The graph below shows the re cqwul (0+j.9q2u kfkizsz4;t lationship between maternal age and the incidence of non- k9tf2lcqs u.z4 wq uij;k(+0zdisjunction. What relationship is suggested by the data in the graph?

  Which stage of meiosis4)yo0n9 cpj wayw 4s afc3xrw2 uz.o12 is represented in the diagram below?

  The diagram below shows chromosomes during meiosis. fot 4gwq64, +rdrpk5y3uwy( f


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 which wo0oiu 1+3meiyz ( zdj3suld be present in the nucleus of a cell as 3z1+(e0 u3oymsd iizja result of each process?

  Which keyword is matched to the correct defini xfu u(z1cm9z5tion?

  Which statement(s) about mitosis is/are truepvoe6 i 3/ag fim*yvd0d3r 61x?
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 le 6 .* d;xfhb7gjjx7rxftter points to a cell in anaphase?

  During which stage of mitosis does the nuclej7ao3wllr5 d +iak*w 5tdh)iiw 8 4e0car envelope break down?

  Which one of the following transport prota.s 6n1sz qz7kda /96n6czw ljeins only carries out active transport?jsaw9q.a zkd66 z n7s 1lc/6zn

  Which process does not happen in the shoke gq)c38rmin,: p9 pnot apex?

  Which type/s of membrane v/ebmibl+j:o-x6..f ( edo pat-mpy 2transport do/does not require energy expenditure?
I. Facilitated diffusion
II. Active transport
III. Osmosis

  The diagram below represents a cell with a diploid number of 4. Which *,hrz(pu)v gastage of cell division is thhz*g, pu vr)a(e cell currently undergoing?

  The photomicrograph below shows a root tip meriste/corq.6lf: e/uuz eta. 4)sxy znbq /.m. Which of the following sentences correctly defines a meristem?u uzze../:ao6c /x ./sqynr)eq 4ftlb

  When does the random orientati*- vi seh 8t::c0h0v2dzazip +2ikwsvon of homologous chromosome pairs occur?

  Which process does not occur during muxie/8 vg b)3seiosis?

  If a cell with a diploiw hq)w, wgpq 7xfc9*i+d number of 36 undergoes mitosis, how many chromosomes will be present in each daughter cell afterh,9ig *f+xcqw7qp)ww cytokinesis?

  The image shows a micrograph of a celsz7:i r:kh(ahry)d 5yl.


What explains the appearance of the cell in the micrograph?

  Which statement(s) about homologous emoq4y 4++44sob2q8h qsex gm, bo 4ccchromosomes 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 aeo:v3q33.y + xetxpuhh:g p2gn individual with Down syndrome.

Which statement is not correct?

  In the cells of a horse (E. caballus) during prophase I v9 lne9(h q i6*dgs/(og- xlkrof meiosis I there are 64 cg(lh9x-i*dgvo(n /k l9rsqe6 hromosomes. What is the haploid number of chromosomes?

  Which arrow is pointing to3r 6 wl.odlkja d1 tv68xx.+qw a chiasma?

  The diagram below represents the structure of a shoot ap4d:k 5ux1.4hm6 3kvdz ;jaxauoy3 gnzical meristem. Which rowk g4a 4:3z56.n;3kmhudx j o xya1uvzd in the table correctly identifies the processes occuring in the structures labeled in the diagram?

  How does meiosis promote variato dupbqnp--i7 64( et4lyhn6sion?

  Which of the following statements is/are correct forbs6 q+kwl g4bjl 343o5yom/q3jgv( ce 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 hvvmhp(42n; 9pw dv.kromologous 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 tumours as la 0jj1d0e66-spqlj qot;vuh ha/* 4aa;q6edua0 jsljlqj*/ah10ap6t4vh o - result of the movement of cells?

  How many chiasmata areejkcxx sdr wxqd3/d)p.-6n9- present in the diagram?

  Which statement is a similarid n8* r25cjme m(je2pbty between cytokinesis in animal and plant cells?

  Which stage of meiosis is matched to the correct descript*w90h;skja hg ion?

  Which statement(s) are true of meiosis I but nohs )4vj gxpfomboq5m8qrc*1 o*+-1 sqt 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 4qs nrq u/q7.hafter the first meiotic division. This results in the fq h.7qq 4nsr/uormation of one large cell and one small cell. What is the fate of the large cell?

  Which row correctly describes diploid and haploid celvm+ (rp i9w5tnkgvyqgr0507 b ls in humans?

  The following table shows the diploid chromosome numbezwy *iq qiizdd5d*,-hg); ne6r of a range of species.


Which of these statements is correct?

  What conclusion can be drawn ffr5 j (jk 9krne-x76fgrom the karyogram below?

  Which of the following processes is characteristic of the / g4kerd 5 zbhx4byu5d5al.h*meiotic and not the mitotica5g*5 45kz/u lybre4 xbhh.dd cell cycle?

  The diagram represents a bud with a shooql*dp 5 g73s(c5x*i1xuykblk t 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. Wg164+uno9;3s pchhzrp) rae ehich row shows the cop9pz se 1e c3hogu)+rahrn;46rrect chromosome number for different cell types and cell division stages?.

