The graph below shows the relationship betweenh sua6x m5qaxs uc93;437twag maternal age and the incidence of non-disjunction. What relatsa7x6hg umsa3uxwaq;t c 5943 ionship is suggested by the data in the graph?

  Which stage of meiosi6lb yyl jiph,q:- b,7js is represented in the diagram below?

  The diagram below shoikd-bcu( -t s/n;,p t obl0,esws 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 the number of alleles of a single gene which 7 2sk9tc6v*i h kaveoo3pis+- would be present in the nucleus of a cell as a result of ea9o*i+2 v psosktv7i a36ek-chch process?

  Which keyword is matched to the correct defzdx *w;j 8hlb0 i*a.u.na qpe 8+r*mfoinition?

  Which statement(s) about )kn3 yna6d6o4ajol q hq+gv-6mitosis 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 lettbg3, ht(xc:brd+9k iser points to a cell in anaphase?

  During which stage of mitosis does the nuclear envelope break down?n8wi0r7se- mz7sl s ipch8t3(0f0e dw

  Which one of the following transport proteins only carries out ny7)exwcm+,zatxz0oz-t vx/ s.n1y.active transport? 0oyxz, ze .xtx-s.vmw/z)1 nntcay+ 7

  Which process does not happen in tdt4u4 +awy c 1ka hrigf6rd):4he shoot apex?

  Which type/s of membrane transport do/does no -1npfptm.llj (hj :g+t require energy expenditure?
I. Facilitated diffusion
II. Active transport
III. Osmosis

  The diagram below repres2ryi q3 gf3i45ob sbf*ents a cell with a diploid number of 4. Which stage of cell division is th45gf isib* rf3ob 2y3qe cell currently undergoing?

  The photomicrograph below shows a root tip; qc :lxs3he1i meristem. Which of the following sentences correctl ;h3 eilcsx1:qy defines a meristem?

  When does the random orientation of homologous chromof6f-cej 02wrs- fx3)mnq -gam some pairs occur?

  Which process does not occur during mg w/l2 efs,ti;eiosis?

  If a cell with a diploid number of 36 undergoes ,1k22t-oyk a(wymb id mitosis, how many chromosomes will be present in each daughter cell af-i1(o,d 2my b2ktykw ater cytokinesis?

  The image shows a mi 55k5 nyhh(hv8 p2suo6upaxp,l rnb.3crograph of a cell.


What explains the appearance of the cell in the micrograph?

  Which statement(s) about homologous chromosomes is/are not tjywzs + h+s 4q14b* mkqt.toh6rue?
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 forf 0 z0 bn7dlkcb+0v/y( zx(vsz an individual with Down syndrome.

Which statement is not correct?

  In the cells of a horse (E. caballusoa:6 a9 81dzhtc(ok uu) during prophase I of meiosis I there are 64 cou8uadt aczoh1 :( 69khromosomes. What is the haploid number of chromosomes?

  Which arrow is pointing to a chiasma? h.+ u3y8t zrt07lv,c1z ldshg

  The diagram below represents the structurze,*: jl whw6ue of a shoot apical meristem. Which row in the table correctly identifies the processes occuring in the structures jezh wuwl:,6*labeled in the diagram?

  How does meiosis promote v8 2 .p,fz6r5siwix boeariation?

  Which of the following statements is/are correct fx3d 3 p6gpmlo6or 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 homcsd( **bo si-515r koid 5gdygologous 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 th ic3*d+th0q :(8 t;r imuou8fx.uzgp ze formation of secondary tumours from primary tumours as a result of the movement of cqx:0*hzct 8tu; mz3( .dupg8f ruii+oells?

  How many chiasmata are pres .9x+3nv -o n.au.quxbegfl ;tent in the diagram?

  Which statement is a similarity between cytokinesis in animal and plamnu1 +rlwdq,:x ra+0fm 6-kwant cells?

  Which stage of meiosis is matched to the corr ,,0lwx5 re6qgkqr /dcect description?

  Which statement(s) are trut,s w uv(26fpke 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. Tr3xk78-ae.w)r2w4f ruom d oj his results in the formation of one large cell and one small cell. What is the fate of the large24kwa jd.ou)7xrmf 3rr8oe w - cell?

  Which row correctly describes diploid and haploid cells in hui2 q* bchju)x kw(6py.mans?

  The following table she1,. cydups uf *b(jqfj/s+udv2j 1/sows the diploid chromosome number of a range of species.


Which of these statements is correct?

  What conclusion can bz;cvu ;w*/8np 6sa xec:wzcns1pt )q1e drawn from the karyogram below?

  Which of the following processes is charac ob1lo4w- k2:zthb(c geq)7cnteristic of the meiotic and not the mito:n1q(ob-k2 g7 4ctob) cwelzhtic cell cycle?

