The graph below shows the relationship between maternal ena9y*w bu(;lage and the incidence of non en(y9w; aub*l-disjunction. What relationship is suggested by the data in the graph?

  Which stage of meiosis is represenolt5,;pq3 zdg 2h o;outed in the diagram below?

  The diagram below shows chromosomes durin5 kssqilx m*5ylf7f07g 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 which n- ugj/lt:4 -tx-rqa,sdfu5lwould be present in the nucleus j l5-tlg uqf4,xad-stunr:/- of a cell as a result of each process?

  Which keyword is matched to vpyx(tp0,igiy2 y2, bthe correct definition?

  Which statement(s) about mitosis is/are trupnch- ycwq7h ogl g(--x ;9,fie?
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, w: ncte )2 cd:y em(d7wmi;e o*twjah01hich letter points to a cell in anaphase?

  During which stage ofv,m)uym br:2, 8le ruk mitosis does the nuclear envelope break down?

  Which one of the following transport proteins only carries out active transpox ;hu3-vnuo0b .mx:.wvq+hfr7ov ; u jrt?;jvf.70 vhwun h.u xvbo3+-x:u qmor;

  Which process does not hap*c rpw( g1caig.1 qiz9 p;tk,ybm o6w) l+a:ikpen in the shoot apex?

  Which type/s of membrane transport do/does ng n.pp /; f-qm)vts6fr4 u 2ci608crrqr ckaf0ot require energy expenditure?
I. Facilitated diffusion
II. Active transport
III. Osmosis

  The diagram below represents a cell4k o4hzd/i d0qh 9nxu7 with a diploid number of 4. Which stage of cell division is the cell currehq 9zinxku44 7dodh/0 ntly undergoing?

  The photomicrograph below shows a root tip,43rs:j5azl b) /.ibm4fnr t c k1facf meristem. Which of the following sentences correctly defines if)z4,fbr 13ks 5can:jat b.ml 4fcr/ a meristem?

  When does the random - xclax526838t f9zo gtwhkxtorientation of homologous chromosome pairs occur?

  Which process does not occur durnctjse nqn8 j9.g6*5*uqb 01g v hvqh*ing meiosis?

  If a cell with a diploid number of 36 undergi8; fut-7xwz 1qf -aqzoes mitosis, how many chromosomes will be present in each daughter ce fxutzfq1 i;78-w-aqzll after cytokinesis?

  The image shows a microgr 4xjh ;xvyk 4 o(+j8g-vvb3kjcaph of a cell.


What explains the appearance of the cell in the micrograph?

  Which statement(s) about homologous chromh9x,da4/fh)tsx:s+ fy z cfx zh (bo-3ass*:posomes 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 withy z ws lhqfjcu)4.bmd23( 2i9y Down syndrome.

Which statement is not correct?

  In the cells of a horse (E. caballus) during prophase I of meiosis I therlvxekckd7 p 6 qy. 7;ed9f:qe3e are 64 chromosomes. What is p k3 7d fvd7:eqlec;ykqe.x96the haploid number of chromosomes?

  Which arrow is pointing to;qp yl8posg*;yh jwf8hs5l+9 a chiasma?

  The diagram below representijmpnjhm0/t fqz8; x a76(pb) s the structure of a shoot apical meristem. Which row in the table correctly identifies the processes pqjbx0i/6t7p;a)fhzn 8m( jm occuring in the structures labeled in the diagram?

  How does meiosis promote variationl )kcw ov+6p6(kpz tu7?

  Which of the following statements is/are.gd3sf3rsokr .b;a2 x 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)/4kq /bhuu/fx0y sa d 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 secondaro zf d)i2jb0)dr,u3ggy tumours from primary tumours as ad,)zid f3 gjoub0)2 rg result of the movement of cells?

  How many chiasmata are present in the diagramu+ a s8nlb 0c75 wir*oqk4b-oy?

  Which statement is a similarity between cytokinesis in animal anv5ide* ub d-.ld plant cells?

  Which stage of meiosis is matched a v ov*,op.ot-to the correct description?

  Which statement(s) aoaoa ;-ic+s0 5;gwe0kvwmx7lre 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 the fzj ab2+b6ks8virst meiotic division. This results in the formation of obav j+bsz28 k6ne large cell and one small cell. What is the fate of the large cell?

  Which row correctly describes diploid and haploid ce9 :. vf06fwa9)ibadkosop s/hlls in humans?

  The following table shows the diploid chromosome numay/iti . sh1 qo/)ve:lber of a range of species.


Which of these statements is correct?

  What conclusion can be drawn from thed( x uhme2ct+d9+wwy 1 karyogram below?

  Which of the following processes is chau8(3pn + q /nm5e.rj9xwh iccjracteristic of the meiotic and not the mitotiw9.(u8c e/p5 i jn h+rjxnqmc3c cell cycle?

