The graph below shows the relationship betwedf/8sry.-) dpan l.rm ,3py kpzkl +h3en maternal age and the incidence of non-disjunction. What relationship is suggested by the data in the graphz k .hd ,)d l+n33lyf.rpma-sr 8/ppyk?

  Which stage of meiosis is represented in the diagra/.wc fn;d b;qw(wvlj+cd+2dev *uog c: r-j1bm below?

  The diagram below shows cx(y4vr;ev ioo0os;r6hromosomes 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 numbp ; icz/);hn wvg.pug1er of alleles of a single gene which would be present in the nucleus of a cell a./1hi;n p)w; pzcvgugs a result of each process?

  Which keyword is matched to app7c;v n1 d4mqiy*2o the correct definition?

  Which statement(s) about maf(-t/gdipuoz+ v1 6(vkkq1z itosis 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 below, which lettextrmfm4.tmq 8mxe cza(i a; g )gu(7(2r points to a cell in anaphase?

  During which stage of mitosis do: u.v d-wgjej b,m43kaes the nuclear envelope break down?

  Which one of the following transport proteins only car 0ijcjf 7aiuv0m:(m d5,a+lkpries out active transport?( m0avjj,l7i:ik05pu c a dfm+

  Which process does not hbx yr) svl0(tdne; q;-mwd qhe4.,wz3appen in the shoot apex?

  Which type/s of membrane transport do/does not require energy expenditure?b95vm 67 c;u4 jvhcf+qmv;s qa
I. Facilitated diffusion
II. Active transport
III. Osmosis

  The diagram below represents a cell with a diploid numberpdfg3qtadhawrb/bj,- (p25 ) of 4. Which stage of cell division is the cell currently undergoing)dbqdrw-b,aa2g jph f 3p5t/ (?

  The photomicrograph below shows a root tip meristem. Which of the fop.hk951)j sgpp kw cti1y5x6rsl/ kv)llowing sentences correctly r sp1ig5 k)h v wktcxp1y56).9/ljspk defines a meristem?

  When does the random orientation of homologous chromosome pairs ocqw(mua/ m;,7k u,9lr alwphl8cur?

  Which process does not occur during meiodhcmb;u10fvd a / /0t desl;a9sis?

  If a cell with a diploid number of 36 undergoes mitosis, how many chromosome9d;tjst2b nngq x y-p))e ee9-s will be present in each gtt-jsxqd9; bn) -2y9 pe)e nedaughter cell after cytokinesis?

  The image shows a microg: bq0i4 4zhnjmraph of a cell.


What explains the appearance of the cell in the micrograph?

  Which statement(s) about homologous ch 3ktq2).yyx-tjjq lhc c )uufu15v :1zromosomes 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 individjda+0pm 9q-- sh+hy 6b gv3ygzual with Down syndrome.

Which statement is not correct?

  In the cells of a horse (E. caballus) during pro tnt lskpoydrju9)624xfa/f( k1re -,phase I of meiosis I there are 64 chromosomes. What is theyr/ fta x41n2sto- (lp,uk fd6ek 9r)j haploid number of chromosomes?

  Which arrow is pointing to a cl0:3rkch2in 7g6or st hiasma?

  The diagram below represents the structud sbhl0/xls*31 s hloi,c6 vg8re of a shoot apical meristem. Which row in the table correctly identifies the processes occuring in the sv36los , dlg 0xb*is/h1s c8hltructures labeled in the diagram?

  How does meiosis promote variavb fgy93 lw)o4tion?

  Which of the following stateml ge,dp+rny-7 ents 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 c1lafrms2(+j , wz,dnmgl:f* s hromosomes.


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 formavrh8-w) qrik5l az+b;tion of secondary tumours from primary tumours as a result of the ) -r 5z8vhrik;bw laq+movement of cells?

  How many chiasmata ar sl fl8hf*619sta5jnee present in the diagram?

  Which statement is a s6t g ye,s* bo*2oz6rl h6jtq5pimilarity between cytokinesis in animal and plant cells?

  Which stage of meiosis)6s7xr,l zm 7pxa id5nft 3(rz is matched to the correct description?

  Which statement(s) are true of meiosis I but not meios/ s cyuw:- zqw;8::) tm3isd idlci9cnis 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 ooci-ak ,ilj2nzb36qgt x -)atj*yte after the first meiotic division. This results in the formation of one large cell and one small cell. What is the fateg lktq a t3,-*6ijai zn2-j)bx of the large cell?

  Which row correctly describes diploid and haploi*z81s ky 5ogaud cells in humans?

  The following table shows the diploid chromoson*gyiu7 /8j0ylcm o j,me number of a range of species.


Which of these statements is correct?

  What conclusion can be drawn f l9(rb+fri2uy rom the karyogram below?

  Which of the following processes is characteoa/vn6xk u l8v-a*nm6ristic of the meiotic and not the mitotic/vnlu*6 6m-ax 8vnako cell cycle?

