The graph below shows the relationship between matg 3 cx)s kl.mvh):(fppernal age and the incidence of non-disjunction. What relationship is suggested by the data inx)ppf)v hsgm:3l ( .kc the graph?

  Which stage of meiosis is represented in the diagram below)nsmw h4z2)m,pep;bb) 1en nn?

  The diagram below shok3rz:vv 6,acaws 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 states thew1( f+/f t/mtd8il cco number of alleles of a single gene which would be present in the nucleus of a c(/t o8f1c/ldc +miwtfell as a result of each process?

  Which keyword is matched to the correv1 yp0a;hrg6:l zn0fj3e3wk.i3qp2thn z;yb ct definition?

  Which statement(s) about mitosis is/are true? juv3i29 8lrxdpl 6mnk9p+ 1 nr
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 m3zbp20p; c4 /tjn)j yl3i+tm;-f ps omz f7rfa cell in anaphase?

  During which stage of mitosis does the nuclear envelope break dowb ty-qg2--xhqn?

  Which one of the following transport proteins oaj(tfkw 04 : dfqwnpwtdp3.0 0nly carries out active transport?pf k03 t4wp.f:wn(qjdw0t a0d

  Which process does not happen in the shoombb0e1 1acvi ;t apex?

  Which type/s of membrane transport do/does nos3mdkyk-1fhu m;h6f 9 t require energy expenditure?
I. Facilitated diffusion
II. Active transport
III. Osmosis

  The diagram below repr 1b+n0gpdgvn;(o pwy7esents a cell with a diploid number of 4. Which stage of cell division is the cell currently undergoin;0wn1gyg(vop 7n p b+dg?

  The photomicrograph below shows a root ti,(cjb cxb;b;v p meristem. Which of the following sentences correctly defines a mexv;ccj,b b;b( ristem?

  When does the random orienta4ez s4lfutq./ejgj13y j 1z:ation of homologous chromosome pairs occur?

  Which process does not occur during melp.; h1pk ;kv)jvch* miosis?

  If a cell with a diploid number of 36 undergoes mitosis, howvd,w4ir6zhc8 b .+pa ix r1:vw many chromosomes will bp. x48 i vz+ w,biwd1h:6racrve present in each daughter cell after cytokinesis?

  The image shows a micrograph of a ce.d1 ins;tjxi1wm(i3fk2 3 z null.


What explains the appearance of the cell in the micrograph?

  Which statement(s) about homologous chromosomes is/a1vb y257 d4bn9lnqgh1(i/pbavt3ek x re 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 syndroxozkp4 wkm; -7me.

Which statement is not correct?

  In the cells of a horse (E. c,i:mf qa s:f2y06bqpqt ui x+/aballus) during prophase I of meiosis I there are 64 chromosomes. What is the ha 2a f:6bu:fmqx0,t+/iy q siqpploid number of chromosomes?

  Which arrow is pointing to a chiab8w9)2p2z z3zsi d +dxyvdx-lsma?

  The diagram below represents the structurej).y 5n qiw7 qnv:j:fe of a shoot apical meristem. Which row in the table correctly ident.yfq7 :qv5n j )jni:ewifies the processes occuring in the structures labeled in the diagram?

  How does meiosis promote variation?tz 2 6mhonr kvv5ny, k+.6ju7f

  Which of the following statements is/are comefbtv/ n)ouxalzn 8lx/.r59j,bxq) 3ey n; . rrect 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 chromosom;z gs usps/w21es.


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 tumours4qi s y9awwi4; from primary tumours as a resu4;4ywiia ws q9lt of the movement of cells?

  How many chiasmata are presbwesaps(bcpm //k1 82ent in the diagram?

  Which statement is a similarity between cytokinesis in anv nba2a2cf95f imal and plant cells?

  Which stage of meiosis is matcz11b.:/xevl2ome jk uhed to the correct description?

  Which statement(s) are truq5+s1hid*7 v x g1h-sp)reri te 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 thf+qln;9u(a)g0 th (qcgv ga+le first meiotic division. This results in the foralq(f g+guvt )aqg;+0(nl9c hmation of one large cell and one small cell. What is the fate of the large cell?

  Which row correctly describes diplw s .s9ww;(hrloid and haploid cells in humans?

  The following table shows the diploid chromosome wuuqev ;c 4.p)number of a range of species.


Which of these statements is correct?

  What conclusion can be drawn from the karyogram belowv i-8y+ty nli*5gt4om ?

  Which of the following processes is characteristic of the meiotic a979p0ee6/ ;phvri 2omjpm jwk nd not the mitotic cvp9e2mo/7h0p9 e jwpim;r6kj ell cycle?

  The diagram represents a bud with a shoot apical meb5(q a o:14 lnv, wuiw-ferz4iristem.

