The graph below shows the relationship between maternal age and the incidfsx.dwk,v * *dence of non-disjun,*d xfsw v*dk.ction. What relationship is suggested by the data in the graph?

  Which stage of meiosis is represented in the diagram beloersl d s;(.gd8arlo)*w?

  The diagram below shows chromosomes during meiosinu4 id bbltr-hm)+hvo-,t9)5tz u1 fps.


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 therfsltto:uxbi1ybd,: w3 c ;2 / number of alleles of a single gene which would be present in the nuclew1b3lb: c2r u/xidys,o;tf t:us of a cell as a result of each process?

  Which keyword is matched to the corcug tz,irt 6m7*7xkz2rect definition?

  Which statement(s) about mi )hh5 * hp)s,dw0smjbltosis 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 anaphays9kx4.7jd o6 k)srt fse?

  During which stage of mitosis does the nuclear envelope break downjhkgo1ndh,y9en4kor v p+( .jgy.n vx;i .q/9?

  Which one of the following transporteih.v +u w-k ftihh7q( ikj3p9mr47u/ proteins only carries out active transport?wk3hp7iv4j7u9kh i fr-u+ qtehm. (/i

  Which process does not(n.t5i hnd5 fv happen in the shoot apex?

  Which type/s of membrane transport do/gy3qwry e )gbc* z*ka4qa-+v 6does not require energy expenditure?
I. Facilitated diffusion
II. Active transport
III. Osmosis

  The diagram below represents a cell with a diploid number ofld+uz q s1gs7. hzu44v 4. Which stage of cell division is the cell u+ sz1h4vugq . zl74sdcurrently undergoing?

  The photomicrograph below shows a root tip meristem. Ww50z t:bepsjk d9u;g/hich of the following sentences correctly defines a merist;0jp b zgwk9t5/s e:duem?

  When does the random orientatg o4v;4pclr-na(lc d (ion of homologous chromosome pairs occur?

  Which process does not ox)ek1oi q/qlzg 5-m. dj5k1hx87m n ezccur during meiosis?

  If a cell with a diploid number of 36 undergoes mitosis, how u 2rlr+de8dvh) r61o3ty 1+ ,lgrfcbz many chromosomes will 3lfrgh c,ed+zv6)d2rtu1 8+roby 1rl be present in each daughter cell after cytokinesis?

  The image shows a micrograrf 5448vpsrx 7+g rtcggk1f r;pfr e77ph of a cell.


What explains the appearance of the cell in the micrograph?

  Which statement(s) about homologous chromosm-apmu53v+8i hs z4yk 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 with Down syndrome0am tgig:4 n f8o1)tyy(c i-ak.

Which statement is not correct?

  In the cells of a horse (E. caballus) during prophase I of meiosklow-/5 f+7lcj6 xl2f 5 sgpxuhs(c5jis I there are 64 chromosomes. What is the haploid number of chrog ufl5 (ol +fcjjps/kw 5l65xx-h2c7smosomes?

  Which arrow is pointing kqi6h/ n+n5s6jth(x gto a chiasma?

  The diagram below represents the structure of1q6i(zt-r u fgcjy2t y; vlgo+ud313j a shoot apical meristem. Which row in the tablelv urqdtg+3 y t i2(f;c6 ojyujzg131- correctly identifies the processes occuring in the structures labeled in the diagram?

  How does meiosis promote v)0s. wtz.unn26xee zkariation?

  Which of the following statements isuj c xj-b4 9i6nkol(*ij3i 3hk/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 pro wjg3,yk1b8 kkduced 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 from primar bvs jl6:ae *)0j4rvcay tumours as a result of the v:e slj4aacb6 0 rv)j*movement of cells?

  How many chiasmata are present in the diagram?f ymzb v, t8(pz;med,9

  Which statement is a similarity between cytokinesis in a mqb/esdu87c:nimal and plant cells?

  Which stage of meiosis is matched to the correct j0md ih ma+*6adescription?

  Which statement(s) aretshalfam-cn3 8-6t 4 f true 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 first meiotic division. This results in6um i(1a tk7bb the formation of one large cell and one small cell. btb71mi 6a(ku What is the fate of the large cell?

  Which row correctly describes diploid and haploid s.hqafrmz9o9294n, c olae2y cells in humans?

  The following table shows the diploid chromosome number oxerjb.:8 wq0zz7e4vwf a range of species.


Which of these statements is correct?

  What conclusion can be drawn fromhlzk9ri+( il/ c n/j;4+ ueivdzr -3vu the karyogram below?

  Which of the following processes is characterisildayi2i8p+j( +bj 1 ttic of the meiotic and not the mitjj2+1+i iiaypld8b( totic cell cycle?

