The graph below shows the relationship between maternal age and the incidence of8kdmleo9ziz8 3v:/*:okse5 l iv/ig r nkei8vvm 5:i /ilo3:l* k9ez / rzgosd8on-disjunction. What relationship is suggested by the data in the graph?

  Which stage of meiosis is represented in t81dytqgk 1(:dtkd i.e he diagram below?

  The diagram below shows chromosodi*hela jhr9toeopj5/ d(yn2zc /;/ , mes 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 at 1bjpg)3)ch6:svmg t71mmxof alleles of a single gene which would be presenm13pahjb6mm g 1st c)g:x 7vt)t in the nucleus of a cell as a result of each process?

  Which keyword is matched to the corrf3 tj z2h*+t( .ideg /lryda4ject definition?

  Which statement(s) about mitosiszh12l2/d- ai) fpn fks 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 lett*qi6n5di p dkem e:qq.)9x7uq er points to a cell in anaphase?

  During which stage of mitosis does the wc* id9mita ,6nuclear envelope break down?

  Which one of the following transport prot;0epys gyl 0auq(*;p0h p; clheins only carries out active transport?(*p;a0qp sl upygl0 ; hhc0ey;

  Which process does not happen in the shoot ape z- :u,(l+jigse ow+yox?

  Which type/s of membrane transport do/does not require energy ex ,. clz,3 oghuba8(hfdpenditure?
I. Facilitated diffusion
II. Active transport
III. Osmosis

  The diagram below represents a cell wvh osm d:bt:+4ith a diploid number of 4. Which stage of c4dh +vb: ms:toell division is the cell currently undergoing?

  The photomicrograph below shows a root tibb nxtlxgr5ai ;/hh0+31pnchs d6f62p meristem. Which of the following sentences co cxshb;i0l/hnpd6bn 3 gh61 frxa5+t2rrectly defines a meristem?

  When does the random orientation of t;yfwo zxd7so me;:o5bqv 5( tm237wghomologous chromosome pairs occur?

  Which process does not occur during meiosi5ay(8v7pzv g ns?

  If a cell with a diploid number of 36 undergopibmp.tvx 7:. a hm- pq58yseym+/ g/pes mitosis, how many chromosomes will be present yx ie q/y8m.p/t+h:pm.pv asp-m7bg5in each daughter cell after cytokinesis?

  The image shows a micrograph s3p2o x*ql o-pof a cell.


What explains the appearance of the cell in the micrograph?

  Which statement(s) about homoll, gztcewvkk0l60: s- ogous 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 syndropy44pkzdoy.t,b,u z5dufx 2 l 7i dwpl2vx;:0me.

Which statement is not correct?

  In the cells of a horse (E. caballus) during proph s79m0n tgbrs5d;ng9aase I of meiosis I there are 649gan d ms ;9gr5ts70bn chromosomes. What is the haploid number of chromosomes?

  Which arrow is pointing to a cshhjfn5s//o60pl k ,uhiasma?

  The diagram below represents the structure of a shoot apical meristem gvtgu x e969n*euasw9*ssj)4+j jhb;. Which row in the table correctly identifies the processes occuring in the structures labe4)9 gjastb; ex99s swe*ghj u*6uv+njled in the diagram?

  How does meiosis promq3la e ej-b9h0ote variation?

  Which of the following statemea7r + 2tu,e:wa-gptr d,oz/th 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 gametes produced from7pf 1ewo6r az2fxga:: 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 tlrrud 3n3tgmck3g3 k s 4i+b;2he formation of secondary tumours from primary tumours as a result 23d3gl34 +km;srcb 3gntriuk of the movement of cells?

  How many chiasmata are present in the diagramwn fap dmq/v-t6)l :*g?

  Which statement is a similarity between cytokinesis in animal a zo/, x-xq+jqsnd plant cells?

  Which stage of meiosis is matched to the correc t nfh;qb0/ys-t description?

  Which statement(s) are tru.+qh*uzplf2r 7/p0dgyrl *vf e of meiosis 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 first7bsb gv;xv-11f 7t4odtr va r( meiotic division. This results in the formation of one large cell and one small v7rvg (f-s;b rodb11x t 74atvcell. What is the fate of the large cell?

  Which row correctly describes diploid and haploid cells in humaguf1v . o+we0 eydw35p(k( f1zb ixgf;ns?

  The following table shows the diploidr+y3fw /2 w6t,enz iny chromosome number of a range of species.


Which of these statements is correct?

  What conclusion can be drawn from the karyogram below? 6lukme /;d,vr

  Which of the following processes is characteristic of the meiotic and not the mn0o +q6wpwo 2aitotic cell cycn6o0pw w2q+oa le?

