The graph below shows the relationship between maternal age ans5krd y0)zi5dks2dc2d the incidence of non-disjunction. What relationship i05drz2k)k y 5cd2dssi s suggested by the data in the graph?

  Which stage of meiosis is represeaol *rp9/ dml -nnt*0u ,ft85sub)bconted in the diagram below?

  The diagram below shows chromosomes during meiosis. lrkq6w:1tl p8pka : -rnwx:u 1


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 k7nml8o ;pq .fevz0 d3./h7ajq)edrwof alleles of a single gene which would be present in the nucleus of a cell as a result of each procle.h.7m3j0eqa pd/f dno w )kr ;8vzq7ess?

  Which keyword is matched to the correct definition n.qo k4yiv 11c0w-w exwr0c1z?

  Which statement(s) about mis6:+9o6*i n o- q atnwxmixas+tosis 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, whi dd:4 5pc*wymgch letter points to a cell in anaphase?

  During which stage of mnaw3h)- a2na .ugu co3 5)ae ap/1vdtmitosis does the nuclear envelope break down?

  Which one of the following transportniq8+ ql ygmo0agr0( /)xmff:x5 /wlh proteins only carries out active transport?:5q rg8lanlf0o)+f wg x/yi0qmh(x/m

  Which process does not happen in th5qbv y xqs, ji/gewr+,q(+f:de shoot apex?

  Which type/s of membrane transport do/does not require energmf8yss g)gt 43cfo82xy expenditure?
I. Facilitated diffusion
II. Active transport
III. Osmosis

  The diagram below represents a cell wi ;3s( tls:fuqx5n,d enth a diploid number of 4. Which stage of cell division is thnxl ;e3ss (tuq fnd5:,e cell currently undergoing?

  The photomicrograph below sidff-p54 k8 ya2zjc1q hows a root tip meristem. Which of the following sentences correctl 418 fafq zpyk52jdi-cy defines a meristem?

  When does the random orientation of homologous chq+x ;t by*n- )p2yd.jvqlik 4wromosome pairs occur?

  Which process does not tals))2g8uz 8o9 alzk occur during meiosis?

  If a cell with a diploid number of 36 undergoes mitosis, 4lhp5d wy911k ffsgdmzco-4:how many chromosomes will be presen4my 1 oldwgfk -:1czs45h 9dfpt in each daughter cell after cytokinesis?

  The image shows a micrograph of a cellulh)3z1 /zu8n3nyag.iezs k8 .


What explains the appearance of the cell in the micrograph?

  Which statement(s) abougjrtntf5:mif2 u3db ch bmy3c3 .y9/*t homologous 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 indi9z(s*cvyx20xxc sow n lm47lt )/q s)kvidual with Down syndrome.

Which statement is not correct?

  In the cells of a horse (E. caballus) durin5q2z qs;bq(vh g prophase I of meiosis I there are 64 chromosomes. What is the hqv(q; 2b5zq shaploid number of chromosomes?

  Which arrow is pointing to azrbfeteg .-,uxl*z*h+ 2 w n0fl,;wqw chiasma?

  The diagram below represents the structure of a shoot apical meristem.zsyf )qu).x+g Which row in the table correctly identifies the processes occuring in the structuresyxsuz f.)g+ q) labeled in the diagram?

  How does meiosis promote variatio pnec+wxy lvg-e,t0 :.n?

  Which of the following statements is/are cos:m*s91 .fwq.myqcwh rrect 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 h,rte hi l:(3l3ni3l3puk j drac4v2 z.omologous 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 pwywilzqb*, cq.5ex ii(1*.nlq v(+y zrimary tumours as a result of the moveme.iq.yvln i1(ib +*zcq5ew*w qx,z (l ynt of cells?

  How many chiasmata are present i/gf 6tdt .5tl)sel*c zn the diagram?

  Which statement is a similarity bet6roq xm;,u oiegy1)1xween cytokinesis in animal and plant cells?

  Which stage of meiosis is matched to du73rxyp*,2q keur, n5i l3b uthe correct description?

  Which statement(s) are true of meiosis I but not meiosis o 6g o7itginya) f.9k09kqu (v8sy6 ggII?
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 i;sdu,km-evxh8, dcq ( 2;f 2zguor*lmeiotic division. This results in the formation of one large cell and one small cell. What is the fate of the large g(d ,c28k foe,-qu2xm;h drul ;z*siv cell?

  Which row correctly zzv+ h/hm;f c54j *: 7wrstlfjdescribes diploid and haploid cells in humans?

  The following table shows the diploid chromosome number of a range of species.3, dnykc5 ep gysq ko4h;mr)-6


Which of these statements is correct?

  What conclusion can be drawn from the karyogram bjqeise0wkr7 u ,q-:8m elow?

  Which of the following processes is charactpg ws gpv5g yr1c6gsx)u90rpda7(1 xdar 8u7-eristic of the meiotic and not the mitotic cell c dpu7u- gp5gxrx0gsr169)cv8a1y( rgp w da s7ycle?

