The graph below shows tmy4u zik80y2o 9 wdvrtd..uc)he relationship between maternal age and the incidence of non-disjunctiuu2vy.dzci.wr )9k4omy0d 8 ton. What relationship is suggested by the data in the graph?

  Which stage of meiosis is represented in the 8jexlc 9m5x6a diagram below?

  The diagram below shows chromosomeso* o2xnno* 7l*wrjg;s 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 ocxvzek/2507e ph/m hstates the number of alleles of a single gene which would be present in the nucleus of a cell as a result of eohe0k7 mxchp2/z5 /v each process?

  Which keyword is matched to the correct defzo0jg x9v a7j6inition?

  Which statement(s) about mit(ovpj co6e*y2z1 sbs 4osis 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 letter pointh 3 h(/xhs:wq0b a,kgms to a cell in anaphase?

  During which stage of mitosis d+u( p b3 y59zphnqg,fkbvc9r7oes the nuclear envelope break down?

  Which one of the following transport proteins only carries opq2gvh7igw vh 72lh,. ut active transport? gv7hl2qwih p2v 7,hg.

  Which process does not 4/jsq8 9y ivjpk;ck)24wylfxhappen in the shoot apex?

  Which type/s of membrane transport do/does nodbn f +hg;y21-: jnpxat require energy expenditure?
I. Facilitated diffusion
II. Active transport
III. Osmosis

  The diagram below represents a cell with a dipl+ewl5elqx(q sx(h93aoid number of 4. Which stage of cell divisio(lh 9(5qq wseexa3x +ln is the cell currently undergoing?

  The photomicrograph below shows a root tip meristem. Which ofd me b* b ik3jbc,8d,1kd,z/bb the following sentences correctly defines a meris,/dm *3ek b d,b1kbij8,bc zbdtem?

  When does the random orientation of homologous chromosome pairs:r lju8 tw98pb occur?

  Which process does not occur durylg; i9f 9 ttisi-.d:ying meiosis?

  If a cell with a diploid number of 36 undergoes ma+ sem*yr2d 87 hots.tqyq0z*itosis, how many chromosomes will be present in each daughter cell after cytokinesis?a+8ry 0z7 ystq 2.qdmoshe**t

  The image shows a micrograoga847b z bxi)w --ofzph of a cell.


What explains the appearance of the cell in the micrograph?

  Which statement(s) about homologz; 1en20x .c8sjgbknhy7w*gvous chromosomes 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 synbysl;tthggab8 n;zm( a.;rh v.se-35 drome.

Which statement is not correct?

  In the cells of a horse (E. caballus) during prophase I of meiosis I therd p uw:qcr9hfe)2 (hp (kzp4fx/-(cfie are 64 chromosomes. What is the haceh4 q: p h9i)p/d-((crffux (zfkp2w ploid number of chromosomes?

  Which arrow is pointing to a cyjr/i(gfprqey6*1 gspd - )2bhiasma?

  The diagram below represents the structure of a,unjvk- bn0 /*s /nblba f4(k)2yh ggj shoot apical meristem. Which row in the table correctly identifies the processes occuring in the structures labeled in the diagbu0s*vh/ ( bl-f,/ jngg)yknj4kb2 n aram?

  How does meiosis promote variatio 2 kxhab2.rc4lli /qn2n?

  Which of the following statements is/are correct foi3 fgn -.fr5/p6:f +xzhjmxk cr 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 chromo5 triy pj+-rpl:glavr:.*8 0 wznssp1somes.


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 tub:dlq8r v6ig 4mours as a result of tq6 idgb r84v:lhe movement of cells?

  How many chiasmata are pr+len10(tq+k ovpg+g x qojmbrk 0rz708n0k9zesent in the diagram?

  Which statement is a similarity between cytokinesis in animal and planvg 4-kauj 5odgh4/j4 )wjnl l(t cells?

  Which stage of meiosis is matched to the correct description?5 )2akrthe 6bg

  Which statement(s) are true of meiosis I but notvyu ku09+qdt ; 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 ooc ,uqt1ezv6,6k* 7zsqiz z n)- yiomo6tyte after the first meiotic division. This results in the formation of one large cell and one s6)6 *ko szq7-,zqmnvit1 , 6tieyzuz omall cell. What is the fate of the large cell?

  Which row correctly describes diploid and haploid cells in humansfn i jw1k6li j,2:9a0qmo/apr?

  The following table shows the diploid chromosome number of a range of species.inxoin0i 05b;sioq+ h49c 9zz


Which of these statements is correct?

  What conclusion can be drawn from the karyogram below?9ln 5tkba/ mn,pjsd5 9

  Which of the following processes is characteristic of the meiotic andmz0x huj 90c0y not the mitotic cell zu9jmy0c 0xh0 cycle?

