The graph below shows the relationship between maternal age and t ;s7y*r/j,0zgt iqb mthe incidence of non-disjunction. What relationsr* bjtq/gi7;y sm, 0tzhip is suggested by the data in the graph?

  Which stage of meiosis is repr1ekwh5v7pk z )esented in the diagram below?

  The diagram below shows chromosomes uso7ll7 *+tt2* c.)eipris: s odyn(y 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 kg+8z 52 c/eoxr *b/sysb 4wrpa single gene which would be present in the nucleus of a cell as a result of each prz2e 5 rr/s+ y/go8b4xp* wbsckocess?

  Which keyword is mat5hg;w *ibf9 l 8vbxk9pched to the correct definition?

  Which statement(s) about mitosis is/ar64o*sbtmaffl 2 h/7dfq-hgs;e 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 a cell in aa ,wi(oi6y zn8naphase?

  During which stage of mitosis does the 8;hds+*9 *7p gn 3qjrcg dcwlfnuclear envelope break down?

  Which one of the following trank9atwe1 bl)0-4f lrf;vwn od9sport proteins only carries out active transport?dn-e r akvw4tlo)9lwff9 b ;10

  Which process does not happen in the shoot apex13b8vufy wy 3a?

  Which type/s of membraneb85 n7s pn8fxz transport do/does not require energy expenditure?
I. Facilitated diffusion
II. Active transport
III. Osmosis

  The diagram below represents a cell with a diploid number of nb c n9a u.)k7kwkb/ao(2k0sb4. Which stage of cell dkbowkcb0 nk7a /. sbk29 ()uanivision is the cell currently undergoing?

  The photomicrograph below hua a mgqpct+yz6 2a)j+q(n2;shows a root tip meristem. Which of the following sentences correctly defines a ctnhy2ag qa pmj+q);62az u(+ meristem?

  When does the random orientation of homologous chromosome pdy2v/;w*vvp e8dos9j ,(e q n korcw0:airs occur?

  Which process does not occu -m9hek2w:dn:f: (haqx1dzil r during meiosis?

  If a cell with a diploid number ofy8qadt7-0so x 36 undergoes mitosis, how many chromosomes will be present in each daughter 0s yxot 8-qad7cell after cytokinesis?

  The image shows a micrograph of a cell. at+,+ow jl3c-kyfk dad/5, fq


What explains the appearance of the cell in the micrograph?

  Which statement(s) about homologous chromosomes is/are notba q;:m38ls(foecgr8hgk w(,i 5 tc( r 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 sy2m5:w9 7 pw/:d0y vlenwrqxsi ndrome.

Which statement is not correct?

  In the cells of a horse (E. caballus) during prophase I of meiosis I md b82t joqsu30l3c 5hthere are 64 chromosomes. What is the haploid number of chromoqjt2 usbmd03h l38 c5osomes?

  Which arrow is pointing to a chiasm t znq91oq5i6pa?

  The diagram below represents the structure of a shoot apical meristem. Whic:eax pwd8ymz) 3yf7j: h row in the table correctly identifies the processes occuring in the3yj d7y):e:wpf 8az mx structures labeled in the diagram?

  How does meiosis promote va g*hi x87,9kbpk6v5q 9fxfrotriation?

  Which of the following statements is/are cnlx hcj;zwb, : xybo1:n 750hborrect 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 homo,vj4)4p82xk ovq yhislogous 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 formatio ypkmmi5l d6we4h*)n,/4ogzv n of secondary tumours from primary tumours as a result of thep z)vw y d5 ln4e4*/6kgiohmm, movement of cells?

  How many chiasmata are pr-4uf) vo8+e-qr ezkwresent in the diagram?

  Which statement is a similarity b5a tva;0qawtkmg:6.fetween cytokinesis in animal and plant cells?

  Which stage of meiosis is matched to the g4s2u7,lcak1gd xf;q* vls)ecorrect description?

  Which statement(s) are true of meio,y.u oie pkodn5gl,0v s5b /-ssis 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 g;n spq qgba*1h/vaf s)6ox.0division. This results in the formation of one large cell anqxqg)pga.60n;s a/ b1f vsh*od one small cell. What is the fate of the large cell?

  Which row correctly describes diploid abkrj (4b xcck.h)askmc:) 5 u1nd haploid cells in humans?

  The following table shows them gsno-ks/d9wx) v. f8 diploid chromosome number of a range of species.


Which of these statements is correct?

  What conclusion can be drawn from the k6 i dc4t1zzv8)swx 2xearyogram below?

  Which of the following processes is characteristic of the meiotic and not ,:/4izrwihca8lby fd * w8qy8o;m/ zpthe mitotic cellyilh848wyzd8/wpfi;/c,az mo r:* b q cycle?

  The diagram represents a bud with a shoot apical meristem950aa cg 8hkd2f 2tci4q 1dxfu.

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. Whicw*e 1nup,w k9rh row shows the correct chromosome number for different cell types and cell division stagew1we,*k9 rnups?.

