The graph below shows the relation,0u y*t fd+fuvu q1(l7.xrmay ship between maternal age and the incidence of non-disjunction. What relationship is suggested by the vlmd.uuqx*y +yfu7 fr0(,ta 1 data in the graph?

  Which stage of meiosis is represenkw /t* zah.lwi*,, yz7e 3.bijf*gstqg;+ epwted in the diagram below?

  The diagram below shx2p x7 f 5n+9fy;jnkknows 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 numb lpz7z33uu2 f0fz0 i*cpcv8r rer of alleles of a single gene which would be present in the nucleus of a cell as a result of each p37 c 2z00rrzcp *ufzv3ilf8uprocess?

  Which keyword is matched to the correct definii602i x.afoak tion?

  Which statement(s) about mitosis is/are true? u 8)/ h 2*slgtlsi,jcn
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 6y,fqvao mo+ua7 n:a5 cell in anaphase?

  During which stage of mitosis does the nuclear envelope bwwr1uvir91po ikg6 t*yl( ; (xreak down?

  Which one of the following transport pr,wc y3rbra1kf2 rw)a.oteins only carries out active transport?rwf,)ckra1y 2 b3r. wa

  Which process does not happen in the shoot apex?;-t7lho7itxb :b.o wu

  Which type/s of memb:ed3p1mxbm-y9 qxysf/ -hys9 rane transport do/does not require energy expenditure?
I. Facilitated diffusion
II. Active transport
III. Osmosis

  The diagram below represents a cell with a diploid number of 4. Whivbinyt mfn.8*k . h0;ach stage of cell division is the cell currentlv.fmh n 80ikan*tb y.;y undergoing?

  The photomicrograph below shows a root tip meris 3.jabxd0zo 6ng /,1s 8hlzex4wiek ,ktem. Which of the following sentences correctly definb6j kelxwg. hz ,4d s10x,83aikn e/ozes a meristem?

  When does the random orientation of homologous chromosome paih8( tte/8x wnn bb:zrx3)xus -rs occur?

  Which process does nohz xd9lojh39 e gb56kn/ x10 0k8crogkt occur during meiosis?

  If a cell with a diploid number of 36 und ua(eosvi82 r)ergoes mitosis, how many chromosomes will be present in each daughter cell)r s2(auv e8oi after cytokinesis?

  The image shows a micrograph of a cnzh g38( jynw/ell.


What explains the appearance of the cell in the micrograph?

  Which statement(s) abouxls 2scyv0 )a+y .qbq a5*,diut homologous 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 individual with9+;pm-brftu z z20mbq Down syndrome.

Which statement is not correct?

  In the cells of a horse (E. caballus) v bf yrk(nh,a ;(qdh*;during prophase I of meiosis I there are 64 chromosomes. Whatrya h(bn;v(*fq h;d,k is the haploid number of chromosomes?

  Which arrow is pointins0g* 0*b.yf3pxct cwq4u m g9ug to a chiasma?

  The diagram below represents the structure of a shoot apical meristem. Whichchz(vvfo9) )7nc6k wn row in the table correctly identifies the processes occuring in the structures labk 69v(7c ohnzcwf)v)neled in the diagram?

  How does meiosis promote (dv8ky 2c0yqrrb 2k8yvariation?

  Which of the following st l+f; mm *dpgz:ttvlk+cp/4/latements 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 chromosim;1 nnrx/(6mpm;j iwomes.


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 secondarytevk5l2,c 2f r tumours from primary tumours as a result of the movement tr5cv,k elf22of cells?

  How many chiasmata are present in the diagpo6j(xe8vs2p 2*s l itram?

  Which statement is a similarity between cytokinesis in animal and plant celr c 8u9jpr 5z/.x1rklwls?

  Which stage of meiosis is matched to the cxe94mi5x zqm7ujh() horrect description?

  Which statement(s) are true of meiosis I buts/wcu/ xu;kobn *1d.t 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 oohyea*657k ,l i kzbm0u*egzm .cyte after the first meiotic division. This results in the formati*k0*bh6ezu5amz7 ,i el gk my.on of one large cell and one small cell. What is the fate of the large cell?

  Which row correctly describes diploi3, kd+lrxz ;c0zo9l qa :l-mcjd and haploid cells in humans?

  The following table shows the diply9 zbm:ssw f:,oid chromosome number of a range of species.


Which of these statements is correct?

  What conclusion can be drawn from the karyogram belowt5:t ogze 90sq?

  Which of the following processes irtt *3t.cc u/gk:7f; h8 -kbv6cal qnis characteristic of the meiotic and not the mitbl-:tgakhc7*vc6u/ ;fkrctq3.8 t in otic cell cycle?

  The diagram represents a bud with a shoot apical merl)7 2,of ofj0 yt(ll/ bv+p(efyiz:xristem.

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. Whici w.pv0zrw /8uy5vhf xv 9ct6/h row shows the correct chromosome number for different i/ fz/ 8wvxrwtyh 5v.p9c u06vcell types and cell division stages?.

