The graph below shows t5+;l txjkfmu da5 2a.)wjt*l fhe relationship between maternal age and the incidence of +m *.ul5jaf t)k; f tlx2w5djanon-disjunction. What relationship is suggested by the data in the graph?

  Which stage of meiosis is reprem;1ue/ l- j.i-f5z. ynvki iphsented in the diagram below?

  The diagram below shows chromosomes durmye s4amm734m0 tb1w n);pabying 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 w 2yu)a.bv nh9qhich would be present in the nucleus of a cell as a re2v yhqbuan9).sult of each process?

  Which keyword is matched to the corre:fd+y7fttu b/0h. jgv qj4a *wct definition?

  Which statement(s) about mitosisw oj2fq)prfb n-. :y+v 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 letter points to a cell in anaphase?dn2.r+4iyhwo44 cvmo/ h4d3hj9mxnx 1) l ikz

  During which stage of mitosis does the nu qcrdnc* .e*d3dk5yy -le7/qxclear envelope break down?

  Which one of the following transport proteins only carries oj g: ;alp,cg1 2bl18agwp ze6uut active transport?zl6 g el: 11a p2ba8juwpc,g;g

  Which process does not y02h3jiwyns6owc ,r9 happen in the shoot apex?

  Which type/s of membrane transport do/does no)8w 8w*cjnnnnb )bl.s kr7+nyt require energy expenditure?
I. Facilitated diffusion
II. Active transport
III. Osmosis

  The diagram below represoy, * 4maoblh+b( an5vents a cell with a diploid number of 4. Which stage of cell,naol + oa5y b4m(h*bv division is the cell currently undergoing?

  The photomicrograph below shows a root tip meristem. Which9r64e2rsi8jkiy/gw a of the following sentences correctly def 9k64 82ysa grjiiew/rines a meristem?

  When does the random orientation of homologous chromosome pairs occk4bk (.q f;n ln2a hnx0mo:i3xur?

  Which process does not occur durinh9sst 63kii9 yg meiosis?

  If a cell with a diploid number of 36 undergoes mitosis, hi )p ecw12u9 58pgg9pvro*w 4qwg-gljow many chromosomes will be presen *g5q)-i9upr81l2p94 wwwg ev ocpggj t in each daughter cell after cytokinesis?

  The image shows a microxu*hhp- sx.*ww8 k 77myx8aihw7ir9rgraph of a cell.


What explains the appearance of the cell in the micrograph?

  Which statement(s) about homologol39u*hrs4 0 l fwowzr,us 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 syndro 4d wprka/nr /m h*8:zitkx87nme.

Which statement is not correct?

  In the cells of a horse (E. caballus) du -p.w8en*jl8cr6 svg bring prophase I of meiosis I there are 64 chromosomes. What is the haploid n -s68*clrbp .8ejwgvnumber of chromosomes?

  Which arrow is pointini cg99. yk6dlu-n7w6d .k ydpfj (1wujg to a chiasma?

  The diagram below represents the structure of a shoot apicat3 md/ 2neb aamvy- viq5a;;5vl meristem. Which row in thed te55mav 2vv;y n m/3iqbaa-; table correctly identifies the processes occuring in the structures labeled in the diagram?

  How does meiosis promote variatio 3rkmui/p z70(qvpe)vbxk.2in?

  Which of the following state8j2p+xi h-rgqments 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 game up f416nl08ue abzy-dtes produced from 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 the formation of secondary tumours f-yvd1u*mu:mq rom primary tumours as a result of the movement v1-md *m yuuq:of cells?

  How many chiasmata are presen9 arlog8 s5fp4r0k)gmt in the diagram?

  Which statement is a similarity between cytokinesis in animal j9f :f divqlrj7ime s()u;+i: and plant cells?

  Which stage of meiosis is matched to th2 j uv )pa-2r;xtscuqhu.0l8 ee correct description?

  Which statement(s) are true of meiosis I but not meiosis II?fq 5,a*fa7ez, m/paxj
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 result;ce58a38wow)fe yop es in the formation of one large cell and one small cell. What8e8oawp)weof3 cye 5; is the fate of the large cell?

  Which row correctly describes diploid an,jte5i gs1e3( uw1pjmgox u.4d haploid cells in humans?

  The following table shows the diploid chromosome numa9zmrn 1ab .hll ;5gi)u4 lph5ber of a range of species.


Which of these statements is correct?

  What conclusion can be drawn from ,jhn:c5 -t;kdrrexl 7the karyogram below?

  Which of the following processes is characteristic of u hor+e)u r6)othe meiotic and not the mitotic c)u eo )6+hourrell cycle?

