The graph below shows the relationship between matef*;gevx ct+gm fir)mp69a27( ,lgb 01w vmkyg rnal age and the incidence of non-disjunction. What relationship is suggested by the data * )+i gg(a mkx6b7pgl9;1efvfc y2vmmg ,0rtwin the graph?

  Which stage of meiosis is repreb :plz qt7tq/)sented in the diagram below?

  The diagram below shows chromosomes du.63 blb i/kmsering 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 s.9uzwv v9 n fe*tx(ue8j .0zvqtates the number of alleles of a single gene which would be present in the nucleus of a cell as a reez.v9ut8(u z .0vn vfj9*xew qsult of each process?

  Which keyword is matched to the correct dnch fz5j1c163ol 0yvh v*ee. 0a-ieedefinition?

  Which statement(s) about 9(vbq p1pab0i5gk.og1, odz 2nyb kh8mitosis 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 6q8 sqwnm74gqa cell in anaphase?

  During which stage of mitosis does the nucleav o9 d- +1mm0scuq9jdnr envelope break down?

  Which one of the following transport proteins only carries out ac79tv ml fpui5 34 gdb+g(teym9tive transport?5mt g+p3g m79bitdeyl4 9u(vf

  Which process does not happen in the shoot a 6ij*s wgrr 9ga,t+1jwpex?

  Which type/s of membrane transport do/does not require energs +8ypqt/a:mmjn9.jy y expenditure?
I. Facilitated diffusion
II. Active transport
III. Osmosis

  The diagram below represents a cell with a diploid number of 4. Which stage of )qaxxjztu 0, 3) ik:q yd74vrwce74yaqrx)ukd ,vtz)wj q3x0i :ll division is the cell currently undergoing?

  The photomicrograph bfoo4ohk r*t0)h nj24 delow shows a root tip meristem. Which of the following sentences correctly defines a meristem? tood ohf4h)4*2rkj0 n

  When does the random orientd66 f/xk1z lodation of homologous chromosome pairs occur?

  Which process does not occurqz fo38 n:npfli 660hj during meiosis?

  If a cell with a diploid numg2i3lew8 ;szsv t*bk,ber of 36 undergoes mitosis, how many chromosomes will be present in each daughter cell after cwb8t; 2,l3*eskz svi gytokinesis?

  The image shows a micr (jp,1o wu,cjp0(ins yograph of a cell.


What explains the appearance of the cell in the micrograph?

  Which statement(s) about homologous chromosomes 2qk6nj( zy8tp 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 with Down synd-8wg)yejq fb( hnbr9g *zem8qh-.a0 irome.

Which statement is not correct?

  In the cells of a horse (E. caballus) during prophase I of mei.lthehv9i79dcr -j0ahvzz 2v4 c 6y6 dosis I there are 64 ch vdd4vvzt2.ah0r 9c h7zyi9el j6-hc6romosomes. What is the haploid number of chromosomes?

  Which arrow is pointing to a4) oy :5 - g,*c9p:vjibc(w,kla oo sqwzlpm*y chiasma?

  The diagram below represents the structure of-r f/hrlgb2l y **csy* a shoot apical meristem. Which row in the table correctly identifies the processes occuring in the structures lahlrbl*2/fy- y cg*sr*beled in the diagram?

  How does meiosis promote var7yki4ube l c-2q134bjwk)g8nbnv h s 1iation?

  Which of the following statements is/are kd. 4kkl p+84b0tx fcvcorrect for meiosis?
I. It is a reduction division
II. It involves random orientation
III. It produces genetically identical cells

  The diagram shows gametq/90hxdmrs p xumg 316es produced 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 secondary tug.wg(vs(agg s ty1,l, mours from primary tumours as a result of theygas,s ,(.glgvg( t1 w movement of cells?

  How many chiasmata are presewv- -uc q,tosfjv jg86o0,zr2 nt in the diagram?

  Which statement is a similaj1 :x2q ww,p-/ vgqyaority between cytokinesis in animal and plant cells?

  Which stage of meiosis is matched ti a 6wh+j8xds*o the correct description?

  Which statement(s) are true of meiosis(ozqr poc + 98d7qyk/k 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 meiotic ga* z90smv,3r,1fb1ofjtfeu division. This results in the formation of one large cell and one small cell. What is the fate of tv019mz fobag ,,t 3s*efr1jfuhe large cell?

  Which row correctly describes diploid and haploid cells in humansbgqog p;(h r,,?

  The following table shows the diplon-gcd ogzg9n/s(j+zn1 xot4 )+ n3rngid chromosome number of a range of species.


Which of these statements is correct?

  What conclusion can be drawn from 2z888hv:yh,d a4-q.wsbncwe 8hop zkthe karyogram below?

