The graph below shows the relationship ax+7m:mo)rvp al l/ 8/ vg)rnlbetween maternal age and the incidence of non-disjunction. What xl: n+)a)m8lam / pvgr vlr7o/relationship is suggested by the data in the graph?

  Which stage of meiosis is represented inh i.+1ynebs8 c the diagram below?

  The diagram below shows chromosomes during m j kamyuwm3;fq 3emi,ek3a/ n 9k+lp*(eiosis.


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 allelegcmi8qh1 7 fdf2j)dx c0va+8. ,cihdg s of a single gene which would beg h7d8i8)df2im,+0.ad 1q cj cvc fxgh present in the nucleus of a cell as a result of each process?

  Which keyword is matched to thel;y mln*u /4r c/m4cyv correct definition?

  Which statement(s) about mitosis is/ +yipwut6 s g+iujm.q8p +8* /hrqjjr*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 letter px, sysqxdoek*uti8 0 3;2x wl4oints to a cell in anaphase?

  During which stage of mitosis does the nu 8 0(u:9v2-sks+rfmjjyx fm aoclear envelope break down?

  Which one of the following transport proteins onl f:ut8,j7k x;rpzy: c*dl/ pqgy carries out active transport?p::l*/ zyxkp7c g qtjd8f,;u r

  Which process does notzn,p xh:oc )j 9r(w0yp happen in the shoot apex?

  Which type/s of membrane transport do/do xyp dezvk0cw/*) ctj6:: ec)oes not require energy expenditure?
I. Facilitated diffusion
II. Active transport
III. Osmosis

  The diagram below reprh s;ar) m9 urb;8 w*yr)hyi7dresents a cell with a diploid number of 4. Which stage of cell divisio8hbsmari);9h) ryr; rwyu7*d n is the cell currently undergoing?

  The photomicrograph below shows a root tip meristem. Which of the followinu j783ci/h jjfg sentences correctcjh7j 38ifu j/ly defines a meristem?

  When does the random orientation of homologous chromosome pairs occur?s/6 7vj/yi4yppva a:k

  Which process does not occur durikk3ggy.;y4 w-lm q+s e(kie2cng meiosis?

  If a cell with a diploid number of 36 undergoes mitosis, how manyz6l b1zq cwx6; 89cxg b7tv83jbg7 jlt chromosomes will be present in each daughter;lb8 g71w8zzc3jtbblc9j6v 7g 6xtxq cell after cytokinesis?

  The image shows a mia4cxk; x5+nmow9) wol crograph of a cell.


What explains the appearance of the cell in the micrograph?

  Which statement(s) about homo;a,ls;4swky klogous 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 individua g1vughfrp98g.+.u xpl with Down syndrome.

Which statement is not correct?

  In the cells of a horse id lykm,6l4 ,uvmiw 86(E. caballus) during prophase I of meiosis I there are 64 chromosomes. What is the haploid number of cykml,864 m,ui6 dlw vihromosomes?

  Which arrow is pointi/ lvho8ui(d.v w9a v5zng to a chiasma?

  The diagram below represents the structure of a shoot apical meris j 1sqkvr4 v+3ujlo17utem. Which row in the table correctly identifvlqouj 37v+uj11r s4kies the processes occuring in the structures labeled in the diagram?

  How does meiosis pro l3aiy-rz) 1ueob0.4 skize.jmote variation?

  Which of the following s6:uwr6 m1igs+gpc,i+ bi ton*tatements 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 gamete4c4s 9o(y/ejwmbe oo3tb :*mqs produced 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 f30k: dc( wxdblormation of secondary tumours from primary tumours as a result of the moveld(03 wxc bdk:ment of cells?

  How many chiasmata are present in yibcy x(6;bj5 the diagram?

  Which statement is a similarity between cytokinesis in animal and js w,u/a.at: wplant cells?

  Which stage of meiosis is matched to the correct du9/2mx.bre1hz 9w wmzescription?

  Which statement(s) are true of meiosi0lo49rh x 7hews 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 rf,+h2m lqmfp- esults in the formation of one large cell and one small cel+hml2ff,-qmp l. What is the fate of the large cell?

  Which row correctly descrink)q bl5y-kidkg v +7-bes diploid and haploid cells in humans?

  The following table shows the dip 4 delp.qc2(o1lcb dxx-+mfz3loid chromosome number of a range of species.


Which of these statements is correct?

  What conclusion can be drawn from the karyogram belbv4edl5*6j ki)fid8+8qije vow?

  Which of the following processes is characten*a + tqtj;i.do hyb8. k3x3wlristic of the meiotic and not the mitotic cell cycle?d+x3an3;q8 j koltwb yt.*.h i

  The diagram represents a bud witw 4 6u7zm4fsut -ok4duh 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 troglodb d w.2,j/buxnytes) is 48. Which row shows the correct chromosome number for d2dw/ .,ju bnxbifferent cell types and cell division stages?.