  The diagram represents h,2z vv4j/ r:qkjw)pea 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 ( v 8kof4*qs6hnsurv.1z6 mdao3: tm)n,q6zysPan troglodytes) is 48. Which row shows the correct chromosome number for diff m dn6 mskrsuya z36sho1)vzoqt48 f*6.v,q:n erent cell types and cell division stages?.

  At the end of which phase of meiosis I does crossing over oc-zf-d4n6l k cncur, and what is the outcome of crossing o 4-d6clnf-knz ver?

  Which of the following sta +ge crmr,obq: c,55y mvr6wv3 cvb5h+tements does not describe a step in the sodium-potassium pump cycle in the neu6o vw :5v5cr3cv hy r+r,mqec,b5+bgmronal cells?

  Which row in the table below is true of meiff-1l1zqt jcox6x u.ifr-rq0 ; ,dp (bosis?

Membrane transport is important for allowing pyw)7;rgavj m/y)wo q3articles to move across the cell membrane a wja )vmo)wy3q;/7yrgnd 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 regulef 08n-wuzl9 jkaj+fg +9t 9aaated 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 cyc,cgvx 0eo,5d 7 klr4fllins during the cell cycle. Which cyclin is inve5ld4x,vglko cr0 f7 ,olved in preparing for DNA replication?

The diagram below shows chromosomes d ne*/)m1e hwas5m, bcduring 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 u0x m5aiz5bzayd5o5 zt6tu 64separation of homologous chromosomes?

  The mitotic index of throat tissm/v f:p nk;; hoid3cgy;z.f9 dues taken from 4 different patients is shown below. Which patient is9/ p.zh:n3k ;fvo m;cgdy;fid most likely to have cancerous throat tissue?

1.Draw a labelled diagram to represent jvpdug5 i+zn/ z5 t07xthe process of crossing over.

2.Compare and contrast random orientation and crossing over.

3.Outline the stages of meiosis.

  The image shows an abn. vuo(gd,z z3 xva5j.gq,.iu pormal human karyotype.


What is the abnormality in this karyotype and its cause?

The graph below shows the relative amount of DNA in one cell during ona(fm 2q( /c(o/ooangvbfgmg8*,io8 r e complete cell cycle. Each letter represents one stage of the cell cycn8,/*g/r faqf((8oic( oboggma omv2le.


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/8ux,(ltmhkx -d/e nvn a male cat that is homozygous for brown, long hair and a f,he x(tkn -dxm l8/v/uemale cat that has black, short hair.


Which of the offspring has a recombinant genotype?

1.Outline how polygeni (0ms(hf ab1zlc traits can show 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-sist px4nk kg6c ,ril-)c 24w4zdmjer chromatids shown in the diagram i24-6c)m4kz4nj c plwrkgxd, below?

  The photomicrograph sh*q sqk2zln 61j-g tsb.ows a pollen grain from L. candidum (Lily). Which stage of meio k *n1zqsb.g2tsq l6-jsis is shown?

1.Outline the events which would lead to an individua0q6 1qoxi 7auql being born with Down syndrome, which is characterised by the presence of t 1xo7i6aqqq0uhree copies 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 gvj:e;;swujz , -lwqd1 rowth. A study was conducted on white onions (Allium cepa), under controlled c;wu;v:zdws- qj1jel ,onditions 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 smc3lfgr+,wb bg-mrl82z u1 *two ways in which cells can divide. The diagrams below show two cells from an organism with a diploid number+rmgl ,l3b12grzs *fb 8cu-wm (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 3 (xlfs1uhp6s)-w 1xx xsy;tkexpression 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 vmdpzn/ x*(b;rent stages of meiosis. Which row correctly n(x/*; n dmpbzvames each stage?

  The micrographs show four phases ugu*bt65 wcc( of meiosis I in a plant. In what order do these phases occur (cwgt5u* b6cu?

Mitochondria are responsible for supplying metabolic energy n.n;*b4g aci pin eukaryotic cells. In most eukaryotes, which reproduce by sexual reproduction, mitochondriapna; 4*gc.i bnl 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 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 r /gtrk9noyjewj3ls2; v,)4tnumber of cells in different stages of the cell cycle in four samples of lung tissue f 9rnt23; sw)ey t/,k4vjolgrjrom four patients. Which tissue has the lowest mitotic index?

  The diagram shows the dominant cyclin/CDK complexes at differ2k (;j gvgd aolq0c6; d7(eangent time points in the cell cycle. Which cyclin/CDK cog qdavd c a(n6j; (0g2;g7olekmplex activates DNA replication machinery?

  Studies have shown that genes such as Cyclin Dependent Kinase 3 (CDq,a4+;5z xwn d yk(sdcKN3) are highly overexpressed c(+4, swdyqdnakx5; zin 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 concentrati (-ifgszbdd;-hz b5 m1on of cyclin E the highest during the cell cycle ?