  The diagram representsd h9lm /h/ke0r(grcu0opib-z6v ()vi a bud 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 t d. ay1hj:ihi-t odd7*he correct chromosome number for different hd-. 17d yo*:i jiadthcell types and cell division stages?.

  At the end of which phase of meiosis I does crossing over occur, and wk z3u1vvc - 1s.v7fdo7r 4ja*0 fmz,i6uisa ldhat is thef c71iozu-6m,3li v s*kvs1uz7. ad4a0 dfvjr outcome of crossing over?

  Which of the following statements do9e amk 90ccd4tes not describe a step in the sodium-potassium pump cycle it0 km4d9cea9c n the neuronal cells?

  Which row in the table below i hnkklu,p7:r 7s true of meiosis?

Membrane transport is important for allowing particles to movs+: mf3+;mhpu)u vlrge across the cell membrane and respond to changes in the chemical composition of l p)rm:hfv+m+;suug3 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 regulaf k ;sz h5*f9f0 gp3cysoza,2yted 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 duvap ;hi:giw+bw ,v)88okrm1nring the cell cycle. Which 1p bg)a,o n8vh;mvr ii+:8wkwcyclin is involved in preparing for DNA replication?

The diagram below shows ch;s-te sa (ht1promosomes 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 hom: n8q9 k p4prgn;oior9ologous chromosomes?

  The mitotic index of throat tissues taken from 4 different patientsw 7pbr.t7lzr7,v 5 lbg is shown bel w5blg7t r,vb 77z.prlow. Which patient is most likely to have cancerous throat tissue?

1.Draw a labelled diagram to represez7r:,,fl* cik d;tqgf nt 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 hs5wm1 8ybqgw+n,:zo human karyotype.


What is the abnormality in this karyotype and its cause?

The graph below shows the relative amount of Dynt o-z2u 2ycxk mf.29NA in one cell during one complete cell cycley.2fto2nc9 -yuxzk 2m. 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 that is homo,yh(+mz5 (tnmd tey;w zygous for brown, long hair and a female cat that has black, short;w5 enzy+ (m td,my(th hair.


Which of the offspring has a recombinant genotype?

1.Outline how polygenic traits can show a normal disttr5 8:lxe/gau ribution.

2.Outline the differences and similarities between homologous chromosomes.

3.Explain why expected and observed Mendelian ratios may differ.

  Which gamete can res* kg/beinh2-;ek.zc 1k el.hyult from the crossing over of non-sister chromatids shown ink . zki1l*/cg bk2;yehee.n- h the diagram below?

  The photomicrograph shows a pollen graintjjuz 1af 31:e from L. candidum (Lily). Which stage of me3zu1 f1etj :jaiosis is shown?

1.Outline the events which would lead to an individual being born wigvq )fjss wz3sft61:y )43vlcth Down syndrome, which is characterised by the presence of three copies of chromosome )stvlfz fj3ws:) 61q43yc sgv 21.

2.Explain how meiosis increases variation.

3.Outline the stages of meiosis.

The mitotic index is an i 2lb grjj fbckvw6:/h04d (oi2ndirect way of measuring plant growth. A study was conducted on wjjc ihv6 l4 b20:obrg(wkf2/ dhite 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 w7 sm 3wn3yx - hkfl1ey2r:n2qohich cells can divide. The diagrams below show twoy7 :w2o2 n qn3fhlx1reys -mk3 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 0*9wpvvkivrbm 2:p( bin 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 number ofz6mw 2t6lwi*0nm-ube 8, in different stages of meiosis. Which row correctly namel wtun-6mm2 wi z*0eb6s each stage?

  The micrographs show four phases of meiosis I in a plant. In what:+l97fzxz plj 3jt 9lu-uqqa/ order do these phases occul9 q:l jfp9jquta+7x3-z z /lur?

Mitochondria are respo3hi5tl-fsmp / nsible 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 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 th h-m iltp3s/5fe 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 the cellkgd9j*dp )n y/ rze9n.p,b 6 +xw/qhof cycle in four samples of lung n)hf. oxnge jwrdq6/bdz+k, p/9p *9y tissue from four patients. Which tissue has the lowest mitotic index?

  The diagram shows the dominant cyclin/CDol),gg1p3xrik)+ 3(a gvfutlK complexes at different time points in the cell cycleug )(a,pr 3kgg+tx if olv1)l3. Which cyclin/CDK complex activates DNA replication machinery?

  Studies have shown that genes such k e mrrq+m16v*as Cyclin Dependent Kinase 3 (CDKN3) are highly overexpressed in cerr*v+ meqrk 16mvical 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 concentralq fv 5/gcvo8*tion of cyclin E the highest during the cell cycle ?