The graph below shows the relationship between maternbc+a:(( /drdr/ esqinal age and the incidence of non-disjunct i+/aq/rbrdencd :(s(ion. What relationship is suggested by the data in the graph?

  Which stage of meiosis is represe il ;94y9 o1pwv5gru(kcf h*janted in the diagram below?

  The diagram below show czazd9v6)v9*pfo dm,c b1 hn)y41jw js chromosomes 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 states the number of allelccgko)v iv:xzz )/-.bg9uu/z es of a single gene which would be present in the nucleus of a cell as a result of e icb g-u/ v/:)) zxg.zock9zvuach process?

  Which keyword is matched to b xd (m.7k2 l,gacj qwoe.a4 5l2evb7vthe correct definition?

  Which statement(s) about mitosis is/are tru*kh4.ahrcgin-u i; v.e?
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 points to a c(*c)mugfq o3v d2uyj;ell in anaphase?

  During which stage of mitosis does the nuclea6 if0iolj)z p2r envelope break down?

  Which one of the following transpo3 xtu w+8-fxukrt proteins only carries out active transport?-w kxutux 38f+

  Which process does not happen in wsx2 s32:ptf wpu0i7bthe shoot apex?

  Which type/s of membramt00 , mtdr)t0zogl(jne transport do/does not require energy expenditure?
I. Facilitated diffusion
II. Active transport
III. Osmosis

  The diagram below represents a cel ns)df0bwm w 4fe m g(0q9+c5w/i7hluul with a diploid number of 4. Which stage of cell division is the cell currently undergoing?w0fm)cq7/09mw (4b u dw + fiu5lgensh

  The photomicrograph below shows a root tip meristem. Which of the following sauivjf() 98rc g7,csz5- erixentences correctly dej8szag)ei5x9iv7 c ru (-fc ,rfines a meristem?

  When does the random orientation of homologous chrobzv zr6sab34ikqw / 58mosome pairs occur?

  Which process does not occur durilj3 .v ttq+ tm5dh5 u7qv1wg9png meiosis?

  If a cell with a diploid h,hhp0 ls9oxsl8leyhj16mzo x3 0 )3anumber of 36 undergoes mitosis, how many chromosomes will be present in each d,h)ell090yx ls hh 6 ap3szjmh1oxo83aughter cell after cytokinesis?

  The image shows a micrograph of a ce*re/q3mq69 ;jb la inoll.


What explains the appearance of the cell in the micrograph?

  Which statement(s) about homologous chromosomes isks euiu w p ua;/6oc.211oxp1uzw :5ft/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 v55q+mm(mp buan individual with Down syndrome.

Which statement is not correct?

  In the cells of a horse (E. caballus) dur rmdik kp*;ed4u.+; 1cp xs6hwing prophase I of meiosis I there are 64 chromosomes. What is the haploid number ofc 1;4pkxsi6p*ukd hr.e;d + wm chromosomes?

  Which arrow is pointingtqg2zqv1dz.t z13 m*v to a chiasma?

  The diagram below represents the structure of a shoot apical meristem.inz9)vx) h o(o Which row i)) (ioonhv9 zxn the table correctly identifies the processes occuring in the structures labeled in the diagram?

  How does meiosis promote va;yypcc,er t 3h9l(k i4riation?

  Which of the following statements -zp/ *,xblp otq*dl5;dqcaf 7,xu+ mh 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 3mpbqdt 6(ik7 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 g 4u3ce/s..oeyysrb4 3l;j m5hw,tip of secondary tumours from primary tumours as a result of the movement of cl..; ymjsw/ cut,i3hp4s5eyb4or3 e gells?

  How many chiasmata are pres:szbc a b57y4cent in the diagram?

  Which statement is a similarity between cytokinesis in animal andotlg7s3b kl3: plant cells?

  Which stage of meiosis is mazr)+ rc+xwnyxm 4 -b8gtched to the correct description?

  Which statement(s) atiauyj40nuo;) n99ryre true 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 dipl/et noe+1 xq 6w+ ,goz-g/+v -qsaetvision. This results in the formation of one large cell and one small cell. What is the fate of the large cell?g/ eo/ztn,xe-+g qqv p-+6tsao le1w+

  Which row correctly d8 *9d/ k qd0zq7exfmuh:dp 0fcescribes diploid and haploid cells in humans?

  The following table shows the diploim((ij 8lgd :oq))5 vmpn.xieid chromosome number of a range of species.


Which of these statements is correct?

  What conclusion can be drawn from0*8 thiicgk(hw.ea5rl 7m q b+ the karyogram below?

  Which of the following processes is characteristic of the meiotic 6zu3tmxu/c pv6ci 1k75r , v(y2 colnrand not the mitotic cell cycle?3cz u5o/ ptir c7ur,yvx6 (6kncl21v m

  The diagram represents a bud with a shoot apicazep pgb:zaen(/bq888mu*3k kl 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. Whi -s;0-fksqpkq 4jikg(+lpkn0 ,a2 nmech row shows the coas 00i 4pkns pf(k jn;g- qlq-kmke+,2rrect chromosome number for different cell types and cell division stages?.