  The diagram represents a bud with a shoot vuazi0 i87pr:bzt,8b 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 sm /8i tt4.cusnl6jw/the chimpanzee (Pan troglodytes) is 48. Which row shows the correct chromosome number for different .i t ts8wn//j6usl 4cmcell types and cell division stages?.

  At the end of which phase of meiosis I does crossing over occur, andncv80a7 lgs1d what is the outcome of crossingsld1v08 c ng7a over?

  Which of the following statements does not desc8orqsri8 a3k 1 cbc, 8crj0gp2ribe a step in the sodium-potassium pump cycle i8gcisrkc2 1q8pr 8,3a0b c orjn the neuronal cells?

  Which row in the table oap gk7q xumu 1b,1-yw *a+2sdbelow is true of meiosis?

Membrane transport is important for allo67uhs(y apaxe 3q9+u w-7ci/h kjko r-wing particles to move across the cell membrane and respondej3u-ksp hur a-q +owi/69 a7h (ykcx7 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 regulated in c y4v j8pq-c1coells.

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 c+zvr,h8 yi1fam ie6v2 oncentrations of different cyclins during the cell cycle. Which cyc,v8 6ez+im1y havf2ir lin is involved in preparing for DNA replication?

The diagram below shows /x6gldc dx7h) chromosomes 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 ofldi;i.qt alb 1-fzbn s-,y 0k+ homologous chromosomes?

  The mitotic index of throat tissues taken fromlnq56p8y .xqwoe ,/bb 4 different patients is shown below. Which patient is most l,.yb8lq op n/w6eq5x bikely to have cancerous throat tissue?

1.Draw a labelled diagra;,ncbpi pcvb lz+e(w86i8n3i m 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 karz/p(l :2gglfog ajzzc2lpda l9 );x+9 yotype.


What is the abnormality in this karyotype and its cause?

The graph below shows the relative amount of DNA il o; gbo1tun0e/bhxv4m q+,e3ogc3 v, n one cell during one complete cell cycle.gxqb1 l cv;beut/,o0g3hem o3+,4v on Each 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 thaiq(tt:;b3 sff 9h9jq3i rk) gvt is homozygous for brown, long hair and ;q ih3f)ti 9(bqfs:j39vt grka female cat that has black, short hair.


Which of the offspring has a recombinant genotype?

1.Outline how polygenic tv :maw:4;fgwk gjou*av6 c6 ;sraits 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 crossing over of non-sister c2ir /qd5u0l flhromatids shown in the diagram /l2i 0udlqf5rbelow?

  The photomicrograph shows a pol )w3dsbbl)wv0y 7q .lolen grain from L. candidum (Lily). Which stage of meiosi ylww)lob3)0qb.v d s7s is shown?

1.Outline the events which would lead to an i x wv(olc5yw5 5l rlmfkbxb,7s ;sp96(ndividual being born with Down syndrome, which 7l(5wwbmlbc k9ry6l;,v( fxx ps5so5 is characterised 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 a8e5z 6;p( .eywmfmsnbn indirect way of measuring plant growth. A study was conducted on whitp8bym f zmw;(ense56.e onions (Allium cepa), under controlled conditions 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 ways in which cells can divide. The diagrams belowx(n o7b zrxlf 8u;udc2pe05 0k s(f8x z u;7xr2ucepldn 0b k05ohow 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 expression in stem growthdzkyes*l )cf4akc,pzq02 ) w :6j9jxv .0 uztk.

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,kds8) a22 7 g*dokd 57ftqzv//idktvj in different stages of meiosis. Wh5o/z/jsv8ik2) d a*7 dt2dvkdfkgq7t ich row correctly names each stage?

  The micrographs show four phases of meiosis I in a plant.hprw /. x*k/syd x1iw(; xa)zl In what order do these phasesp1xld(y* rk./z)ax;w hw x/is occur?

Mitochondria are responsible for supplying metabolic energy7rxc j95yy8 ih in eukaryotic cells. In most eukaryotes, which reproduce by sexual reproduction, mitochondrial DNA (mtDNh yc5ryj879 xiA) 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 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 on cd b293.zb,r+x :(gc5 hrx8hed ozznumber of cells in different stages of the cell cycle in four samples of lung tissue from four patients. Which tissue has the lowest 5crrc9+hdo:n,z . xxz2d g8ebb( hz3 omitotic index?

  The diagram shows the doid (;ur4tcgm (vb9bf*minant cyclin/CDK complexes at different time points in the cell cycle. Which cyclin/CDK complex activates DNA replicationcurdi4 v9*b; fmgb(t( machinery?

  Studies have shown that genes such as Cyclin Depj9 wsr9wb :-txendent Kinase 3 (CDKN3) are highly overexpressed in cervb-w : s99wxtrjical 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 highkfhn.*1p p cr)est during the cell cycle ?