The graph below shows the relati3c2v d8 uu-zzm j7xj0fonship between maternal age and the incidence of non-disjunction. What relationship is suggedmz 08zj-v 32c juxfu7sted by the data in the graph?

  Which stage of meiostlcp; cki-w+apn*:t 5 is is represented in the diagram below?

  The diagram below shows chry * e/pjv(q0lwj+e *qfew.t,domosomes 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 e.o xnvppd+r*l0;)7 nx4mr mkthe number of alleles of a single gene which would be present in the nucleus of a cell as a result )v.o4 r7dp+*rneplmk mnx0;x of each process?

  Which keyword is matched to the correct definition84ro : xwrbe)a?

  Which statement(s) about mitosis is/are truta i5ik:lk vxt+-u s)agc 0;v/y0jbep 9,goq8e?
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 poin oidz/pk6,2h mc hxp5,ts to a cell in anaphase?

  During which stage of mitosis does thf 2.hy4j9t brg: n8lq5wuof:vda w32ne nuclear envelope break down?

  Which one of the following transport p/(5u7a el wg-5civnw ani:: oiroteins only carries out active transport?w7aiwiin:nac5vu(og l-5e :/

  Which process does not happen in the shoo-vx *: o,umgmp 38y5ccclnk0+0 yjkaqt apex?

  Which type/s of membrane trgr u6hzjm6e4p,h8pz 2q yqg 08ansport do/does not require energy expenditure?
I. Facilitated diffusion
II. Active transport
III. Osmosis

  The diagram below representhjigfl- w+-;as a cell with a diploid number of 4. Which stage of cell division is the cell currently unh wga-l; j+-fidergoing?

  The photomicrograph below shows a root tip meristem. Which of the folt-llw:4;.dxocmaqrk)a /u *wlowing sentences correctly defines a meristem? :oukwql raw ; x c-*td/).4lam

  When does the random orientation of homolzf bp8al6vr-d, k y7*vj)v fh6ogous chromosome pairs occur?

  Which process does not occur dffn:nig62n/bz ar (7huring meiosis?

  If a cell with a diploid number of 36 undergw:0z zk9pv5fue,r nx. oes mitosis, how many chromosomes wirzwk. v,n9p 0 zu:5fxell be present in each daughter cell after cytokinesis?

  The image shows a micrograph of a sjfh0v c(3g8t cell.


What explains the appearance of the cell in the micrograph?

  Which statement(s) about homologous chromos-; 9ffcoqst/:gehx.t6rkg; y 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 for an individual wit..4k4awui ;fy 1+mnd 5yuozqow d)btvs,/k0 fh Down syndrome.

Which statement is not correct?

  In the cells of a horse (E. caballus) during prophase I of meiosis I there ar16zezw a)5 va6 iy(mive 64 chromosomes. What is the haploav y(6wvma 5izzi61)eid number of chromosomes?

  Which arrow is pointing to(ykx n9, )apjj- 0govw a chiasma?

  The diagram below represents the structure of a shoot apical meristem. Whichl,rxzm cho:v2v6 t7dv17v rb/ row in the table correctlozxmh6rtdvv7:bvc2, vl 17/r y identifies the processes occuring in the structures labeled in the diagram?

  How does meiosis promote var (g/0i kky /lfe/veo2qiation?

  Which of the following statements is/are cos cz4oid,q,v 7el6c:hrrect 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 houq by;l;gll )9mologous 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 from pri iyi/1owo2 b()ycqu7a mary tumours as a resulioawqc1bouy/i2 ) y7(t of the movement of cells?

  How many chiasmata are present in thkvsg6ednb 7/ 8 sr(zqg+qo8v6e diagram?

  Which statement is a similarity between cytokinesis in animazr rns 6uoew,6sj6g4f9/ 8z wul and plant cells?

  Which stage of meiosis iai-kdhq 2 z)k4s matched to the correct description?

  Which statement(s) are true of me)htr-r/4s e(ay evk,miosis 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 relxl2)z u/a ud9sults in the formation of one large cell and one small cell. What is tl/2a dx) 9ulzuhe fate of the large cell?

  Which row correctly describes diploid and haploid cu zmr xj(3j;oo 3wwb1t8,q0ouells in humans?

  The following table shows the diploid chromosome number of a range of nah .c(y(qi5a ua;b (yspecies.


Which of these statements is correct?

  What conclusion can be drawn from t*50wlxmh; wez he karyogram below?

  Which of the following processeh.xxk2hr4v1zki im* )q m+h3w s is characteristic of the meiotic and not the mitotic cell cyclex2mvq. i1hwhk+4 km3 ihx)z*r?

  The diagram represents a bu:*o82 8muo hxfn;qyukd with a shoot 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 the chimpanzee (Pan troglodytes) is 48. Which row shows th bzwz b/drr8 ,(5 ;*f+lmqqcffe correct c5m/brd+8z(wf qzr,*;ffqb l chromosome number for different cell types and cell division stages?.

