of measuring plant growth. A study was conducted on white onions (Allium cepa), under contds1p nn2o:n x7-axq5x rolled 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 diagrl3(rct ja)anw1f q1v*ams below show two cells from an organism with a diploid number acnjta 1)1rfvl*3 (wq (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 p ( uqis-5da72ym qxb)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 diploi5rgf uw( wqj:.d number of 8, in different stages ofq: u f5w(wjr.g meiosis. Which row correctly names each stage?

  The micrographs show four phases of meiosis I in a plant. In what order do these b, 3lcgb hzz:) k:ir0uafcj01 phases f)hkbjg00i,1 a:luz z 3rc:bcoccur?

Mitochondria are responsible for lr- r o2b. ck4:7xijdbsupplying 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 rr .lj7 idxbk:c4-orb 2eproduction 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 j gc3wr u/i(+xin different stages of the cell cycle in four samples of lung tissue from four patients. Which tissue has (c ju/xi+r 3wgthe lowest mitotic index?

  The diagram shows the dominant cyclin/CDK complexes at different time poibin w0: lwsv1 k*-bwz7nts in the cell cycle. Whi*zw:nwws1bb0k l i7v-ch cyclin/CDK complex activates DNA replication machinery?

  Studies have shown that genes such as Cyclin Dependent Kdehdfs:vo* .byrenmvgb4+t. 01 )3 o hinase 3 (CDKN3) are highly overexpressed in cervical tumours. b0d:fe 1hrv dnye)3..*mh4sg vb+oto


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 thk0k1aypuf- 4v8 4ab sqe cell cycle ?