The graph below shows the relationship between maflox*p( r8 hsk6wq44u 3( mkw (viv,grternal age and the incidence of non-disjunction. What relationshxm ifw w v k4ulorr, hkqv((6*s8g4p3(ip is suggested by the data in the graph?

  Which stage of meiosis is repfm46/+t.h9rpa kd 4tirv;whtu 1jlse )4u 9k oresented in the diagram below?

  The diagram below shows chs:2rk)oznunyyy;*8 7nwobm,mj 1 o v+romosomes 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 alleles of a sppw5yf3p 820qwwb :kby4 n(z)j)nlq ringle gene which would be present in the nucleus kq5bw l :f4 328nwj(zw) q )byprnyp0pof a cell as a result of each process?

  Which keyword is matched tosbw f*-/j ,oaf the correct definition?

  Which statement(s) about mitosis5(m*s-x flqtq 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 letter powez9dp qqt3-kc 6,a 8rints to a cell in anaphase?

  During which stage of mitosis does tn * ;qyjcnkec3o;n5 u/he nuclear envelope break down?

  Which one of the following transport proteins only carries out active transp 45wtsy8go tccs5 bg*7ort?5 gc4 y57bc8g sotswt*

  Which process does not happen ie* u zw4;8kuz3qtp hy (d akw6)lpn/6en the shoot apex?

  Which type/s of membrane transport do/does not require energ :wp55s tstme35+ach uy expenditure?
I. Facilitated diffusion
II. Active transport
III. Osmosis

  The diagram below represents a cellx*y.y2hs6xl a with a diploid number of 4. Which stage of cell62x x.*sya hly division is the cell currently undergoing?

  The photomicrograph below shows a root tip meristu8lkp b8-w6b olppr agy ;;gb2)i.h /vem. Which of the following sentences correctrip2plgv ;puahb.8o kl/y8) ;bb6gw- ly defines a meristem?

  When does the random orientation of homologous chromosome pairs occurgb(4 ,be.9f g/tn cush?

  Which process does not occur during meiosis(y ua 2d9un3zas fmfr7, 1wy/k?

  If a cell with a diploid number of 36 undergoes mitosis, how manysem6bs2z+rs nz:-;r x chromosomes will be present in each daughter cell after cytokiner 2m-:n;s+sxzrzseb 6sis?

  The image shows a micrograph gs ja -;h;(p um3w424:y)h qckcoomavof a cell.


What explains the appearance of the cell in the micrograph?

  Which statement(s) about homologous chromosomes is/are not j r1ey*.4:se 9udvtwr 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 syndhn.y kz)iw.0jrsi1 /p rome.

Which statement is not correct?

  In the cells of a horse (E. caballus) durinqplg3au9a(xz*7v+ p ug prophase I of meiosis I there are 64 chromosomes. What is the haploid number of chromo9+*uvpa7(3p l qza xugsomes?

  Which arrow is pointing to a chiasmas*zku0 h4w-lx8 bder 0?

  The diagram below represents the structure of a shoot api*o*btiabr;6txd t9q,cal meristem. Which row inqi9r**to x tatb,b6d; the table correctly identifies the processes occuring in the structures labeled in the diagram?

  How does meiosis promote variatirnmx z3l *vt v)3.iah3on?

  Which of the following statements is/are corc 4,sw3f xvmi/k ij, 4fgj4t:af( puw;rect 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 homologoumwtu*,qdm c:mc3i5e1otu ( i. c)cf6 gs 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 tumourslo5 +:iqaba mn-g*3kh as a result of the movebhn+agiqo :k5 m- l*a3ment of cells?

  How many chiasmata are present in the dijw - e(etgl2m n.4flb,agram?

  Which statement is a * oo6;zootf77 vnvrr ak*3i+p9nrpl7 similarity between cytokinesis in animal and plant cells?

  Which stage of meiosis is matched to the correct descripti+-tf.3 tnxkv pon?

  Which statement(s) are true of meiosis I but not meiosis Il t hv/bo)oui00ms l(s4qt6t-8t4 wpfI?
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 faj)6 x4rigntzs9 yo8/irst meiotic division. This results in the formation of one large cell and one small cell. What is the fate of the large cello 94r xn8/6siat)g yzj?

  Which row correctly describegu2ij80 v0y7yjvul2w s diploid and haploid cells in humans?

  The following table shows the diploid chrof kk .2 ub )f r4f:ndi-ja,48 padcn(d4it)hygmosome number of a range of species.


Which of these statements is correct?

  What conclusion can be drawn from the karyogram below?m77st*w vgaksa9e1 -h

  Which of the following processes is characteristic of the meiotic and not the mih vykq;4s0t 4okq. mozc ):twwf 2rw.0tmw)02fwsw.yt: orqk4co . v; k h0qz4totic cell cycle?