  At the end of which phase of meiosis I does crossing over occur, and wham qzpyytgf 5lwths49ms/ ow(l5 m)ox/;.a+, it is the outcome of crossiw h)pq +;w y4m/olssgyzxf oa ,l(i5m/5tt .9mng over?

  Which of the following statements does not describeox 3vv +opezh72p-cb ) a step in the sodium-potassium pump cycle in the neuroz)+ov cpbo2ev 7-3 hpxnal cells?

  Which row in the table below is true of meiosi3, kmjhbb s51dw3q 2hjs?

Membrane transport is important for allowingl;po )lqzc) x l(-1ytc particles to move across the cell membrane and respond to changes in th(ozll) ;-1c ylp)qxtc e 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 recahteh/9t1hpjq7a pp9,h 0y2gulated 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 concentrations of different cyclins during thew n1rnseu22ef5 y 3/c 5pyj1kq cell cycle. Which cyclin is involved in pre/ nep5u52nf3 qe2w1scjyy1krparing for DNA replication?

The diagram below shows chromo, dc- vu, 88p43 wxkqza*ymwdasomes 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 hodo p.; a3u.ur-qtbdy;mologous chromosomes?

  The mitotic index of throat tissues taken from 4 different patients iq--z y4,x8o lx0tsb0nv1v ocrs shown below,l8 t1 y-x0zcsxrvbo4-vo qn 0. Which patient is most likely to have cancerous throat tissue?

1.Draw a labelled diagram to represent the process of crossing pgsmvo :,ip/hr: 4f ,qover.

2.Compare and contrast random orientation and crossing over.

3.Outline the stages of meiosis.

  The image shows an abn5law1vx33 c2y riofs2 ormal human karyotype.


What is the abnormality in this karyotype and its cause?

The graph below shows thu* bu w+9t)x,kfcx;j v u lztvg+/1q,ke relative amount of DNA in one cell during one complete cell cycle. Each letter reprewkgt uv ,x ;x 9j/,qk)+f1bu+cltvzu*sents 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 homozygors-v 03db5 rvqus for brown, long hair and a fema r0-3brsdvv5 qle cat that has black, short hair.


Which of the offspring has a recombinant genotype?

1.Outline how polygenic traits can p u hp*exzdg37hgm7hm.fj 2vv y9r;*8show 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 ov y g9sw3r5bt mylj5z:-er of non-sister chromatids shown in the diag l 9bg3:5yjz tms-wr5yram below?

  The photomicrograph shows a pollen grain from-2os xebysm( +gu,w,d L. candidum (Lily). Which stage of meiossd+,oes2-(ubx, g y mwis is shown?

1.Outline the events which would l)ghxfq8h.gqge i4 :2 head to an individual being born with Down syndrome, which is characterised by the presence of three copies of chromosomg:qihh ehx) 42 g.qfg8e 21.

2.Explain how meiosis increases variation.

3.Outline the stages of meiosis.

The mitotic index is an indirect way of measuring plant growth. A study was condjqn0:jj 1a5 0n 0 f:4kzkh xnjy g8nqp3to9y;nucted on white onions (Allium cepa), under controlled conditions in a lab, to investigate the effect of soil pH on tzgj0:n5jq 9j fpoyj:3 xq1th04nn0ya8 k n ;knhe 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.mq;wn y41z )44fofowj6movj( j4jiu: The diagrams below show two cells4qizn:mjuwoo j46)ffw1 (jyjmv4 ;4o 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 ig0q*v9 ymbpn:n 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 kgn 0k v4tp+ym9y1b tfz-9ov.number of 8, in different stages of t0+y 1b.yf -n94kzgmo9v tkpvmeiosis. Which row correctly names each stage?

  The micrographs show four phases of meiosis I in a plant. ezd 5.w-kc .eee9t jmus2y0d) In what order do these phases occur? mysde9wzj-.0c k.2 )e u5 teed

Mitochondria are responsible for supplying mezk0kumqw-l) r 4h/.em tabolic 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 backgrokr. lm-)zwhuk0 m4 eq/und.

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 thd oqs pr.0p-/pe cell cycle in four sa0 dp. rp/qosp-mples of lung tissue from four patients. Which tissue has the lowest mitotic index?

  The diagram shows the dominant cyclin/CDK compl8unl +5oj 4 ngkky;*mtexes at different time points in the cell cycle. Which cyclin/CDK comu g 8 n;4k+jmkt*l5yonplex activates DNA replication machinery?

  Studies have shown that genes soyv(y:nbkz+h7 g1g 4 nuch as Cyclin Dependent Kinase 3 (CDKN3) are highly overexpressed in cervical tum (k7b y+o1vggy n:z4nhours.


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 -i+ex/l wu+(fu,x ze0fk fy n,5:ayvs the highest during the cell cycle ?