The graph below shows the relationship between maternal age and the iz0i0.cd 7mu;kz1nqu dncidence of non-disjunction. Whzkqc. im0;7z1u nu0d dat relationship is suggested by the data in the graph?

  Which stage of meiosis is represe0un g2-dynuh:q6fm 8rnted in the diagram below?

  The diagram below show.g/duysl v* g)1 hwr;dx 3u3vys chromosomes 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 statfg)2r g70i h)gybubf, es the number of alleles of a single gene which would be present i rbhgif)0bf)2 u ,7gygn the nucleus of a cell as a result of each process?

  Which keyword is matched to the corre xl;2d/ae*fb cct definition?

  Which statement(s) about mitosis is/a lmj k833rh:q ) f0iurbspe.)hthw)a51g;ops re 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 lege 5(n0fb xicxi9a::ltter points to a cell in anaphase?

  During which stage of mitosis does the nuclear envelope break wsw.z 48 irr5jz0o6wldown?

  Which one of the following transport proteins only ca2q -4af9lpyofrries out active transport?oay9 2qf-4p fl

  Which process does not ha r.t3aaou:db. ppen in the shoot apex?

  Which type/s of membrane transport do/)nq1:lc 3lxvs*4f4oj r vl+tzdoes not require energy expenditure?
I. Facilitated diffusion
II. Active transport
III. Osmosis

  The diagram below represents a cell with a diploid number of 4. Which sta+.c-awp66sp x5,o g*:9qqlidwmt tc tge of cell divisi wt:+9 at-qpg*xl56toc ,cd sqpw6 m.ion is the cell currently undergoing?

  The photomicrograph below shows a root tip meristem. Which o;qn..m) ibs do; pzmw+f the following sentences correctsqn;p+ m.zdim.)b; w oly defines a meristem?

  When does the random orientation of homologous chromosomemk63os d s4.)nzjg h1f pairs occur?

  Which process does not nwv0yi40nyw8;s 4 5eq napz7z occur during meiosis?

  If a cell with a diploidw( z +*dhkm1f8ey4d2)h kwalo number of 36 undergoes mitosis, how many chromosomes will be present in each daughter cell after h+l2ek4adh (w)k1 wo * myzd8fcytokinesis?

  The image shows a micrograph o04rj6w l - v(a+u:l2ogtforiff a cell.


What explains the appearance of the cell in the micrograph?

  Which statement(s) about homologous chromosomes is/are not truj;k l5(lm (0f+ 0rm5ximmma dle?
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 w1nd e:7 ;7ilkg nrqa5dith Down syndrome.

Which statement is not correct?

  In the cells of a horse.xxeip1 rs86c (E. caballus) during prophase I of meiosis I there are 64 chromosomes. What is the haploid number of chropie6 cx8.1rs xmosomes?

  Which arrow is pointing to a chiasm.6jn:.)y s4 et lvpghha?

  The diagram below represents tmna8iukhr1l -h t(p8.n4 - 76vfhly zlhe structure of a shoot apical meristem. Which row in the table correctly identifies ttf6h8ua m-1-pk( 4inlvzh rylhl.n87he processes occuring in the structures labeled in the diagram?

  How does meiosis promote j ur/k oy.h;g3variation?

  Which of the following statements is/ fqd:y8*e/btd( vt4ej 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 chromosomes. tisiw9-,ib;pj t*ya1


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 secondaryzkhy x y+b5uqsha 5pn-+h9 f1. tumours from primary tumours as a result of th1 f bp.xh+n9+5qy 5zhusa -khye movement of cells?

  How many chiasmata are present in toxkq+c3x5xnoujn -* 5he diagram?

  Which statement is a similarity between cytokineocq 4j/6 17ywzsbe x1bg6 k(fnas7j 8wsis in animal and plant cells?

  Which stage of meiosis is matchedl:fag4p .lo;7ejtga1j b n;d 7 to the correct description?

  Which statement(s) are true of meiosisck+;wp1gs6su kw3aj8 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 meiotic6-dq7 rbnqoammm 3(b nrjj1k6h 3d8(s division. This results in the formha8n (j- k7qm d6d3mnqbsbmjrr3 6(1oation of one large cell and one small cell. What is the fate of the large cell?

  Which row correctly describes diploid and ogy py0c4;w8e y4nxv6 haploid cells in humans?

  The following table e/dht3 y(kcf(8px 9kki3 tib9 shows the diploid chromosome number of a range of species.


Which of these statements is correct?

  What conclusion can be drawn fromlm e6w6)/taduknn 9-y8ox3q c the karyogram below?

  Which of the following processe+n a3c88e1c xpcr+ uwcs is characteristic of the meiotic and not the mitorc+np+c8w cu3c1a8x etic cell cycle?

  The diagram represents a bud with a shoot apical r2mk-kmgvk3+vg ) 6 zdmeristem.