  Which of the followinwo djcif(v .k*1h*z) sg processes is characteristic of the meiotic and not the mitotic cs. iv1(jo* wf )kcd*zhell cycle?

  The diagram represents a bud with a shoot apical meris* k nom2mp48jl u7pi+.ss6ebqg3p/jp tem.

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 (q,+eex 98sdq8q+ btub Pan troglodytes) is 48. Which row shows the correct chromosome number for different c8 dbe8sx9be qt+,qu+qell types and cell division stages?.

  At the end of which phase of meiosis I does crosyb:*uq :6soqbpad (t9sing over occur, and what is the oua6*(yd sqp::qb buto9tcome of crossing over?

  Which of the following statements does not describe a step in the sodio (o7zf9r:a 4 fjoxb.kum-potassium pump cycle in f:o.r9ab fo(4oz j k7xthe neuronal cells?

  Which row in the table below iu/d+5ljg gh 47yfnw +ds true of meiosis?

Membrane transport is important foycvrkc8l1/w:g6 n3l*itv )ukr allowing particles to move across the cell membrane 8 / 3l:k6ltkc*y)wv1gvurci n 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 is regulated in n5fd ybb 1iw1-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 cyclins dud.s) mwd bqd2:ring the cell cycle. Which cyclin is involved in preparing for mb2d:dd.)qsw DNA replication?

The diagram below shows chromosomes durwjr ,wtn*59oja fev)81og-r o ing 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 thh)a)3htnntvxa(8 q2bg3k so 5e separation of homologous chromosomes?

  The mitotic index of throat tissues taken from 4 dify *lii1, 5ex mzr:papawwm. t+-;d2ios oke+-ferent patients is shown below. Whici*mm : 1 ,.eia-eowp+p-5x asd;2+yizlr wtkoh patient is most likely to have cancerous throat tissue?

1.Draw a labelled diagram to rep9 wi90wh, yynnresent 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 1m dh+yqi:;q ukaryotype.


What is the abnormality in this karyotype and its cause?

The graph below shows the relative amount of DNA in one cell duri2):qmus0nnslh t0j 3ong one complete cell cycle. Each letter represents one stageqhl0) sj 3tnm2nuos:0 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 croqqv;ypn(ts73 o1 x4q,d ;tc yiss between a male cat that is homozygous for brown, long hair and a female cat that has black, , qq7 ;i3o;tdc nysptvqx( y41short hair.


Which of the offspring has a recombinant genotype?

1.Outline how polygenic traits5lovh 0a4.bf4brhpp( 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 chromakboc+h;h9m 2vs vosm3-- coc2 tids shown in the diagrah2-o9cmh c2bs+voom3-v s; ck m below?

  The photomicrograph shows a pollen grain f,d qepo u 624edvq(9lsrom L. candidum (Lily). Which stage of meiosis is sqdvd lu 49e2sq,(e po6hown?

1.Outline the events which would lead to an individual being born with Down synk +:i4f)ppc9/or qtdpdrome, which i) itpdcorf kpq4p+:9 /s characterised by the presence of three copies 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 growth. A stud*.h8 gvp(na t 1ykpc(xy was conducted on w8ayh*(c x .pg k(nptv1hite 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 cells can da30se*vg aux ; tk)1duivide. The diagrams below show two cells from an organism0g tu*e d1sk auaxv3;) with 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 expressfzpq*+ ol; j.eion 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 si7gr 5t2uw qu3how a cell, with a diploid number of 8, in different stages of meiosis. W5rwu 7t32iq ughich row correctly names each stage?

  The micrographs show four phases of meiosis I i+zp. gfx0zx)x-g3 n 3ds2kc xln a plant. In what order do these phasedskcxx.+x x z-zgln g0f 2)p33s occur?

Mitochondria are responsible fo/qd9m(xdb 9*thvdo j :r supplying metabolic energy in eukaryotic cells. In most eukaryotes, which reproduce by sexual reproduction, mitochondrial DNAmoxt: *qdjd9b 9dhv (/ (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 in different stages of the ce(f) qepbucv 6j5)6 usyll cycle in four samples of lung tissue from four patients. Which tissue has the lowest mitotic indesuj6)vf(5bpye )c u6qx?

  The diagram shows the dominant cyclin/CDK complexes at different time p )5y jcr0o3 dph)iwcp7oints in the cell cycle. Which cyclin/CDK i35 7)wc)ppj0dorhcy complex activates DNA replication machinery?

  Studies have shown that genes such as Cyclin Dependent Kinase 3 (CDwzw: /gu1n ;hphvpgy)3)vi/ rKN3) are highly overexpressed in cervical tumoy/ u3g 1pn)v: zp)g;v hwihw/rurs.


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 crd;tsm8(zw 9rell cycle ?