  At the end of which phase of meiosis I does crossing over occur, ae 1-ifco(h+e g1 p0z6vl/ra qund what is the oqh+c l u zprv01a1f(ei/ 6e-goutcome of crossing over?

  Which of the following azwm42b odxz.,sy, y6kj u8b-statements does not describe a step in the sodium-potassium pump cycle in the neuronal ce ,xyasd8zwk4u6b,o2-zj.m yblls?

  Which row in the table below is true oyiw.jka07cb;zpi . /kf meiosis?

Membrane transport is important for allw7caqap9 3nx3 d0w z(vowing particles to move across the cell membrane and respond to wnvpx7cd(3 93zqaa0w 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 cellsc5m)oj3jztzkg i2i3) 1x 4hrk .

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 cyclins d pkn g+98nki /r)e6bfauring the cell cycle. Which cyclin is involvbkp/ir+)f9n ekga68 ned in preparing for DNA replication?

The diagram below shows chromosomes during meiosis. s*xpx6d2 :kclqh -,x (r1wfln2 uzkr-

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 chts rpcl (e8b)f vp-;q3romosomes?

  The mitotic index of throat tissues taken from 4 different patients is shownf 1ct93atympbc9m6x*t40x qj below. Which patient is most likely to have canb0 cpt3 a9xcmmx tt*fyj6q419cerous throat tissue?

1.Draw a labelled diagram to represent the process of cd5 y0rzw*0bx:4tn6 ayb uegb-rossing over.

2.Compare and contrast random orientation and crossing over.

3.Outline the stages of meiosis.

  The image shows an abno*g,,h f/si hz4)mwinprmal human karyotype.


What is the abnormality in this karyotype and its cause?

The graph below shows the relwu ay2brm-x,. ative amount of DNA in one cell during one complete cell cycle. Each ley r.xa,2-bu wmtter 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 sho *1bbeyq,0; big2ujki v+ boa8ws a cross between a male cat that is homozygous for brown, long hair and a femal*;j,b0uig ae2k+qi8 ob bb1v ye cat that has black, short hair.


Which of the offspring has a recombinant genotype?

1.Outline how polygenic traitsysa ave:6 tx ;7.7,xhd/pkgrx 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 8nb 9 w+ emidrw+)g;xmf -zwq.shown in tg;+8qbm +- x)z ed.wwfmiw r9nhe diagram below?

  The photomicrograph shows a pollen m h.hukh+:3x,hwc /kq5wl* m- x v-viograin from L. candidum (Lily). Which stage of meiosis ,+mh l.qmwu/x :h*o5hkcv v3wh-x -kiis shown?

1.Outline the events which would lead to an indi)smmpp + )y)sm+3ly d3x.i-jf dk;kpx vidual being born with Down syndrome, which is characterised by the presence of three co3 mp)yd;k.md+ ifky -smppj)+l) xx3spies 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 2+ h.qzj evn50t/ zy vza a+.)j)yptojgrowth. A study was conducted on white onions (Allium cepa), under coy.5p+atj )z+ t j0/on vvh)jze.2zqyantrolled 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 dividedf6 7cs4bl .ta. The diagrams below show two cells from an organism with a diploid number (2n) of 8.stfb 4ac.7 ld6


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 7k )hed72:gk0 nn6ee idmyd8f 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 qer:o c1+u0dbsi-mu29tp. d9 v wu)tq a diploid number of 8, in different stages of meiosis. Which row correctly m c-u990iqddboqt1:v )t+wus.p r2u enames each stage?

  The micrographs show four phases of meiosis I in a plant. In what o5 gm39; i0t qn.jxzuxirder do these phases u3jn xitx 9i;q5m0 gz.occur?

Mitochondria are responsible for supplying metabolic energy inw yipsa,6.+mq+6 qfs0g hj8qy 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 reproduction between two different yeast species, could be influenced by the parent’s genetq qq06 y if.8apw+jm+ ,6yghssic 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 dws 99d8fnqad sgj r46o3v 2;7ofcug k+ifferent stages of the cell cycle in four samples of lung tissue8jkq d99o+rvwgf 2cg nd4oss;u673fa from four patients. Which tissue has the lowest mitotic index?

  The diagram shows the 6r)v91a6llm8;3axhznc /qu oqil1j n dominant cyclin/CDK complexes at different time points in the cell cycle. Which cyclin/Cnha ;j9 zc) l6amq1lniu6/1r3v l8o qxDK complex activates DNA replication machinery?

  Studies have shown thatyskekc p; 2c ).o .7e*xy6a8hsqpj,nbh-e y;y genes such as Cyclin Dependent Kinase 3 (CDKN3) are highly overexpressed in cervical tumours. k qej27;xyb6pecahc so;y,..ye spy *-h )8nk


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 jczvx.3o 6 fn3ntw )7ecyclin E the highest during the cell cycle ?