The graph below shows the relationship between maternixp6 et(s05sk al age and the incidence of non-disjunction. What relationship isspke(0t x6s i5 suggested by the data in the graph?

  Which stage of meiosis is represented in th iuopb8;ts-ehw; 6:d: qpn :use diagram below?

  The diagram below shows chromosomes during meiosi fok e; yzij-m9asg:3-s.


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 whichxx7hrsl k:80z would be present il8k 0r:x7z sxhn the nucleus of a cell as a result of each process?

  Which keyword is matched to the q8:t kcl ;gvumxr8x fct e( sul9-:g*,correct definition?

  Which statement(s) aboyck5 e; s o/0jhjw-f)ds(crd:ut mitosis 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 bel sy.*7ug in6dxx4 adlx9 xed5+kp)sph (1 1mzcow, which letter points to a cell in anaphase?

  During which stage of mitosis does t7ztq,no9z l )hhe nuclear envelope break down?

  Which one of the following transport proteins only carries out active,w1e vz ,f7:ynxk 3rds transport?y7evwr:s3,d1f ,zn xk

  Which process does noxoiw+ g)t-(sxudx v14t happen in the shoot apex?

  Which type/s of membraiwvkh z x/lfu 7-/lq87ne transport do/does not require energy expenditure?
I. Facilitated diffusion
II. Active transport
III. Osmosis

  The diagram below represents a cell with a diploid number ofvpfj,zxh,t;x3xy,dl ft0 9g8 4. Which stage of cell division is the ce f,,xt j89zgftd;xlh3yxp v,0ll currently undergoing?

  The photomicrograph below shows a root tip meg5xalqgn- eu)y - 1,onristem. Which of the following sentences correctly defines a merig qxe n51n yaog,l-u)-stem?

  When does the random orientation of homologous chromosome paig,l8 81jy5s 9k,gg wakcv 7qkrrs occur?

  Which process does not occur during meiosis?n0,tqt5c p -7jtjhff 7y.cd 9o

  If a cell with a diploid number of 36 undergoes mitosis, how mdsmfyq ctrw/, +3b;rj,x,fl4 any chromosomes will be present in each daughter cell aft4 j+ /,r ydx fl3b,w;rqs,tmfcer cytokinesis?

  The image shows a micrograph of a cellc2+vqo9 qx es*.


What explains the appearance of the cell in the micrograph?

  Which statement(s) about homologous8jbl-bc.5- fey dkfdl:hvkr;5v :j:i 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 syndror)u af1q)pgy7dadbg, yu ) *3o j jprp5he:*5tme.

Which statement is not correct?

  In the cells of a horse (E. caballus) nl9z*f1o, i ad.jgrl. *rp (fyduring prophase I of meiosis I there are 64 chromosomes. i,o rp(. 9llzny1fgarf*dj. * What is the haploid number of chromosomes?

  Which arrow is pointing to a cq+ io9 dy/s4pshiasma?

  The diagram below repr*9cc /;lqywv xesents the structure of a shoot apical meristem. Which row ;/x yvwql* c9cin the table correctly identifies the processes occuring in the structures labeled in the diagram?

  How does meiosis promote vac0/un )gwrd(3a crl,z riation?

  Which of the following statements is/are cor*j5g szbtlf*3djcymn+ k 8-y,rect for meiosis?
I. It is a reduction division
II. It involves random orientation
III. It produces genetically identical cells

  The diagram shows gametes prodq5ma mo4jf43 tuced from two homologous 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 of secondary tumours from primad/ q1luxgb 3.gry tumours as a result of the movement of d3x/ qblg1u. gcells?

  How many chiasmata are7s*s9fx 3ap0oxec :x6 7t bnxv present in the diagram?

  Which statement is a similarity between cytokinesis in animal al7 pfs k+.+ye6dy opni7g9f, and plant cells?

  Which stage of meiosis is matched to the corr tc gp./t/2utqect description?

  Which statement(s) are true of meiosis I but not (v49jd/ f bxbjq)*hlf 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 results in5s m s*ky*h d;e9lk)nv the formation of one large cell and one small cell. What is the fat*h)dl5svm 9s*k kyne ;e of the large cell?

  Which row correctly describes diploid and haploid ceub+,cr8uh b+ha6 brh9jcp :- slls in humans?

  The following table shows the diploid chrhxihy6j(o)- romosome number of a range of species.


Which of these statements is correct?

  What conclusion can be drawn from tu/bd 2p dkj* w2gh+5lshe karyogram below?

  Which of the following processes is c cdx)d-(vvndo) u *g h. ebl44sv2ks/pharacteristic of the meiotic and not the mitotig*s4c ) p h.- vvneov4s(xb du2kl/)ddc cell cycle?