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 wwx4)pyp+dmhx6mli 694 h;sstroglodytes) is 48. Which row shows the correct chd p 9sim64 my)whlxh6x;p4s+wromosome number for different cell types and cell division stages?.

  At the end of which phase of meiosis I does crossing nu7+0d)gu m3a+3ujz u rkjsm 4-4tb. aqkgp j)over occur, and what is the outcome +bd0+p.j u- sg74r3juga4k tn)mazu mu3)j qkof crossing over?

  Which of the following statements does not describe a step in ukl e6qec+ 6)qthe sodium-potassium pump cycle in the neuronal celeq +6qk)c6ue lls?

  Which row in the table below is true q.n3 ebnny5 6bof meiosis?

Membrane transport is important for allowing particles to move acrosshri 0wnfd u7 a*5ags-) the cell membrane and respond to changes in the -as 07ru*) ihadnfwg 5chemical 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 mitosisi,5dsfa9bzn 1 is regulated 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 sho t7 39agq: 0;e ;omvqok6o yi-nu2aassws the concentrations of different cyclins during the cell cycle. Which cyclin is involved in preparing foro;o-sa;2m onut 7 seay: 9kqvi60g q3a DNA replication?

The diagram below shows chlb so 9 g(5:bzbq)op)dromosomes 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 h13ixeuy w9: zcomologous chromosomes?

  The mitotic index of throat tissues taken from 4 different patients ua z(jpr75nu-9 wl86vson+wa is shown below. Which pzp-w u(lonrwn 678sa5avuj+9atient is most likely to have cancerous throat tissue?

1.Draw a labelled diagram to represent the f1a7 i saj(u--miln *zprocess of crossing over.

2.Compare and contrast random orientation and crossing over.

3.Outline the stages of meiosis.

  The image shows an abnormal human karyo/u+ atv y*ja6htype.


What is the abnormality in this karyotype and its cause?

The graph below shows the row,z) f .rv6ve9 o8yc sv xi*fh+mrf)4elative amount of DNA in one cell during one complete cell cycle. Each letter represw 4ryosfoz9,+.e ifr )6m8vvf v*hxc )ents 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 malxtt /uf q;e6v2b v,o/ke cat that is homozygous for brown, long hair and a female cat that has black, short h/6ef2btqv /t oxk; u,vair.


Which of the offspring has a recombinant genotype?

1.Outline how polygenic traits can show a nok.)rfn9l + j73 cycgynrmal 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 crossing over of non-scovty+e 4e1 ckt )k9fh5 zj:r,-kgep)ister chromatids shown in the diagram below?hkfp+59 c oe 4 rk1ye-et)t:zvg,jck )

  The photomicrograph shows a pollen grain from L. candidum (Lily). Which str z6o 4.ztrq1zage of m4 tzzo6.rr1 qzeiosis is shown?

1.Outline the events which would lead to an i+gqs 7 3t *dknbsy7pb2ndividual being born with Down syndrome, which is characterised by the presence of three copies of chromos3bn+k2 7bytqp7sd * gsome 21.

2.Explain how meiosis increases variation.

3.Outline the stages of meiosis.

The mitotic index is an indirect way of measuring plan culss/wa 9057ja/s pnt growth. 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 roots.uj95/s as/s7 pl0wnca


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 cf +vqc27t )nvaan divide. The diagrams below show two cells from an organism with a diploid number (2n) of 2fvca+)7n tqv 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 vr5w8jw8d *ohjxi+3y expression 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 shopc yx hc66l54cl4grty0;g 4tdw a cell, with a diploid number of 8, in different stages of meiosis. Whicrly6dc hp5t64 tglgx ;y0 4c4ch row correctly names each stage?

  The micrographs show four plp6g (a-u2, jpi ubme2zedy 7)hases of meiosis I in a plant. In what order do these phases7zejm)ab 6l , 2pd-g uy2u(epi occur?

Mitochondria are responsibg.:p 1aj1ec kw4h8ua lle 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 has1kc.1 hwejp4a g8au :l 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 ofjqr(h(l* u2 tc jtts5+ cells in different stages of the cell cycle in four samples of lung tissue from four patients. Which tissue has the lowest mitotic index?*u( csq+ljt52trjth (

  The diagram shows the dominant cyclin/CDK complexes at different time *g0rybcf:0t/kq/2wdai - 9w qgy/ebbpoints in the cell cycle. Which cyclin/CDK ig90dqk 2: 0r//af*-y ewbqbwybtc/gcomplex activates DNA replication machinery?

  Studies have shown that genes such as Cyclin Dependent Kig0autd :0..qcmklaup dy2,l- nase 3 (CDKN3) are highly overexpressed in c,0kuapa.um q. g2 :0c-dltyldervical 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 the highest during the cell c(zc i35jv(,3i2uuq6 gjgmunu- tzk d: ycle ?