The graph below shows the relatht-bu 5das7 vjj+g/a5ionship between maternal age and the incidence of non-disjunction. What relationship is suggested by the jdaghb+5vs75aj u/ -t data in the graph?

  Which stage of meiosizryi66rs mqoaco: 50 55 nqpr9s is represented in the diagram below?

  The diagram below shows chromosomeo g66/e .b* v hmv:qvj je.j-6u/xnafds 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 single gene whie)ube l )7woz8ch would be present in b zewue78ol) )the nucleus of a cell as a result of each process?

  Which keyword is matched to ofifjjvq9a7qttb,g: zo* upcb74 50 7the correct definition?

  Which statement(s) about mitosis is/are true 8v:zo f)oqo(wy6xb/ p?
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 bezdby h*e:g45p low, which letter points to a cell in anaphase?

  During which stage of mitosis does the nuclear envelope break dy7, zjrn7mh k0own?

  Which one of the following transport proteins only carries ovr6m l*y ag(j0 wy(n+xnv +bp1ut active transport? 0y(n(myjxb ga vn*6wlp+1+ vr

  Which process does nonb.- j.5urgcc t happen in the shoot apex?

  Which type/s of membrane transport do/does s ie6:w. x/ kyju x3iz qhywzis.oew9y5j*3 6-not require energy expenditure?
I. Facilitated diffusion
II. Active transport
III. Osmosis

  The diagram below represents a cell wi;wh 3db liac1r9s-)xeth a diploid number of 4. Which stage of cell division is the cell currently uir edhl s bc;3)-x9w1andergoing?

  The photomicrograph below shows a root tipm)k e rqn8j6++x6u rug meristem. Which of the following sentences correctly defines a meristemq kgx r+e umn6u6r+8)j?

  When does the random orientation of homologous qadgq dec 9n65*g0;qw* ffc pvoz+fo41s)vb2 chromosome pairs occur?

  Which process does not occur during meio8* k .puhkuj467xgfps sis?

  If a cell with a diploid nrum+ (o oj/e1bumber of 36 undergoes mitosis, how many chromosomes will be presentmb+j ouo(er/ 1 in each daughter cell after cytokinesis?

  The image shows a microga,6b4 ztzj6 ns )tfp+tz7- znrraph of a cell.


What explains the appearance of the cell in the micrograph?

  Which statement(s) about hodhu.:jp a00ay6i yhf-xiov 93ib ,7gvmologous 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 individual with Down syndj s--)ghi5i3schhim 5(a c3xwrome.

Which statement is not correct?

  In the cells of a horse (E. caballusvmso ob7 r aug7o3b1f5 7 sh1v,vrbp06) during prophase I of meiosis I there are 64 chromosomes. What is the haploid numb3p0m17ob vsr5 v7bh rfg6u,as1vbo o 7er of chromosomes?

  Which arrow is pointing to auiszrw g--26 a chiasma?

  The diagram below represents the structure of a shoot apical merist/*tl g)y.ekq tem. Which row in the table correctly identifies the processes occuring in the stlge) qt yk./*tructures labeled in the diagram?

  How does meiosis promote variatio-6u :8z)pgnsq88td vqde njtcr*hl9k6- :n ccn?

  Which of the following statemerx:46pelp q(ivam w8:nts 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 ga pe:34y/tmq)wgg/ utrv v g8u0metes 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 fol:vqmw (he(g4rmation of secondary tumours from primary tumours as a result of the movementg vhl:meq(w(4 of cells?

  How many chiasmata are present in the diagrdikm t7+9cjmyr38 (yjam?

  Which statement is a similarif0m.iv 6g :vzjd:f bz:ty between cytokinesis in animal and plant cells?

  Which stage of meiosis is matched to the core,w(i ypa i dm 0 7pqyw7)p+:is7)xaqjrect description?

  Which statement(s) are true of meiosis I but not/.0mv p-u baur 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 oocytegv7ak8,d+-wbdposab3 f4 *lg after the first meiotic division. This results in the formation of oneakog4l b37-g*8d+psvdw baf, large cell and one small cell. What is the fate of the large cell?

  Which row correctly describes dipl9s.;1 gfjzq wsstldhj 1i 0-k.an)vf6 oid and haploid cells in humans?

  The following table showsz nhjx* p99zi2 the diploid chromosome number of a range of species.


Which of these statements is correct?

  What conclusion can be dra)o q-,p*s4ve1fi fi .zjk yx1rwn from the karyogram below?

  Which of the following processes is characteristic pf r6pv* 6t qshid6psb7-fqnl 2e+ (p0of the meiotic and not the mi-lq0*( 6 n6t2 qfephpf pp v+bisd7sr6totic cell cycle?

  The diagram represents a bud wit;j kn*2qvh6 qbhk ;c2sh a shoot apical 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 shows j 9u+2pzs(lx 9chg41- hgfncbthe uczp9(x h +jfhg29- 1bcnlgs4correct chromosome number for different cell types and cell division stages?.

