The graph below shows the relationship between maternal age and the incidencea ap ;)s8y/mc z3f)ufrcorw 2ty5m.7l of non-disjunction. What relationship is suggested by the dm8f ycy7trm;fs )pal 3uz.wcr/oa)2 5ata in the graph?

  Which stage of meiosis is representeddrhow: 3.vr5m in the diagram below?

  The diagram below shows chromosomes durirxrlo ,ov: 4d3ng 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 state 4se3d 6 m-hvvuojzh 2e ,w hz6f;eu;zpfa;82ts the number of alleles of a single gene which would be present in the nuclev a3fmhou;z-edjs,vezfp48;6 h whet 2u; z62us of a cell as a result of each process?

  Which keyword is matched to the coq,cc azn (6h/vrrect definition?

  Which statement(s) about mitosis is/are true? (b yf1d8q( c*qjshzz5
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 letl7 du r3ph l.5o4,e+ujgmgvy*ter points to a cell in anaphase?

  During which stage of mitosis does the nuclear envelope breawpn /drt)sygc:6lh49-r u/ps k down?

  Which one of the following transport proteins only carries out active transpor+dr .m/f9sik qt?/sqf.d kimr9 +

  Which process does not h*kpg)zh-0 tfm s3xkxqj+ -3qj28 9hpmzbp2mhappen in the shoot apex?

  Which type/s of membrane transport do/doeslzk)u68+pkvl h v*h;2l3ec qt 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 st; z.)a zghyk;cage of cell division is the ce)z; a ckg;hzy.ll currently undergoing?

  The photomicrograph below shows a root tip m sgp7r*0dc. n,8cox rreristem. Which of the following sentences correc npgro xrd,c*0 87rsc.tly defines a meristem?

  When does the random orientation of homologous chromoso , ez)q8dfqszddl/t 6*me pairs occur?

  Which process does not occur durvn,llgan)s 2v s7yo +)ing meiosis?

  If a cell with a diploid number of 36 undergoes mitosis, how many ch5son7k 5k8 hsaromosomes will be present in each daus7s 8anho 55kkghter cell after cytokinesis?

  The image shows a micrographg hgl zx6q6pgh+pq4if(w:a ;, of a cell.


What explains the appearance of the cell in the micrograph?

  Which statement(s) aboutd w52 c6e*/fw*3 d mkh4jkxfie 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 individual with Dow 7n x+sl96wuwnn syndrome.

Which statement is not correct?

  In the cells of a horse (E. caballus) during prophase I n+ozpl 1+rk75sg9 uomof meiosis I there are 64 chromosomes. What is the haploipr l57g9unm sz+1 ok+od number of chromosomes?

  Which arrow is pointing to a chiasmbm4 wfa(a;ax3 a?

  The diagram below represents the structoo + :bstyv8 x-q6 i4/sv:vgfaure of a shoot apical meristem. Which row in the table correctly identifies the processes occuring in the stxs:g/ 6q-8sti vobvfv o+:y4aructures labeled in the diagram?

  How does meiosis promote t9qp-c-* w++fw 7k5kjjebeni variation?

  Which of the following statementsv:o/ kx;e-0my:v qyqk 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 gametes produc hi(qk+5 fv:zped 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 describes70 qtd9t hyj(x the formation of secondary tumours from primary tumours as a resul9qt jt0x7y(dht of the movement of cells?

  How many chiasmata are prdc3cg8 0koun h/pwa 7:esent in the diagram?

  Which statement is a simil(mh q88 z v4py0lkirhtyr1 y-*arity between cytokinesis in animal and plant cells?

  Which stage of meiosis is matched to tjdk9pz5w17 cz he correct description?

  Which statement(s) are true of meiosis I but not meiosis ax u3x;zzyhvzg8 )q -y v/o7o1II?
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 b*:u0vhde3k hsnbf;i r+*h)xoocyte after the first meiotic division. This results in the fh*e is; *:3+hrxvb bdu)kh0 nformation of one large cell and one small cell. What is the fate of the large cell?

  Which row correctly describes diploid and haploid ce bnu 8y7t1amb+lls in humans?

  The following table shows the diploiy rhwtj1/pcbgo ol(4d l .:e*+d chromosome number of a range of species.


Which of these statements is correct?

  What conclusion can be drawn fr:7s7jlymh; nn(dai 7kj, ukr1om the karyogram below?

  Which of the following processes is characteristic of the meiotic and not t6r6y, 6 rvkii+ yby-ic s+5synhe mitotic cell cyc-n v yi,5bi cy6i+yy6rs6+r ksle?

  The diagram represents a bud with a shoot apical m 33sl4snac0p h2y7 useeristem.

