The graph below shows the relationship beh -tzk+zf)z8.7hvl2yftnv 3 htween maternal age and the incidence of non-disjunction. What relationship is suggested by the data in3+ t8zz -kfft2h. lnv 7h)yvhz the graph?

  Which stage of meiosis is represent/to wkyvn:t8e 9g 54yqed in the diagram below?

  The diagram below showsj.9 1lexiwog 3za .q4f chromosomes 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 awqrsma:z (96s*o u 9-wm hsq6ulleles of a single gene which would be 96u6umqsossww*-z: r m(aq9hpresent in the nucleus of a cell as a result of each process?

  Which keyword is matched to the correct de4tj70* z*6kly+m vfoi.yq vzkfinition?

  Which statement(s) about mitosis is/ap);2xhr 0sp:sf* flt+ow26s x llxv2are 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 ;fhtneb 3+)l-lahkub;lsi 7;anaphase?

  During which stage of mitosis does the nuclear envelope brezrkfk so* yr 8. y)ef4p9 /i:g 6-fdc(efkoh5oak down?

  Which one of the following transport proteins only carries l 5eoe: 0 ;icyc/slmp.out active transport?e :/e5ym o0.lcilc ;sp

  Which process does not happen in the shoot3+q 7 faeg e6u azfi4foo-;ox7 apex?

  Which type/s of membrane transport do/does noo d xrqjninnya5f 59*38y/pk 3 v4nrr7t require energy expenditure?
I. Facilitated diffusion
II. Active transport
III. Osmosis

  The diagram below represents a cell with a diploid number of 4. Which stage owq9z;myh9+x g *wyoz - 7vs fz1pbub+/f cell division is the cell currently undergozyzwuyz-bs*vgo h9b p97wf qxm++1/; ing?

  The photomicrograph below shows rybpa r+k1 ) dzc.0d/ga root tip meristem. Which of the following sentences correctly defines a meri+adrpcyr dz b0g1/k).stem?

  When does the random orienta/w2 tp-c p6cgmvm)t2h3 bktg .tion of homologous chromosome pairs occur?

  Which process does nwn xjq8qw p9 89ljt7z2ot occur during meiosis?

  If a cell with a diploid number of 36 undergoes mitosis, how many chromosomes wd d,/tpzt vk*1ill be present in each daughter*pt d/tvk,dz1 cell after cytokinesis?

  The image shows a micrographwpckw5+(m9v g9i +nkuuff8jd3061 oq l eqr7f of a cell.


What explains the appearance of the cell in the micrograph?

  Which statement(s) about homologous chromosomes isz:m9xl7zdv sp + vw;/w/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 syn93b7n/8/gppdd+r kowfy- j k rdrome.

Which statement is not correct?

  In the cells of a horse (E. caballus) during prophase I of meiosis I thf95; hyd;ec nt v1gkw;ere are 64 chromosodgw1;k;c95;tvh efny mes. What is the haploid number of chromosomes?

  Which arrow is pointing to a chiasma? - +rwbv)rs0p7yip /jxt-- gvh

  The diagram below represents the stxs m84xbt-/ hxructure of a shoot apical meristem. Which row in the table correctly identifies the processes occuring in the structures labeled in the 4xbt8mxshx -/ diagram?

  How does meiosis promote variatiy5 4-d wgxabh4on?

  Which of the following statements is/are correcn8lq5) jcwehje 1t+9k t 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 homolo6z,9i 3qeo6al1rl h tggous 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 p s7uzx mg1mhf-2ywh22rimary tumours as a resu271 xsg -h22ymmuzfw hlt of the movement of cells?

  How many chiasmata are present in the diagramwqictxo9 sz5enyo4 r--9,ma z*1xir-?

  Which statement is a similarity between cytokinesis in ,fg5if y4n,ll animal and plant cells?

  Which stage of meiosis is matched to the correct d;t1k5n9 mw : z;aog:cpts),m 4 rwtvsvescription?

  Which statement(s) are k u h 35 ,ywt-o,+/jsvknspwu9,b/zud true of meiosis 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 after thew *ld -d,5laakxu 3-yv first meiotic division. This results in the formation of,x*l ay ulwd a5dk3-v- one large cell and one small cell. What is the fate of the large cell?

  Which row correctly describes diploid and haploio94o dx.lcqol4v1q 7wd cells in humans?

  The following table shows the diploid chromosome number of a range of species.m .qxkfupok sf7 8pj +u.,k*r 917wtju


Which of these statements is correct?

  What conclusion can be drawn from the karyogn)oy9gtj+9t8k yfjoza /n,p, gk; c)gram below?

  Which of the following processes is characteristics5ey ):lf96dxtv u+ ls of the meiotic and not the mitotic ce5 uf:yst+sv d9)x ll6ell cycle?

