The graph below shows the relationship between maternal age and the in;jq+lt zbi3zj8 5o8yhcidence of non-disjunction. What relationship is suglqj z8bzjhtyo53i ; 8+gested by the data in the graph?

  Which stage of meiosis is represented5 mgho,k2*sok1/f u dj in the diagram below?

  The diagram below shows chromosomes (a4pgt3 xuk+no1xcl6 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 which would ng9p v 9se43m*:h-akdz,zwcrbe present in the nucleus of a cell as a result of each z:94,gwvha 3pc*zrskd e -m9n process?

  Which keyword is matched to the correct d1 lpv754+nf(acbz1p3t;wkss huv r e.dp ,9dhefinition?

  Which statement(s) about mitosis ife kf39m .zj3cu7z:jks/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 anaphas8pw(qb kkz;jg ;/oq9xe?

  During which stage of mitosis y. 5 1* ljlb*i2hdky x5kg1cundoes the nuclear envelope break down?

  Which one of the following transport pj:t 6xb+chx j,roteins only carries out active transport?+:bjx h,6jx tc

  Which process does not happen ino/b5purt+;ffjmbr.ief3q e69) l h8x the shoot apex?

  Which type/s of membrane tf((hbe.oe 8ip l0vm( wransport do/does not require energy expenditure?
I. Facilitated diffusion
II. Active transport
III. Osmosis

  The diagram below represents a cell with a diploid number of 4. Whiiwv3uqgi90 b . 8s0wjdch stage of csbqg0 i0u3 8.v ijdw9well division is the cell currently undergoing?

  The photomicrograph below sho,5gs45bhbi fwws a root tip meristem. Which of the following sentences correctly defines a meristem?5, 5hi4wsbfgb

  When does the random orientation of homologous chrovz vgkay//l-,nc91z72fez f g mosome pairs occur?

  Which process does not occur d-y5 3(b6sdouehv aqh;uring meiosis?

  If a cell with a diploid number of 36 undergoes mitosis, how many chromosomes wb 5.0p -jru1usdmsam 4ill be present in each daughter d a.s rmm- pu15ub4js0cell after cytokinesis?

  The image shows a micrograph of a l 3sv+qso(ldpj85( ek cell.


What explains the appearance of the cell in the micrograph?

  Which statement(s) about homologous chromosomes is/are not evk:5p za i.bh/zst53 :-pvtg8yin2s 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(cr ) *creo lx+3xzh(j individual with Down syndrome.

Which statement is not correct?

  In the cells of a horse (E. caballus) ddv hau( 9y;(o2zthaj*e) k3 rnuring prophase I of meiosis I there are 64 chro9n2aj(; )y3e h*htourk( za dvmosomes. What is the haploid number of chromosomes?

  Which arrow is point,rn g.: 0zfg0*h y17a ahd4tbuhotx/t ing to a chiasma?

  The diagram below represents the structure of a shoot apical meristem. Whiyh 4 lb- srlv)*9cuy6lch row in the table corrycvsrbly64 l*h )l -u9ectly identifies the processes occuring in the structures labeled in the diagram?

  How does meiosis promote varn+(e315ak 8f qvu en s8trco3diation?

  Which of the following statements is/are correct for mxpi4 p k56 y9nn-dgc.deiosis?
I. It is a reduction division
II. It involves random orientation
III. It produces genetically identical cells

  The diagram shows gametes produced from two homologu7 1:k y.bsfbfous 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 ;0yqhje h h+,k,7jhxnthe formation of secondary tumours from primary tumours as a result of the movement of cnkyx qh,j7hj+ hhe,0 ;ells?

  How many chiasmata are presentkau;(e .tqym ld3(g/ u in the diagram?

  Which statement is a similarity between cytokinesis ivj-x3v-su v 6z)akxmlp vc644s;z iu9n animal and plant cells?

  Which stage of meiosis is matched to the correct descripozw +2v.ys ef3tion?

  Which statement(s) are true of mei i z*d *gvf)y7nqc0/c6vj(tososis 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 division. This resultb/gqi/ ej 0+yb -5xa(s asr:cgs in the formation of one large cell and one small cell. What is the fate of the largsc+s/:xe/bb0yqj5 aa(-ri gge cell?

  Which row correctly descy/xe; 5lr;n hzribes diploid and haploid cells in humans?

  The following table show;z(t0hdkvww d zx9on -66q (nfn 3po(js the diploid chromosome number of a range of species.


Which of these statements is correct?

  What conclusion can be drawn from the karyogram belowrbi50(g e-*l* vgvl,hp1. qn.pr vxu o?

  Which of the following processes is characteristic of the meiotic an+ghl fm p4c;y d-gww9:d not the mitot f49;c-phglm :d+gyww ic cell cycle?

