The graph below shows the relat;:x)c pb4ete6 bade3 0rm gls,ionship between maternal age and the incidence of non-dibxl64gt;p ce d,asm 0:be e)r3sjunction. What relationship is suggested by the data in the graph?

  Which stage of meiosis is rv4t;vxr jd*z3epresented in the diagram below?

  The diagram below shows chromosomes during meiosis(oex vd9kg ).b.


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 which would yf;q.re:cfuqixw kb5.e7 8h1be present in the nuqqxhu:;i. frye.k 5c8e wf7 1bcleus of a cell as a result of each process?

  Which keyword is matched toc9x7u 3nm6 w3sd c5bli the correct definition?

  Which statement(s) abouw--ax /irnw)e t 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, which letter points toj 8o 5cvrua ts gtunn1;882i0e a cell in anaphase?

  During which stage of mitosis does ubohkrmy b(x h6ka twa0n662 2ld*-t3the nuclear envelope break down?

  Which one of the following transport proteins only u74ohyn .-9zk 5ejvd5 i8qlax carries out active transport?j7nv d5 l 95o8u.e4h qy-xkiza

  Which process does not hab9l7t9 0-tfye4kk ilz ppen in the shoot apex?

  Which type/s of membrane transport do/does not require energy expenditureo*g( wbwit97ln yr)n.?
I. Facilitated diffusion
II. Active transport
III. Osmosis

  The diagram below represents a cell with a diploid number of4ijf0hj i(xiy;g0mzi 4* bu-e 4. Which stage of cell division is the cell currently undergoing?* bf04(ime0 ui;z giiy4xjj h-

  The photomicrograph below shows a root tip meristem. Which of sagpht4h dqouar6(u,907 .li the following sentences correctly defines a merish (.aitl ruguh ,o7sp4d96q0 atem?

  When does the random orientation of homologous chrome v;+5y 8v tbf x-ohlkfd:ic:2osome pairs occur?

  Which process does not occur during ms*jc-p x7n( bc q2th(peiosis?

  If a cell with a diploid number of 36 undergoes mi 9(d xsoqfvx. 2kukfj2 x1(gx fe80gt.tosis, how many chromosomes will be present in each daughter cell aftert0x8x2 (v.jf(d . uxg2foqx k eskf1g9 cytokinesis?

  The image shows a micrograp;0 yay 5,2uswoirjxqo1 kig/+h of a cell.


What explains the appearance of the cell in the micrograph?

  Which statement(s) about homo nkq0vsdsg ,q+xhg7o*t-y;5elogous 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 indivia a(0-*pv hhkwdual with Down syndrome.

Which statement is not correct?

  In the cells of a horse (E. caballus) during prophase I of meiosi,szb f ;g6:yd0( rvrmys I there are 64 chromosomes. Whavg:fr my ;sd zb6,(0ryt is the haploid number of chromosomes?

  Which arrow is pointcfs 0u/ wo*9la*vz5-x qp mh8ring to a chiasma?

  The diagram below represents the structure of a shoot apical meristdut :6(ycr48jim(dq hlb,qu4 em. Which row in the tiq6(q4 ,ry(hu :4bc j umd8dtlable correctly identifies the processes occuring in the structures labeled in the diagram?

  How does meiosis promo,,;ce0n,u.yd5lorcx*g pk 6 f *swukzte variation?

  Which of the following statements is/a5emy j*wum+-j -u/jjm/8 tyesre 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 t hgvt ah945r(,- iv- eoosuha4wo 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 sunw4cy:1;,8qx kr xpdeh6 kgfmc*4 e+econdary tumours from primary tumours as a result of the movement of cell+nr, quwyk 4;*d14 h6c gfxekc m:p8exs?

  How many chiasmata are present inbj7i- )m(0bd/7ldska6dfl mj the diagram?

  Which statement is a similarity betw .k-5wfdvvft s 8a:xh (43rxikeen cytokinesis in animal and plant cells?

  Which stage of meiosis is matched to the corrnkk9y nb0iwr aq k)xmf h10v :j4 6zyro--w1z:ect description?

  Which statement(s) are trum5khdjr/ 3y/ ue 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 the first khqq0ypl 9:8 gmeiotic division. This results in the p:k0qqlgh98y 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 humansk7ykm*mwfj(vt 4d w1+?

  The following table shows the diploid chromosome number of a by5c0,v cfvu6/ hk9i trange of species.


Which of these statements is correct?

  What conclusion can be drawn from 9*or uo 90v)ir yb,vo)jpb.zrthe karyogram below?

  Which of the following processes ise3 z7t/(vx i4zpqi9vd characteristic of the meiotic and not the mitoip/qd viz49(ezt3vx 7tic cell cycle?

