The graph below shows the relationship between maternal age and the incidenc: xw os krk)ji;,cxzgs;19d*f e of non*k9 ,gssf o dx;i:;wc1xr k)jz-disjunction. What relationship is suggested by the data in the graph?

  Which stage of meiosis is represented in the diagram bw5lbip mv2+ th 22buf9elow?

  The diagram below shows chromosomes during . i0z3s*d8k*kmlsjef 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 which woulcwh, kee9;5ai d be present in the ee ;,c aw95hkinucleus of a cell as a result of each process?

  Which keyword is matched to *nq2yy(*i5rdtxo m are7 f8l5 the correct definition?

  Which statement(s) about mitosis is//fq nnm8j-8k yare 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, wh8t5 kproeoe6i54c cd,jn )3 rbich letter points to a cell in anaphase?

  During which stage of mitosis does the nuclear envelope bh loaovzueb108 6awejp7k2s j 4f4l.7reak down?

  Which one of the follg9s saqk 6 *3,m7,kgoqblrp i7owing transport proteins only carries out active transport?7s*pkq3ri glqbs9a, km,76 og

  Which process does not happen in thqvy/dfyh 4n*-3to wbv; b28ca e shoot apex?

  Which type/s of membr(zgn 0ayi)zsc0d j9x1ane transport do/does not require energy expenditure?
I. Facilitated diffusion
II. Active transport
III. Osmosis

  The diagram below represents a cell with a diploid number of 4. Which stage of g0uj22so1n i4qg u g)wcell division is the cell currently undergoing?ougig2q0) ugsw12 4jn

  The photomicrograph below shows a root tip meristem. Which of the fp90aqvc hn3 n*iq4g) oollowing sentences correctly define)c qn vi0 o3*h4pg9aqns a meristem?

  When does the random orientation of homologous chromosomul+z,iz: vxp3ntco: t.n im61bc5 la.e pairs occur?

  Which process does not occur dki-wuv)zs,l t9oje . ;uring meiosis?

  If a cell with a diploid number of 36 unde aohgz*fhil0b8* *6 anrgoes mitosis, how many chromosomes will be present in each daughter cell after cyt*n*0 hha*li8f6aob gzokinesis?

  The image shows a micrograph of a)zq9r,dd+k+g0 xe6it naxb-z cell.


What explains the appearance of the cell in the micrograph?

  Which statement(s) about homologous chromosomes is/are n8ee0yg dhk /b7ot 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 .67 fph9gt(ezw 9v dplsyndrome.

Which statement is not correct?

  In the cells of a horse (E. caballus) during prophase I of meiosis I- oooabdq 2aays 197iv-u b012al hn-t there are 64 chromo2b-n7u0dqt 19ao- ol2havi 1- asbya osomes. What is the haploid number of chromosomes?

  Which arrow is pointing to n5v g:4 a5ontwa chiasma?

  The diagram below represents the structure of a sho iin5q7v6e*xuot apical meristem. Which row in the table correctly identifies the processes occuring in the structures labeled iqn vuie*x75i 6n the diagram?

  How does meiosis promote variatg bmwil /- i-b66oufq*ion?

  Which of the following statements is/are cnf+ /7wgoag)jorrect 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 homologou oi)0h ljg:h;ys 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 tum5*kl5mmjm gb/;dndq x, n. u:id gi76jours from primary tumours as a result of the movemn ib.gx,6; d7mjki 5 *5dnmlmj udg:q/ent of cells?

  How many chiasmata ar.gz n)3jd 8nupe present in the diagram?

  Which statement is a similarity between cytokinesis in animal cyn..ryr0 qou-- zn7n and plant cells?

  Which stage of meiosis is matched to gjxn3n 6w 0wv7k,z8 je(l p;rbthe correct description?

  Which statement(s) are true of meiosis I but ki xux -hx,(l)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 lea9)1*y x dp(sjb 81ehki 7:xinqw6 bdivision. This results in the formation of one e n hp)biks dj:qwx6i(19l*1x7ey8a blarge cell and one small cell. What is the fate of the large cell?

  Which row correctly describes diploid antwi, 2;6c,qyndwb p -vd haploid cells in humans?

  The following table shows the diploid chromosome number of a range of specgd7b9r (ik3da e 9ph1c) hy/fzies.


Which of these statements is correct?

  What conclusion can be drawn from the v/osuq*b*c1ghqm dv* t 08e4akaryogram below?

  Which of the following pr-ibud 2)yaod5f /m cyu+:5mceocesses is characteristic of the meiotic and not the mitotic cell cycle5-u/:ccuded ymb fi ym52+)ao?

  The diagram represents a bud with a sho -x.88 ihde0xbd+ksx m1sc n9qot 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 th tc;e.p)6on mmbz0aw7 tk 5sn9e correct chromosome number for different cell typem7bnec z;n.0 awpm)st 59kt6os and cell division stages?.