  The diagram represents *k3w*ig nla- wrp22p ca 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 m3yvz n;ad*0 grow shows the correct chromosome number for different cell typ;nzvgdym*0a 3es and cell division stages?.

  At the end of which phase of meiosis I does cros2plgu1+ewn(*3jv)erx9(6f 7nf qu:p pxjndt sing over occur, and what is the outcome of ljve(gnu 6(xu* +tnxw9r 3fdp2f 7p qejnp: 1)crossing over?

  Which of the following statements does not describe ab 0c5hxdi 7 ,e7i)ttoj step in the sodium-potassium pump 07hb , t di7x)tejoi5ccycle in the neuronal cells?

  Which row in the table below is true of meioz+kzdn 3 :x5oosis?

Membrane transport is important for allowing particles to move across the ce3j1j dnfd+ ,qks 1lu+rll membrane and respond to changes in the chemical composition of the extra u+d3snj,+l1fq1rjkd cellular 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(v 4su ) 7pwas3h1bzny regulated 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 9hk*8t- ;q ) yzi7z*sadoge 3oaxlt 6acyclins during the cell cycle. Which cyclin is involved in preparing for DNA rxhl3y;sq *gio)a8 tokd*az -a9ze76t eplication?

The diagram below shows chromoso/sd8i. pus ud: 9f.t hn9u6vhhmes 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 homologous -fu50:tx-x4 q1, artw ia ebvozg2o3qchromosomes?

  The mitotic index of throat tissues taken from 4 different patients is shown s(3jc a ;bqq 6uy9:bqh*(maeqbelow.*q:h(bq 63y ( ms9ae; cbqqjau Which patient is most likely to have cancerous throat tissue?

1.Draw a labelled diagram to represent the process of crossing rc/p6t2tu,uiat -:zh over.

2.Compare and contrast random orientation and crossing over.

3.Outline the stages of meiosis.

  The image shows an abnormal human oj6 6lu,li hedbh 2b89karyotype.


What is the abnormality in this karyotype and its cause?

The graph below shows the relative amount of DNA in one cell during one complete4: )1g h1nh5/y0(w hwivrx riuouep9m cell cycle. Each letter represenvh iuwxie10hw r1g45p)hru/9 :oym(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 male cat that is homozygous for vdxyy(n 7w nfq7v 203zbrown, long hair and a female cat tha q( zn2xn0d3 vy7fy7wvt has black, short hair.


Which of the offspring has a recombinant genotype?

1.Outline how polygenic tr.ud b, 8wgvd4luc b wr/:u(fu8aits 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 chromatids shofoyt7 t(mx7zc2yppd4..1 lw1;i mz igwn in the diagram below?p (iz2w l1g 4ic;o.d.ytxz7 tym7pfm 1

  The photomicrograph shows a pollen grq/bk 1,vl,lqeww :o ,uain from L. candidum (Lily). Which stage of w,qu,/1: lk,ebl wvqomeiosis is shown?

1.Outline the events which would lead to an individual gxuz d;zyx5 32being born with Down syndrome, which is characterised by th ;z2z gxxy3ud5e 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 measuod33 whcb+ ib9vz 4dej erqjucx 237*3ring plant growth. A study was conducted on white onions (Allium cepa), under controlloi3cd4 379eq3jj 3bwhux*vbcedz r2+ed 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 cellsr / (rll80k oic-v9of 8pa-xeu can divide. The diagrams below show two cells from an organism with a eu/ x-8rc(8kvploo90lr fia-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 expressi:)tz eq 2o1vc*qn)css on 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 hcxi lqz* 9*v,8, in different stages of meiosis. Which row correctly names9c*xzil h,v q* each stage?

  The micrographs showdofbuwz89)v ,ln /l6c four phases of meiosis I in a plant. In what order do these phases occur?u 8c/l6zf l)nwb9 vo,d

Mitochondria are responsible for supplying metabolic energy i ;iqyfjs3*.bomli)f7cyf 5:yq m5q s )n 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 backgrobyifo s7)* 5cyfm:jqsq5l3y ;q i.f)mund.

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 of5w t)3 /yrfxbax )eq+w cells in different stages of the cell cycle in four samples of lung ti3f)5 tq xrw+wax/eb) yssue from four patients. Which tissue has the lowest mitotic index?

  The diagram shows the dominant cyclin/CDK complexes at differqq/,( ecm+,ziagiqh fvj()9 went time points in the cell cycle. Which cyclin/CDK fi/9 (+j zgvi,qcq )ea,q hm(wcomplex activates DNA replication machinery?

  Studies have shown that gene ,mi: be 5owdh3qvufvzp -)w*:s such as Cyclin Dependent Kinase 3 (CDKN3) are highly overexpressed in cervical tumvwduemov hf,p-ib35) *w:q :z ours.


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 d0hq*d o zfa)oru7-ni; uring the cell cycle ?