  At the end of which phase of meiosis I does crossing over occur, 8ggoq05wmr8xwj4wq9 agy + s (and what is the outcome ofaox4 g 8j0gw895qwyr( s+wgmq crossing over?

  Which of the following statements 5y4av( u2n 7edodar +qdoes not describe a step in the sodium-potassium 27d+4eavry ndq 5a(oupump cycle in the neuronal cells?

  Which row in the table be4(5oq-v c2t)mc wvjdp1z (m kdlow is true of meiosis?

Membrane transport is important for allowing particles to move across the cell mj oupb:,w:ef6hw :(j7/e n*ikkpedj9 embrane and respond to changes ,ofkjniej:kb :6(wwej* e d:up9hp7 /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 df+hf/qk9kb; 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 differv:t(p57 iq tzpent cyclins during the cell cycle. Which cycliqz t5:p v(ipt7n is involved in preparing for DNA replication?

The diagram below shows chromosomes during meios-31 *f spysyg/9 icgkris.

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 involvestf8a6ht +utfe0dky,l;r 5kea h180es the separation of homologous chromosomes?

  The mitotic index of throat tissues taken from 4 different patients i2iz *uy 45qvnza, *evws shown below. Which patient is most likely to have cancerous throatazvqv*4 eny ,25ziu*w tissue?

1.Draw a labelled diagram to od5m* j rk1**crmq aq7hma*c(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 huma-o-r2c1umk i-he 0 bk ug*uut7z,jdz 2n karyotype.


What is the abnormality in this karyotype and its cause?

The graph below show(mfh )8yo:)f;tm imh js the relative amount of DNA in one cell during one complete cell cycle. Each letter represents one stage of the cell cyclh8o:my)t) fj;f mi( mhe.


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 homozygous for brok4: gexc 1ei,(vrb4 grapa*.iwn, long hair and a fembe1gx 4r,4 arave.k:p(i * cgiale cat that has black, short hair.


Which of the offspring has a recombinant genotype?

1.Outline how polygenic traits can show aw+zl bdm*g t45uy*8w.k* p*n ofjkd9t 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 shownm: .jcoez+sl0euvz*.sl*, cr in the diagram bel.zr*c* ose0+:e,u czl.msjvl ow?

  The photomicrograph shows a pollen grjm0ppu260 xfi ain from L. candidum (Lily). Which stage of meiosis is s 00j2mfi6ppxu hown?

1.Outline the events which would lead to an individual being born with Dow o*tfqg*;x t,tvc5yu (n syndrome, which is characterised by the presence of thre *yvco gx;tu(tf tq*5,e copies of chromosome 21.

2.Explain how meiosis increases variation.

3.Outline the stages of meiosis.

The mitotic index is an indirect way of measuring plant growth. A6lr-* 2 umpjpb study was conducted on white onions (Allium cepa), under controlled conditions in a lab, to investigate the effect of soil pH on the mi-mpu lp* jb6r2totic 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 divif1m+ 7 - qyk/1*kiqyhedoxzl 5de. The diagrams below slf +hy ikmkqx-od/*z7 q1e51 yhow 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 expression in stem groww c nhsqpy:0ai ;o3c2*th.

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 na q j(xssx/ly1hwf6f*cal /tp+0o ijf93tg,5umber of 8, in different stages of meiosis. Which row correctly nam*0i(axc6fo3gy9 /s/, 1t xqf w+ll hatjps5jfes each stage?

  The micrographs show four phases oywz3rq ;qq1;6;iw yqj*qi a)lf meiosis I in a plant. In what order do these phasesy;lja wz6q iw1 qrq;yi);q*3q occur?

Mitochondria are responsible for supplying meta uyvvf p+)g0 eyg8:lx4bolic energy in eukaryotic 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 contrastgy)8f gl e+ u:40yvpvx 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 numbe3pt17wfx* c otwt7iz: r of cells in different stages of the cell cycle in fourwf*71t7 zxtpi 3t :cwo samples of lung tissue from four patients. Which tissue has the lowest mitotic index?

  The diagram shows the dominant cyclin/CDK complexes at difx evpk7vteeo m ;2( *jlyj22sy /ce3g/ferent time points in the cell cycle. Whi egkj;m2op3v2 le/yx/t2*j c(es7eyv ch cyclin/CDK complex activates DNA replication machinery?

  Studies have shown that genes such as Cyclin Dependent Kinase 3 (CDKN3hrh9(hs np*me42x *mk ) are highly overexpressedhmrhmn*hsp (x9 e4*2k 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 duhuqu s+ (kx6zw:+n l; )dmmv04xtk 3dhring the cell cycle ?