  At the end of which phase of meioz/6j 6g nxrkp .k 6ldn+ve,cv s8+- e/uzwd0upsis I does crossing over occur, and what is the outcome of crossing overx/ +s0/+eukeznv ugn6 l86vwddp j6c kr-pz,.?

  Which of the following stateme7-v i; xrr;bgwnts does not describe a step in the sodium-potassium p ;ri7;x wrb-vgump cycle in the neuronal cells?

  Which row in the table below f1v6r6rk,c qdd1 7jpn is true of meiosis?

Membrane transport is important for alc; 31gxkv*k bqlowing particles to move across the cell membrane and respond to changes in kx3q *gv;c1bkthe 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 iuxl6 zu ckg4,,*ax( san 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 concentr 7l86hfoxt+s uations of different cyclins during the cell cycle. Which cyclin is involved in preparin6 x8tof hs+u7lg for DNA replication?

The diagram below shows chromosomes during meios rw4s h95yjv r *x0*pmorz4r0wis.

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 homol* 9cq/gan** olq x/p1bqf;kw wogous chromosomes?

  The mitotic index of thro5lugafsw a+svu+, c37r;c6u sat tissues taken from 4 different patients is shown below. Which patient is most likely to have cauwssfar5us ++ u,cl7cvag63 ;ncerous throat tissue?

1.Draw a labelled diayjk,dzx 1 9(3vyyiark 5)9hicgram to represent the process of crossing over.

2.Compare and contrast random orientation and crossing over.

3.Outline the stages of meiosis.

  The image shows an abnormal human karyotypejsfssun*i2)z y ysi;)1bo v59 .


What is the abnormality in this karyotype and its cause?

The graph below shows the relative amount of DNA in one c2pyzkwi8zo:p 3ag-g +;ig d5f ell during one complete cell cycle. Each letter represents one stage of the cell cycle. g i8w5pzif+;g pzd3y kg:oa-2


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 shk6 ;o l1vausc4 (/gjoz.a w4(vaizdt*ows a cross between a male cat that is homozygous for brown, long hair and a female ca.1 (vi;cj ztl(sw uoaodg k4 /zv*46aat that has black, short hair.


Which of the offspring has a recombinant genotype?

1.Outline how polygenia:sw:a rq l:t*ia zza+8 )rl8tc 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-sister chromatids ,ydf1rw9l8o zshown in the diagram belozf ,o89lwyd 1rw?

  The photomicrograph shows a pollen 2ymom)sanbu4 2a 0c:sgrain from L. candidum (Lily). Which stage of meiosis i)y mn:u bs4 sc0amao22s shown?

1.Outline the events which would lead to an indi mm .n+,0(ecl ep zo+2ea 8r)c0prftzkvidual being born with Down syndrome, which is characteri0pa)ntm mr(rkl 2fez8e 0c ,eo.+zpc+sed by the presence of three copies of chromosome 21.

2.Explain how meiosis increases variation.

3.Outline the stages of meiosis.

The mitotic index is an ind*8 ck -jjlm)1bjni)ixirect 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 roots. jnj) j1) mc*lxi8bk-i


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 m/b/ wkh.(w072tht-xf uwf sdcells can divide. The diagrams below show two cells from an organism with a diploid numbe 2skt /-x. h7m0tuwdfw hfw/(br (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 expression in soof ko:gxln1r w :w54;tem 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 numberc1 ff21hb9lxu /wu 1wi of 8, in different stages of meiosis. Which row correctlx1u2l1f icf1/ubw wh 9y names each stage?

  The micrographs show fo2h q/gjl+tr +j*h4.et+m hkmwur phases of meiosis I in a plant. In what order do these phases occur?2rqh4.m+et j+h/m lj wt+ g*kh

Mitochondria are responsible for supplying metabolic energy in eukaryote e7+ 3sdfif4u x5w4uiic 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, which are the result of sexual reproduction between two different yeast species, couf f+uewiide4 u s5347xld 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 diffeztu;r o abz*vxb6+,d2rent stages of the cell cycle in four samples of lung tissue from four patients. Which tissue has tu,rzazv2 6+xt*o;b bd he lowest mitotic index?

  The diagram shows the dominant cyclin/CDK complexes at dif7/ z .j zghe znzms1o0nj,wg*(ferent time points in the celmjhnj,1(.7 wgzez0z ng/*oz sl cycle. Which cyclin/CDK complex activates DNA replication machinery?

  Studies have shown that genes such as Cyclin Dependent Kinase 3)b6u85ufje do s.lv+ y (CDKN3) are highly ove)+.fbuuldj8 6 yo se5vrexpressed 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 xeolvkx -9 ao:0g-9aln)ygw2 highest during the cell cycle ?