The graph below shows the relationship between maternal age and the incidence ofd za d8vdd48 n5*o5gnq non-disjunction. What relationship is suggestq8g5ndna ddz4 8o5dv*ed by the data in the graph?

  Which stage of meiosis is represented in the diagram below? j- fdrf;bvyt 22/(ewj

  The diagram below shows chromosomes during meiosi)s b(z tkjvjemmz :(71t:* eass.


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 whichw+y5 0e:)urjapdyy* ndxh 0v2 would be present j ha 50):d+rye 0n2uyypvwx*din the nucleus of a cell as a result of each process?

  Which keyword is matched z-+jwhyyfqpme39 3,qto the correct definition?

  Which statement(s) about mitosis is/are true*oy cb43x9*b)5 6clls 6hy ipjgjo;:lwy oxi.?
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 letj2beay6jo2 (jter points to a cell in anaphase?

  During which stage of mitosis does the nuclear envel zi9bk4, obpb5ope break down?

  Which one of the following transport proteins only carries out active transporsp- c25 q*qfqpt?sp -q pf*cq5q2

  Which process does not happen i1dyh ;2m: v6*bkyoe 51k7lgj:c ytgpp n the shoot apex?

  Which type/s of membrane transport do/does not require 8+,bo ip2e tvlenergy expenditure?
I. Facilitated diffusion
II. Active transport
III. Osmosis

  The diagram below represents a cell with a diploid number of 4. Whichja zk uvh6a4 *2g4 3iyyrby9p+ stage of cell division is the cell currently undergo2vyr yai 4 3h+kpg6zb*4 yaju9ing?

  The photomicrograph below shows a root tip meristem. Which of the follywwk 0aw 1n,p0yww:p9pe. fa0 owing sentences correctly defines a mew y:n.w0 p0yaaf,keww1pp 9w0ristem?

  When does the random orientation of homologous chromosome pairs occur?1h.tzj-+zejz y djyk,,zr b-s8 f s,z8

  Which process does not occur durs0 l.j zcf8j2h.d fk0ring meiosis?

  If a cell with a diploid number of 36 undergoes mitosis, how many chromosomwr 2bczz ox+kcw3ty8p ,73tk.es will be prebpto,yr+c3wzz.tk73x w2k8 c sent in each daughter cell after cytokinesis?

  The image shows a micrograp1cnlmku m:m3i1va.ce8 rx ( r.h of a cell.


What explains the appearance of the cell in the micrograph?

  Which statement(s) abov ..b*xni5v t2yqg98+fdi toout 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 a ixkg /+(+fj) c godz:7jggyt8n individual with Down syndrome.

Which statement is not correct?

  In the cells of a horse (E. caballus) duri9q)oz8d:b/p5dun l e mng prophase I of meiosis I there are 64 chromosomes. lq: 9ebu)z/8op5mdndWhat is the haploid number of chromosomes?

  Which arrow is pointing to a chias e+jy4x 9 97ivn,c9/ekrg ntvpma?

  The diagram below repcw1o7g vi:i5d+ry z 4qresents the structure of a shoot apical meristem. Which row in the table correctly identifies d w goiirz4:ycv5 q+17the processes occuring in the structures labeled in the diagram?

  How does meiosis pro5,8g:u dbs xfwmote variation?

  Which of the following statements is/a n,j2r zlem0p.;izq i,re correct for meiosis?
I. It is a reduction division
II. It involves random orientation
III. It produces genetically identical cells

  The diagram shows gametes producwoz k 0fy2+sr :54jdgned 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 primary tu6 r+j. ppkj:sbmours as a resj k.br 6+:ppjsult of the movement of cells?

  How many chiasmata are present kng12 mr0 + d66xi5sr a0iahpbin the diagram?

  Which statement is a similarity betwhul xu2(1+ r0w hlft)i;sdbn7een cytokinesis in animal and plant cells?

  Which stage of meiosis is matched to the corre)aie /)5hk d-1n5dc6mmrui hqct description?

  Which statement(s) are t.; f o*orsj; eiv;nl7 yfd4z/qrue 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 oocyte after the first meiotic division. This resultsh5a/6nsz( tduc8 o :2soo3ghw in the formation of one large cel2oa/wz5hd3s:to8snuh ogc(6l and one small cell. What is the fate of the large cell?

  Which row correctly describes diploid and haploid cells in hug a apx161jg 0*zya1hymans?

  The following table shows the diploid chromosome np9;t. 5jd 5me8vf l t6p dtp;mrglvg-*umber of a range of species.


Which of these statements is correct?

  What conclusion can be drawn from vr+is fr 0nr5fw p3;0gthe karyogram below?

  Which of the following processesue,q n7f1p oiq 5s:4ys is characteristic of the meiotic and not the mitotic cell c,f 17o5euypqq4 sn:siycle?