  At the end of which phase of meiosis I does crossing over occurlw b,imhd7;(e . e ;ngmez4fh9, and what is the outcome oe;,f7mg mb dlzh nhi ;ew4(.e9f crossing over?

  Which of the following statements does not describe a step i(6voje l 7pma;n the sodium-potassium jov(ep ;a6 m7lpump cycle in the neuronal cells?

  Which row in the table below is true of meiosiwi+4 0 wsnyrj9g 3sxf;s?

Membrane transport is important for allowing partih i ,b 63s:hh(b ndxhwk5+ awnj r)(tq6q0v9dwcles to move across the cell membrane and respond to changes in iqwnj(3 hd r hq9+wkbs,d)vh6:0w nxtb5(a6 hthe 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 cellsiu3vgs oka50 ex )d)3c.

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 thex5 66i.es33es uplxzu concentrations of different cyclins during the cell cycleezu x5pesl63.s3 6iu x. Which cyclin is involved in preparing for DNA replication?

The diagram below shows chromosomes durvq q aycml8dt4,3*6taa 7 :niring 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 separati;jlv,r :j-*)m8e3f shop a xuoon of homologous chromosomes?

  The mitotic index of throat tissues taken from 4 different patients is shown bell-g,g5n 4 qsn9u7r+csoyn+2fy q(l rmow. Which patient is most likely to have canceroyu2 (s5g+g9-s nrn ll 7qny+f,rmco 4qus throat tissue?

1.Draw a labelled diagram to represent the process o1 p:in+;9;thkt nmqckf crossing over.

2.Compare and contrast random orientation and crossing over.

3.Outline the stages of meiosis.

  The image shows an abnormal human karyotype. cvl *q8kc6q7xcf7s) 98snan y


What is the abnormality in this karyotype and its cause?

The graph below shows the relative amount of DNA 0 cpd(mptz+ eiftdjrwr )mu(.v7() p6in one cell during one complete cell cycle. Each letter represents onevc7)j 0)d6wti(rm mtre(u. p (fzp+dp 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 cron06nl5 : bore7)c feahx.cax. ss between a male cat that is homozygous for brown, long hair and a female cat that 7a:b) c5r.nef oxx6n0hcael. has black, short hair.


Which of the offspring has a recombinant genotype?

1.Outline how polygenic traits can show a normal distribution0 ,g8k fp.hvr2 -dguhg.

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 cross/;ghpl :gy yt-k xtf-0ing over of non-sister chromatids shown in the diagram below?- /-f tgx;tl0yhk:gy p

  The photomicrograph shows a pollen grain from L. candidum (Lily). Which stage of0 ma t e0g +.yihre0bbzsta46v(.zcx8 me r.evaehta bi.z4sg 0(6cyb+0m8t0 zxiosis is shown?

1.Outline the events which would lead to an individual being 5gr+*re4 phgkb x*w -cf,5avaborn with Down syndrome, which is e *p a+-wra,* xgrf5cg4hbkv5characterised 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 st,1qnx5lxas.ll 0axe3i* aou1z m1 p8w8o,pnxudy was conducted on white onions (Allium cepa), under controlled conditions in a lab, to investigate the effect of soil pH on the mitotic index of the roots. xx*mpzl n8au8l1ie 3n 150pwlox.oq ,sa,1ax


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 diagrams belchr2t (*n)awp ow show two cells from an organism wrc wtphn)a(*2 ith 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 expression in rk2z qai:tlt+h )fn* +6h n +zhb-:fpjstem 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 dip iqvqfvt6u;rvk--.f ,loid number of 8, in different stages of meiosis. Which row cor .vtu-r,-qf vf;k6ivqrectly names each stage?

  The micrographs show four phasero/ dcs w;j48hs of meiosis I in a plant. In what order do these ph;h /48w osdjcrases occur?

Mitochondria are responsible e14hy-7ytpq q for 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 organisms, inheritance patterns of mtDq 1tyq4pe-y7h NA 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 tlpie1*atst5(ql z ) (hhe cell cycle in four samples of lung tissue from four patients. Which tissue has the lowest mitoti hesl(pz lt(5aqi)1*tc index?

  The diagram shows the dominant cyclin/CDK complexes at different timerpi2 2f: 2c7i 8ziezsz points in the cell2c2i 8zfprs2:iez i7z cycle. Which cyclin/CDK complex activates DNA replication machinery?

  Studies have shown that genes such as Cyclin Dependent Kinase 3 (CDKN w8s-/pqqcbptvd-z /,f-6 fbt 3) are highly oveqf, -pbdq 6f8 t-s/ wp/b-cvtzrexpressed 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 cyhrq0 1b6wrcs osk-* p(soy6:iclin E the highest during the cell cycle ?