The graph below shows the relationship between maternal age and the ips +2s.8 q 5r6e2lc .e37bo tnxuxbdku7yn(gk ncidence of non-disjunction. What relations223yp. cgeoklr8x 7b. 7tbss56e+k( udnn qxuhip is suggested by the data in the graph?

  Which stage of meiosis is represe akog77 +it/5iu h jky-q5gurfv-v9;f nted in the diagram below?

  The diagram below shows chromosomes d7 b63d t0 5 99nxidgkhj(vtvihuring 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 sievz2o d1p1zf:m.. )i ljnns +qngle gene which would be presel )vqzpnf21in1.+mjz. so de :nt in the nucleus of a cell as a result of each process?

  Which keyword is matched to the :hclw6fm ea+z/:+;pdjqyyhy -n q:.scorrect definition?

  Which statement(s) about mitosis is/are true;0myiz/ d/d5(wpb(sv*i 8x llm sx8 zq?
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 anaphase3ebk a2 3mlo)h?

  During which stage of mitosis does the nuclear envelope t+per)*p1h0kcl u2vc break down?

  Which one of the following transport proteins only carries out active transpokwu0 -rdd- .wirt?wurdd.- wi-k0

  Which process does not happen in tq3k;h: wh;eerje y7: she shoot apex?

  Which type/s of membrane transport do/does not require energy expenditug6rz5un b1a)f6 lt -fe0r o7iire?
I. Facilitated diffusion
II. Active transport
III. Osmosis

  The diagram below represents a cell with a diplokhasmxn.p.zcw:e7 )vs3 7p+s uk a:0sid number of 4. Which stage of cell division p7zks0 : cewkn:.smux.ssv+hp 3 a)a7is the cell currently undergoing?

  The photomicrograph below shows a roo)/7:rvb;j ca eq:lwsu m+a,tv hn/0g it tip meristem. Which of the following sentences correctly / ;u0aa sn:w7rqv)b g, j:vht/+ lmceidefines a meristem?

  When does the random orientation of homologous chromosome pairs occux 6qmpjfy,(, nr?

  Which process does not occur during meiosis?9xrojar )j2. 4 vmthv .7w /9uv1ovchd

  If a cell with a diploid number of 36 undergoes mitosis, how many chromosomes bc-qae; l4tz wt/j9jvc* 5ed6will be present in each daughter cell after cyt-j b*edlwc6taj54; vq/e c9 ztokinesis?

  The image shows a microgra o8kjm8 r5p-etayq7 v)8reh,b ph of a cell.


What explains the appearance of the cell in the micrograph?

  Which statement(s) about homologous chromosomes is/are not true? m 1j(vj.kth-(a q/gmr :t; h 6q2zys, ihq-uls
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 anq jjs: su98 08zp6qq ichot:8w individual with Down syndrome.

Which statement is not correct?

  In the cells of a horseem,lmwo/ s 4kpl2 gn,dn-p :v/ (E. caballus) during prophase I of meiosis I there are 64 chromosomes. What is the haploid number ofs/ nw:4m 2nmlv,d ope,g/k -lp chromosomes?

  Which arrow is pointing to a yzgsb* 25mq/ru 2uoaoz498 v uchiasma?

  The diagram below represents the structure of a shoot apical meristem. Which rcye e -;rcq.y7ow in the table correctly identifies the processes occuring in the structures labeled in the dia y; crecqy.7-egram?

  How does meiosis promotebu-,imjs(-ntfk,3hd:8ts b fll7jz/ variation?

  Which of the following statements n6zpr s97n (6e to;jlofr 1(plis/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 homologou 8.z8xw (kq:qo u9wmtts 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 ofw/u9y bdyt x ye(mq f6 *qg)p)42y3mpc secondary tumours from primary tumours as a result of the movement of xye(4pqumqb)9fdpg )y c2y/mt*6 3ywcells?

  How many chiasmata are present in theck ;/7jrnzi5 nkq1t2b diagram?

  Which statement is a similarity bet;3ag h goi:8o pti6ow2ween cytokinesis in animal and plant cells?

  Which stage of meiosis is matched to the r cz.sri2;)-7 uqhaug4*o;n i 8brlhncorrect description?

  Which statement(s) are true of meiosis I be+b5snnnz6w7d3umk c mobvm;,; +g 9cut 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 meioti n)r6qgj +a(s,pu3p twbgzp3u v/ g93oc division. This results in the formation of one large cell and one small cell. Wharj wqpgt(9)3ug +b/,p36uv znap osg3t is the fate of the large cell?

  Which row correctly describes diploid a. qikejtqcrwn+s.c,klf98 2. nd haploid cells in humans?

  The following table shows the diploid chromosome number of a range ofl3slwd ugkkow3)/7x(-7 xoqm species.


Which of these statements is correct?

  What conclusion can be drawn from the karyogde v.)t;g,ojl ram below?