  The diagram represents a bejs. xc9naa0fn;q) 7v ud with 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 troglodytes) is 48. Whichn(*n c7yy7ho b row shows the correct chromosome number for different cell type*hn7 o(cb7 yyns and cell division stages?.

  At the end of which phase of meiosis I does crossing over occur, and whs8;h60lkrnz s bjh4 1hat is the outcome of crossing1jh hk8lsz0h b4rs 6;n over?

  Which of the following statements does not describe a step in the sodium-potgqedz) wp nm)1v ,ygm)2vqn 5,assium pumg )d,p)w1eq)vyqn2gz m n,m5vp cycle in the neuronal cells?

  Which row in the tablpdd9 h y h8hmpn0(udb1:8rwt5e below is true of meiosis?

Membrane transport is important for allowing particles to move across the cell w. y0hq 2y(ld+/jyj nsnx 24iojyu/u9 membrane and respond to changes in the chemical composition of the exqj j us/ihn+ oxu 2/ly.ndy0(49jyyw2tracellular 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 regula;xe0r 5/qfhaqx/u, ;wt k-qi pz gcj:/ted 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 tw1 p7,u..ux0xo s(p 3swft + k ga+c9cj4tbtkche concentrations of different cyclins during the cell cycle. Which cyclin is involvf,.skj4gt +xbcu a7s9p.t( cowt 1pwu0 +cx3ked in preparing for DNA replication?

The diagram below shows chromosomes during meiosisgk22ykj.wpj(qo wx-4leu*y , ,y i9n d.

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 homologous chromosome;qe rx3rl+z,es?

  The mitotic index of throat tij7 zf3:y to*gxo: l.)-cvnb0qlx c xw1ssues taken from 4 different patients is shown below. Which patienq*xlz0v bo o)lcxjw- :n: yc1tf.73gxt is most likely to have cancerous throat tissue?

1.Draw a labelled diagram+ 5 fvfnbgr+,v 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 hus-0b. o.tg wwyman karyotype.


What is the abnormality in this karyotype and its cause?

The graph below shows the relative amount of DNA in one l n* 7hki/b0lk0,hk qhcell during one complete cell cycle0/ ,k n*kbllkhi0hhq7 . 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 a male cat that is homozy*(m ekw/daf(90 yfzplgous for brown, long hair and a female cat that has blac9 wy(mef fd*/k(zpl a0k, short hair.


Which of the offspring has a recombinant genotype?

1.Outline how polygenic traits can show a noi) l5 whs5txg:rmal 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 shojpg d*x:inpwifkc :/ zaon73)a;3dv 0wn in the diagram below?ad;okdf w7i:avp/ *ijngnp:)0x33c z

  The photomicrograph shows a pollen grain from L. candidum (Lily). Which st7lhv9 x5klg2xkw2z7j5 kmu0 sage of mwz kk u2gl2m97s0k75l xjh xv5eiosis is shown?

1.Outline the events wh.4wa32ophq*)k mup r lich would lead to an individual being born with Down syndrome, which is characterised by the presence of three copies of chrom2*)l.o r kh4a quwppm3osome 21.

2.Explain how meiosis increases variation.

3.Outline the stages of meiosis.

The mitotic index is an indrg * .rsqku9 6fal43uzirect way of measuring plant growth. A study was conducted on white onions (Allium cepa), under controlled conditions in a lab, to investigate the effg3sul ru 6r9 4.*fqakzect 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 diagrams bz0h ukapr1avv/7 dl40elow show two cells from an organism with a diploid number (2n) ofz0v a1v4ralkhp07/ ud 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 + yek ;dlz6s77t xai59/ywowlin 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 diplc6u ouo )t(ju53z zc,s0x j)zxoid number of 8, in different stages of mexojz3o)(ztu )5cc6jx zu ,s0uiosis. Which row correctly names each stage?

  The micrographs show four phases of meiosis I in a plant. In what order do c +jwqyr scjxoc*297( these phc x*cqc+jw(9 rs 27yjoases occur?

Mitochondria are responsible for supplyinps6w + /q+or ,yao*arag 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, whicos,a*6r/+ yrp+qoawah 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 o *w68;x bjarvbf the cell cycle in four samples of lung tissue from four patients. Whichrj;a wvx8*b6b tissue has the lowest mitotic index?

  The diagram shows thagxrohlr t,ijj+1:3g / y.l+fe dominant cyclin/CDK complexes at different time points in the cell cycle. Whxh, t3.gjg1lrl ofj +:/i +rayich cyclin/CDK complex activates DNA replication machinery?

  Studies have shown that genes such as Cycprvxz)jw s-+2 lin Dependent Kinase 3 (CDKN3) are highly overexpressed in cervical tumoursr v+ )jxzw2ps-.


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 Elt3 )v bkp vu3*15tfusk7+qkc y: (haj the highest during the cell cycle ?