The graph below shows the relationship between maternal age and the inchcjgvunl h y rj4t-*i03:bdt3n 3o 4*iidence of non-disjunction. What relationnho c34gy:l hi-3trj 43nbuv*d0jit *ship is suggested by the data in the graph?

  Which stage of meiosis is represented iwkxtys ;b11j wfz): )nn the diagram below?

  The diagram below shows c1m4je9n (e/nmtcqv z wuicf69rj 46p/hromosomes 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 m l,,hgig,y2-2.s2wmpfykr esingle gene which would be present in the nucleus of a cell as a result of each pr2iy, hfm re 2w-gs.k2l,gm,y pocess?

  Which keyword is matched to the correct (0+ v5igsj)vj,p, jlnbrj p1t9jqj0bdefinition?

  Which statement(s) about mitosis is/are true? z3 i- a2j7pjmf*8pp tm
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 stglk;4j(gnq)g,b) q to a cell in anaphase?

  During which stage of mitq eci;0ejge9i :/wb5 tosis does the nuclear envelope break down?

  Which one of the following transport proteins only carriao4 dxf,f07x 11vykdr -,,gxrzs ot e9es out active transport?xrfg4xd-f01yo 7or,dz, tev,xa1 9 ks

  Which process does not happen in the shoot aptfjj)z,b 5 cz(ex?

  Which type/s of membrane transport do/does not require energy expen(uodaw. x+ n5 :dnar.aditure?
I. Facilitated diffusion
II. Active transport
III. Osmosis

  The diagram below represents a sufd ;1aei*.3yeyj )fcell with a diploid number of 4. Which stage of cell di.e) y; s fe*yfjau13idvision is the cell currently undergoing?

  The photomicrograph below shows a root tip meristem. Which of the i6*yz: jo1) w w0bu2ccjpe lu;2asya/following sentences correctly 2cez)6y1walwcu2 j */aip o:j0;sbuy defines a meristem?

  When does the random orientation of homologousoao 4:.6ms-5f mjb-e uttrqc4n4 m9so chromosome pairs occur?

  Which process does not oc6at;)heozk 8ucur during meiosis?

  If a cell with a diploid number of 36 undergoes mitosis, how many chrd(rg4k cx 16e/n i9xwpomosomes will be presen g 1icnxk4wx6r( 9d/ept in each daughter cell after cytokinesis?

  The image shows a micrograph of )11n;zm,gah0i 82qrxaglyqc a cell.


What explains the appearance of the cell in the micrograph?

  Which statement(s) about homologous chromos,w.gn7w yyb0 g.0zsai omes 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 fosav y)*. j qob6nbyp,*r an individual with Down syndrome.

Which statement is not correct?

  In the cells of a horse (E. caballus) dwp ti lck 21 a(fah0+v-rjtk7 zfm63*ruring prophase I of meiosis I there are 64 chromosomes. What i-k ijcff2a a r zhttwrm+706k *31vpl(s the haploid number of chromosomes?

  Which arrow is pointing to a ch0yqf0dy *p0ydoa q8/x e5nxf ;iasma?

  The diagram below represents the structure of a shoot apical meris4byj:grml +m. v9 jt*:qxhs c5tem. Which row in the table corcl:9 jj bvms*xtr5 +m4q: g.hyrectly identifies the processes occuring in the structures labeled in the diagram?

  How does meiosis promv3-; v hl e5,zim/nexsote variation?

  Which of the following statements is/are corr f l 4msvojei*0oq;zc/;)wt 1dect 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 chromosome e z19u nf-ntdr2wwqm61k 2mw6s.


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 formationm2 rjwom zwbc8 y220r: of secondary tumours from primary tumours as a result ro 02r y:czj 22wmbm8wof the movement of cells?

  How many chiasmata are present incp,a *++co5po rsx/ eo the diagram?

  Which statement is a similarity between cytokinesis in animal and plant qnwx:njx xo0 .k *.z7ycells?

  Which stage of meiosis is matched to the correct d gf0v0egw8 pt2escription?

  Which statement(s) are true ofondl8zg) 9c; d 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 first meiotic dmnj: a2ps6+g(-xih lnivision. This results in the form(g ls hjn:6-minxpa2 +ation of one large cell and one small cell. What is the fate of the large cell?

  Which row correctly describes diploid and haploid cells clg u2;pvfljmt8( k8+in humans?

  The following table shows the diploid chromoso0g9npq 9u: vm itk )d2e2c00: shjncpdme number of a range of species.


Which of these statements is correct?

  What conclusion can be drawn fb 9k8ldlmhoc0 +)/3ynws)9h dxu fji/rom the karyogram below?

  Which of the following processes is characteristic of the meiotic and not the mru 68b+i6(ewl*:vvy jbjvm5b i vbvb5 :8lrimb e(vyu66*jjw +totic cell cycle?

