The graph below shows the relationship between maternal agei5h87 z.m kjxf6 al,hh and the incidence of non-disjunction. What ,khxlzh8 j7m fa.6 5hirelationship is suggested by the data in the graph?

  Which stage of meiosis is represented in the diagram be::gb(; lisgkjlow?

  The diagram below shows chromosomezeold1cg(a r+36b 4ae l4osn7s 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 alleles of a singq: f0u; hlup91 j gn2zh;hjkj3le gene which would be present in the nucleus of a 3zq91;u h f:jjlp nuk ;h2jgh0cell as a result of each process?

  Which keyword is matched to the correct del8,o2e-l.yy votq i*:e h:hl )2bpiqb finition?

  Which statement(s) abouh+0 wa k,2tnv (t(gf0kcm3ylqt 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 to a cell in anal)h02h 3mufvj- e n.uvphase?

  During which stage of mitosis dovdekvw zb0v0hynrx6 .:5 e 9j(es the nuclear envelope break down?

  Which one of the following transport proteins ondq5:.w ;sp*dtslgk2trv3mp 6ly carries out active transport?rlt2vqdwm5p6g* k3; sp: ds. t

  Which process does not happen in the shoot apex?av b66lchmc 69

  Which type/s of membrane transport do/does not require energy expenditurh sz b:7jy5lw3e?
I. Facilitated diffusion
II. Active transport
III. Osmosis

  The diagram below represents a cell with a diploid number of 4. Whichmaxr7y2v .z(d stage of cell (.x avd7rz 2mydivision is the cell currently undergoing?

  The photomicrograph below shows a root tip meriste j58 1wnjca.ebm. Which of the following sentences correctly defines a meristem?n5j1c.je w 8ab

  When does the random orientation of hokp wf *5x*a(l0wn xeng4-nq(k mologous chromosome pairs occur?

  Which process does not occur dur3z pd3x o ph*od,a+rjob;vkuq0q;p ;;ing meiosis?

  If a cell with a dipllezzcc7/ yf dop7i j/olei wx+f- o)+r /u(55joid number of 36 undergoes mitosis, how many chromosomes will be present in each daughter cell after cytok7ip+ oj-(7)y wfxjel cf 5dze/u+irooc/5lz/inesis?

  The image shows a micrograoe2dp(u(mjb.w, r, uz4pmam .ph of a cell.


What explains the appearance of the cell in the micrograph?

  Which statement(s) about homologous chromosomes pzm58jo.9yj-q8 v2xav0b qscis/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 syndrozia 0m :djsh1)me.

Which statement is not correct?

  In the cells of a horse (E. 7attj3w.o- pe8 7u gdfcaballus) during prophase I of meiosis I there are 64 chromosomes. What is j7oe3-dtp .gwfuta 87the haploid number of chromosomes?

  Which arrow is pointing to a chias46d 3f10cthw* nneytvma?

  The diagram below represents the structure of a shoot apical mertgf8t *ww uj;la20(pvistem. Which row in the table correctly identifies the processes occuring in the structures la8au2 w*g f(tw;vt 0lpjbeled in the diagram?

  How does meiosis promote vap7 giw .ag95j.1 srq3oow rf;ub/t*wx riation?

  Which of the following stat;nhy0alrm a) *ements 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 chromosomes2m7cy3sxmy 5cd2v g*e.


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 forvf* qe cvn6cvhf)w+xf5) r8f:mation of secondary tumours from primary tumours as a result of the movement of cel8vx f*eq)rnh) c +5wf6cfv v:fls?

  How many chiasmata are present in the dd ,-vdf ypo:1h-i7uc giagram?

  Which statement is a similarity between cytokinesis in animal jl)*/vly q1x tand plant cells?

  Which stage of meiosis is matched to the correct de18wx vqr p6rowd(),wil:2a gi scription?

  Which statement(s) arnw xg*reoe)rca g6cu-8 6 nz+1e 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 first meiotic dij 2fgb,ocs44ehvzt8vn w/ x:7vision. This results in the forma s wvcfo:8,g2b4j7t n x/hz4evtion of one large cell and one small cell. What is the fate of the large cell?

  Which row correctly de fuhv2q45 aje:scribes diploid and haploid cells in humans?

  The following table shows the diploid chromosome numj rp,iy4,f.r ff40fa,9furv sber of a range of species.


Which of these statements is correct?

  What conclusion can be drawn from the kjrzkxqr (+*lznrl 4 5*aryogram below?

  Which of the following processes is characteristic of the meiotic and not the qdjuo 9s)(p-b: zl:q de+fkj: mitotic cell e+ :-qdu):k 9sj:qlfopj(dzb cycle?

  The diagram represents a bud with a shoot apical vhi92biwgt71z+fvs: mb 5c(ameristem.