  The diagram represents a bud with a shoot apica 6mh qng1j;f+a3 msd0zl 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 (Pnt ,i -i. iei2u;xf( eo11dtvgan troglodytes) is 48. Which row shows the correct chromosome numbe ,t1;i txei (o-ei 2vn1u.dgifr for different cell types and cell division stages?.

  At the end of which phase of meiosis I does crossing over occur, and what , jg)llpx1l x+is thelj,l xl1xp )+g outcome of crossing over?

  Which of the following statements does not describe a steru. ;suh0cjk (p in the sodium-potassium pump cycle in the neuronalksr.u h; j(c0u cells?

  Which row in the tablzsm0l *itp o9pab22)y e below is true of meiosis?

Membrane transport is important for allowing partc +(,p4tshm(* zcizm ahe b*8yicles to move across the cell memba 4(c*it,pz by8sc *(hzhme m+rane and respond to 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 iy ry //; pq5b9fmxhao-s 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 shows the concentrations of different cyclinni ;;.xs wiq crrt*k)8s during the cell cycle. Which cyclin is involved in pre;irs tkr.8)n;xw*q ic paring for DNA replication?

The diagram below shows c1;zsgb8qx gv-k3bx 0pkt; ig)hromosomes 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 thehwp ntj(6v- +v1x0su z separation of homologous chromosomes?

  The mitotic index of throat tissues taken from 4 different patients is shown bkeu9 v1gh6v j5hf8 8fdelow. Which patient is most likely to ha 81uffed98 hgjv56kh vve cancerous throat tissue?

1.Draw a labelled diagram to represent the process ofiuh .fn; qae0a p6o(a2 crossing over.

2.Compare and contrast random orientation and crossing over.

3.Outline the stages of meiosis.

  The image shows an abnormal human karyotype v4* u10(akos kzw ogvedr; 8+3jefp:q.


What is the abnormality in this karyotype and its cause?

The graph below shows the rh 74ud bd-r8nl8 qjm*relative amount of DNA in one cell during one complete cell cycle. Each letter re4udqjb-*r 7d8 mn8 hlrpresents 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 homozyg7wxlt /u )fs,jous for brown, long hair and a female cat that has bl )wxj,fsl7/ utack, short hair.


Which of the offspring has a recombinant genotype?

1.Outline how polygend h voj6n3n-:.h8cdyzic traits 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-si/h7s:(,,z ia7a jvfvso w0gosu -bc8 yster chromatids shown in 7(so, ,j0- /vssu baocf8hw7a y :igvzthe diagram below?

  The photomicrograph shows a pollen grain from L. c*qj nf;lfa4 o,andidum (Lily). Which stage of meiosis is showafj* fo,l;qn4n?

1.Outline the events whichznns 19m.i*xq would lead to an individual being born with Down syndrome, which is characterised by the presence of three copies of chromosomei qs.n*9m xz1n 21.

2.Explain how meiosis increases variation.

3.Outline the stages of meiosis.

The mitotic index is *kry ag-24kbt an indirect way of measuring plant growth. A study was conducted on white onions (Allium cepa), under controlled conditions2 k-ra 4g*bkyt 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 dhsyt.6(j u0bb ;du7-)lcr znjiagrams below show two cells from an organism with a diploid u)cy h-d;(.07bt rn6u sbzljjnumber (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 l jcb hduuk(8ahb;6-1growth.

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 numbe343lvat0k6k ye j :r pmmz.l)er of 8, in different stages of meiosis. Which row correctly names eaclk4v).eem 6 tpy0 3:jr3km alzh stage?

  The micrographs show four phases of meiwxik lt-pidp 3(+6 t8z+ aj3zndw3nx5osis I in a plant. In what order do these phase5dn6( int zpkda zixt3j3l+x83 wp +w-s occur?

Mitochondria are responsible f2rvp3t5e y- bc;9q5xn*mhc :psk c 2kaor supplying 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 okhyn :s p3;-tq*c 95 ecmc5kbpr 2v2xarganisms, 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 in different stages of the celph6nie e2ge gx0( sxw 01kp90dl cycle in four samples of lung tissue from four patie6npkph0d 0 9xw1e s(iexe2g0gnts. Which tissue has the lowest mitotic index?

  The diagram shows the dominant cyclin/CDK complexhvxv rgpc 46-5:oap4g es at different time points in thepx-vv6gpcg4 h:4 5a ro cell cycle. Which cyclin/CDK complex activates DNA replication machinery?

  Studies have shown that genes such as Cyclin Dependent Kinase 3 (CDKN3) a)jmab2umrpvt3, uwwe+j 5. l, re highly overexpressed in cervical tumourj32a) epjm+.bww,vt5um,r uls.


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 mao ae na25 t;2e,8ycnthe cell cycle ?