  The diagram represents a bud with a shoc-y:zmx9y sryviz6 8jb it6;7 8aj8ex ot 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 (Pay,t obr4g9/ r9jfnw1j,yc u;r n troglodytes) is 48. Which row shows the correct chromosome number for different cell t/j ;nr y r 9yfow1tbj,9grcu,4ypes and cell division stages?.

  At the end of which phase of meiosis I does crossing over occne(d 7xtu p3n2ur, and what is the outcome of t(xune ndp732 crossing over?

  Which of the following statements does not describe a step in the sodium-potas 5t26bv2onzabrf0 *bgi*tn n0sium pump z5*t tig62b2*nfbna on0b0 vrcycle in the neuronal cells?

  Which row in the table below is true of meiosis ap942af**q3fwyrd5b n (a fdn?

Membrane transport is importa 5k/poz(,om we+u ,l ;3ehoxusnt for allowing particles to move across the cell membrane and respond to changes in the chemical composition of the extracellular fluid.;zl mpo/ eu,(eox3uh 5ow, s+k

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 m56x a4 r gc6/ug*gbyrregulated 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 theoomm :k9 zcj/7 concentrations of different cyclins during the cell cycle. Which cyclin izj /ko9:mm7ocs involved in preparing for DNA replication?

The diagram below shows chromosomz j-ltr4nkh /f*/ygu7es 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 homola0t)fdwv vbd-96fnp*rt*1x-o(yfz hogous chromosomes?

  The mitotic index of throat tissues taken from 4 different patients is show ubynem6g g8.:(:szvr n below. Which patient is most likely yuv8 g:z: (.n6gbsrmeto have cancerous throat tissue?

1.Draw a labelled diagram to represent the process of crossing over3m2 tnxzkqa1)qjm+ 7g .

2.Compare and contrast random orientation and crossing over.

3.Outline the stages of meiosis.

  The image shows an abnormal hihs .*. asy0pvuman karyotype.


What is the abnormality in this karyotype and its cause?

The graph below shows the relat);rjy4ozn0h*u g j 3bcc4-0k9iax x pkive amount of DNA in one cell during one complete cell cycle. Each letter represents one stage of the cell yugzibcx); 9 -4*0 kp4 0jacjrxo nhk3cycle.


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 besdh7rkry :wju 0f.-9o ,tcej* tween a male cat that is homozygous for brown, long hair and a female cat that has blackjte rks, hfw.ord*0:9cj7 uy-, short hair.


Which of the offspring has a recombinant genotype?

1.Outline how polygenic traits can show a normfy, ;d,b.kgzs al 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 zf jn:6+q8yz -kj,o6jl2tdw sover of non-sister chromatids shown in the diagram 68+,zj2njky-zq s6fotjd: lw below?

  The photomicrograph shows a pollen gr,z.k 3pm xr/vc0tr: nuain from L. candidum (Lily). Which stage of meioz ru0r ,.:xpknc/3vt msis is shown?

1.Outline the events which would lead to an individual being born with/( m/ ejb4j,k3u s4bihz(udih Down syndrome, which is charact4j(uhubei d/k3hbjm z/i4s ( ,erised 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 indirect wauvnlw,;oj h p/p ;qy,*2s g8gqy of measuring plant growth. A study was conducted on white onions (Allium cepa), under controlled conditions in a lab, to investigate the effect *sjung8oh2 y,; qp /,gwvqpl;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. ;.q)4br4ktyesss k8 /rpfx37g :3za; b tm tbqThe diagrams below sttx gb z3bs).t /br qqaf;:3kr;4es4mk p8sy7how two cells from 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 e1g0e.tx8ppt ypyq*e 2 xpression 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 num7*l q6 n4xjidtber of 8, in different stages of meiositx*q4ji67nd l s. Which row correctly names each stage?

  The micrographs show four phases of meiosis I in a plant. In what order do th/r q+ l9ek,5fib74tex kgnqr:ese kixrnrek +4:be q7q g9/5t,flphases occur?

Mitochondria are responsible for supplying metabolic energy ingsj/asg ypd+thd,zeo )85; u,;+uf fo eukaryotic cells. In most eukaryotes, which reproduce by sexual reproduction, mitochondrial sy d,phj;uofga5o+ze+ u /d s;8t,fg)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 cyclenkt d79 6pzy;o8sdzx0 in four samples of lung tissue from four patients. Which tiss9otndzpy8 0ksd 76xz ;ue has the lowest mitotic index?

  The diagram shows the dominant cyclin/CDK complexes6e(+ r csapg-qs(5z 8f0yvocd (c ifp4 at different time points in the cell cycle. Which cyclin/CDK complex activa -y8ocr(q cpdp5 vzeff4(si (c+s0g6ates DNA replication machinery?

  Studies have shown that genes such as Cyclin Dm04ruu/ pq6qbependent Kinase 3 (CDKN3) are highbu 6mqr4p/ uq0ly overexpressed 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 concentratq8o+: w 6 ojwzx0a z;rm*.tchrion of cyclin E the highest during the cell cycle ?