  The diagram represents a bud with a shoot apica.9* bjy8crtdy:e+hcn+ obg/ nl 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. Which row shf vh pbo *(lr44*3uhl;ui3xfeows the correct chofh x4 fu3h3bp*(;*ui4l r elvromosome number for different cell types and cell division stages?.

  At the end of which phase of meiosis I does crossing over occur, and whsj,+7 v v(yex)ykzc z(f0+rqfat is the outcome of j,s kr+v e70(xqf+ycf)(z z vycrossing over?

  Which of the following statements does not describe a step in the sodium-potassiq1 n,9oag6js,:klyw r um pump cycle in the ne 9 slrqwj:,6,g 1aokynuronal cells?

  Which row in the table below is true of meiosist z.r6:)qa nqs?

Membrane transport is important for allowin;nyb qhflk q.5 ap 7hp3r5,k5wg particles to move across the cell membrane and respond to changes in the chemic; , k3qa575q5bfnhkpp l.hrwy al 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 r,wk o,rbi* ( 9se0 rzhxz9k2baegulated 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 the concentrations of different cygv-8mg5 y4vjh clins during the cell cycle. Which cycligg5- vv4yj mh8n is involved in preparing for DNA replication?

The diagram below shows chromq3qvo lh 854r8an;t/st qaj*c(bww( hosomes 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 homologous chroh/4(5,q3zfi p mutmwr mosomes?

  The mitotic index of throat tissuesnzd8wid ztiyz kf,z*kn2/88k)d 3)ss taken from 4 different patients is shown below. Which patient is most likely to have 2k8wfki*k szz)3z/sd)ddnyn ti z, 88cancerous throat tissue?

1.Draw a labelled diagram to represwj, lpxq;8 s)acq 6lo/ent 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 karyotm7dto,f+ bx/( yz 0lm5mb mw:dype.


What is the abnormality in this karyotype and its cause?

The graph below shows tjn- 3v v-zqnab4m k; pwzt.rw:q ie*u 32s:b;she relative amount of DNA in one cell during one complete cell cycle. Each letter represents one stage of the cel:qb-;ve3 v* zqzbs2n-i 34.nwrw u;: ja skpmtl 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 homozygoukk cg 1v,fdj(yj k+;d(s for brown, long hair and a female cat tha,cv;+dj gkd( 1ky(kj ft has black, short hair.


Which of the offspring has a recombinant genotype?

1.Outline how polygenic traits can show a normal distribution-1 /u,jv fnfkf.

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 coxvu:+ e6fn-g gx+e b3jm5 n)rrossing over of non-sister chromatids shown in the diaju3 o+xxer gm6:fn)b5n +-gvegram below?

  The photomicrograph shows a pollen grain from L. candidum (Lily). Whr0xqm+ai(1 gd ich stage of meiosis is shown? +ra 0 1(dxmgqi

1.Outline the events which wouldv0.tg ak:e 9y:,t jesu lead to an individual being born with Down syndrome, which is characterised by the presence of three copies of chromosome 21u:ee t jy gv0ks.9ta:,.

2.Explain how meiosis increases variation.

3.Outline the stages of meiosis.

The mitotic index is an indirect way of measuring plant growth. A study was con ;3e8twoa1l*fh( kq pyducted on whi1yol *pq;thea8w( 3fkte onions (Allium cepa), 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:mmn9j+8 jmds3l mz 5s cells can divide. The diagrams below show two cells from an organism with59:3dj z + mj8msnlsmm a diploid number (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 exp 7c0:ag 52qtq5 gpeuoxression 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 nnw z(90w7z 7 yd: lrhrknnks)2umber of 8, in different stages of meiosis. 9:nk r nrdwhwzl2nz )0ksy 77(Which row correctly names each stage?

  The micrographs show four phases of meiosis I in a+ fb)ck)y 78y(wtm4wezm, jzh plant. In what order do these phases occur? f, j)h ) k tcby8y+7w(e4mwzzm

Mitochondria are responsible for supplying metabolic energy in v1 kxv b:7dpu( apl)t00occ* yeukaryotic cells. In most eukaryotes, whia d *tk)b(0pv7cx0l:coup 1v ych 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 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 i eofnd5m.p ojb/ /)ky0n different stages of the cell cycle in four 0/o./dfpy )bo jk 5mensamples of lung tissue from four patients. Which tissue has the lowest mitotic index?

  The diagram shows the dominant cyclin/CDK complexes at diffj2x/*dprnx*t:s odb 0d8f0k l erent time points in the cell cycle. Which cyclin/CDK complex activates DNA re* :xb drn/js0*x 2kd8l0fodt pplication machinery?

  Studies have shown that genes such as Cyclin Dependent Kinase 3 (Cnjnod;xhgfwqpq 8wg i2,n+)+/6 ; gvi DKN3) are highlyw 2 h6qp+);wnxgi, g;/+nofg ji dvnq8 overexpressed in cervical 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 the celi*9lt* v 8epbal cycle ?