  The diagram represents a bud with a shooy b i9g 8m485vbq;unpklvhb*. t 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 troglodytes) is 48. Which row sho/3qtn4v w - ofs 4.ep5hh7yn mkxpp7/bws the correct chromosome number for different cell types and cell division sty5/hx3.ehp kntv7-np7w/ fqpsb4m 4o ages?.

  At the end of which phase of meiosis I does cross v(fh7*:rj ccu9, sjwwing over occur, and what is the outcome of crossing ovvh:s9rw c , jc*w7(jfuer?

  Which of the following statements does not describe a step im-pm ;k+-h*w iryewaitg ;.-yn the sodium-potassium pump cycle in the neuronm t+wi-k hmy-pya-eg;.;r*w i al cells?

  Which row in the table below is true oa-z 8jwv7z x0vf meiosis?

Membrane transport is important for alld0 j.g: - agydlbsp1*hxr;je1owing particles to move across the cell membrane and respond to changes in the chemical composition of the extracellul0l1gpg se -r1dd.j:b x j;*hayar 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 cells.g/bi ng3w .crdti;0u+

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 t2(syd f5g h55dp7m s0qvjf h5concentrations of different cyclins during the cell 5y tg(fpd 0v57 jdsh 5m5fhqs2cycle. Which cyclin is involved in preparing for DNA replication?

The diagram below shows chj6bpy9ysp ; ,-:sijyh81lggqromosomes 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 inwag 8l 8pk3st4ma m2fmpjom 5b3t6/) 2pdjl) cvolves the separation of homologous chromosomes?

  The mitotic index of throat tissues takk3vt7qqg2tanh * db,-vo,w ,w en from 4 different patients is shown below. Which patient is most likely to have cancerous t tqhvk w2b* tvdwq7 3-ona,,,ghroat tissue?

1.Draw a labelled diagwzhe63ur;x)5, jdy(j 7i erhnram to 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 h3npooz2j s93z0wx yus k-*r:wuman karyotype.


What is the abnormality in this karyotype and its cause?

The graph below shows the relative amount of DNA in one cell during one completeg ny(-/gtzq h(6gs sj*x0 uch id1cp2- cell cycle. Each letter represents one stage of the cel*uh1-itqyp-zn g c d2jcxg60 s(g(s/h l 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 jsh*n4nj+u2spozg 9j30i9q erq 6h8 ed 7-mcw between a male cat that is homozygous for brown,j7e4 09ozmnqsnjuc d se*i 2 hw3j6hpr8q9+-g long hair 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*fxzdbfas00//h15 k y7t ljdc 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 chromatid5 r2o n;ut6cg6 ex0zgcs shown in the diagram below? z;r2cungt06o e 5xg6c

  The photomicrograph shows a pollen grain from L. cand3/s :p- g o *ggmf1tduam/unx,idum (Lily). Which stage of m so,ax-/mgpd3gt1gfuun /:m* eiosis is shown?

1.Outline the events which would lead to an individual being bor6bog691qdf qt kv0d-bn with Down syndrome6 0bv6- 1bfq otkdq9dg, which 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 plan t)(ocu4-ubuubf1h ,wt growth. A study was conducted on white onions (Allium cepa), under controlled conditions in a lab, to uuu t-1)wf, c4 o(bhubinvestigate 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 cellubtur(7 a5 xxent zvzv*cw7ky;2/..v s can divide. The diagrams below show two cux27.(. /k 5zb*wtvrvxe c yvzna 7;tuells 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 grozll7.n 94 b:,h ghyjz*x 4sdyuwth.

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, wik aieue23e f,hi/ /7ybscti.p ,kb a28th a diploid number of 8, in different stages of meiosis. Which row correctly namepe8/2u3c iy7skfe2b b/ i ,a, a.thkies each stage?

  The micrographs show four phases +gt8 j n: le7okn:)d(sqb4ekkof meiosis I in a plant. In what order do these phasqlk4sge:onkndb7+ jte ( :8)kes occur?

Mitochondria are responsible for supplying metaboli,jl aw:x 0auk6ldx 4)rc energy in eukaryotic cells. In most eukaryotes, which reproduc x)4xwd, 6u 0ajakr:lle 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, 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 differen*758c *sp hz7xk/zpp i 6zpqxyt stages of the cell cycle in four samples of lung tissue from foz6ph5 p/p7ixz xsc*z qp*y7k8 ur patients. Which tissue has the lowest mitotic index?

  The diagram shows the dominant cyclin/CDK complexes at dif9z s4 c3 4hniv8xd4pp0on jl6g(old w/ferent time points in the cell cycle. Which cyclin/CDK complexdlzd483n4os/6cx(lvph no j pw04 i 9g activates DNA replication machinery?

  Studies have shown thgi bl/6 jo8f-( gg;mv3/udty povu(.l at genes such as Cyclin Dependent Kinase 3 (CDKN3) are highly( uopv6btfd;u ig//gjy8gl om-v(.l 3 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 concentrat st* :n::60pscexoogi ion of cyclin E the highest during the cell cycle ?