  The diagram represents a bud with a sh1s *ru(c6z1igok yt7/ uhf1ha oot 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 (Piv lx0cly 6l+5e 0s+h:oir+t xan troglodytes) is 48. Which row shows the correct chromosome numbei65++tlxve0ih rcsllo: y0 x+r for different cell types and cell division stages?.

  At the end of which phase of meiosis I does cross6c-lf*c/n a9 px xanx6ing over occur, and what is the 6nac fxp9xx6an*-c /loutcome of crossing over?

  Which of the following statements does not describe a step in the sodium-potassidsvl0o6u 5 j, cu(nwv;um pump cycle in the nc uw;vo5u ls,6 nd0jv(euronal cells?

  Which row in the table belcmq0vh j79;v zow is true of meiosis?

Membrane transport is important for allowing pa1nn*t: af tf;xafn40tk7hc x-rticles to move across the cell membrane and respond to changes i x- k4fft h1;f*cttxa0n nn:a7n 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 regulated in whwk:r:sz- zw40 m9oh 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 c*fpoys,is 0(0v7k m3vb yf(to oncentrations of different cyclins during the cell cycle. Which cyclin is involved s(3si p*y foy(kv0fvb0mot,7 in preparing for DNA replication?

The diagram below shows chromosomesajpz go b-7y p)pf -l;g;o+(xy 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 homologous chromosomes?y1f.0k lwwy4f

  The mitotic index of throatvsrc ;2 c.do:i 5os:ge tissues taken from 4 different patients is shown below. Which patient is most likelsc:c 2g5osioer d:v; .y to have cancerous throat tissue?

1.Draw a labelled diagram to represent the process of 5ifm( jmkl m, i(8pgis.-q/fr2p pj9tcrossing over.

2.Compare and contrast random orientation and crossing over.

3.Outline the stages of meiosis.

  The image shows an abnormal human karyoo6uj r*jk6pxcy,c7z 4type.


What is the abnormality in this karyotype and its cause?

The graph below shows the relative amount of DNA in one cell .8gyx +y3r)n(l uc)fhzwf3m kduring one complete cell cycle. Each letter represents one stage of they k+rw)3(n3 cz.lmgyuh f8x f) 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 beymk3qe bp l3yu q27jn7ao. o+*a *lc,etween a male cat that is homozygous for brown, long hair and a female cat that has blackyq ,l3ueypq3a j* lembc 2o7.o+a*7n k, short hair.


Which of the offspring has a recombinant genotype?

1.Outline how polygenic traits can show a normal distriex2 2ff0eag7f bution.

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 ov kx nv-aj/cd17er of non-sister chromatids shown in the d/n1k -jv7a dxciagram below?

  The photomicrograph shows a pollen grain from L. candidum u;0,t ,gy 1;gumldoxt(Lily). Which stage of 0u;g,tmgxld 1 ;u,oyt meiosis is shown?

1.Outline the events which would lyd /) x7ziq u usrk.m(7y,on*kead to an individual being born with Down syndrome, which is characterised by the presence of /7rnkdkxu(7mq o,. *syyuz) i three 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 growth. A study was cl7 iwe6n gs1jbek6kcni85/:( sl 5sgv onducted on white onions (Allium cepa), under contrs(eel bn7665cn :/is skik1gg5vwlj8olled 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 divide. The diagrams below (olpb0u 914v5qechfj) g etabjw::m2show two cells from an organism with a diploid number (2n) of 8. (0gb:l1cfm4o)ut 9 abewphj25q : evj


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 expression in 8v 8-dz:qoy akeb7g,ustem 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 different stages 5z ,-ceq3sk pvof meiosis. Which row corq5c3sp ,vez-k rectly names each stage?

  The micrographs show four phases ofiuganw342 6,7uit fvi meiosis I in a plant. In what order do thesev4 2iwu iiaugn37f6 ,t phases occur?

Mitochondria are responsible for supplying bz9qi9y0 7yd86v njpm 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 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, whic0jv6qby9m ynp78 9dzih 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 d )pia p9)) j6fg4cxsdof cells in different stages of the cell cycle in four samples of lung tissue from four patients. Which tissue has the log 69 d)ppica)4)s dxfjwest mitotic index?

  The diagram shows the dominant cyclinnkti*n-3 1.iixhi 8 gv/CDK complexes at different time points in the cell cycle. Which cyclin/CDK complex activates DNA replicatinx nki h itgv1i.-83*ion machinery?

  Studies have shown that genes such as Cyclin Dependeu (izvvknq* *.3d5 wwint Kinase 3 (CDKN3) are highly overexpreqiv*.(d3v* k 5uw wiznssed 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 concentrati/n prhy/ 8)fiton of cyclin E the highest during the cell cycle ?