The graph below shows the relationship between ma5epjf:cetavf(74pm 7:7 xqcr0c 0k8h h1m lehternal age and the incidence of non-disjunction. What relationship is suggested by the data in x:jhc7e7qt0php ee4ffa57 0 8 ccmkmhvrl( :1 the graph?

  Which stage of meiosis is represenxig5 3o3i9vl( bwp1i+putx 6gstrxf65ts/u ,ted in the diagram below?

  The diagram below shows chromosomes during(bez ymb wf*gn)g,5 *1o8ifin 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 enon3q0s( )uc8 rvv2 palleles of a single gene which would be(03c o nvsr)8unv2e qp present in the nucleus of a cell as a result of each process?

  Which keyword is matched to the cor9bjyw8-y rgupd49u;j rect definition?

  Which statement(s) about mitosis is/are truej-wknw: 21ov v?
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 anaphase?vnpg5 fn(c.a*

  During which stage of mitosis does the nuclear envelope break do-oh sr ty7eq78wn?

  Which one of the following transport (ck.m p 5y5kmz5d, 3pq) amvodproteins only carries out active transport? p)5 yko,mzdqvk.dmac55 mp( 3

  Which process does not happen in the sh9n85 vqgf73g 1g0i 7novsam bioot apex?

  Which type/s of membrane transport do/d :*lm9kuo zc68j wy/kmoes not require energy expenditure?
I. Facilitated diffusion
II. Active transport
III. Osmosis

  The diagram below represents a cell with a diploid number upqr.3bvh7j-)w s 8kh of 4. Which stage of cell division is the cell-r b)q3 uk .wsvhjhp78 currently undergoing?

  The photomicrograph below shows a root tip meristem. Wh 9kuej vlwxa4:nwh60;ich of the following sentences correctly defin;k 0vhunwx9e64laj :wes a meristem?

  When does the random orientation of homolo tr0tbp)- x6rfgous chromosome pairs occur?

  Which process does not :vbvghd s4qw(-ev. 5zntl b5 v- va8o,occur during meiosis?

  If a cell with a diploid number of 36 undergoes mitosis, how w8 - v5pqc(e e2hjwe,mg8;caimany chromosomes will be presa( jh25mqv; 8wee ciewgp,-8c ent in each daughter cell after cytokinesis?

  The image shows a microgk bx6 x,3li:huc9u ot1raph of a cell.


What explains the appearance of the cell in the micrograph?

  Which statement(s) about homologous chromoso z;fd bra tprq(7;qe6hto x837mes is/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 individual with Down 0p+a0 pxe7,zlyxj 1yihux ;h4syndrome.

Which statement is not correct?

  In the cells of a horse p(7sba x wm:p1(E. caballus) during prophase I of meiosis I there are 64 chromosomes. What is thxp wa(mp1 :b7se haploid number of chromosomes?

  Which arrow is point ks76 cqonfo6;ing to a chiasma?

  The diagram below represents the structure ofp2 (,tm, i d6 4k/w emeqvf8jcef*a3yt a shoot apical meristem. Which row in the table correctly identifies the processes occuring in the structures labelefmk p6ejq,f8ai 4y3eecv*tm 2wt, d/(d in the diagram?

  How does meiosis promote va1yy; db isq8.briation?

  Which of the following statement iyj0;fkh ;9i-c(pn ogs 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 chromosomes+-p)dip iohhw;nq z 65.


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 primary tumokv9y ;)ox:9c ramga) surs as a result of the movemeo9 a9rykasmv:)cg );xnt of cells?

  How many chiasmata ar6c ff 5 m ,9sb:uuitdstw8y/o6e present in the diagram?

  Which statement is a similarity between czz, u2a:z:6xqsdi ,e wytokinesis in animal and plant cells?

  Which stage of meiosis is matched to the corre;akf ivb6/x d1ct description?

  Which statement(s) are trupzbqis,wb r c*z99md+2x3i 5g e 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 gur5/5 rpt ghc av1k3zh:e7n 8oocyte after the first meiotic division. This results in the formation of one large cell and one small cell. W k51 rz8 gn a3pch7tuh:e/grv5hat is the fate of the large cell?

  Which row correctly describesv itww0csi h u,z8 .pu69q)l9m diploid and haploid cells in humans?

  The following table shows the diploid ma oeb0axosfx a /jfe.u.vvn gcn: 6b( 12:++gchromosome number of a range of species.


Which of these statements is correct?

  What conclusion can be drawn from the karyogram below?i g-8w k 62tdsc7t3kfvr:s i/f

  Which of the following processes is ch/)j x) qyo5s(jyhj*cz aracteristic of the meiotic and not the mitotic cell c( qjz) j*xh)yy5s/ojcycle?

