The graph below shows the relationshit3x)unco 9 +a vrp,4obp between maternal age and the incidence of non-disjunction. What relationship c4a3ro xbpvn ) 9uto+,is suggested by the data in the graph?

  Which stage of meiosis is represented in /nhc 9;nxw6pwiva)d+ the diagram below?

  The diagram below shows chrom 818/umrgqxstj s6i +oosomes 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 +bw63icy vbb-x c:4et2 5 np2wwo:a*xirau)cof a single gene which would be present in the nucleus of a cell ::xw6iatwu vwi2 yo5e)4 *bc n+a b3b2c rp-xcas a result of each process?

  Which keyword is matched to the correct definitioni -yej23(h hfh?

  Which statement(s) ab6a x- ra.v ozd6ld6:zxout mitosis 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 a cell in anaphairn4.2+io1sjjc9p3tm:*yly 7z cij0e dx vq 1se?

  During which stage of mitosis in+r 5kmemgwv 2)u*h;does the nuclear envelope break down?

  Which one of the following transport proteins only carries out arw dd*q9k ;sybhqiry)oln -16g7e75dctive transport?67-dk e y7r rgqnobhy *5ql)d9; d1isw

  Which process does not happen in i./ipewd, p 7sws kk7.the shoot apex?

  Which type/s of membrane transport do/does not require biidu sw7aqjptuk1 q.;9:a19;t j,qq energy expenditure?
I. Facilitated diffusion
II. Active transport
III. Osmosis

  The diagram below represents a cell with 7kg ch:mz-iut 1oypgfw1; -k 0a diploid number of 4. Which stage of cy-zfwp:-iu1t01ckgh kom7g;ell division is the cell currently undergoing?

  The photomicrograph below shows a root tip hrbp bdw;h9 dm+b9 k5j64a9snx*cx y1meristem. Which of the following sentences cor4j9 babcd*;ws p9+b6y r5k 19n hxdhmxrectly defines a meristem?

  When does the random orientation of y ,n0yedg.he9 ze- h-uhomologous chromosome pairs occur?

  Which process does not occur during meigemo -( injtci0g 2 +ny8i1b/sosis?

  If a cell with a diploid number of 36 undergoes mitosis, how many :whji4x0czj58 / i7m *x iwjkschromosomes will be present in each daughter cell after cytokinec8 s54*x/mjikjjw 7x:iz0i hw sis?

  The image shows a micruj blbh7- /dt fde2)*p.dua-i ograph of a cell.


What explains the appearance of the cell in the micrograph?

  Which statement(s) about homologo-)dlec t3 ur5dus 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 wib):fpz5t:)zd,ye9g )fo ju hc th Down syndrome.

Which statement is not correct?

  In the cells of a horse (E. caballus) during prophase5,)c yawiwzk: I of meiosis I there are 64 chromosomes. What is the haploid number o,:cw5zw)yak if chromosomes?

  Which arrow is pointing to 8,)u3yf yk5cvm s2gvl a chiasma?

  The diagram below represents the structure of a shoot apical meristem. Wp tz8ki xwud/ep9d ;o sw,36f:hich row in the table correctly identifies the processes occuring in the structures labeled in8ufp9k/ew,:;z dp dt6x sow i3 the diagram?

  How does meiosis pro*w mta:aoot/8 mote variation?

  Which of the following statements is/are8(onehi 0 xza 8nh1)lj correct 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 homologous chromosomes. my7br9c* h 6qq


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 tumog y .84u(oneerd t0zd+1nvar1urs from primary tumours as a result ooued+ 1vadyg4(trzn0er1n8 .f the movement of cells?

  How many chiasmata are present in the diffm*x1 lp (. jbf)adi,5rcoclb(1oo+agram?

  Which statement is a similarity between cytokinesis in animal and plant ce0hk j1vdn1cf+ig*zvat 44 k1)evyoz(k.h r u *lls?

  Which stage of meiosis is matcht .+ vx)x8e7)nj*gmh8m uvvrxed to the correct description?

