The graph below shows the re./:pn9hhy8mz9xumbe g ini7/k)-g fvlationship between maternal age and the incidence of non-disjunction. What rem.nm v:gh fg-99xki8/7u/ ih) ybnz eplationship is suggested by the data in the graph?

  Which stage of meiosis is represec i6yc)ppq) c2nted in the diagram below?

  The diagram below shows chromosomes during meiosy3j0k ca; vg20 ,ddjgsis.


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 q ne:e,nvgw65 kf.n2 rof alleles of a single gene which would be present in the nucleus of aq5 2:enk rw, vfeg.n6n cell as a result of each process?

  Which keyword is matched to the ;8uqsqy vs-e:correct definition?

  Which statement(s) about mitosis is/ab+a7(c9z k2qoc1dqm xre 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, id 0ps 6v1sg2uwhich letter points to a cell in anaphase?

  During which stage of mitosis does the nuclear envelope brecgs ebxwje+h g.*7, j/ak down?

  Which one of the following tranodbg2e3,e*8eb6s4w aak x fg7ek (ny(sport proteins only carries out active transport?kaxb ayw3o(e2,neefg g* 8( 4bk7sde6

  Which process does not happen i8fus05o,gs-p saw*g(zz c c3,fs3 nuin the shoot apex?

  Which type/s of membrane transport do/does not require energy expenditureru h7*3i*ogzkf)1q w l?
I. Facilitated diffusion
II. Active transport
III. Osmosis

  The diagram below represents a cell with a diploid number of;8m5 dvvlecup 6 j1b6f 4. Which stage of cell divisi5pu vflebd6vc86; j1mon is the cell currently undergoing?

  The photomicrograph be0qjca 9+hpo/z s/y0 oklow shows a root tip meristem. Which of the following sentences correctly defines a meric9jy 0o/ks0h ao/q pz+stem?

  When does the random orientav*h cw zj-st(:hpju7ifm5u5 1 tion of homologous chromosome pairs occur?

  Which process does not occur duri vj;dtw*it ,x2ng meiosis?

  If a cell with a diploid number of 36 undergoes mitosis, how many chromopmh;oeikdjy ) 2dqr 18np5vhhm7 :* d2somes will be present in:e1 j )2q p2mpnddh hmh*rdyi587kov ; each daughter cell after cytokinesis?

  The image shows a micrograph of a cell.iel4tmzxj(w vrq5drg, 13 2 :b


What explains the appearance of the cell in the micrograph?

  Which statement(s) about homologous chromosomese(ohb8mc tmr;ah) f 7jak37w/ 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 wit ox9*od )jdmn:h Down syndrome.

Which statement is not correct?

  In the cells of a horse (Ehhek p.51,ld ec(9ux a)kmm8 x. caballus) during prophase I of meiosis I there are 64 chr.8m hl15ap, eckk(9hdxm) ue xomosomes. What is the haploid number of chromosomes?

  Which arrow is pointing to p a/7sm:p aeb(a chiasma?

  The diagram below represents the structure of a shoot 1jh2l d k9k fa*0ur yc5u-kb/rx)cky -apical meristem. Which row in the table correctly identifies the processes occuring in the structures labeled in h r*/f95ajdkky2y -kbccu1ul -x)0 krthe diagram?

  How does meiosis promota 5hx 54(z re6r.a eobfifqdbjk o0wj/) 7ap2-e variation?

  Which of the following statementv 9uk)/ gqp5d6 ijoosy3:76ye(evts as 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 chromose9yv)ly aq(/k:( exsb g6 rur8omes.


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 secondaryk y8 bb3ox5j0do rjt)( tumours from primary tumours as a result of the movemen3bj 8rb ko(jox)0 t5ydt of cells?

  How many chiasmata are present in the dia vujh:ae 36,tggram?

  Which statement is a similarity between cytokinesis in animal a; u1e d w)laxxw7q1x-knd plant cells?

  Which stage of meiosis is matched to the correct descript x vjvlmh2ku.1d1l2k / 4bg7vtion?

  Which statement(s) are true of meiosis I but fy*ea7 +k- vt -pp,ouknot 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. This resu b,er/btumqk u r)/ts7b+o0tdwu:0 5slts in the formation of u:s mtbw5/ord eb,bku0sr+q7)t/ 0ut one large cell and one small cell. What is the fate of the large cell?

  Which row correctly describes diploid and ha clt5 6o*ugrqs7;83:ow nm4(lfdk wn gw+;nhyploid cells in humans?

  The following table shows the diploid chromosome number of a range of r8*f4q.s gmau p9t)ac;t oq*w species.


Which of these statements is correct?

  What conclusion can be drawn frqp 2ggvoos14,om the karyogram below?

  Which of the following processes is charactez ysjips6 8s;p* 3hl1+7 fcdumristic of the meiotic and not the mih8+f yul 7sc3 pp;zsm*1j6 sidtotic cell cycle?

  The diagram represents a bud with a shoot apical m/r5pgwbu.j xno z. - q4 s9cmrjf0k,0xeristem.

