The graph below shows the relationship between maternal age anedakjn0yg8: ttg q8 32d the incidence of non-disjunction. What relationship is suggested by the data in the graph? 38g enk8 q:tg02jdyta

  Which stage of meiosis is oq k(gjn cvt;5uvk )6p.ak p1;represented in the diagram below?

  The diagram below shows chromoso j1z zhq ps+znp s1k--ym+hn28mes 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 n a/0h1, stb /duzjqaqz(.z1uvumber of alleles of a single gene which would be presezu/ a1vudbzt .1zsh/,j q a0(qnt in the nucleus of a cell as a result of each process?

  Which keyword is matched to the correctaukpt: ,:osjrho4 a gg)+vl2 ) definition?

  Which statement(s) about mitosis is/are tru3 f v* begq(sgy.gsu;.e?
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 celg4wjj/vk.en7 g+yap-+o:j 1f9tx3 yvz1mp f hl in anaphase?

  During which stage of mitosis does the nuclear enveleta/ n- 0ul/se;vmxd7 ope break down?

  Which one of the following transpor6cpm 0x mxp:,uj* wb4gt proteins only carries out active transport?4px, 0* xju6pcwbg:mm

  Which process does not happen in the sw+t+ p:0ryxyl 2-tbo,q5po7 bnzp.w shoot apex?

  Which type/s of membrane transport do/does not require energy exh7 1/mhm6sqvgp 4evv2penditure?
I. Facilitated diffusion
II. Active transport
III. Osmosis

  The diagram below represents a cell with a diploid number of 4. Which stage of ci, /quh eiqfk 46die:+ell divis q:6,uf+iqe /h4dik ieion is the cell currently undergoing?

  The photomicrograph below shows a root tip m3n,r7,gn kvrcs j4o7eeristem. Which of the following sentences correctly defines a meristeej3rno7gk,scn ,4 r v7m?

  When does the random orientationn k 7l15;cr(u8a9iicmlt )xog of homologous chromosome pairs occur?

  Which process does not occur duringy3)tscf,kmvao)h . q)j .v sx7 meiosis?

  If a cell with a diploid number ofera7rv2z2 nys ;so mb b0*4e,a 36 undergoes mitosis, how many chromosomes will be present in7 4avsy0nmzs,;r 2rb*2e eoab each daughter cell after cytokinesis?

  The image shows a micrograph of a cell. zik7oba5/y9z m- t8eyur):sj


What explains the appearance of the cell in the micrograph?

  Which statement(s) about homologous chromosomes is/are noff3 m9v9cjftv6a a:: et 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 D,qs 5vu, t.skpown syndrome.

Which statement is not correct?

  In the cells of a horse (E. caballus) during prophase I of0 ..9kivnifnw meiosis I there are 64 chromos.w9ikvin f.0n omes. What is the haploid number of chromosomes?

  Which arrow is pointiup;d+yi k 8qr6z0 x55qso7wj zng to a chiasma?

  The diagram below represents the strwp:k -lxl*+ x,b3t7w h2 9crkl*nexesucture of a shoot apical meristem. Which row in the table correctly identifies the processes+x,kee pw7: kxtlcl s rlx2b 3hnw*-*9 occuring in the structures labeled in the diagram?

  How does meiosis promote variatio.,5uok5 hrt idn?

  Which of the following statementn5rh.- eimi n*q8hq )rs 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 gametes produced from two homologous chrom-*nrn4 1kk:m / bqezqp:qlbr2osomes.


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 buq3aofjr- 3,l6ti 2ytumours from primary tumours as a result of the movement of cel-ui2 lytr3f,a6b jq3ols?

  How many chiasmata are present in the di qq1xydm5xb3h eo4 h/d4,/uek agram?

  Which statement is a similarity between cb vlcjtpklw*-m) h/ f.pt( z8/ytokinesis in animal and plant cells?

  Which stage of meiosis iyl:jl f lg36s3s matched to the correct description?

  Which statement(s) are true of mep:vhsv4/lf -(a/ mnpziosis 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 resultszfuvlm +93wc7ioh :6wfo 7cd *c: *vcl in the formation of one large cell and one small cell. What is the fate of t79dhwo* f+:c3u z ifl: wmcccv6l*7vohe large cell?

  Which row correctly dej9( jsm(8 tmg.d b(fzzscribes diploid and haploid cells in humans?

  The following table shows the diploid chromosome number of a range ofj* :ioe-w 1 sa55zorof species.


Which of these statements is correct?

  What conclusion can be drawn from the karyogrx3z(,jc1zuq ztgwm/ -xk z( k*am below?

  Which of the following processes is characteristic of the meiotic awg2q2e3enl tk2hew,zc i7v09/f 7axund not the mitotic cell2lq9c 2z0ehvwn3x wkaef7/te7 i2 g, u cycle?