  At the end of which phase of meiosis I does crossing overktv)lns sc3h ,luqu7*etptu;8 *i6wf q1 80em occur, and what is the outcome of crossinqu0 8nc37ls; ltuwi kh8 t t,fqvmsue*) e1p6*g over?

  Which of the following statements does not def3a7/zjo r k s 6rw2ww95dmes.scribe a step in the sodium-potassium pum5rseorf7kj 9 waz62wwdm/ 3 s.p cycle in the neuronal cells?

  Which row in the tabq5,/hx mrdm(a ;.s xl-:aokiale below is true of meiosis?

Membrane transport is importat( /k7b kl t,:ovqhwf9xz7 p5znt for allowing particles to move across the cell membrane and respond to changes in the chemical composition of the extracellk/fzov ,kb97z t(5p l:hwtqx7ular 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 fvy k4w5roc 0 ve3 we1jh-1 8+wtit1unis 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 cyclins during the-gfbht5+8ue*q i y,x /lg ,zsj.ksbq/ cell cycle. Which cyclin is involved in preparing for *b gklq+sxt /qs.,5g8 -eyiujbfz/,hDNA replication?

The diagram below shows chromn uainujp+7lq1:.su 2zs2 cj,osomes 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 homologoubm:ste rqxk;l jdl0to/e5.n*0 j7 l r8s chromosomes?

  The mitotic index of throat tissues taken from 4 different patients is e a h cq+d.hf(i;x(wqkfr8e8*6bs9dcshown below. Which patient is most likely to have cancerous thhq(c 8bse8 .h *;dq+f r96weka (cxifdroat tissue?

1.Draw a labelled diagram to represent the process of cbgtrt/x1d z 2l6 sm(a,7bga9 xft 6 9fus/mn0lrossing over.

2.Compare and contrast random orientation and crossing over.

3.Outline the stages of meiosis.

  The image shows an abnormal cr:93x oi fsw4human karyotype.


What is the abnormality in this karyotype and its cause?

The graph below shows the relative a+k 8obn kqx62t ga4ml/mount of DNA in one cell during one complete cell cycle. Each lex+8 o/ktnm42k a6lq gbtter 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 crops- ihcb-/pe *ss between a male cat that is homozygous for brown, long hair and a female cat that has black, shoreic*p /b- hs-pt hair.


Which of the offspring has a recombinant genotype?

1.Outline how polygenic traits can sh -ut/h qp1bdzwu,77cyow 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-sejeu.4cs :tzpouu o;v(b*9 q(ister chromatids shown in the diaseue(pz.ot 9 :4 uob*cqjuv(;gram below?

  The photomicrograph shows a o2-zo xe f62yuqn1(ok pollen grain from L. candidum (Lily). Which stage of meiosis is sho22zok1- qx6oy(nu ef own?

1.Outline the events which would lead to an individual1w 5xb2j vsk.u iogq4* being born with Down syndrome, which is characterised by the presence of three copies of chromosome 2kj*u4.q bvig21ws xo51.

2.Explain how meiosis increases variation.

3.Outline the stages of meiosis.

The mitotic index is an indirect way of measuring pfht/s4- 0 ;nchywh*jslant growth. A study was conducted on white onions (Allium cepas/nh 4 ;h* syt-jwhf0c), 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 waxdr) k,hh(z .zys in which cells can divide. The diagrams below show two cells from an organism w .zzhd,)(hkxrith 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 stem1lbrei,he2j q3-. tcklv u3h6 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 stageo( 6 ahqars it;/gq;2 t0k1gtxs of meiosis. Which row correctly namesr tx20ts( ah1/ig;; tkgaq o6q each stage?

  The micrographs show four phases of meiosis I in a plant. In what order do thesig0(;n,c *mlcnxg 02p p cgxo0e phases oc i2;c(0gcg ,l*nxn0c0xgpp mocur?

Mitochondria are responsible for supplying meyepfe 1f2)h.u ;mcz8cf j(.avtabolic 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 parentspf fcz ma8 (.e1vhj)e.c y;2uf. 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 cells in differecx2kshb:wzp7.96f( 7tm q; zrc wt2r ynt stages of the cell cycle in four samples of lung tisst t rc7(fw9sc2:px26zq.k7h;ywz mb rue from four patients. Which tissue has the lowest mitotic index?

  The diagram shows the dominant cyclin/CDK complexes at d0/os7s jktv*v m 9wm9tifferent time points in the cell cycle.vv 9sk9 /mt* 07omstjw Which cyclin/CDK complex activates DNA replication machinery?

  Studies have shown that genes such as Cyclin Dependent Kinase 3 (CDKN3) are highmf6g s; ei8duhnz f*vv2a:7 2bidm2a 2fvbh e87 sg6fv*n:;uzly overexpressed in 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 cycle ? (o fzxup kvbr;59unz)w d q,r7b4 :gq2