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 chimpan3c, 4sq tn5: jaqufb5z:ub* h*ktzx o4zee (Pan troglodytes) is 48. Which row shows the corr ,z4sn:u5z: qtb45t *3hx * cuabfkoqject chromosome number for different cell types and cell division stages?.

  At the end of which phase of meiosis I does crossing over)lrk1 il: spvsqjw sfv9)k.f 55-wrv1 occur, and what is the outcome of crossing over?j:fsr5.-l wv1lskkv5s)v9qiw r1p)f

  Which of the following statements does not describe a step in the sodihhai v .4wfw*py .u6-eum-potassium pump cyclfh.*h6.-u4 wy vwipa ee in the neuronal cells?

  Which row in the table bel1olt0ugt 5cw:xx-n kiji)2d0 ow is true of meiosis?

Membrane transport is important fomql2kyj;2 aen6ez t bz* r3m(,r allowing particles to move across the cell membrane and respond to changes in the chem,ameqj3;*t br n lzzem(26ky2ical 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 regulated in ez v jtg jl5ts;13kqz,,4ma-e 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 p353 n0f: x t0wlbrfrdconcentrations of different cyclins during the cell cycle. Which cyclin is inv0r3n x0pbf3tlr d5: wfolved in preparing for DNA replication?

The diagram below shows chromo ,tqrj,ejj*d/mk 0u3 ysomes 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 tew7 w) cbzvs1.he separation of homologous chromosomes?

  The mitotic index of throat tissues taken from 4s/v f 6iqrz6m0 different patients is shown below. Which patient is most likely to have cancerous throat t q6f6si v/mr0zissue?

1.Draw a labelled diagram to represent the proces6bq )4uqbj t;cs of crossing over.

2.Compare and contrast random orientation and crossing over.

3.Outline the stages of meiosis.

  The image shows an abnorma z5i,ac8dsrn 5l human karyotype.


What is the abnormality in this karyotype and its cause?

The graph below shows the relative amount of DNA 5 ng:/a,k wufl-yy .egin one cell during one complete cell cycle. Each letter represent g./k5,yl:w-nuy fae gs 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 ,3vvei w-6reeo lt wtt)/y- x , ia4(xag3hnh7that is homozygous for brown, long hair and a female cat that h hxetren)/3gt 6wwohx iv-3i 7,ve 4ly,aa-(tas black, short hair.


Which of the offspring has a recombinant genotype?

1.Outline how polygenic traits can show8 3gkgk6 m7rwv 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 crossi nsmswny-8f6;y(v 0i2h i9esang over of non-sister chromatids shown in the diagram ss;092hisy 6nyv niw -(a 8fmebelow?

  The photomicrograph shows a pollen grain from L.:yiru /+9kg o q0gr2jqi1*hn v candidum (Lily). Which stage of meiosis is sokyg1 un/q 2g:rji qi9 0+h*rvhown?

1.Outline the events whr kvd kkso 40e3m (22pcdyxj:+ich would lead to an individual being born with Down syndrome, which is characterised by the presence of three copies of chromosome 21sek m cvd x3d0okj p242y+k(:r.

2.Explain how meiosis increases variation.

3.Outline the stages of meiosis.

The mitotic index is an indirectg)fm bs3ftx+i ; yc3r( way of measuring plant growth. A study was conducted on white onions (Allium cepa), under controlled conditions in a lab, to investigate the effect of soil pH on the mitotic index of the rbffxg; t3)y(c+ rim3s oots.


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 diagre khreg2 r7 oyuj-e.s2o.k- 7nams below show two cells fry-g 7.ue- k27 n2ooesj ek.rhrom 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 eds i4ug84al7v xpression 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, wit 0-fchfdrw6 b.9 +,pwignvn;hh a diploid number of 8, in different stages of meiosis. Which row correctly names each sf b .,0+hpfdn;cw6ihg-r 9wnv tage?

  The micrographs show four phases o*vs2kna6 dtp0v( r (am59dgy af meiosis I in a plant. In what order do these phases o rvsmtaa6y2vnda( k5(90*p gdccur?

Mitochondria are responsible fo n4: 3cwah .n3pfi/25 qdyadis o+di:cr supplying metabolic energy in eukaryotic cells. In most eukaryotes, which reproduce by sexual rf4 iinocw :2pcy: 5dq +sh33/.naidad eproduction, 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 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 numberg )t *-cdps6qu of cells in different stages of the cell cycle in four samples of lung tissue from four patients. Which tissue has the lowe)us dgq*pt-c6st mitotic index?

  The diagram shows the dominant cyclin/CDK complexes ats ica;odb.tm.: a7a 1n different time points in the cell cycle. Which cyclin/CDK complex activates DNA replication machint d;sm.7ai .1acb:na oery?

  Studies have shown thao ek.h9 9cihdmr+m5)f t genes such as Cyclin Dependent Kinase 3 (CDKN3) are highly overexpressed in cervical tumorf59)mhhm +.9ikd oec urs.


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 concentratts;f f7 -x :l;nre6ddkion of cyclin E the highest during the cell cycle ?