  The diagram represents a bud with a shoot apiz.x oukt41+ .qfdjlxe: 5 af,wcal 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) imqs 4ti8hd u3j)0s (bws 48. Which row shows the correct chromosome number for different cell types and cell bw(4hsu0 mjst3q)8d idivision stages?.

  At the end of which phf nv8ff e/,h:oase of meiosis I does crossing over occur, and what is the out/nv8f:h eo ,ffcome of crossing over?

  Which of the following statements does not describe a step in the sodiumpoy2 fr3s2mpp/ fqgal8-8v 7h-potassium pump cycle in the neurona/h 8o3qp2pg fs-rf 27al v8mpyl cells?

  Which row in the table below is true of meiocof)a) awj -kfe)qw: )sis?

Membrane transport is important for alloc m0. hcbhugc5x8a9:bq /fv5 owing particles to move across the cell membrane ano5cqu08cg/9c: b xh.ha f5vbm d 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 r +o typ-g s7qyl7v(jl/egulated 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 concentration sh nuhans/+bxt.:j09h;cx2e s of different cyclins during the cell cycle. Which cyclin is involved in preparing for DNA replicati9he;s/nn jh2.+as u:0hxc txbon?

The diagram below shows chromosomg441:mn- hz1ec3jtlm q jnh 2ees 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 chromo)e+05orr;9hy m)s 1ysff al5rsfw ce xj ;0rb,somes?

  The mitotic index of throat tissues taken fd9 qwi;6f p4hnrom 4 different patients is shown below. Which patient is mos6 n;p9qidhwf4t likely to have cancerous throat tissue?

1.Draw a labelled diagram to represent thv4s2 9kq l lnqv3a7;. qdq1bjje process of crossing over.

2.Compare and contrast random orientation and crossing over.

3.Outline the stages of meiosis.

  The image shows an abnormanjft 7lzhgc 14.b6nm7s /t oiccedh7 964n,wal human karyotype.


What is the abnormality in this karyotype and its cause?

The graph below shows the relative amount of DNA in one 0/myt1tmp v3m cell during one complete cell cycle. Each lett3 tm1pyvtm m0/er 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 homozygous for brcbch k:kme bopq;3ec* n:9o 9gur5:k0own, long hair an5:qp:;k3ub9 cogk:e 09ocn k*m cber hd a female cat that has black, short hair.


Which of the offspring has a recombinant genotype?

1.Outline how polygenic traits can show a normw0j7sj04l:-c 1rw q ul,nmqyeal 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 crossi, 8rjfefbio:g3p8,pvi ny8 q5ng over of non-sister chromatids shown in the difvg j388i,5i p8 fb yo:,rqnepagram below?

  The photomicrograph shows a pollen grain from L. candidum (Li ru7)6k1 drthrly). Which stage of meiosis is shownth dr17k6rur)?

1.Outline the events which would lead to an indi;pkaqnza5 / gwl48*npvidual being born with Down syndrome, whiclwn*k5aq pngz;/ap4 8 h 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 indirect way of measuring plant growth. A study e:xru,voe)wevt q.wc 6wm938t: 1ssy was conducted on white onions (Allium cepa), under controlled conditions in a lab, to investigate the effect of soil pH o6vrett wv e::e1w s,m9q8 3 xus)ywc.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 diagr75g5ybvk wq2o*ifh,i ams below show two cells foy*iwb7 ,h5g ikq 25vfrom 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 in stem groeaqfp :u+x 1+e* k2u4uy qgj-nwth.

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 ab(n/npmy: --jvib.) qagpag / diploid number of 8, in different stages of m/mbigbgjq ( /vynp:.ana-)p-eiosis. Which row correctly names each stage?

  The micrographs show four phases of meiosis I in a pl, 7v-ida8j zriwe: 7ecn ;jrq/ant. In what order do these phaaijiq c7;d n 7jv:erwr,-/e8 zses occur?

Mitochondria are responsible for supplying metabolic energy intc1) v/g nw)w;s+j viu 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 b)w us j1v)v+c/ng;iwt e 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 stagessn9 gis+ )b.fq qyxc0bcn7j; 2 of the cell cycle in four samples of lung tissue from four patients. Which tissue has the lojsb0. cgqqsx+yfi9bn)2 n ;7cwest mitotic index?

  The diagram shows the dominant cyclin/CDK complexes at differe5/(bhqz50 eh6lbby2g on vay4nt time points in the cell cycle. Which cyclin/CDK complex aygzbybh4q /l ban2o 05 e6v5h(ctivates DNA replication machinery?

  Studies have shown that geegl, uea0ubtr5.voi2;,h -5+f esg o wnes such as Cyclin Dependent Kinase 3 (CDKN3) are highly overexpressed inuu- as +erh, 5b,5 0.wleietoo2vg;g f 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 cycleco.+xt hbk /a0 ?