  The diagram represents a bud with a sx kg2y ;*9 juwya4)w ncnvxkm5h; sv71hoot 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 chimpanz fzwcgavs3 x )6m.85h0zd v3jfee (Pan troglodytes) is 48. Which row shows the correct chromosome number for different cell types and cell divisisf3h0.xgvczf 6 w az53)dvjm8on stages?.

  At the end of which phase of meiosis I does crf uau3 tjc,47fossing over occur, and what is the 7fj3 u cauf4t,outcome of crossing over?

  Which of the following sqf;w ,1c2oc) tumq2ebf :imd.tatements does not describe a step in the sodium-potassium pump cycle o.f2 mfteqm2i :cc1 b;q,wu)d in the neuronal cells?

  Which row in the table below is truj 6pxaib)n(1ke a.: mte of meiosis?

Membrane transport is phx9 h0rbt:fxqst7to/.,b 9qimportant for allowing particles to move across the cell membrane and responbts r /q9p,qhttf xh. 90o:xb7d 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 mitosic/2(ptv 4fsixsg 0ir0s is 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 concentrationk74r,,8,hcu/ex o d ,iqy1:*i reyaizmeg: y ls of different cyclins during the cell cycle. Which cyclin is involve7ecg:yir4ay:h ixqkdiuozy, 8, ,reml e,* /1d in preparing for DNA replication?

The diagram below shows chromosomes during me kf-c)bm:xg2 f8 bo o4xo.l7xjiosis.

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 homolo 7dy3 -bs0dm+3xisz vogous chromosomes?

  The mitotic index of throat tissues taken from 4 different patients is shown b09bz,y9l ls c./kyowe62fx uselow. Which patient is most likely to have cancerous throat tissue/x bkeu.9w2f9soyslz, 0l6cy ?

1.Draw a labelled diagram to represent the p2t+n tfo; 1vxorocess of crossing over.

2.Compare and contrast random orientation and crossing over.

3.Outline the stages of meiosis.

  The image shows an abnormalii8zht h9ult6c4 (uecb g(43z human karyotype.


What is the abnormality in this karyotype and its cause?

The graph below shows the relative amount of DNA in one cell durkniapuhb13o r5mpm u: a 2gi(q/ -t/7jing one complete cell cycle. Each letter represq37ujppkb m:a-ouihr/ /i(a5t mg n12ents 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 cs5nu*)3 ykavgmv,8gd at that is homozygous for brown, long hair and a female cat that has blamgua35gk,8dn yv* ) svck, short hair.


Which of the offspring has a recombinant genotype?

1.Outline how polygenic traits can show a normal distrgisqozo; 8mk 63d60imibution.

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 crossi)b/(7is c zsmbng over of non-sister chromatids shown in the diagram belmsbcib /( s7)zow?

  The photomicrograph shows a pollen grain from L. candidum (Lily)bf lvnlw t112,. Which stage of meiosis is shown?12 fb ,n1vwllt

1.Outline the events which would lead to an individual being born with Do8qszsldhc*5uyk0 2; wqt 5zv/wn syndrome, which is characterised by the presence of three copies of chromosome h 5*scl;v 52/utq0qs8w zdkz y21.

2.Explain how meiosis increases variation.

3.Outline the stages of meiosis.

The mitotic index is an indirect way ohth)4of ai1-1 tqcc, f1mnv2rf measuring plant growth. A study was conducted on white onions (Alliuohq-f1)1tc1 h v2mf,nrc4i atm cepa), under 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 ar,uzgs8vo8 zn/ e two ways in which cells can divide. The diagrams below show two cellu zo ng8sv/z8,s 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 stem093ymt03xlqiwfy0m 1r-:vns j -bo ry 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, i 5cx0ed ke97hyn different stages of meiosis. Which rowee 9yc7hx d0k5 correctly names each stage?

  The micrographs show four phases of meiosis I in a plant5okcr90eet (0bfvl6 r. In what order do these phases occur?f 05 6okcr rtvbel9e(0

Mitochondria are responsible for supplying metabolic energy*wvtgv3j o s nldl4jyc;75pfy+.bi** 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 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, couldiwovn pfld3y*t ljjy;cv+ 5*.7s4* bg 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 nul1,kh*d 1vob +rrv.t zf.usf; uamq 41mber of cells in different stages of the cell cycle in four samples of lung tissue from four patients. Which tissue has u, 1dbuf 4f;.1lhoqtr mvk*v1sza.+rthe lowest mitotic index?

  The diagram shows the dominant cyclin/CDK complexes at different time pointm iu0.loiyin5+0o0 dos in the cell cycle. Which cyclin/CDK complex activates DNA replication d5o 00omi0ioy+.lnuimachinery?

  Studies have shown that genes such 8gcd a9q.exbw2*-bq8f6og hyx,fto -as Cyclin Dependent Kinase 3 (CDKN3) are highlyh8o,bt*9xgwe2. fq-b g- 8ax6dcyf oq 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 concentration of cyclin E the m9c *wzj n ;x2msvfa.6highest during the cell cycle ?