  The diagram represents a bud with a shoot apical meris+r.6nf3ff mr 1e5poljtem.

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 chip:ha (xr 4wlv ya;q,w3/0 slezmpanzee (Pan troglodytes) is 48. Which row shows the correct chromosome number for different celswa xh:lv,q (ry04;w aepz/ 3ll types and cell division stages?.

  At the end of which phasey ri7p ksfi+uga- d;t 256c2hb of meiosis I does crossing over occur, and what is the outcome of cr -tb5ik ;y27adh+s2cup frgi6ossing over?

  Which of the following statements does not describe a step in the sodi -jqf 34ernbx8 -c5o5t2fytyuum-potassium pump ct c- 25xeynftfu bo5j8q4 y3-rycle in the neuronal cells?

  Which row in the table below s lp1l4 pmj.e8*f ii*islwn (-is true of meiosis?

Membrane transport is important for allowing pabbrtd32zgym gqb1:69rticles to move across the cell membrane and respond to changes m1zq: btby 9dg62 rgb3in 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 regu ;6vs0u/5rcj nmci v4a j4a7nclated 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 th:.4 lgi73+qo/cb2osw8czwz.of rmue e concentrations of different cyclins during the cell cycle. Which cyclin is involv7iz/e c8os24 ozqocl..w wr b+3gmfu:ed in preparing for DNA replication?

The diagram below shows chromosomes during meiosis.ko 63e z:,ax kox)q+kl

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 homologous +e+ti vc:oi9qchromosomes?

  The mitotic index of throat ti5 h+g jzuki( esc6lw2.ssues taken from 4 different patients is shown below. Which patient is most i5hj(u 62ckwegl s+ .zlikely to have cancerous throat tissue?

1.Draw a labelled diagram to represent the process of crossing ov4*b3j wcr m+tver.

2.Compare and contrast random orientation and crossing over.

3.Outline the stages of meiosis.

  The image shows an abnormal human karyotypyg5v+ypx9x* vldoil* k,x2 ol :lu/b*e.


What is the abnormality in this karyotype and its cause?

The graph below showt84:a,+srap;2g9 qkvxj lvd n )q u1rcs the relative amount of DNA in one cell during one complete cell cycle. Each letter represer8 cv2adr9aq ; 1t qkglvpsun 4)x+j,:nts 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 bh-icwf 6ql+ cfoz:wj7g 72c* male cat that is homozygous for brown, long hair and a *c lccgo6jhwb77f-wi2f+q:z female cat that has black, short hair.


Which of the offspring has a recombinant genotype?

1.Outline how polygenic traits can show h1f u7stf :ymtnu0a o 1dax;,/wk*(pga 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 ofomv nb2m*wgy-.wb 2 c0 non-sister chromatids shown in0.yvb oc n-*wg2mm2w b the diagram below?

  The photomicrograph shks/f*vetu-l,;wa m u8 ows a pollen grain from L. candidum (Lily). Which stage of meiosis is shown? mfuv,u/t *;e-la8wsk

1.Outline the events which would lead to an individual being born with Downrv, ,nbzv+ +ty syndrome, whi+tb,yzvv+n, rch 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 an i0e ftjx,lj-z ff7n)a qy8(pi.ndirect way of measuring plant growth. A study was conducted on white onions (Allium cepa), 0j qj)-fpey, nit7 af.(fxl8z 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 bplnih-uw:i t90 qr;; celow show two cells from an organism with a diploid number (2n) of np:h; iq;r0c-wl u 9it8.


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 siogz:8 ro/ 25yefm5qatem growth.

2.Outline how growth is controlled in the shoot apex of plants.

3.Explain the process and applications of micropropagation.

  The diagrams below show6k b3am he3*,dt c1ekw a cell, with a diploid number of 8, in different stages ,he dk3kae1*bt6w 3cmof meiosis. Which row correctly names each stage?

  The micrographs show four phaseskuf9l7v3prgd8i6 1r m of meiosis I in a plant. In what order do these phasesdu vg9r1m3k76f 8ir pl occur?

Mitochondria are responsible for supplying metab:8gag8 .4ttzj*qb gcxolic 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 inheriteda tgj:4 *8b8zqgxgt .c 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 in different stages of thme+3l:lb t+mve cell cycle in four samples of lung tissue from four patients. Which tissue has the lowest :v+l3l+b mtmemitotic index?

  The diagram shows the dominant cyclin/CDK comp(5/ vdr rj3dcg*f8 knblexes at different time points in th(cbr dgj5vnd3/krf 8 *e cell cycle. Which cyclin/CDK complex activates DNA replication machinery?

  Studies have shown that genes such as Cyclin Dependent Kin;mjc v;m)uxe9ase 3 (CDKN3) are highly);;mj 9c muxev overexpressed 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 cyclin E the highest during the cell cql;a/-3gfank- r id, b7yma t,ycle ?