The graph below shows the relatio7):0juieowbsw39l 6 p dz+jvunyv- ;ynship between maternal age and the incidence of no yw+:b6v u9;julpdi o n)jsw70e3zyv-n-disjunction. What relationship is suggested by the data in the graph?

  Which stage of meiosis is represented inhj2it( 1 xi-ft5 z-sud the diagram below?

  The diagram below shows chromoso6s(n)r/s05 ytc ,capo g5yzc emes 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 statevrpaft1nz7)fn l 5n95s the number of alleles of a single gene which would be present in the nucleus of57 lnzn9vr)n ptfa5 f1 a cell as a result of each process?

  Which keyword is matched to tov*:w6e svjte.;mv4kfgs+ +rhe correct definition?

  Which statement(s) about mitosjw8/ja 0kz6lpis 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,z ik++9s9ounjnf2 xv; which letter points to a cell in anaphase?

  During which stage of mitosis does the nuclear en dfnvbma67 a5 58e3 xmr-6umfyvelope break down?

  Which one of the following transport 5q/cs7czk h+r proteins only carries out active transport?s /+ r7cckhq5z

  Which process does not happen in theki;x pnlu ;i:5 shoot apex?

  Which type/s of membrane transport do/does not requin;xq8 .l tl f64b9ujxlre energy expenditure?
I. Facilitated diffusion
II. Active transport
III. Osmosis

  The diagram below represents a cell with a rxoj-/8hvt./ mjot5qz a y4;0k5p rjgdiploid number of 4. Which stage of cell division is the cell currej;g - m0.j8 o5o/a/tjrr h5z txkvy4qpntly undergoing?

  The photomicrograph below shows a root tip meristem. Which)mqca.)okkqg r s 70.sq1 hv-x of the following sentences correctly d1kr0cksg7.qo.msqqa -v) xh)efines a meristem?

  When does the random orientation of homologouj2yu,um 06b hni/dd1as chromosome pairs occur?

  Which process does not occur durin - olj;k,4syojw g2ww)6p7x tcehs 6:ng meiosis?

  If a cell with a diploid number of 36 under. jk8elfn p/3o*m w;hkgoes mitosis, how many chromosomes will be preo8hpw /mf.kn kelj*3;sent in each daughter cell after cytokinesis?

  The image shows a micrograph o r;m**x+ pd:h,vurxe gf a cell.


What explains the appearance of the cell in the micrograph?

  Which statement(s) about homologous chromosomes iswtbobq4)bp th;*u l-4l ( 0ulc/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 ncw:jeb i63(;jw(/0y f mdxizindividual with Down syndrome.

Which statement is not correct?

  In the cells of a horse (E. caballus) during prophase I of meiosis Ivtp q (2l;p5cajjy ((vdnh0a ) there are 64 chromosomes. What is av) nta(pjdq2 cy(lp5h0;j(vthe haploid number of chromosomes?

  Which arrow is pointing to a chia4.sxs:d rn7 2c tdyry8sma?

  The diagram below reprezkn/*a; 9fsg csents the structure of a shoot apical meristem. Which row in the table correctly identifies the processes occuring in the struc z/gnsk9fa; c*tures labeled in the diagram?

  How does meiosis promote vap o2jfp-ga:9q riation?

  Which of the following statements is/are correc;:,5,chc db gaulcxyds l48 v-t for meiosis?
I. It is a reduction division
II. It involves random orientation
III. It produces genetically identical cells

  The diagram shows gametes prodovgh ;t:l0q.gbzr a*v0;da h5uced 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 pri u6e 9fdz.nlr5mary tumours as a result 65 urdlz 9f.enof the movement of cells?

  How many chiasmata ar8x0 f b+4+ 9cqtl j9uh-s9gdffwidu x;e present in the diagram?

  Which statement is a similarity between cytokinesis in animal and ats s5gsm7e ,9plant cells?

  Which stage of meiosis is matched to the correct descria m+ 2niuy;q+pn3 fj8vh5ulm;ption?

  Which statement(s) ar6ht :wu1zwyz/e 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 inut4y uj2bk-c lszx.g *(te:50x yn ,sd the formation of one large cell an,y(t tynks:2 zd4-* l.0ugujxe 5bxcsd one small cell. What is the fate of the large cell?

  Which row correctly describes 3zl )j*vu mizksm(4l1 diploid and haploid cells in humans?

  The following table shows the dip*d1 +z,mk mrewloid chromosome number of a range of species.


Which of these statements is correct?

  What conclusion can be drawn from the karyogr* -2zojzc914htji qtp9 *mutjam below?

  Which of the following procespv8:9k)nv mz7akh-ya )d a x 69ozia(eses is characteristic of the meiotic and not the mitotic cell cycle o 8n7 z9(pv9vzed:)aak)6ak ax-imy h?

