The graph below shows the relat6/ncp6 ifymkl0)y6c s ionship between maternal age and the incidence of non-disj)6 fy0ksn my/6ic6 pclunction. What relationship is suggested by the data in the graph?

  Which stage of meiosis is repre)m)h1dicmac *eiugne 7 ht-2nvp+; )osented in the diagram below?

  The diagram below shows vu/ b6c, /k;dcocrl1zchromosomes 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 alzk(2 (q6yoorsleles of a single gene which would be rs 6(o(k2yqoz present in the nucleus of a cell as a result of each process?

  Which keyword is matched to the correct defs6j3 oeant( c/8xwz6tlcw*we+h y 9l5 inition?

  Which statement(s) about mitoyps)xg 0o,x b.fjcnt)z(8 g;x e0ov 0vsis 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 points to ;b xsx2pex j.g-5vip5a cell in anaphase?

  During which stage of mitosis does the nuclear envelope breoifs9m/ .7)9 acjccluak down?

  Which one of the following transport proteins onl9w ry * npflb630vfy69vtoz1 oy carries out active transport?b6vfol31wzf96*o yptv 90nyr

  Which process does not happen in thoijj nqi5)86h fv8m.ng:ww4 be shoot apex?

  Which type/s of membrane transport dox;ht* xp c,um w;yc03l/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 stage of c 13fezz ,io+wuell division is the cell curr+zieowf ,uz13ently undergoing?

  The photomicrograph below shows a ro 4dksn+5n7hba ot tip meristem. Which of the following sentences correctly defines ad na+n4 5ksbh7 meristem?

  When does the random orientation of ho .h)m pvwyxg,9mologous chromosome pairs occur?

  Which process does not occur 6 q8pr6.3kkp, ygs jjqduring meiosis?

  If a cell with a diploid number of 36 undergor(zn:o k7w2k :.ugzct es mitosis, how many chromosomes will be present in each daughter gz zwck:n7( t:2rku. ocell after cytokinesis?

  The image shows a microg oln s:+1ez6gxv-92l :mrla srraph of a cell.


What explains the appearance of the cell in the micrograph?

  Which statement(s) about homologous chromo2n;x4zbw qdg- somes 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 wit-p0tnk(c+7 ds(gpffczcyv ua w(+x (ojt43 /u h Down syndrome.

Which statement is not correct?

  In the cells of a horse (E. caballus) during prophase I of meiosis I therxu(m3l 3 bqt+79dq*i5ucv kvwe are 64 chromosomes. What is the haploid number of chroml9 53(* +xvcqk udwvitq mub73osomes?

  Which arrow is pointing q iz4 -fe tid+(*h;njrkb4lu5to a chiasma?

  The diagram below represents the structure of a shoot apical meristem. Which rog9(xo,. idu lmw in the table correctly identifies the processes occuring in the stru(9 xug iod.,lmctures labeled in the diagram?

  How does meiosis promote varim) a;s ag*1ld m*nr(kkation?

  Which of the following statements is/are correct f *r(pi 6-d vex/muazz3, w)6z zuomf(yor meiosis?
I. It is a reduction division
II. It involves random orientation
III. It produces genetically identical cells

  The diagram shows gametes produced from nps1; + 3ugu qhp3muu4two 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 formation of secon b7 ygp-a rrszckxq+).)3 jx,bdary tumours from primary tumours as a result of the movement ofxc7 , pbr )akqgjsz.3)-br +yx cells?

  How many chiasmata are prese0g8p * qftzjy/9(b7ga yhgf 7hnt in the diagram?

  Which statement is a similarity between cytokinesis in a;b22; cfaeu9 tj kdn-animal and plant cells?

  Which stage of meiosisnk d557sgqty2k04o qy is matched to the correct description?

  Which statement(s) are true of mnycj +pumh n c2g4i*g)/j;-u 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 oocytqk --/l(l/jw4hute; c vg cbl0e after the first meiotic division. This results in the formation of one large cell and one small cell. chb-lgqlvw(e4jlt - cu0k;// What is the fate of the large cell?

  Which row correctly is 3x w/lfy;3 p v1rll29f*grxdescribes diploid and haploid cells in humans?

  The following table shows the diploid chromosome number of a range of h jeev,ffv q9f;zu8b y8)(mv0u vmh(:species.


Which of these statements is correct?

  What conclusion can be drawn 3+37igfrs4ia hg639dwoywphs m.sh 7 from the karyogram below?

  Which of the following processes is characteristic of the meiotic and not the mi9zsi sn;b1g3jf)l0 s ltotic cel jn f0l1sl 9s3sgzi)b;l cycle?

  The diagram represents a bud with a shoot apical mex2ehrh 2n-sn tgv58mi/ l j7b+ristem.