  At the end of which phase of meiosis I does crossud;5 (vxw+k6dai3kb xx3 wgo 6ing over occur, and what is the outcome of cr(366wo kgbu3 w;kd+xd5 v aixxossing over?

  Which of the following statements does not describe a step in the sodium-potas*3gbkouq mvtma57 ;n(sium pump cycle in the neuronal cen t;35kovm(aq b *gm7ulls?

  Which row in the table below 2yvy -e 3kd omhyh.,:dis true of meiosis?

Membrane transport is important for allowing particles to mt55c 1 5q-b4)btlgf +nou bwfzove across the cell memb 5cb5 l-)41gnof z+ t5wbbtfqurane and respond to 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 ree/y ey9gzqhiti r-/n (;vwk.2gulated in 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 concentrations of different cyclins d5mfq: p)6k hegqr li 0)syre*daw*a41 uring the cell cycle. Which cyclin is involved)m pr:i15lqs) rg * 6e0*4yafdhkw qae in preparing for DNA replication?

The diagram below shows chromosomes during meie 4jvy3kah/ky;e o 22oosis.

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 -s9 rhjuf3/lya2jp5nhomologous chromosomes?

  The mitotic index of throat tissues taken from 4 different patients is shown bem ar/.yj qcq0m5d( wusw /om8v34bux6low. Which patient is most likely to have cancerous throat tissum.m/6m /qxwd5w ao4u08y j (cvsb q3rue?

1.Draw a labelled diagram to represent the pm()2urt luywk05bc *l;n qz v;rocess of crossing over.

2.Compare and contrast random orientation and crossing over.

3.Outline the stages of meiosis.

  The image shows an abnormal human karyha+ s* kiwbfwd 3jen+/ m8yucos e*7.1otype.


What is the abnormality in this karyotype and its cause?

The graph below shows the relative amount of DNA in one cell during one comwzv7a6mkhr ,/+- f cjzsd-szkk7/v ( dplete cell cycle. Each letterhw(a-sjcvd+- / vkr/ 6z7km z d7sfk,z 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 homozygousds)he/ :yx6lr )n 6(fcv.hsaj for brown, long hair andc: e)6n6slj)ys/(hr h.fdxa v a female cat that has black, short hair.


Which of the offspring has a recombinant genotype?

1.Outline how polygenic traits can show7b5+i t. f4es qfgsw*tmq+/qo/vfh p- 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 f5g+ ok)gue6 cjrom the crossing over of non-sister chromatids shown in the diagr+ekog)g6u c5 jam below?

  The photomicrograph shows a pollen grain from L. candidum (Lim0fs+r:s;z2,k* ed lobb ca mm/9mkl.ly). Which stage of meiosis+;m*m o:f,0 sskl lk9 e2mda/cmr bbz. is shown?

1.Outline the eventseaeqx 6d4kr 58 which would lead to an individual being born with Down syndrome, which is characterised by the presence of three copies of chromosome 2kxaqe6 edr45 81.

2.Explain how meiosis increases variation.

3.Outline the stages of meiosis.

The mitotic index is an indirect way of measuring plant gje:vlajgm zq1 7s; ,c;rowth. A study was conducted on white onions (Allium cepa), und1 m ,lqasc;je;g:vz j7er 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 aos)f,q )5j kj5 ejjb9gre two ways in which cells can divide. The diagrams below show two cells fjejjsj9)5k 5b)o ,gfqrom 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 expresga 3 ,hppn blynfro769dn -uurzt5- 83lod-n1sion 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,tgx5kks p(fx2a.v yul6 l46 -r 8ca3hk in different stages of meiosis. Which rosk gk8(-xc6r4th3k. lylfv 6u5axp a 2w correctly names each stage?

  The micrographs show four phases of meiosis z58uh bae* ,cia)yn y6h; 75t2 myyyd om(dm1nI in a plant. In what order do these phasesue52y mtd,m6h oaya)d*5hbimcy ;8n 7 nzyy(1 occur?

Mitochondria are res+q4m5vow4sxvayz/l+s 6 q 8f/rxy w +oponsible for supplying metabolic energy in eukaryotic cells. In most eukaryotes, which reproduce b6vay oyfws5s z+48v /lxm+o4qr/+ qwx y 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, 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 ce jfhdk 4j3-a+bb 6-mualls in different stages of the cell cycle in four samples of lung tissue from fourf 3b ku+mahadbj-4-j6 patients. Which tissue has the lowest mitotic index?

  The diagram shows the dominant cyclin/CDK complexes at different time pk fo ;bjkqmca7f;m. :;oints in the cell cyclkqfof:.;b ;a; cmkjm7 e. Which cyclin/CDK complex activates DNA replication machinery?

  Studies have shown that genes such as Cyclin Dependent Kinase 3vj0ax 3z0ldj ) (CDKN3) are highly overexpressed3l d j)a0zjv0x 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 thg62uu1ewdbuku8-4 yo e highest during the cell cycle ?