  The diagram represenw, v*ie6+r kypts 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) is 486xf3+bp;7 4bvja uw pt. Which row shows the correct chromosome number for differ;b73bx4jv+6awup t fpent cell types and cell division stages?.

  At the end of which phase of meiub7d bx x+fqmtsw3941osis I does crossing over occur, and what is the outcfs7q ut+bxmw4xbd39 1ome of crossing over?

  Which of the following statements does not dqtzyznz;9 8o/ej7b: aescribe a step in the sodium-potassium pump cycle in the neuronal cele/j79yn :8o;zqta bzz ls?

  Which row in the table below is tr-bo6d +i s g/ ).besx)kt ks7i2epwcn/ue of meiosis?

Membrane transport is important for allowing particles to move rglx k0p6d5q.across the cell membrane and respond toxd .pl0kq56r g 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 regulated in c l rc:k5lo/jph4 dvr/(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 6g*z n qth0n2uthe concentrations of different cyclins during the cell cycle. Which cyclin is involved 0zughq*t 2n6n in preparing for DNA replication?

The diagram below shows chromosomes during meiosisi61t.cxk v+vzlnl 2:b8 bq)ob .

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 i+dk6 xda1cqu57 8yj plnvolves the separation of homologous chromosomes?

  The mitotic index of throat tissues taken from 4 different patients iztb 9;gx:-/kvq2jssbubc6 7 bs shown below. Which patient is most likelyu/ bxcjs;sk:qv bgb6-b97z t2 to have cancerous throat tissue?

1.Draw a labelled diagram to represen4/sd 30rhkzz h7rtq,h t the process of crossing over.

2.Compare and contrast random orientation and crossing over.

3.Outline the stages of meiosis.

  The image shows an abnol +6kx1vou0 vg+;s;hp)n pnc hb.nee0a,.f jmrmal human karyotype.


What is the abnormality in this karyotype and its cause?

The graph below shows the relative amount of DNA / 7gtvpxj(vvg/fz s e13br/0pucf7v7 in one cell during one complete cell cyc(prvgsv /7gbft fp/e v0 7u13x7z/jvcle. 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 ;umc *.hm9co( zv8l(o q ffqj:qt/zs9homozygous for brown, long hair and vu.ofh z qzs j/q9(;f tm9clo:8cmq( *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 distribux+6xtvhc4k 7t7 ufsl6 t,v a7ltion.

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 oveu + l:e2br m91cvrcj8er of non-sister chromatids shown in the diagram beu j9er+r:mv1lec cb 28low?

  The photomicrograph shows a pollen grain from L. candidum (Lily). W60m 6j6sigt mchich stage of meiosistcg mmj6is606 is shown?

1.Outline the events which would lead to an individual being born with Dodz8axe)c + /wuwn syndrome, which is characterised by the presence of three copies of chro/+z da8uw)e cxmosome 21.

2.Explain how meiosis increases variation.

3.Outline the stages of meiosis.

The mitotic index is an indirect way of;m : j6v7vguyv measuring plant growth. A study was conducted on white onions (Allium cepa), under controlled conditions in a lab, to investigate the g mjv:67vyv; ueffect 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 whichw*(a)b-.7ylne mmc ab9:yow k cells can divide. The diagrams below show two cells from an organism with a diploidmbycak w(o7:a).9n*blyem w- 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 om m)3qb1;c;vb nkd59; pgi vv-ctmo6sf gene expression 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-eafj cn *)jh+rent stages of meiosis. Which row correctly names *j e+a)fnjc -heach stage?

  The micrographs show four phases of meiosis I in a plant. In whot i gq.f4:i2ncb.8tqat order do these pnq:b8g .2c.tot4f iiq hases occur?

Mitochondria are responsible for supplying metabolic energy in eukarg5ba daf9v;ts.*pl mql 89a3oyotic 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, l osaa.9 8a9b35pmqvtlg*d ;fwhich 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 t re,zhs/ g,+lthe cell cycle in four samples of lung tissue from four patients. Which tissue has the lowest mitotic in/e,tsgz,+ r hldex?

  The diagram shows the dominant cyclin/CDK complexes at differe9rjgc, -68xr* xsxd p200zuyqv vhse:nt time points in the cell cycle. Which cyclin/CDK complex activates DNA replryvx zdr2c xh-s6jg:9e,qx8p vu0 *0s ication machinery?

  Studies have shown that 8jdx,:gmqn*oq na crx.-+*ti j 57zazgenes such as Cyclin Dependent Kinase 3 (CDKN3) are highly overexpressedq7aj*gazc,x 58iodn -r:jt+ nmz*.qx 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 concentration of cyclin E the highest during the cell zm g*nsfew. fja2.m2+ cycle ?