  The diagram representj:jow lir 7e:n7/enf1 s a bud 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) ikc7oy8 3nt p cdktsubtx38775 s 48. Which row shows the corrykbpk85uc8tc7 dt7t on373 xs ect chromosome number for different cell types and cell division stages?.

  At the end of which phase of meiosis I does crossing over occur, terxd)b2;me 5fu-..ugow 3lf and what is the outle.xgote f5b;mu. f u3d )wr-2come of crossing over?

  Which of the following statements does nbc+e vpj/)0p hot describe a step in the sodium-potassium pumpp ) ebcjh+0/vp cycle in the neuronal cells?

  Which row in the table below i :9 f:jjw-oete)e6rr es true of meiosis?

Membrane transport is important for allowing particles to move across the celyeu6 n m 90vm73mx-sj dgsz:g9l membrane and respond to changes in the6m0mx d9 ju3n9-zg :ygvmess7 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 nq 79-:ijb xm 9mswz v60(wydmregulated 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 r-x). / ker3syllaf/zdifferent cyclins during the cell cycle. Which cyclin is involved in preparing for DNA replicaty/)kl3 flr z/ xe.ras-ion?

The diagram below sho 6p*lz 6 yvp7mitdb84kg0 753jfxfgen ws 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 separat8wccfp49s ph*b .jrq5ion of homologous chromosomes?

  The mitotic index of throat tissues taken from 4 different b6abj 6uf (;rzpatients is shown below. Which patient is most likely to have cancerju( f6;r6bzbaous throat tissue?

1.Draw a labelled diagram to r3;3a74 3njaah*d rifny-, wvxw iqqr:epresent 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 5+u76wkkarvlt q n*m w6p,zm9human karyotype.


What is the abnormality in this karyotype and its cause?

The graph below shows the relative amount of DNA in one cell d o8 w6 23xq/vc)d(lymlhqzsl 5nl-6 myuring one complete cell cycle. Each letter represents one stage vzwxl8ol6 23-n6h lc qsy( m5d) lmyq/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 +t p)*b*elb8gmq 7yjmbetween a male cat that is homozygous for brown, long hair and a female cat thatb8qt* )elyg+*jb m7pm has black, short hair.


Which of the offspring has a recombinant genotype?

1.Outline how polygenic traits can show a normal di)mp*k-*qwavso3 vy1f stribution.

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 crossiv48nlpd3nj7cy:c7 y(7j1itjk 9 sbv ong over of non-sister chromatids shown in the diagram below? 4sidjcyvt:p cnv9 bol8y7j73(7k nj 1

  The photomicrograph shows a pollen grain from L. candidum (Lily). Which staut2 (:(o,yhl c:. g;il8ewd hzzs 4dwzge of meiosi:yzd: h zw8zc.swe,d ohlul(4t ig2 (;s is shown?

1.Outline the events which would lead to an ar e y(httu:rdb.*)4q individual being born with Down syndrome, which is characterised by the presence of three copies of chromosome 21. (:.r yr)udhq*bt t ea4

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 was conycy- c:-fpix4i.hq/. xc .ggyducted on white onions (Allium cepa), under controlled conditions in a lab, to investigate the effect of soil pH on the mitotic inde/ .xi- cg c -ip.yyfxycg4:hq.x 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 b.zx wma-xql 22xt2 /tvelow sa.2-xtlz2q2x vmxw/t how two cells from 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 expre0 edfmcb-cb2. ssion 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 numb9hzx3cs 3 7aikwd7e g*er of 8, in different stages of meiosis. Whic3*x ceh 79zw ag7i3ksdh row correctly names each stage?

  The micrographs show(42m xhks5xq y four phases of meiosis I in a plant. In what order do these phases occur k2 5h4xx(ysmq?

Mitochondria are responsible for supplying metabi cae(+no;8 ksz du+b3olic 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 nucleuci ka8nb +z+seo(;3dar 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 cell60hj gat4(7d a7qgil0v6dh zms in different stages of the cell cycle in four samples of lung tissue from f7607lm6htj i (ad 0zvgaq4hd gour patients. Which tissue has the lowest mitotic index?

  The diagram shows the dominant cyclin/CDK complexes at different time points il od7zh/2n4*:. rvgj,kv 7eijzuz2vt n thjiu r2 2tvj dvokz7nz* ,e4:v/ 7.gzhle cell cycle. Which cyclin/CDK complex activates DNA replication machinery?

  Studies have shown that genes such as Cyclin Dependent *ffywilj/zji9 7 1us8/ sxgf)Kinase 3 (CDKN3) are highly overexpressed iwf8 9lf yji//g*ji)ux1sfs z 7n 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 cr.+ )ha7fi4:9a h vsx +kgdspo5t-nwnell cycle ?