The graph below shows the relationship between maternal age and the incidence owo.nl pv;ku60pyq 1 6wf non-disjunction. What relationship is suggestepo ;u.n6p6qlw k1y 0wvd by the data in the graph?

  Which stage of meiosis is represnvj6;w,/z 1io;6 (i3q my zey/p fabjgented in the diagram below?

  The diagram below shows chromosomes duringix0y-2pld g-;y zhr o4 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 alleley iz(poav:isz, :(if df 3f)t/s of a single gene which would be present in the nucleus of a cell as a refzf((:dfz/spii a:)oy it3v ,sult of each process?

  Which keyword is matched to the correct definit 3a1ishygo 1i ga3 lm9e*-95iamfvic9ion?

  Which statement(s) about mitosis is/are t w2l go c-vf-x3l wg u6ooi003uyvy4w4rue?
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 leuhk 59z-kybmk td9;*otter points to a cell in anaphase?

  During which stage of mitosis does the nuclear env7l/9ko o fb:qkelope break down?

  Which one of the following tr.(tet rzm wg+;ran45 xansport proteins only carries out active transport?4t (;.ztxwrega5 nrm+

  Which process does not happen mb topi*mkr-c w )(+y)in the shoot apex?

  Which type/s of membrane transport do/does not require energy expenditureahw4yiw,ll v1 i68vz+?
I. Facilitated diffusion
II. Active transport
III. Osmosis

  The diagram below represents a cell with a diploid number of 4. Which stage of4w67yr * g)izdc re3yy cell division is tdzr7* i 6e4 yyrwc)g3yhe cell currently undergoing?

  The photomicrograph below shows a root tiqyvgrz.b 9 7e9p meristem. Which of the following sentences correctv79z9yq gb. rely defines a meristem?

  When does the random orientation of homolsii*ap w/t:; mogous chromosome pairs occur?

  Which process does not occuygzttusur0 7dj .n +723s04jyjrg*h rr during meiosis?

  If a cell with a diploid number of 36 undergoes mitosis, how 8; n r*9rvtz9th0rornmany chromosomes will be present in eacn ovz8*r t0hrrt9;r9 nh daughter cell after cytokinesis?

  The image shows a micrograph of a cell spxoy.+ v6 ow4p(h,an.


What explains the appearance of the cell in the micrograph?

  Which statement(s) abo2 7,sip 6p6 oebkqsxc.ut homologous 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 1 wuexvcs b -9+u8jz2jDown syndrome.

Which statement is not correct?

  In the cells of a horse (E. caballus) durin kw abh/z09ep7g prophase I of meiosis I there are 64 c bw9peak/7h0zhromosomes. What is the haploid number of chromosomes?

  Which arrow is pointing to a chiasma?1zmuqu3c79j t7rm1zxut :5 7tj3f ice

  The diagram below represents the structure of a shoot apical mer xq)1i6k 3qxriistem. Which row in the table c6ii3q1qxrk x)orrectly identifies the processes occuring in the structures labeled in the diagram?

  How does meiosis promote variakw1zbv5v5 3mpus3kd7 tion?

  Which of the following statements is/arwyui5,o; pk v/e correct for meiosis?
I. It is a reduction division
II. It involves random orientation
III. It produces genetically identical cells

  The diagram shows gam-4 qeczcw8;mj;vb 0 yp lmigfi4* l3x/etes produced 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 fre 1y+: pwcm drlt/))mtom primary tumours as a result of tetl rp)t)c/y :1wdm+mhe movement of cells?

  How many chiasmata are present in the moos9p,svxb.3:f z3j diagram?

  Which statement is a similarih /w wdz9x m1 9t9a8ytjb1d+nlty between cytokinesis in animal and plant cells?

  Which stage of meiosis is matched to the correct descx kma,xw2xx5s)sht 62ription?

  Which statement(s) are true of meiosis I but not meios.mu r b 0emnerq8.ie6.is 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 divi7 ima2-ft)0 kjcqh *s )ni5urpsion. This results in the formation of one large cell and one small cell. What is the fate or 0cfpm7nu)s*qtka5ij) 2-ih f the large cell?

  Which row correctly describ/5yey(c wt0 jre qj z589vv.ises diploid and haploid cells in humans?

  The following table shows the diploid chromosome numbeyadl6o-u+ cqrw 7 48gur of a range of species.


Which of these statements is correct?

  What conclusion can be drawn from the karyogram below?4xfe56qc./bgm-oq8k cdz9/bdo;m g e

  Which of the following prochp+62hsy4i b 9bld kwr- m.x/besses is characteristic of the meiotic and not the mitotic d4rws-y bp 2+ .lmxh/9b6kbih cell cycle?