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. Which +h .a dk tk c3f+l2ztlgq-07zirow shows the correctikh7+z0 a 3z l.lft-ctkd2g q+ chromosome number for different cell types and cell division stages?.

  At the end of which phase of meiosis I d6qfwb4ua) gm*):wd oeoes crossing over occur, and what is the oe6b:w)uwg4a* d)mf q outcome of crossing over?

  Which of the followin+gf.+f4 lqgvlg statements does not describe a step in the sodium-potassium pump cycle in the neuronal cellgv q.gl ff4++ls?

  Which row in the table below is true of meioh48/eaje yh8s(, s6vwi pve.8vr jr;tsis?

Membrane transport is important for allowlmt kqdepzw7z s(6u 9c7lc;2f; 2 l(rking particles to move across the cell membrane and k;w(t;q7d62lcf p 2l zsz(rm 9lkceu7respond 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 reguz 8, ms/zbr+vpvs xl wz3:d8)alated 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 concentratiojv: h ) cuadp/7lra- -rofz6c0ns of different cyclins during the cell cycle. Which cyclin is involved in preparing for DNA replicat6l:/p0)r-hav cz-or7 aud cjfion?

The diagram below shows j;8abs)n 2 ccisri 2 ijc43th2chromosomes 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 separationo.dnc*ilp3r 4+dwop: of homologous chromosomes?

  The mitotic index of throat ti3imy09po,qs az6 (46hj fahbessues taken from 4 different patients is shown below. Which patie,0(y3soh i6abam6 zpqf4 e9jhnt is most likely to have cancerous throat tissue?

1.Draw a labelled diagram to represent the process o dd .ppxgd60v.f crossing over.

2.Compare and contrast random orientation and crossing over.

3.Outline the stages of meiosis.

  The image shows an abnormal human karyoc1egmqqn9/08e nev.dtype.


What is the abnormality in this karyotype and its cause?

The graph below shows the o s/z/ipk/vqx 68(m/xe8cd ht relative amount of DNA in one cell during one complete cell cycle. Each letter represente kt8dc6(/v/hm / xqzoxs/i8ps 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 ca7t .d47ix-(ts kguxoi1 ) guqst that is homozygous for brown, long ixsd) 77iut4g (t1.u gosqxk -hair and a female cat that has black, short hair.


Which of the offspring has a recombinant genotype?

1.Outline how polygenic cyei ts u/bp9czmh* 4+/bb l3,traits can 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-sister chromatids sho93p *1pj0gs ( holan,tm gtc8fwn in the diagram 9tjc38tm ,lg (hspapf*o0n1gbelow?

  The photomicrograph shows a pollen grain fhzmfxo 5n t/-vjiqo 8:3t51wz rom L. candidum (Lily). Which stage of meiosmtzwi-hzfo 83 /51vq5tj: xon is is shown?

1.Outline the eventsh2-o 4cff ogugb+6*4xe+ isyz which would lead to an individual being born with Down syndrome, which is characterised by the prey*4x gco24h- +u+ogfzsfi b 6esence 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 measuring plant growth. A study-mj* w iitl l0e:6cq.h was conducted on white onions (Allium cepa), under controlled conditions lmqcej-6i.*w t0l i:hin 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 are two ways in which czv:+ 7 2gv4lbmifag 4sells can divide. The diagrams below show two cells from an organism w2vv+ a:f4i4lgm s b7gzith 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 growth. l)rcls3)q+wyk.pe hwv olg 0c q*20w8

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, in dio:z;63 zeev) om m:0.xrpeirpfferent stages of meiosis. Which row correctly names eacr:m m); xp6ze.zpe:oi0 eo rv3h stage?

  The micrographs show four phases of meiosis I in a plan5csry/ oin2r5t. In what order do these sc/ ryn2 5r5oiphases occur?

Mitochondria are responsible for supplying metabolic e)xinqgc8xlt n 4s40,9i 0psmxnergy 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 bett4x4i00s9)g8spxqm nx ln ci,ween 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 differegxu :z)p43iy 4-t9o fn/q1 eadr1 bbwznt stages of the cell cycle in four samples of lung tissue from four patients. Which p/1dnxq:f 31 it9z b-woz 4e4 gruby)atissue has the lowest mitotic index?

  The diagram shows the dominant cyclin/CDK complexes at different 5fyl 7/3z6dytbmu ns1time points in the cell cycle. Which cyclin/CDK71dlm3 bn5yuyfszt6 / complex activates DNA replication machinery?

  Studies have shown that genes such as Cycha3ye/ 7fvqlp hao00mr.0az *lin Dependent Kinase 3 (CDKN3) are highly overexpressed in cervical tuy0 mhohaaqa*frv e0.370/z p lmours.


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 durxoj/3svih+l f22x ndu/:e)jmp3x4c s ing the cell cycle ?