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 shows4p sc;l0rt4r etymb.1k5nyc9hm +ji3 the correct chromosome number for different cell types abp3ny44k. l rcy1;jsir5 ct +9etmhm0nd cell division stages?.

  At the end of which phase of meiosis I does crossing over occur, and what is ther629u cln;b a48(drlu2yv jf/ nmsc 8h outsjcmb(/8h 29 d24;uu6anfvlc nrr8yl come of crossing over?

  Which of the following statements does not describe a step in the sodium-potac8g2qb;kfwn1ntywd-2e9 rq e v.zb;9ssium pumbg 29;dq-nzbn qc2e 8tf.rk9we1y;v wp cycle in the neuronal cells?

  Which row in the table below is true of meiosus8ubx6,xe2wew8 yr0h pa *1vis?

Membrane transport is imnn j*a+6 vkal 7kyhm4k7 km(i9portant for allowing particles to move across the cell membrane and respond to changes in the chemical compomkj6(* +kah9lkyn 77n viakm4sition 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 i0dqx; t :ed+xas 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 concentr 4h x)jl,1i) usewfax9ations of different cyclins during the cell cycle. Which cyclin is involved in preparing fohjl 4,xux )as1 )fwie9r DNA replication?

The diagram below shows chromosomes during meiosis.x9mkb(zv 9d/ f

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 homologou( (bnw.d,jq ers chromosomes?

  The mitotic index of throat tissues take xl;o j) )vzjnye59h5yd a1lx6n from 4 different patients is shown below. Which patient is most likely to have c)a1x5nhy ; zxj d65l 9yveloj)ancerous throat tissue?

1.Draw a labelled diagram to rep-j-mfbbu87 nolj,ld7ntm8 v*resent 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 humanbwd,96i+ 1rwbyb+vxp karyotype.


What is the abnormality in this karyotype and its cause?

The graph below shows tht+/c ks x1d9j0nt)dkixa: 2ihe relative amount of DNA in one cell during one complete cell cycle. Each letter represents one stage of th9/x 02is)n1ahktx:dik+tjd ce 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 that is how 1sxucl;0bw7j*s2t wmozygous for brown, long hair and a female cat that has bl;* 7u1cb02tw wswxs jlack, short hair.


Which of the offspring has a recombinant genotype?

1.Outline how polygenic traits can show a normal distribution...nsjahg 7 fc2

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 chro mgj;mt6ks a,74rtt,umatids shown in the diagram,sta4 kutr7 ,m6mj;t g below?

  The photomicrograph shows a po87zi4z/8a u 7grongyqo o8a1d6b v(bwllen grain from L. candidum (Lily). Which stage of8 z8qag(/z rio bbwy6g4nu871 a7ovdo meiosis is shown?

1.Outline the events which would lj ptkc4 12,tyvead to an individual being born with Down syndrome, which is chara p kt2jy4cv,t1cterised 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. A6hqwelr1tl -.yv +2s g+u)epo study was conducted on white onions (Allium ceg orp-1sevylhw6eq l2 ++tu) .pa), 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 are two ways in which cells ca2 h e7i htoj r+a0vf;8jtd48-ilg 2nqd 2ml:unn divide. The diagrams below show two cells from an organism with a diploid number (2n) of 8. h0dl8fjetg udt 2r :j7lv2mqi4hoi; -8 n+ a2n


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 ex3japab +52+z-w,u wzqffk)mapression in stem 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, in differeola9ycxo1d+;f 8; zh4yhef,a nt stages of meiosis. Which row4o;,;x ay9az codfl ehf81 +yh correctly names each stage?

  The micrographs show four phases v 2xjv9kb2qd wl+putv;*g3z7of meiosis I in a plant. In what order do these l 3v7 jk9+wd t*2; gpzxvq2vbuphases occur?

Mitochondria are respondyl)rh1c0 sxxx8. w w;sible 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 reproduction between two different yeast species, could be influenced by the parent’s genetic backgrowcx ryd.;)1 s0xh 8lwxund.

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 stagezv2vk:yghh jvs q9jm411e(f/ s of the cell cycle in four samples of lung tissue from four patients. Which tissue has the lowest mit12:vk4/ 1zfeg jqmh9(y hsjv votic index?

  The diagram shows the dominant cycliutv(qq b/e5i.q 5chg i)5 6ywdn/CDK complexes at different time points in the cell cycle. Which cyclin/CDK complex activates DNA repl/6v qh.ugeb5 qi cdq wty5)5i(ication machinery?

  Studies have shown tha2l d o j fq5mln9gkenf;:s5.)yt genes such as Cyclin Dependent Kinase 3 (CDKN3) are highly overexpressed n9d .jg; oklymfnefl:2 )q55sin 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 t3vqs0hlx3mq+ityn(7 p9 ;ik xhe cell cycle ?