The graph below shows the relationship between maternal))yffqem3 ux n:x .gm/cz ied 5lk6t4i:.a/pk age and the incidence of non-disjunction. .e6n:g xd)ie /:tlm4qx/. y ukkzmcf)i 3pa5fWhat relationship is suggested by the data in the graph?

  Which stage of meiosisci95noe v;y/ 5a;ugx: gchu1b is represented in the diagram below?

  The diagram below shows chromosomes during meiosis4e ywnib m,)3,tb*lln.


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 allelm68(ib.x 4plyly mpt/ es of a single gene which would be present in the nucl/i486 xmly p(t.mbypleus of a cell as a result of each process?

  Which keyword is matched to the correcbupo rmz)wka:44 m xey/b7 1k3t definition?

  Which statement(s) about mitosis is/o.h8pm1 d8nezare 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 an-(n/,k tqvw x cell in anaphase?

  During which stage of m sn)-p1e-eaw2r zq5ob itosis does the nuclear envelope break down?

  Which one of the following transport proteins only carries out/d xat4vr833l)ed, f(1 ynyec8yi bm*iq 2zj k active transport?8rbci*(1 m4a,)3 kjq e2x v8ilt/dd nf y3yzye

  Which process does not happe7o*lvw(+qtgnx: my ol-( ey9sn in the shoot apex?

  Which type/s of membrane transport do/does notsvd d7p1v6k um er7)9y require energy expenditure?
I. Facilitated diffusion
II. Active transport
III. Osmosis

  The diagram below represents a cell with a diploid number of 4. Which fq, jb9cl)8gadot 3 (gstage of cell division is tt, )cad8fb(9loj3gg q he cell currently undergoing?

  The photomicrograph below shows a root tip meristem. Which of the followinc5 un- km+i ho,ziop818dut,eg sent cum+ope5 dtzuo,nih8ki, 18-ences correctly defines a meristem?

  When does the random orientation of homologous chromos(2(m ay7t kd,yu cvvyz89mh3 bome pairs occur?

  Which process does not occur during meiosi 1-/lktciyq6 ls?

  If a cell with a diploid numbey q7cx*t/ 2nzrj m-t.vo(* abmr of 36 undergoes mitosis, how many chromosomes will be present in each daughter cell after c rb2xcy*oq t.tmn-v *(jam7z/ytokinesis?

  The image shows a micrograph of a cel0gwl. */k,2cuqsxlt)+c y5 fk qft +osl.


What explains the appearance of the cell in the micrograph?

  Which statement(s) about hom74fn 1ylli6,gce 0)epi3dv upologous 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 individma7 39iar:b 2c0 ar+zxhda7 sfual with Down syndrome.

Which statement is not correct?

  In the cells of a horse (E. caballus) during prophase I of meioso tpg7)g.f hz+is I there are 64 chromosomes. What is the .po+h 7z)tggfhaploid number of chromosomes?

  Which arrow is pointing to a chiasma? ),sj fo9r)uuenp1 xxq pith*- ln1b/6

  The diagram below represents the structure of a shoot apical meristem.r z)b 97(a0mrxnbiz e: Which row in the table correc0:zzn9e( mbb)xrra i7tly identifies the processes occuring in the structures labeled in the diagram?

  How does meiosis promotid/:er.6oqp6pki9 7 u yi *94fj toztre variation?

  Which of the following statements is/are corre2dpftnj/ t+.lbb.e /ict 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 chromosojdkq.+ a 8l v3wy7/hurmes.


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 tumours from primar91ejl.pmg.h g rh k-bac8 ):dzy tumours as a res cz:-a)p .dhberg.j8 l1k9hgmult of the movement of cells?

  How many chiasmata areb o: 3 -vrs9pu+cbbojpg1*bmn8:sy6t present in the diagram?

  Which statement is a similarity betwk)nu6 nsv+xqh.v gfi w n5/3:m2w*yzseen cytokinesis in animal and plant cells?

  Which stage of meiosis is matched to the cor6j k6 4.,dnqvpk3x sctec7*e jrect description?

  Which statement(s) are true of meiosis I bu6v)n:edq, rag 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 oocyte after the fisupe 0fxh5z; bh.z:7yrst meiotic division. This results in the formation of one large cell and one small cell. What is thsx0 hzfz:upbe;y 75 .he fate of the large cell?

  Which row correctly describes diploid and haploid cells in humanse;cci 6fq l*/dhu3-uhmwu-+s ?

  The following table shows the diploid chromosome number of a range of species.zcgg02(j(q nu


Which of these statements is correct?

  What conclusion can be drawn from the karyogram :89 urj.k.: l4 v , re1mntmq8mhgeonsbelow?

  Which of the following processes is charawv ;ar+ +icl2pcteristic of the meiotic and not the miw;irvlc2a+p +totic cell cycle?