  The diagram represents a budip19/ tk pfadan.85g f 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. Which row shows t 2gj1z3fkp+ rohe correct chromosome number for different cell types and cell 3f gzo jrp1k2+division stages?.

  At the end of which phase of meiosis I does crossing over occur, and what 0lbe)0 *lcft eu 9:wbzis the outcome of crossing ouzbe0fl l b:)twe90c*ver?

  Which of the following xb/h7s;sdmh.mcz zq+(y +u6 * r1mgkjstatements does not describe a step in the sodium-potassium pump cycle d*zhyxjk .6q1mszb;uhm/g rs cm(7+ +in the neuronal cells?

  Which row in the tablet; qf cjs6/j0h below is true of meiosis?

Membrane transport is imp , t0kyx,,-zar9t kdibortant for allowing particles to move across the cell membrane and respond to changes in the chemical composition of the extracellular fluid.-, ,x9,t tarkki0yzbd

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 ceq/rwm 0y9cz. ells.

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 differec sszq+wyl h9*;3y9uj nt cyclins during the cell cycle. Which cyclin is involved in preparing ; ly9jszuhcy39+*w sq for DNA replication?

The diagram below shows chromosomes during meix .artk37s8 prosis.

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 chromosiwjkma k/)3y8 ca j5k86t b6huomes?

  The mitotic index of throat tissues taken from 4 different patients is shown be uogr5i;1qs 0tlow. Which patient iiso0; tq g1ru5s most likely to have cancerous throat tissue?

1.Draw a labelled diagram to represent the processu6g f03mm13 fmrwx j.b of crossing over.

2.Compare and contrast random orientation and crossing over.

3.Outline the stages of meiosis.

  The image shows an abnormal human karyotj4 q7pdfwf v7/rh b..aype.


What is the abnormality in this karyotype and its cause?

The graph below shows the relative amount of DNA in one cell during one cox:kzp;9ilvw 7l+fr 1ompleteix p:1 rv 9wl;ok+flz7 cell cycle. 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 that is homozygous for q.(jdh-.lnk glpy 2u5brown, long hair kl.(n2gd yql hpu5-j.and a female cat that has black, short hair.


Which of the offspring has a recombinant genotype?

1.Outline how polygenic traits can show a normal distribuah ,pult;/ he3tion.

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-sister chromatids showpjq doelrusb.2aw:;sz : 8q)/ler7m*t: pl, yn in the diagram belowrz 7w,tes: ba 8sjo.u:l*;2pe)/: ld qmlpqyr?

  The photomicrograph shows a pollen grain from L. candidum -tj 24suz*cga (Lily). Which stage of m4t-u zgj*c a2seiosis is shown?

1.Outline the events which would lead to an individual being born with rg0 0a etzk7h0Down syndrome, which is characterised by the presence of three copies of ch rtaz0e k0gh70romosome 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 wanbtswe:iq:6 2ldxq)2t8 o(s (x ym e5hs conducted on white onions ( s(:md(ti8weboh xlx) neqs6 22q:yt5Allium cepa), under controlled 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 arecdba3c y .*dg8 two ways in which cells can divide. The diagrams below show two cells from an organism with a diploid number (2ya*d.ccg8b 3 dn) 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 expression in stem y jz)5:x )omeogrowth.

2.Outline how growth is controlled in the shoot apex of plants.

3.Explain the process and applications of micropropagation.

  The diagrams below show l4ske/):rms c a cell, with a diploid number of 8, in different stages of meiosis. Which row correctly names each stage?) m 4slkre:/sc

  The micrographs show four phases of meiosis I in a plant. In what order 0 vy4ybem)th6aga:t3n-g mo )do these phases occur?g)b :eh4gy 3an mvt-amto)6y0

Mitochondria are responsible for supplyir;/clwdp/cs 1-mey vi w7 mh76ng metabolic energy in eukaryotic cells. In most eukaryotes, which reproduce by sexual reproduction, mitochoy cr /w16l;pv/edw -cmms7 ih7ndrial 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 number of cells in different stages of the cell cxr re:e: )nrp;9o,b gbp4dj *sycle in four samples of lung ti;es r*)o:r9e4g,p bprjxn :dbssue from four patients. Which tissue has the lowest mitotic index?

  The diagram shows the dominant cyclin/CDK complexes at different timjnj c l3gl,:nnuu t37h)/cit(-1eemme points in the cell cycle. Which cyclin/CDK complex activates37 chj1 /j u(mn 3genittu c-em,)l:nl DNA replication machinery?

  Studies have shown that genes such as Cyclin Depende k*yihe ;4 j2wmcm/2m,fi 9nrent Kinase 3 (CDKN3) are highly overexpressed in cervical tumours. e ie/r9;2n2h,wmm4kf ji*cym


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 cycxxt3 s*cpcz+,g 8y)+eg yr f 1ri93symlin E the highest during the cell cycle ?