  The diagram represents a bud with a shoot apical merir+6.ftu) so3ab i+hfo3 +xsfqstem.

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 rowvuc: /z 95.vo w/*j/vin/ioczk gu 6wt shows the correct chromosome nuoc w/viu:cw/n9.o// uki*vvz g56zt jmber for different cell types and cell division stages?.

  At the end of which phase of meiosis I does crossing over oc 8lcy49p8j 9hfxgpak1cur, and what is the outcome o99hg8l8p14x cpfj ay kf crossing over?

  Which of the following statements d t2tj+f a; pc6,yq;scroes not describe a step in the sodium-potassium pump cycle in thq ;tp2s ra;6cc,j+f tye neuronal cells?

  Which row in the table below is true of meiosw0vvpmd 7.x7i is?

Membrane transport is important for allowing particles to move across the hq7tzsp*2ite(k *. jticdz1 .cell me2 .c i(p7.*z1th tqj it*zskdembrane and 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 reg5n5tg.9 5j czanlv 4hlulated 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 trw j-a nlx,tzb* 18hq t-p ej62okc(3the cell cycle. Which cyclin is involved in pree-cp1ktq t at8hj loj r36zbn2( w*x,-paring for DNA replication?

The diagram below shows chl d *vlf1gkrb9kh 8w-:0;k:x.wju i hbromosomes 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 y*zr3qh uqr11w i.m ch;qn:*hseparation of homologous chromosomes?

  The mitotic index of throat tissues tac)+kylm+20, )rdrnee aq 6yk uken from 4 different patients is shown below. Which patient is most likely to have cancerous throat tissue?y l+dk u,kacrr6)n2q)emey 0+

1.Draw a labelled diagram to represent the prowiefkmagz ;; d 5p ek,,p8t6/rcess of crossing over.

2.Compare and contrast random orientation and crossing over.

3.Outline the stages of meiosis.

  The image shows an abnormal0c/.pzfr6odbu. 9 ptc human karyotype.


What is the abnormality in this karyotype and its cause?

The graph below shows the relasy7e n ;6 +2jg9s)jmm9apssuutive amount of DNA in one cell during one complete a9y2s)sn sj+9j m e usgu67pm;cell cycle. 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 ma+ht9j13r skh+6 qsb uf9s,pwile cat that is homozygous for brown, long hair and a female cat t1 uj+r,9h9b ifpt qssh3s w6k+hat has black, short hair.


Which of the offspring has a recombinant genotype?

1.Outline how polygenic traits can show 2aer7ygkao o v.*)/gkr1em 8vf-) eppa 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 che7m).jbhlyoc(h zts/)3 j fzo:3a -qzromatids shown in the diagram belomh33ozf/: zby(o)je.7hzc- l tq)js aw?

  The photomicrograph shows a pollen grain from L. candidum (Lh/ kr8,e*ze +xqrq y4bily). Which stage ofb,kyqr4zh*exqr +8/ e meiosis is shown?

1.Outline the events which would lead to an individual beinln7q jy+f0 c+bvp1f miqi-2c k*4s x6og born with Down synd4xfb-*f qyi1o67q i 0pvj klc s2+cmn+rome, which 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 indireu/dcfvh oc/( +ct way of measuring plant growth. A study was conducted on white onions (Allium cepa), under controlled conditions in a lauf(dvch/+ o/cb, 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 cells can divide. The diagrams bel3s ff 8paj/fnw)t qom:/*xa+now show two cells from an o+f as pa 8/nf:not3/*wx)mf jqrganism 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 ;mdtnn8p. 8c.j y4pe m4xgn; qexpression 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 diffpza)2 pk y+-ecerent stages of meiosisapp 2-e cz+y)k. Which row correctly names each stage?

  The micrographs show four phases of meiosis I in a plant. In what order do thesufu/ bz,ma id)d) qkf7m 8(bt1e phases occu)udi )a,zqf8bt d k/7(mu bmf1r?

Mitochondria are res bsn mk uu lx.kyrw+o7hz krat042(338ponsible 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 paremb4 03t lw+hku7( 3zu .8rak2sknoyrxnts: 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 number of c7qekj4a(noez c 8g:+mells in different stages of the cell cycle in four samples of lung tissue from four patients. Which tissue has the 4 zn+ g8e7e:k (qmocajlowest mitotic index?

  The diagram shows the dominant cyclin/CD2f, :yns ed4pmzxl(o+K complexes at different time points in th2szpo +(m xl4e ny:fd,e cell cycle. Which cyclin/CDK complex activates DNA replication machinery?

  Studies have shown that genes such as Cyclin Dependent Kinase 3 (CDKN3) are h5 qetheg) e0.righly overexpressed in cervical tutge 0.eheqr)5 mours.


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 thexg. k;q kuqv6a)c x)gf 2b0+mn highest during the cell cycle ?