The graph below shows the relationship between mj.3 n qmh8f0bu6,ays waternal age and the incidence of non-disjunction. What relationship is suggested by the data in the gy,0hb83 fqwsanuj6 .m raph?

  Which stage of meiosis is represented in the diagram belovxeyg5x)dqd46 j3x, sw?

  The diagram below shows chromosomes during meiosis. p/ p9x1vtl.hd*r,bbz


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 nmxae jobf+d/e.6 -u;which would be present in the nucleus jfdo6.u ne+ae- mxb;/ of a cell as a result of each process?

  Which keyword is matched to the correctv - 9)b ,dvvhigtn5awrng.a4ugwv5q d8 yb-,7 definition?

  Which statement(s) about msicmk 6k9yt wb-s5-n: 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 bele6e( a2zhz8vgzqoo9h w0o6 o*ow, which letter points to a cell in anaphase?

  During which stage of mitosis does the nl1 v hddybje: n95c)g8uclear envelope break down?

  Which one of the following transport proteins only carries sw4a2s9ftd* s3 dasbt(g )kt1out active transport? ds9ds*3g s)at4a(2w kt ftsb1

  Which process does not happen in the shr orp6cm71(8fvf9r wu ny v0+woot apex?

  Which type/s of membrane transport do/does not require energy expenditu/bjl:8 o yoovs);5g xvre?
I. Facilitated diffusion
II. Active transport
III. Osmosis

  The diagram below represents a cell with a diploid number of 4. Which stagexl :bu3uv u6x9 of cell division is the cell currently 6ux3b vu:u9 xlundergoing?

  The photomicrograph below shows a root tip meristem. Which of the folly* w7a,dif* fyowing sentences correctf *y*a y,fid7wly defines a meristem?

  When does the random orientation of homologous chromosome pa ihv6 np-v6a8yaa 6wp0irs occur?

  Which process does not occur df3ab m5ssw 5*yv9f5cj i ,r)gzuring meiosis?

  If a cell with a diploid number of 36 undergoes mitosis,-j bp2ftpb+5vn,:wv u how many chromosomes will be present in2up-:tb+5 v vb, wjfpn each daughter cell after cytokinesis?

  The image shows a micrograph of a celanc*,g1f2 o;v1adk iol.


What explains the appearance of the cell in the micrograph?

  Which statement(s) about homo 0v(dulhp2 fp4logous 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 Down syndromefo)g: /hig2) pvo.jya.

Which statement is not correct?

  In the cells of a horse (E. caballus) during prophase I of meiosis I thel rn(l qrw*1sktzu 1:j6,0usq26mvncre are 64 chromosomes.1 (,tjnsqqukn6u*r m02v6:lcszr1l w What is the haploid number of chromosomes?

  Which arrow is pointing to a chi b/nzx:on;/m hasma?

  The diagram below represents the structure of a shoot apicaje r2xf7;i 1vc(s 5jgll meristem. Which row in 2sj1cef 5vljgri(;x7the table correctly identifies the processes occuring in the structures labeled in the diagram?

  How does meiosis promote +*pdtfn7fc.r- wsu 5 y5mbtl8 variation?

  Which of the following stateo*jdi r e+e 829w;byacments 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 chromosomq u/tksl).,1tmtbm2fluku1cn9w/ )x es.


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 tht(l -v 8upff gaoc73abf3ep)lj /.x8oe formation of secondary tumours from primary tumours as a result of the movement ofo tf8e-jlalupf(p v/37a) 8cb. fog3x cells?

  How many chiasmata are present in the diagram? ysw sa27jr9ymvjoded ;5+ o.rfl 8b3:

  Which statement is a similarity between cytokinesis in animal aq1w p v.p 54i1)cg 8ne3edihkmnd plant cells?

  Which stage of meiosis is matche, jhg z*ejs2c;d to the correct description?

  Which statement(s) are y: z+mod8 , z*z*1l)iqvsepbstrue 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 divi,k ozwl4 (f(8dioh it9sion. This results in the formation of one large cell and one small ce f8( oidowz 9tlik(,4hll. What is the fate of the large cell?

  Which row correctly describes diploid and haploidmf6nw /l lj*s widx-nyj*5+p + cells in humans?

  The following table shows theb6k2p6+ qmdw i4lt5v s9 dzy9u.hp2id diploid chromosome number of a range of species.


Which of these statements is correct?

  What conclusion can be ( c u,lt blgcx90wl.x;drawn from the karyogram below?

  Which of the following prd- tz vjt)4jnj* (:e-tehl,jrocesses is characteristic of the meiotic and not the mi ntjrtv) de-:z*j,e -jh4jl(ttotic cell cycle?

  The diagram represents aw46/ kagh2a:mls*bdp 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 (w 5hu+vrfsc g g(5+z3vof5w+k)erx o,Pan troglodytes) is 48. Which row shows the correct chromh(gu5gv,3)osvzof+ ekwx rrc 5w5 ++f osome number for different cell types and cell division stages?.