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 iay.u6k. de eo xx 9*r+ss* cd2om.i.zshows the correct chromosome number for differe2eo*o +xa9zi k .mc e.sd.6du*irxs.ynt cell types and cell division stages?.

  At the end of which phase of meiosis I does crossing over occur, and wha q/oy8mjdsde490u( df t is the outcome of (0eqd u9fmsj/y d4od8 crossing over?

  Which of the following statements does not describe a step iyg c/66 0pn71yp ufhbt03yuay n the sodium-potassium pump cycle in 17/fp 3yc b6t n0yauh6pyy0 ugthe neuronal cells?

  Which row in the tabl/z.1zx 2b0*s:c*, gqm7lkmd b onczgx e below is true of meiosis?

Membrane transport is important for allowing particles to mo8ct6 sarh,+hg ve across the cell membrane and 6ghthc a8s,+r respond 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 regulatedm dxtjcor4b.4 8ex*w7 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 differ k dgfgcda11ug9emvv529:t z 5ent cyclins during the cell cycle. Which cyclin is involve zgv vk15m ud1:9g92fd teac5gd in preparing for DNA replication?

The diagram below shows chromobs cuo49n 0)4 rif2fgmsomes 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 d sddewz0 2 c1vwr-2j(involves the separation of homologous chromosomes?

  The mitotic index of throat tissuessky/i(hci )) b/,no8 fvibtx- taken from 4 different patients is shown below. Which patient is most likely yx/ckt nbi/ -obhs)i( v) 8fi,to have cancerous throat tissue?

1.Draw a labelled diagram to represent the process of crossing overpm urc:xjqx14/ a0x* e.

2.Compare and contrast random orientation and crossing over.

3.Outline the stages of meiosis.

  The image shows an abnormal human karyotype.0ar,bq d an4k8


What is the abnormality in this karyotype and its cause?

The graph below shows the relative amount of zscec,zh8fa: tb ra- 2ssv,3) DNA in one cell during one complete cell cycle. Each letter represents one stage of the cell ecz-b) ts3,rsa:8, c saf2vhzcycle.


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 homozyu0 mp d8ot+-c1bvas6bgous for brown, long haira+c0-b 18usm opv6bdt and a female cat that has black, short hair.


Which of the offspring has a recombinant genotype?

1.Outline how polygenic traits can show a normal distriuyzlm6-7v.gpi n)we8 :a q)bqbution.

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 nbhcbrg.f l).u7ff s6p)s evn8 7 hd+fbxa/(8j on-sister chromatids shown in the diagr8g fs76 +hdjbx )able(f crs/7v.) pnf8ub f.ham below?

  The photomicrograph showsk,6yxwyojp 2;,t (v gf a pollen grain from L. candidum (Lily). Which stage of meiosis is6g 2xp ,f (tj,;yyowkv shown?

1.Outline the events which would lead to an individual being born vhary8vjy;yc (. v9 5jwith Down syndrome, which is characteriyhr;av( j c85yvv9 yj.sed 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 indirect way of measuring plant growth. A study wagijkmh ,8 gq, x9fff/1h;ud4os conducted on white onions (Allium cepa), under controlled conditions in a lab, to investigate the1 4o;dgx8kh ,q/ih9fm gf fuj, 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 arv ;es7rb1n-mi7neg1 de two ways in which cells can divide. The diagrams below show two cells from an organism with a diploidevig;d1n enb- s71r7m 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 jqf8;2h )ulxw 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 show a cell, with a diploid number of 8, in different stage 2.6muwl ah:1t*jg4 eq 5nflhms of meiosis. Which row correctly names each stage? 4 e:6h1mt2unh.5l *w fq agljm

  The micrographs show four phases of meiosis I in a plant. In what order do these n(k31d;ktb;s(lb fs a phases osstfa ;d ;nbb((3 l1kkccur?

Mitochondria are responsible for supplying metabolic energy in eukaryotic ceadne : qgi*7n8lls. Igend ia* n:q87n 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 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 num-4xu)ye , qncmber of cells in different stages of the cell cycle in four samples of lung tissue from four patients. Wh,ueqc4 -nxm) yich tissue has the lowest mitotic index?

  The diagram shows the dominant cyclin/CDK complexl* ff :zhzyj ch8.c2q0es at different time points in the cell cycle. Which cyclin/Ccf chh2jlf*0 .z y8zq:DK complex activates DNA replication machinery?

  Studies have shown that genes such as Cyclin Dependent Kinase 3 (CD3ed(pwc3ah8k m4+quofx, -tvKN3) are highly overexpressed in cervical ,v+3ep38c dfoh- utqm( xkwa4tumours.


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 8 zxaj/p 27owlan6pj:c dq*5c q-8hyaE the highest during the cell cycle ?