  The diagram represents a bud with a shoot apical meristem. 8k idr)0vwu 2)ibsn(e

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 -(q s pw010k7ello dlq3m0ma echimpanzee (Pan troglodytes) is 48. Which row shows the correc1m3ll-sk mw70aed q0(qlp oe0t chromosome number for different cell types and cell division stages?.

  At the end of which phase of oirtmb15l;rjp3c k97 4ds n s9meiosis I does crossing over occur, and what is the o rn;4o93ilj1pdcmr s 7st k95butcome of crossing over?

  Which of the following statements does not describe a step in the sodium-potasln(nkt(1 r tgcz y4qb9+- p t,ipu)6;*nne qtosium pump c*qp-zcnqkto)u 6n1(4n+tnr,g 9pl ( ty;ibetycle in the neuronal cells?

  Which row in the table below is true of m8c4f8 l0t q2n.w7vmq*yy t ackeiosis?

Membrane transport is important for allowing particles to moveyfdh7nbrs)1- across the cell membrane and respon sh1bfy-)d7rnd 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 regulatru a4n7b,0cf ted 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 concen ap7m*/9odd bztrations of different cyclins during the cell cycle. Wm/7oz* b 9dapdhich cyclin is involved in preparing for DNA replication?

The diagram below shows chromosomesrcb9,bs:zt1 8j.(dl l aat pz; 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 6xa4jjw qf-s7volves the separation of homologous chromosomes?

  The mitotic index of throat tissues takentih2 jv1u (n3o from 4 different patients is shown below. Which patient is most lik23(1ti n hjvuoely to have cancerous throat tissue?

1.Draw a labelled diagram to reprek-r. 1d ckvui6sent 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 karyotype.rc46.h9vgpn 96yzxo r


What is the abnormality in this karyotype and its cause?

The graph below shows the relative amount of DNA in one cell du,63yrm ayq4v24arlf kring one complete cell cycle. yql6a24avk4f r m3 ,ryEach letter represents one 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 cross between a male cat that is holpy, +1:ioqt 9xg5k 6.bg gpnomozygous for brown, long hair and a female cat that has black, shx6tq ,ng 91pk:bpogogli.y+5ort hair.


Which of the offspring has a recombinant genotype?

1.Outline how polygenic traits can show a norte(,k ar, 0tab;wfm9(qhahz 5mal 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 t4tgxin 2.;47 1otke*4wdjxwh 0tovdo2mg9 kthe crossing over of non-sister chromatids shown in the diagomk wvw90 4no2*gd t hjixt17.4d4;2tgoekt xram below?

  The photomicrograph sh 9ecgiq;v+zn , aasz,6ows a pollen grain from L. candidum (Lily). Which stage of me i,6z; azcq+9sngv, aeiosis is shown?

1.Outline the events which would lead to an individual being born with Down q e2apvsbbd h*a/.21xsyndrome, which is cha 2v 2 *a1a.bxqe/dsbhpracterised 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 ind5ex;xi wi4emm dv4); oirect way of measuring plant growth. A study was conducted on white onions (Allium cepa), under controlled conditions in a lab, to investigate the effect of soil pH on thed xv;iow m45e ;xm)i4e 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 divide. Thesk4p2p2o-mca:5ixo53knzll d/ j e j ) diagrams below sho3)cjk2/d - mzosi54p5 op nl2kxl:eja w two cells from an organism 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 expres *nmb.nwwzj5 2sion 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 x7gm c40xq u7vcy):jba diploid number of 8, in different stages of meiosis. Which row correctly nqu7xgjym bc4 ) xv07:cames each stage?

  The micrographs show four phases of meiosis I in a plant. Ingu)sf)l.v2aqp *ia q43cha 4o8 efha5 what order do these ph)5aosqe2u 48 i. q4ghcafp 3*afl vah)ases occur?

Mitochondria are responsible for sup5f41p v bbsgqj9 1ks1w5ou6a jimkt7* plying 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 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 backgrounqvj1fpw *6jok m1ui9 tsk g1b sb5547ad.

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 cell q3f6 . tg/sh65krshuk cycle in four samples of lung tissue fro3fus 6hkst rqk6g.h5/m four patients. Which tissue has the lowest mitotic index?

  The diagram shows the dominant cyclin/CDK complexes at different timesf0 .hwiy07u r points in the cell cycle. Which cyclin/CDK complex activates DNA replication machinerfwh 7y0s0r .iuy?

  Studies have shown that genes such/:+,c ako )gewu4gc lbbm-r-z as Cyclin Dependent Kinase 3 (CDKN3) are highly overexpressed in cervical /ubme-gawzc,l4-:c r)gbko +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 cyclin E tha)vabub2( :gy e highest during the cell cycle ?