  The diagram represents a bud with a shoot apic)xagr4nq)k7cm v9t.q snqo9/ al 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 thvjdk0 yyg0+ 9me chimpanzee (Pan troglodytes) is 48. Which row shows the correct chromosome number foy+jmgyd9 kv00 r different cell types and cell division stages?.

  At the end of which phase of meios-ua* 87s vm8a oyu,fsboxmy4-is I does crossing over occur, and what is the outcome of cro8yfuy 87b-4vo*xsmm,-u a o asssing over?

  Which of the following statements does not describe a step in the sow.b.gmecxj2 n.v.rt 3dium-potassium pump brj nwc 2.g.t.mxe 3.vcycle in the neuronal cells?

  Which row in the table below is ax*oav+2o (y;9 0.r,lhiij6 t vuvbkbuge1x/true of meiosis?

Membrane transport is important for allowing particles to move acrost ,ponm(+f n-)5f)ug. hwz n ohu:m9pjs the cell membrane z w5p9. ),)htg o nfmu(:+n-nohujfpmand 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+m817 kemz3vnz.jy i x84ujs ugulated 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 b/j 7et 5/j d,qu0hjfeconcentrations of different cyclins during the cell cycle. Which cyclin is involved in preparing for DNA rep/qt 7d /j5jebueh0j,flication?

The diagram below shows chru+ 5eleuv-w9mkl1b*t nm7sf .omosomes 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 chromosomes?: yu nyr9o.ef3

  The mitotic index of throat tissues j41 wfd2-dslc tv3es3ozjn54 ,u3ovf taken from 4 different patients is shown below. Which patient is most lil4ctws zno4v,vo d523ud 3fj3js -fe1kely to have cancerous throat tissue?

1.Draw a labelled diagra 6 qvl2jw9u0/ilia3 cam to represent 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 kar:lc8*8.gyw.;w ktkjwau *b g syotype.


What is the abnormality in this karyotype and its cause?

The graph below shows the relative amount of DNA in /6xirqp/h: hl one cell during one complete cell cycle. Each letter represents one sta:ihr x h6qlp//ge 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 tha2(6(nbdg l(ex-mextu 7r wxt9 0bi:jdt is homozygous for brown, long hair and a female cat that-mn:b6r(2tw9i d b xtd((g0 eu je7xxl has black, short hair.


Which of the offspring has a recombinant genotype?

1.Outline how polygenic traits ;bkyhn j*(krqz6 o 2:pcan 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 resultjro..te nfem7my 8(t zp*+xr- from the crossing over of non-sister chromatids shown in the diagram belo.pj e x7.mreyt+*nzf-m( t o8rw?

  The photomicrograph shows a pollen grain from L. candidum (Lily). Which cg:o zn*ceg+gy n/)5j stage of meiosis is segz n5jcg /*+)cgy: nohown?

1.Outline the events which would leju1iy rqf8gz )w) pd*wp0v 66r7g.jcyad to an individual being born with Down syndrome, which is characterised by the presence of three copies of chp8 wjv6 g qpu.r)zg6 f)c0dyj1y7wir*romosome 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 study was condf, (vue+. sbalucted on white onions (Allium cepa), under controlled conditia(bvse , ulf+.ons 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 waypqcn1 ,sjohp7-3 y6rgdax)i * u5+mlfs in which cells can divide. The diagrams below show two cells from an organiscq)+ lunh idf xgm-3a1j7 *,p5poy s6rm 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 ex(n1p l9w 0few.o k*enepression 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 ,q(xkm(cw1,a:t c ttenumber of 8, in different stages of meiosisxm , t1c:teac(,tq wk(. Which row correctly names each stage?

  The micrographs show four phases of meiosis I /ec-aoxz1 0biin a plant. In what order do these phases occur?xc ze1b/i0 ao-

Mitochondria are responsible for supplying metabolic energy in eukaryotic cells92*jn r2 ei(pdn+nlzle)*sdu+u y0 rl. 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 genetri9lne j l2u + *s rld*dy+0nn2(eu)pzic 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 ofjb,up5e 8kz1 1p+,y;t z1qaa4wrwyik cells in different stages of the cell cycle in four samples of lung tissue from four patients. Which tissue has the low1wk1ar;azj ,y5kbuy81qw eippt4z +,est mitotic index?

  The diagram shows the dominant cycliny7dso ;r+opcf,mew()nd b (p7/CDK complexes at different time points in the cell cycle. Which cyclin/CDK complex activates DNA replicatb, f7 (;en7rw ooc)y(d+ppsmd ion machinery?

  Studies have shown that genes such as Cyclin Deps s(+*j q5ueh fpbvzc;;1h0ewendent Kinase 3 (CDKN3) are highly overexpr*zh1sev ;pc+qj ef (sbuh w;50essed 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 omxad p :1br+6af cyclin E the highest during the cell cycle ?