  Which of the following prf4(ls ium ;+vrocesses is characteristic of the meiotic and not the mitotic cell cycl(;4m fv+s ilure?

  The diagram represents a bu wa1c1 j*.umh +-ihnyylw j;pvfrn85-d 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. Whichc;ca+-km e:yh row shows the correct chromosome number for different cell h+:a-; me yckctypes and cell division stages?.

  At the end of which phase of meiosis I does crossing over o:p4m*.9 ju3 9a qpw.hsuktqjzccur, and what is theuj.tz* wjkaps. u: p9qq4h9m3 outcome of crossing over?

  Which of the followia8rr0s 3ie 6/md :jekpouys23ng statements does not describe a step in the sodium-potassium pump cycle ip3yuaker des3/0:j2rim o8s 6n the neuronal cells?

  Which row in the table below is true our3sn6yw;f - 3 :bg d1bbyr1uxf meiosis?

Membrane transport is important for allowing particlp)(nktiyzlv9w )j;( ye8ez: ues to move across the cell membrane and respond to changes in the chk l tw)i n(zvp)j:9zee y8(;yuemical 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 regulatl65wf perwh3zj /5 tg0ed 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 duri:/s: tj/xjqb png the cell cycle. Which cycjqs /::pjxt/b lin is involved in preparing for DNA replication?

The diagram below shows chromosomes during meiosi7j lpxz0kw o;b ,ae8x-c.o.be s.

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 i kvu+gapznaw3;5;u 9mnvolves the separation of homologous chromosomes?

  The mitotic index of throat tissues tak60vpex5p ws :wen from 4 different patients is shown below. Which patient is most likely to have cancerous throat tissues:xw0pp evw6 5?

1.Draw a labelled diagram to fj- 9ou.a;e*gb /+ tgxnrr2fjrepresent 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 hums yvw07a;nfbx*5qi,xan karyotype.


What is the abnormality in this karyotype and its cause?

The graph below shows the relehln5ert(/d5 vxp6 q3 /ps5ffative amount of DNA in one cell during one complete cell cyc6hf ep5tvr5s xep/ldn ( f35q/le. 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 male cat thlqb;rpt3 5t tow+d9+ eat is homozygous for brown, long hair and d t+eo5t93rpl+t q bw;a female cat that has black, short hair.


Which of the offspring has a recombinant genotype?

1.Outline how polygenic traits can 85hzp-q 8 zlu j x8y32vq5inifshow 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 fr4 h5vxtsvy(h3jt(; t rrot;p;om the crossing over of non-sister chromatids shown in the diagram tp4 orthj;;(ht trx vy3;v(s5below?

  The photomicrograph shows a pollen grain from L. candidum (Lily). W2j4 9 h. rcn.fnc)tcl2-vglvmhich stage of meiosis 2v2cclgjrm chv) 9 n4f .t.nl-is shown?

1.Outline the events which would lead to an individual being born with Down s +to kcued53x.yndrome, which is characterised by the presence of three copies.od3cetx+ k5u 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 st, w:vxrj/h1dere2 mz. udy was conducted on white onions (Allium cepa), under controlled conditions in a lab, to investigate the effect of soil pH oe.e,1mjwz/rhvr2 :xd n 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 celljj12hgqq6)dc s can divide. The diagrams below show two cells fhjq6)1q jg d2crom 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 o9,:i/1m gkd o3xap w4fw yf,lpf gene expression 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 n1/:pmc sl 5mg1rm. aevor k/7dumber of 8, in different stages of meiosis. Which row correctly nam57s. m1mae /p rv:1codkgm rl/es each stage?

  The micrographs show fi9e1kq; zi so5xu /l76omia)kour phases of meiosis I in a plant. In what order do these po;i6k5a u qe zs)oxk9l7imi/ 1hases occur?

Mitochondria are responsible for supplying metabolic energ9:d f7jyz jbi+y 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 parents. It has been suggested that, in some eukaryotic organisms, inheritance patterns of mtDNA found in hybrid cells, which arejbjy 9zif:+7 d 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 different stages of the cell cycle in foq b)c3q k7o2abec 7qein.*w ppr-u 31 dtcq-a:ur samplcbc2qn*o-ui3a 7pk d p:qew. 3e- ac) q7q1btres of lung tissue from four patients. Which tissue has the lowest mitotic index?

  The diagram shows the dominant cyclin/CDK complexes at diff e2,puncsn)jl- s;l o6erent time points in the cell c) j;sp elsn-2nu l,o6cycle. Which cyclin/CDK complex activates DNA replication machinery?

  Studies have shown that genes such as Ca0m7o kr c fukz;61l:kyclin Dependent Kinase 3 (CDKN3) are highly overe 1 7u0zk ca:rkkfolm;6xpressed 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 high;en22bs;4innw9 u rf0.xxwk nest during the cell cycle ?