The graph below shows the relationship betwo j)qx;:j0od 12nil vween maternal age and the incidence of non-disjxwn dj ;jvoo0i2q1) l:unction. What relationship is suggested by the data in the graph?

  Which stage of meiosis is rercoa00t5 nc1 q)yu-4t9f v7t x3vbof cpresented in the diagram below?

  The diagram below shows chromosomes during mvh6l(j: 6u kfv07ugi-.syr y q36 wpuzeiosis.


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 /a kcr(pw1p7o, f. vwvof alleles of a single gene which would be present in the nuv ap vwp./c71 (orw,kfcleus of a cell as a result of each process?

  Which keyword is matched to the+wga85zd:tkmw. il+f 41sd3oiem3y x correct definition?

  Which statement(s) about mito v9 hokdd(hu1ehne bk/(fg+*zt ;q2i/sis 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 a85r8xc+p*t :y uyoti4m gxf,imt4;q q naphase?

  During which stage of mitosis does the nul.bg 1qpz7) apclear envelope break down?

  Which one of the following transport proteins only car3ai 4vdhs* zkdnb8 g-/ries out active transport?dgv/8k d3*4 i z-nbash

  Which process does not happen in th(5-uh(5vhyyyjx cj lne)4di4e shoot apex?

  Which type/s of membrane tr*ns 7p n9qd8pyansport do/does not require energy expenditure?
I. Facilitated diffusion
II. Active transport
III. Osmosis

  The diagram below represents a cell with a diploid -k6cxzy** u mjnumber of 4. Which stage of cell division is the cmc u**jk6 xy-zell currently undergoing?

  The photomicrograph below shows a rde(cv90:v ov3ui pofs+ 3 ,egqoot tip meristem. Which of the following sentences corevqf9:g vi ovc0o se 3,(d+up3rectly defines a meristem?

  When does the random orientation of homologousjoz.bl gd)-osh01pge 5wj4;l;(xwh w chromosome pairs occur?

  Which process does not occur bqv /ddbp-6y5 during meiosis?

  If a cell with a diploid number of 36 undergoes mic l)whq9ab63etm5 o i,tosis, how many chromosomes will be present in each daug lc,taem5 39oh)6b iqwhter cell after cytokinesis?

  The image shows a micrograph of axe 5sgu; 0dydeh .jd rv,tx640 cell.


What explains the appearance of the cell in the micrograph?

  Which statement(s) about homologous chromosomes is/are sqmi18 gq;b v6not 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 indivinbkw7.( y+ s8vt7yphb dual with Down syndrome.

Which statement is not correct?

  In the cells of a ho, uwf ii0:uf+urse (E. caballus) during prophase I of meiosis I there are 64 chromosomes. What is the haploid numberuu0:if,f +iu w of chromosomes?

  Which arrow is pointing xi*; mygqgx hn76g21vbpx h x1 jm8-,mto a chiasma?

  The diagram below represents the ss.qn-j 6l1g/b 5d2lq wd)uhk0 jhz2bztructure of a shoot apical meristem. Which row in the table correctly identifies the processes 5.g6kh1zjl2qjws b-h 0uqd dbl/2z)noccuring in the structures labeled in the diagram?

  How does meiosis promote variu/igq 80x+xiz6 achv x)((ub t*r g(iqation?

  Which of the following statements is/are 5im5p(+o esb acorrect for meiosis?
I. It is a reduction division
II. It involves random orientation
III. It produces genetically identical cells

  The diagram shows gametes prodc5ff2ln;7 yn,h +f2m 0 isrncauced from two 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 second0g.yi6jc a5:m-wox*h bc z ;kqary tumours from primary tumours as a result of w0c;z6.oi-mx : yg bcja* h5kqthe movement of cells?

  How many chiasmata are present ixz)gx;.cf.xm4, l t con the diagram?

  Which statement is a similarity between cytokinesis in wosws*9.4 jdnq4aey( animal and plant cells?

  Which stage of meiosis is matched to the correc: tjm jg,p:m4dt description?

  Which statement(s) are true of meiosis I butd8p:8rq7my *h-qw8df3ft gp s 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 firs rmi e,5t;8iy j1ao4frt meiotic division. This results in the formation of one large cell and one small cell. What is the fate of the large cell?4ey1ao;r8,j rm fii5t

  Which row correctly describes diploid and haploid cells in:mn2-.1xqi( mclbek o humans?

  The following table shows the d( )zimjnglq* 5t4 k;,fe,ipfe iploid chromosome number of a range of species.


Which of these statements is correct?

  What conclusion can be drawn from thn eua 5v;4i)sie karyogram below?

  Which of the following prfd duw4 tdit )1-* ifmj gc47xgzk44m7ocesses is characteristic of the meiotic and not the mitozdf jct4*4wdu g -14)tf4xmk7i7dmi gtic cell cycle?