  The diagram represents a bud with a shoot apical m jsr/8 f1tlrv1eristem.

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 showse m; wdo (780n (gql2glvcmkd) the correct chromgcn ; mo()2ld8wk 0v(ql7edgmosome number for different cell types and cell division stages?.

  At the end of which phase of meiosis I does crossing over occur, and what ijce* v8z/u bdkd*4exp2x2gk1s the outcxk bk *z /du4 v2dc1g*82pejxeome of crossing over?

  Which of the following statements does no2-q ypecux*/z t describe a step in the sodium-potassium pump cycle in c* p-xz2/ yueqthe neuronal cells?

  Which row in the table below bcw e n3z .w8+j6i0kaxis true of meiosis?

Membrane transport is important for allowing particles to mov5gq).-hfd-ncbal 6 x be across the cell membrane andhc-lq)xbgnf -b 6.5a 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 re8x)q82bfobmtjnvus yppdq1(+ 9 97ro gulated 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 concentratio9pgw)sz a mt15ns of different cyclins during the cell cycle. Which cyclin is involved in prepamp5g 9wtsz1) aring for DNA replication?

The diagram below sh u 8l4lr3 3th6fpe,znjows chromosomes 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 hbh1c;(vj/hf o oe8s 0somologous chromosomes?

  The mitotic index of thr7p,4(o *khitf2 n 84tqkcwpfboat tissues taken from 4 different patients is shown below. Which patient is most likely to have cancerous throat tissu4hiwt*kn,2p( f8po tcqb7 f4ke?

1.Draw a labelled diagram to r7:t1 s b 77iqrnl: )emubow:yfepresent the process of crossing over.

2.Compare and contrast random orientation and crossing over.

3.Outline the stages of meiosis.

  The image shows an abnormal human karyotype. 7z xqk bn9g. jh:af9qvpp.c)3q- un3w


What is the abnormality in this karyotype and its cause?

The graph below shows the relatiqo1q- 58wc, e9vauuxt nsf1t:ve amount of DNA in one cell during one complete cu8a9qt w5-11f:c u vstn, xoqeell 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 betwee bkdgs07 (35jwy pws5sn a male cat that is homozygous for brown, long hair and a female cat that has black, short hai y5j3sw7b(kwgd0 sp5 sr.


Which of the offspring has a recombinant genotype?

1.Outline how polygenic traits can sh/a/nr(j mr;h21qoyl dow 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 shown iip f6(,l k,*hqqg9ou( grtai67 6kigvl35ryl n t(6fhv a,r76ikqg q it(lg3ri , pl65o9lyu* gkhe diagram below?

  The photomicrograph shows a pollen grain frq qth 9d 3pq n0q7z1; scqo,hwrl3ck96om L. candidum (Lily). Which stage of meiosis is;3scq3h7t0 q9rcow,hpnldzq1 6k q q9 shown?

1.Outline the events which would lead to an individv)ak+uxteyk f;*n+ct u w 4)*wual being born with Down syndrome, which is characterised by the presence of three copies of chromosom+t4*k w) )kwx+ynvu;fut *c aee 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 sgvtl( 6n 4a x: 8rfoppfx6981diil ak0tudy was conducted on white onions (A4 vfxno(k 6gi a tpla06 ild1:x8r9f8pllium cepa), 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 ways in which cells can;c go;eh,8mqxis :n+bq+azb1 d(m tb, divide. The diagrams below show two cells from an or;o1c;t+ :n m hbi8+dsxe,b(z ,am qqgbganism 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 wa8vn xi2h31nexpression 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 diffe p4ae e57gk.sn u9-tjsrent stages of meiosis. Whietu-gk457j9 ps.ae nsch row correctly names each stage?

  The micrographs show four phases of meiosis I in a plant. In what order do th/dt795mq a stz,,wfm dese phases odat/m q m ,9s7fzw,td5ccur?

Mitochondria are responsi9r ,crx 84 q sqcwdaaur,/p.p7ble 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 parents: the morp,8. xw/apsc9 rq4d,7qruacther 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 cells in d,d l+o5quwv:ui1 s:0j;fvtjb ifferent stages of the cell cycle in four samples of lung tissue from four patients. Which tissue has the lowest miw ;i +ofj0u:,sjq:v5 1tudvlbtotic index?

  The diagram shows the dominant cyclin/CDK complexes at different time /+jmvgmfv8 vqj4qc *z-r6 a6fpoints in the cell cycle. Which cyclin/CDK complex actiff8/j *azmvr m+6j6- g4qcvvqvates DNA replication machinery?

  Studies have shown that genes such as Cyclin Dependent Kinase 3; dilghn- :*tg (CDKN3) are highly overexpressed in cervical;l-ggn d* h:it 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 y .drc2s(k3 sllt :7zmhighest during the cell cycle ?