  At the end of which phase of meiosis I dsp1 umj r:pfip)wlgg, at. 1h95wg:s:oes crossing over occur, and what is the outcome of crossing uj gm:gh5. pwg9 fs,awsi :11) :rpltpover?

  Which of the following statements do m h , 3,ebo (w3(nda11jj4scjd4tqvffes not describe a step in the sodium-potassium pump cycle in qj4ocjh(1st(e 4aff d w3v,m d3,jn1b the neuronal cells?

  Which row in the table below is tspccaum+z83z- iz a,nc19 4m brue of meiosis?

Membrane transport is important for allowing particles to move a+: 2dbeifvll3f 1f5 ndcross the cell membrane and respond to changes in the chemical composition of t n+315fb2dllvie:ff d he 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 il r7+zwnytgh-y96 i)js regulated 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 fa2p:y 3ns)1unu0k vxof different cyclins during the cell cycle. Which cyclin is involved in preparing for DNA replication? 2n)pxyufnv0a 1 uk3:s

The diagram below shows chromosom0umn*rol)km* u-r p6ues 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 7 .d3af2opq*t) ssoiaof homologous chromosomes?

  The mitotic index of throat tissues taken from 4 different patients is shown bvok i+)d k*vglnu q-561xf( sxelow. Which patient is most likely to have cancerous throat-d* k1s nq k+ox5(f6vluig xv) tissue?

1.Draw a labelled diagram to represent the process od .p-9p3ua nlssski 8*;nr:cef crossing over.

2.Compare and contrast random orientation and crossing over.

3.Outline the stages of meiosis.

  The image shows an abnormal human karyaqqmgd83:ime;4 ( 5x t workq/otype.


What is the abnormality in this karyotype and its cause?

The graph below shows the relative amou-3z1ygoot r2oz)uq *k nt of DNA in one cell during one complete g-3 zu)2o1krotz q oy*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 m5ip;mx; cy+2duo ar5is homozygous for brown, long hair and pa5um+id;2om; c5ry x a female cat that has black, short hair.


Which of the offspring has a recombinant genotype?

1.Outline how polygenic traits can bg1 y(cbuq+a3pt z/z.8 ;8ljqj6cp zx 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-sa;q1q ke*- dvaister chromatids shown in the aeva;d1qq*- kdiagram below?

  The photomicrograph show-0soh 7h9zp7t mhmsl( s a pollen grain from L. candidum (Lily). Which stage of ml70 7(hhsm sm -htp9zoeiosis is shown?

1.Outline the events which would lead to an individual b33(rsu ) y fj rp2) )hqf/sjqq3eoojk+eing born with Down syndrome, which is characterised by the pres /e2+)qfh yq3)srj(k ojsj33oq purf)ence of three copies of chromosome 21.

2.Explain how meiosis increases variation.

3.Outline the stages of meiosis.

The mitotic index is an indirect way of measuri;dqiptn hj 16k 7xci+.ng plant growth. A study was conducted on white onions (Allium cepa), under controlled conditions in a lab, to investigate the effect of p k ix7jq6;in 1d+th.csoil 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 tn0t-o6sf q; rkrt2v*oknh 3c+wo ways in which cells can divide. The diagrams below show two cells from an organism nsktfhok q6 r+;o -0v32c*trnwith 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 expression ipd7,frs26d z dnta l(+ik3o9zn 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 shoas15wygj hhf n2u5not eo3551 th1o0 ow a cell, with a diploid number of 8, in different stages offtjh oangot1w135oh5 ye5s 50nu12o h meiosis. Which row correctly names each stage?

  The micrographs show four phases of meiosis I in a plant. In what order 4 rjzoww ib1*l2 k0ij6do these p w1ojbkz*4 6w2j0irilhases occur?

Mitochondria are responsible for supplying metabolic energy in eu4x js5u1t o-c+imrcpf 9cjeq aj5c):;karyotic 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 beccu5:icxcamj4o 1 fq+ r p;-se9 jt)5jen 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 cycle r)gyh eichuc87 s3.y2in four samples of lung trs .7uih2)g8 ye3cychissue from four patients. Which tissue has the lowest mitotic index?

  The diagram shows the dominant cyclin/77uwi * la-cjccr:xpt)hahuc nxy:63+q n*,m CDK complexes at different time points in the cell cycle. Which cyclin/CDK complex activates DNA replrnl3uanaut-mxxw:7i*qp+ 7,) : h6cy *ccjc hication machinery?

  Studies have shown that genes such as Cyclin Dependent-:e8nbvt9q 7ofrv cs-z*h21qi s, gvt Kinase 3 (CDKN3) are highly overexpresssgv-72:t q-z,tnfvcre8*19h sb iqvoed 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 higheso l-zaaf)u+7e (,ljqit during the cell cycle ?