  The diagram represents a bud witk1r6 k j )x5-5w ors2ds9faixsh 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 thek()yt fjh7l b- chimpanzee (Pan troglodytes) is 48. Which row shows the correct chromosome number for different cell tyfh(7 t)kly- bjpes and cell division stages?.

  At the end of which phase of k2 rcv tv2 z7do;,/wgtmeiosis I does crossing over occur, and what is the outcome of c;v rc/o2tkvg7,w d2ztrossing over?

  Which of the following statements does not describe a step in cxkn0dvl6d k7j q xr8oeq);+8 the sodium-potassium pump cycle in tqvrn0; 7ol8c)j+q d8 kd6xxk ehe neuronal cells?

  Which row in the table below govh+ ip)daaz9p.ux s 87a+yj1v1s0w is true of meiosis?

Membrane transport is important for alloqkx3 9y; rpml6wing particles to move across the cell membrane and respond to changes in the chemical coml69;rkpx 3m yqposition 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 celc 4njx/4*lkgf* n8 sclls.

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 differed q l(*3 dd).vpauid vn-pt8n(nt cyclins during the cell cycle. Which 3dap)(u8nvi-dd(p q.d vtnl* cyclin is involved in preparing for DNA replication?

The diagram below shows chromosomes during mp .nui-coy,f:o w2)ln eiosis.

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 separatio h2+cu 5d urot1:rb8wwn of homologous chromosomes?

  The mitotic index of throat tissues takew.x/7i+do r4ew 3hfd tn from 4 different patients is shown below. Which patiwrxd. 3hdt+/ oe 4w7fient is most likely to have cancerous throat tissue?

1.Draw a labelled diagram to represent the process of crossin4qp 6 +bm1ud)k bn x.3fwqpnjr-2nbf*g over.

2.Compare and contrast random orientation and crossing over.

3.Outline the stages of meiosis.

  The image shows an abnormal human karyotypeium 9x hk7/fmot.b : uh7k/je9.


What is the abnormality in this karyotype and its cause?

The graph below shows the relative amount of DNA in one cell during one comp v5.eq 8u+7nw nh4(jd (pmqvpwlete cel+qv vq u7hw(54njdm8wppen .(l 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 a cross between w2dm -q5,xtap6xwn4 c a male cat that is homozygous for brown, long haipwnxc4 ,6xqt mw-2d5 ar and a female cat that has black, short hair.


Which of the offspring has a recombinant genotype?

1.Outline how polygenic traits can s+ s3h*f7o spwkhow 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 crv6m,9 eb7e*+cgt uo fwossing over of non-sister chromatids shown in the diagram bgw eobv c,*+96mfute7 elow?

  The photomicrograph wyldqv7h0- u8shows a pollen grain from L. candidum (Lily). Which stage of meiosis is showd h qluvw0-y87n?

1.Outline the events which would lead to an individual being vmpdc3z2,j etgdtt;/p2y8. wt 26mud born with Down syndrome, which is characterised by the presen / e.twydmztt,tp 32vu 2;dcgp8m26jd ce of three copies of chromosome 21.

2.Explain how meiosis increases variation.

3.Outline the stages of meiosis.

The mitotic index is ag8o6 ;ujhtuexy 1/k z+n indirect way of 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 mg+kue6 huozj t 8x/y1;itotic 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 wavlj6 eml0b;.sys in which cells can divide. The diagrams below show two cells from an organism with a diploid number (2n) of leb v.;j6l0ms8.


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 gthuac4 y8*cc g.oz6pj/m r8 2k5i6 yjkrowth.

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 diploi/lt(rkz .a q5 uibd7v/d number of 8, in different stages of meios il( /bvdu5t z.q/7rkais. Which row correctly names each stage?

  The micrographs show four phases of meiosis I in a pln lc n(p6d3u7j3ilzb+ant. In what order do these pha76ldlj3+ci3pz n(b n uses occur?

Mitochondria are responsible for supplying metabolimc9p q.5pwa,u c 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, inherita. c,m5pu paw9qnce 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 staghxva r c sqccn.e9cz )z/7j25dbf2g(7 es of the cell cycle in four samples of lung tissue from four patients. Which tissue has the lowest mitochzqa nf9)7c.c 22z7 5 vx(sbegrcj/dtic index?

  The diagram shows the dominant cyclin/CDK complexes at differe5 ffip:2nowq6bg5c4sk 3 quj3ay4r :d nt time points in the cell p:5w 24u3gscaqkof6: 4 ry5 bnd3qijf cycle. Which cyclin/CDK complex activates DNA replication machinery?

  Studies have shown that g li/x+gxhmop .8kr7u 52h n/xwenes such as Cyclin Dependent Kinase 3 (CDKN3) are highly overexpressed in cerh.lwng 8xk/+o7/uipx5 hm2 x rvical 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 the highest during ttzu:- lzy2i /rhe cell cycle ?