  At the end of which phase of meiosi6e xek(ad7 eh*s I does crossing over occur, and what is the outcome of crossh6k*ee 7xde(aing over?

  Which of the following statements vg*so/d4nj+ qtsr 2-v+c) kvp does not describe a step in the sodium-potassium pump +t )sc/-2vvvjqp*r d4kn +go scycle in the neuronal cells?

  Which row in the table belowj sn5.erds/e mpv8p,a;)do 3t is true of meiosis?

Membrane transport is important for allowing par(r6 5 1gsgoix j *or/ut0gco4e jat:c8ticles to move across the cell membrane and respond to chan5 uacxo4rji(8 o gc0: /r6gsjto1 eg*tges 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 regu )j o q7 qqrmcid9*5mp ezdo(p)o7dkf 5g54t0clated 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 of sd 841vrof8cl different cyclins during the cell cycle. Which cyclin is involfsr8cdv18 o 4lved in preparing for DNA replication?

The diagram below shows chromosomes durxwf;h* rc(qfm4dyy71fiq4, c r3;nzbing 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 jqk bj3 (tzl 2c8h.5k7vt7 uatseparation of homologous chromosomes?

  The mitotic index of throat tissues taken from 4 different patients is shown qj)32cnjzwxf zvuz3)bj,. o; -sbaj 0 below. Which patiennjuv;)0o xbazq )z j,fj 3sj-.2zwc3bt is most likely to have cancerous throat tissue?

1.Draw a labelled diagram to represent the process ocw 3bb* mh70 dw1usox82t9 dxef crossing over.

2.Compare and contrast random orientation and crossing over.

3.Outline the stages of meiosis.

  The image shows an abnormal human karyotype. dk1i9n4 00 v* kyhmpun


What is the abnormality in this karyotype and its cause?

The graph below shows the relative amount of DNA in one cell during one complzn 8vq (g5 dtsrz13:6y+nhcj rn9re68 a5 jeioete cell cycle. Each letter represeh +3y5d6 jejz s89r8tve r:cn6in(1ga z5rn oqnts 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 or( w2 clab6-jthat is homozygous for brown, long - o6 clra(2bwjhair and a female cat that has black, short hair.


Which of the offspring has a recombinant genotype?

1.Outline how polygenic traits can show a normal distributionqht+ (0.;1rohtd lovk.

2.Outline the differences and similarities between homologous chromosomes.

3.Explain why expected and observed Mendelian ratios may differ.

  Which gamete can result from t k k(lwdzq *u)kdur8g:)y9nn) he crossing over of non-sister chromatids shown in the diagram below? zgwd8 )k9( ) ukrl)*ydu:nqn k

  The photomicrograph shows a pollmxu c3f t4w/n yok5dnq74i; 7cen grain from L. candidum (Lily). Which stage of meiosis in74c4 wum 75yoxdnfit / ;c3kqs shown?

1.Outline the events which would lead to an individual being born with Down syndh;7etw .0* huvrshqll pg.m 7-rome, wh qhtmhg weh- u.7 0.7s;vlrl*pich is characterised 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 way of measuring plant growth. A studkpsmt,0pz t7p a01w n(y was conducted on white onions (Allium cepa), under controlled conditions in a lab, to investigate w zk,pa07mnpt(spt1 0 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 whii: njoi4/ 6td q)e.l ygf0 6+ltubf3urch cells can divide. The diagrams below show two cells from an organism with a diploid number (2n) ofd lt34i6 .on:iryt )g0 6eb luufq/+jf 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 gro,ewm4oslrq6hmpei fe2;+ * o.vm.zn,wth.

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 different stages kt*hv(+ 20gedbi: k jdof meiosis. Which rohi2 ktgv(0:dde*b + jkw correctly names each stage?

  The micrographs show four phases of meiosis I in a plant. In what order d/ v;)shquc/ dzt ;f ew-*gx5lro these phases occu/h/;;-flx5*crq w zde vgs)t ur?

Mitochondria are responsei0fmlw80 )ym r7- ,jcdtet +xible for supplying metabolic 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 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 reproductioe0ty)xm+i 87 m0el cfr-d ,wtjn 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 cefkxcnip)a x q-a..)(wh ks4 +fll cycle in four samples)c xf+ax(n)hs ia kf4-qp. .kw of lung tissue from four patients. Which tissue has the lowest mitotic index?

  The diagram shows the dominant cyclin/CDK complexes at different time umxqhc3 f9 b26points in the cell cycle. Which bx 29qufc mh36cyclin/CDK complex activates DNA replication machinery?

  Studies have shown that genes such as Cygtz; ;*mf);etv-q dhcm(5 in lclin Dependent Kinase 3 (CDKN3) are highly overeitc -e t;gq) zm;(*dn;fmh5 vlxpressed 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 during the cellph : t,p(vi/a5o5qj . nfibi;d cycle ?