The graph below shows the relt 4djy.rf ;9o*vji 1ywationship between maternal age and the incidence of non-disjunction. What relationship is suggestv1jtj4dif; yw9or * .yed by the data in the graph?

  Which stage of meiosis is repre;rijem4q h sd2i9(g7psented in the diagram below?

  The diagram below shows chromosomes during meiosif xxog6(j3 r8as.


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 allel2np3o jg06sf x(fas, kes of a single gene which would be present in the nucleus 2g(kj0pf6sxfs, a3noof a cell as a result of each process?

  Which keyword is mat eq: ldb(;th3ahdjp z1ln 34f/ched to the correct definition?

  Which statement(s) about t3g.f5 s .s d2bo:bs; +tyhksxmitosis 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 an; a (l+injz, oxv+e(tmaphase?

  During which stage of mitosis does the nbf 1u+8;bw umfuclear envelope break down?

  Which one of the following tbjmol4 e)i 0 f+u9c-na3 ahqn1ransport proteins only carries out active transport?ab-f +mu iqch)oe lan09jn413

  Which process does not happen in the shoot ape14m9ad* e2)jdu5ttyn( zbl eux?

  Which type/s of membjc6cru7skn6i 4l m+1d rane transport do/does not require energy expenditure?
I. Facilitated diffusion
II. Active transport
III. Osmosis

  The diagram below represents aninvg * oc ,edgnw* 04f2d+x,k cell with a diploid number of 4. Which stage of cell division is the cell currently undergoing? ,edx2g+cd*n *wk 4no,0fv gni

  The photomicrograph below shows a root tip meristem. Which of the following*7gd uvs3g j1t sentences correctly defines3 vdjuts1*g 7g a meristem?

  When does the random orientation of homo( (v 5l/qqselqlogous chromosome pairs occur?

  Which process does not occur durik d7 9hw)hfgfyff73g; ng meiosis?

  If a cell with a diploid number of 36 undergoes mitosis, how many chrom0)d assm8xz, uosomes will be present in eacsa x0)uzmd8s, h daughter cell after cytokinesis?

  The image shows a micrograpw3p6y oqi)o7 oit7y:/l t-vwkh of a cell.


What explains the appearance of the cell in the micrograph?

  Which statement(s) about homologous chromosomes x4r nr5x -bvp gt2 ncl7l4;l/zis/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 withwr;fw9 qjv)3y0o2v,oc yw8ig Down syndrome.

Which statement is not correct?

  In the cells of a horse (E. caball3vy)xs gr hlun u()g19us) during prophase I of meiosis I there are 64 chromosomes. What is the hapl(9y gu)xr)vhnus 1 gl3oid number of chromosomes?

  Which arrow is pointing to a chiasfzh*/ m)zt(j03 gydkgma?

  The diagram below represents the structure of a)ma3 o-2ln2zyyw :umg shoot apical meristem. Which row in the table correctly identifies the processes m3 2)mln:og uw- y2ayzoccuring in the structures labeled in the diagram?

  How does meiosis promote vek(th kpbn ga.:z r/kr x1-g60ltd 4kk62vdd*ariation?

  Which of the following statements is/aroe 3ot-(t ;zrge 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 fro.b a2v l2wawc(m 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 tumours f)w* aaka0;nx;r;ugwx 61 em qwrom primary tumours as a reswuanw16aqg ; 0xxwerak )m*;;ult of the movement of cells?

  How many chiasmata are present in the diagvw6nb mpa2.9,yqokm 0ram?

  Which statement is a similarity between cytokinesis in animsib;v9t)- jolb f yi*.al and plant cells?

  Which stage of meiosis is match*7; vm5v a:qr77+azv d zy( jfwk7fznxed to the correct description?

  Which statement(s) are true of meiosis I but*bk3 pij8 (xti 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 me /+qeamq5)hlzq,d -tliotic division. This results in the formation of one large cell and one mqzd-l a)q/qeh+l ,t5small cell. What is the fate of the large cell?

  Which row correctly describi)qt m5c-g po j40/vcdf;1 8;ygnkiztes diploid and haploid cells in humans?

  The following table shows the diploid chromosome number of a range oq9t1 vr r2wfrbr* u7p,f species.


Which of these statements is correct?

  What conclusion can be drtd( ou*fr hiav:- ll*9awn from the karyogram below?

  Which of the following prhan 86n-m7 5 2nskwknb2 6mymzocesses is characteristic of the meiotic and not the mitoti6 mkm7 -y65nbawsn2n 2 mkhz8nc cell cycle?

  The diagram represents a bud with a shoot apical meri*-uee dhae4n8g(9ot k stem.