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 shows thuw+eoiip k;; 8p6p;d he correct ciew;6hd ;8pppi u+k;ohromosome number for different cell types and cell division stages?.

  At the end of which phase of meiosis I does crossing over ocia5t2az a*wiv: m ug+;cur, and what is the outcome of crat5 ai*2;g mzau:v+iwossing over?

  Which of the following statements don zev0i/1ph0wl;1dyw es not describe a step in the sodium-potassiumz 1elwwvn/h00pdyi;1 pump cycle in the neuronal cells?

  Which row in the table vz 8m9umy4zyk-6 v e9pbelow is true of meiosis?

Membrane transport is important for allowing particles to move across the cib- h)m- a4 stv5d/tfgx(wu 0gell membraihgx)ft s(/gbum-dv0tw -5 a4 ne 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 re z-0k: dprc1rlgulated 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 concentratie 4dkcff+.,htons of different cyclins during the cell cycle. Wt 4f+hfek.c, dhich cyclin is involved in preparing for DNA replication?

The diagram below showsp3dj77) ,uzqg yd:dhn chromosomes 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 separatik0 q.ruv5zs8k7er h;qon of homologous chromosomes?

  The mitotic index of throat tissues taken from 4 different patienf dszdjk+lf y ;5*j;n,bg-g4ets is shown below. Which patienl-;z,ys5fge j kngj 4+f ;ddb*t is most likely to have cancerous throat tissue?

1.Draw a labelled diagram to represent the process of crossatd fllzx o* y45+ 5pm+j(:fsfing over.

2.Compare and contrast random orientation and crossing over.

3.Outline the stages of meiosis.

  The image shows an abnormal human o7- , )wteosqx5l+6 dqvpl a:skaryotype.


What is the abnormality in this karyotype and its cause?

The graph below shows the relative amount of DNA in one cell during one complebm( ky1c, uu;fte cell cycle. Each letter represents cbuu( ,mfk; y1one 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 crosspnbt8n84x(pc6 7jaqj between a male cat that is homozygous for brown, long hair and a female cat that has black, short hair. 8n c(bppx 7jtnq64a8j


Which of the offspring has a recombinant genotype?

1.Outline how polygenic traits can show a normal distrim3 tt1fl( z)piw42tiu kl4m (zia .6fnbution.

2.Outline the differences and similarities between homologous chromosomes.

3.Explain why expected and observed Mendelian ratios may differ.

  Which gamete can resu;klw4a qc ,wcod hd(66lt from the crossing over of non-sister chromatids shown in the diagram below? dq6 c;whl wdkc4,6oa(

  The photomicrograph shows a pollen grain from L. candidum (Lily). Which stag;0jf7tg / gvdge of meiosis is shogfdj; 7t0 vgg/wn?

1.Outline the events which would lead to an individual being born with Down syk 5soyqo;j*nw3:fze 5 ndrome, which is characterised by the presenc;5zwq*ok fe5 jno:y3se 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 stuhfb5 mpe 8t6 fwuh 59u/dkyo4+dy was conducted on white onions (Allium cepa), under controlle ou59b h84 +65y/fuphtwmfedkd 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 celu dryi9x6k26uu96se o3gvw /;mg- betls can divide. The diagrams below show two cells from an organism with a diploid number (2n) og369 v y s6uxdm-/2u6e9eb twoiu;g rkf 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 qrdb * ps-ja4iq6ej91growth.

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 number of 8, in different stagp(of ;ai.rp7a,dw -uf es of meiosis. Wh, a(ff7 owpud- i;ra.pich row correctly names each stage?

  The micrographs show four phases of b c6g e2q(7bgdmeiosis I in a plant. In what order do these phases occub(2e7 bqcg g6dr?

Mitochondria are responsible for supplying metabolic energy in eukaryo:istrh-b7 6 wong./; ja aeg;ktic 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 genetic bagwksa b/; .ti;- h7era :jg6onckground.

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 stagesg6ahbp1:k h. m n4pq*xgka ),r of the cell cycle in four samples of lung tissue from four pati :rkq4k. paaghb,)ngxmp 61*h ents. Which tissue has the lowest mitotic index?

  The diagram shows the dominant cyclin/CDK complexes at diffag0p4uk:e d,nm nu4y+erent time points in the cell cycle. Which cyclin/CDK complex acti 4p4g:ue nkany,0u md+vates DNA replication machinery?

  Studies have shown thti( zs4*i*m*qlmqur txd 0 m*6at genes such as Cyclin Dependent Kinase 3 (CDKN3) are highly overexpressed in cervical tum4l*0isimur t*t**6mqq dm (xz ours.


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 ck(nkyko1)w /0d.lj yiell cycle ?