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 qpi 0:6bln+3 u1j,0isu d:hkof2 q wszshows the correct chromosome number dswh il,iq0k:0j2 zbu1: qn3uso+pf6for different cell types and cell division stages?.

  At the end of which phase of meiosis I does cf-kwg v,ux zsv78c8j-rossing over occur, and what is the outcome of crowz k7,-u 8v8jv- fscgxssing over?

  Which of the following statementpg2; pypjn p08s does not describe a step in the sodium-potassium pump cycle in the neuronal cells?g82j 0p;pp nyp

  Which row in the table below is true of meiosisal:6iop+z i (et3ioe)?

Membrane transport is important for allowing particles to move pf kieau3gy))4; y d8ebk +u9wacross the cell membrane and respond to changes in the chemical composition of the extracellula fky4 ae+p)u98u);eybd3iwg k r 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 celld w yr77 8hirrbf*6vi.qr:pp) +:lrwss.

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 diffnckscftdu6hm 3x0 ; u-a+ji 4/erent cyclins during the cell cycle. Which cyclin is involved in preparing for Dtf0diu h ca 3u;snj 6/km4-+cxNA replication?

The diagram below shows chroz,:vof/ mqnp94x pet3 mosomes 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 in)p o (c)6*p/e lnd3f n6sfnkiwc+l ai1volves the separation of homologous chromosomes?

  The mitotic index of nci p i3l;dc-y:a2m :wthroat tissues taken from 4 different patients is shown below. Which patc pn-ci ml:ia2d3;w: yient is most likely to have cancerous throat tissue?

1.Draw a labelled diagram to represenb0dl2u s,tws2 t 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 karyotypwg-p;m br;f0g+c 2lmjf2 o 4yze.


What is the abnormality in this karyotype and its cause?

The graph below shows the relatickjbs6hrul .:h,, (up jhur: 0wmf3l 6ve amount of DNA in one cell during one complete cell cycle. Each letter represents one stage of the j,pjl(l,mhs :u ub:6h .3chu6kr0rwf 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 bfo a+0dav/za 85nhvg64/yt jletween a male cat that is homozygous for brown, long hair and a female cat that has bl odaf6jt80nl54z/h /+ aav gyvack, short hair.


Which of the offspring has a recombinant genotype?

1.Outline how polygenig9s 7jxr;qpt-:f u1xo aa y 4h-l,mfw4c 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 crossip c6ve mris5*,g:km a)ng over of non-sister chromatids shown in the dim* m piscvg a)ker5,:6agram below?

  The photomicrograph shows a pollen grain from L. candidum (Lily). Which sta p6w c 2ir)tk;yoq4*ptge of meiosis is sho;2*6iy4tptkp oc r)q wwn?

1.Outline the events which would lgbbcnw/a s- ,9w-dc t1vez43em5f8qj ead to an individual being born with Down syndrome, which is characterised by the presence c,svb g5c beqa-89nm341few/wz j -tdof 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 growthg* i ;e/bctr 6lu(mqz1j ;zq+g. A study 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 rooz+le *b cquig 61r/(qt;;mzgj ts.


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 tw9* sqvnbqgh)amm6+ rvesc643 o ways in which cells can divide. The diagrams below show two cells from an organism with a diploid number (2nhs)mv4v6sr bn m3c*9 g6+qaqe ) 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 expressu h-obl2.sqm/ion 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 number of 8, in differenjk+kopcb/ - 8zt stages of meiosis. Which row co-8/ p+k kbojczrrectly names each stage?

  The micrographs show four phases of meiosis I in a planz4n3oxxj6 u- a jtjs3*t. In what order do these phases occur?txz3j3*6 jx -u4naosj

Mitochondria are responsible for supplying metabolic energy in eukaryotic cells.rss,o2 q4rrjk5ub 7;h(gyw7a 2kb5ur In most eukaryotes, which reproduce by sexual reproduction, mitochondrial DNA (mtDNA) is in b2ayrro 5uh(k;wj42 q, r7k5sbu g7rsherited 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 ecm/hl;c 2 s(sf/ d)zjin different stages of the cell cycle in four smc2/ejc) h(s sz;/fdlamples of lung tissue from four patients. Which tissue has the lowest mitotic index?

  The diagram shows the domig5nj+ fc e+k481obffjnant cyclin/CDK complexes at different time points in the cell cycle. Which cyclin/CDK complex activates DNA replication machine4jo1++fbck 85ej fn fgry?

  Studies have shown that genes s:c: eod4qe6n m;se)g+ mvch2much as Cyclin Dependent Kinase 3 (CDKN3) are highly over) mo;vdnce4m6 gce2se mq:h: +expressed 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 concentratio1.ef5jk z ewr5zm:; mtn of cyclin E the highest during the cell cycle ?