  Which statement(s) are true of meioatd5ijnmmdq:x )+hqb(s9g , n (q3z+x sis 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 afb5c -;7paanq6z goa8s ter the first meiotic division. This results in the formation of one large cell and one small cell. What is the fate of the large cell?a 75 bacg-qzs;6o8npa

  Which row correctly describes dipl +udk nxfg2)q5 ksb;9eoid and haploid cells in humans?

  The following table shows the d ffe79c3 bes ,flz8m9tiploid chromosome number of a range of species.


Which of these statements is correct?

  What conclusion can be drawn from kzkei m6:hu*+j ., 65qkfy9yguvka v)the karyogram below?

  Which of the following processes is characteristic of the hq* ta j)i eszku1(5p.meiotic and not the mitotic ce au)z i(hkqsj.1 e*tp5ll cycle?

  The diagram represents a bud withc p f 5zdb).jm4y0s8hlows47y a shoot 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 troglodytf+pk*j/q ip0tes) is 48. Which row shows the correct chromosome number for different cell types and cell division sk ijqt+ */f0pptages?.

  At the end of which phase of meiosis I does crossing over rjvg :6 .iqe6ooccur, and what is the outcome of crossing ov.eo6 g6ijrq: ver?

  Which of the following statements does not describ8up61e bi dtl(e a step in the sodium-potassium pump cycle in theie8ub dp t(l16 neuronal cells?

  Which row in the tabljb*4tluxc80fi6 n9j p e below is true of meiosis?

Membrane transport is d.jhpq8 fh thb (g-4 m9*i1va;3lstrf important for allowing particles to move across the cell membrane and respond to changes in the cheihgjfarh* (4qth .tp9l;8m - s3vdfb1mical 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 regulated in cellh 2+3(ir 7alj pf6cdtxs.

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 cooav2c e+ xj53qncentrations of different cyclins during the cell cycle. Which cyclin is involved in preparing for D5+ae voj 3cqx2NA replication?

The diagram below shows chromosomes during meios3y9ybj x2bo/o r:ek4sis.

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 homolnu/ zwo1x-hr(hk,2hu ogous chromosomes?

  The mitotic index of throat tissues taohaz8mw i:1/;e aw mp7ken from 4 different patients is shown below. hpa mamw71o/:i;z we8Which patient is most likely to have cancerous throat tissue?

1.Draw a labelled diagram to represent :/bph+s u 4-xz+eyu withe process of crossing over.

2.Compare and contrast random orientation and crossing over.

3.Outline the stages of meiosis.

  The image shows an abnormal human karyotype...y7x2tg(dj h v5us xxyh9,qh


What is the abnormality in this karyotype and its cause?

The graph below shows the relativr13gryozs,a2) 7f-xoc i 0x qee amount of DNA in one cell during one complete cell cyclxa)-f3q s1 7ogi rxorz2,e0cy e. Each letter represents 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 k-ng+ 8gi.zx /sim9 ju +j5gema cross between a male cat that is homozygous for brown, long hair and a female cazkm 8inmsg5+-.gj9+/ u xjiegt that has black, short hair.


Which of the offspring has a recombinant genotype?

1.Outline how polygenic tdp 1o qg;ht.lx5o( 8tiraits 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 resuldl f*g,50l6 3sw9r;ytuifvzy9yi / vj t from the crossing over of non-sister chromatids shown in ti0f6yy5*3wlf s9 j 9vz;lu/r vitg yd,he diagram below?

  The photomicrograph shows a pollen grain from L. candidum (Lilx)oq1 uhw 0ipds16ag+y). Which stage of0uo6)+ 1p 1wq shixadg meiosis is shown?

1.Outline the events which would leadq 885irk4f nan to an individual being born with Down syndrome, which is characterised byrn8i5q48n kfa 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. tk4dy.jyj)kl,h ejg +9/t4v0ieh : naA study was conducted on white onions (Allium cepagj j.alhi 449 kh+t: ,jy key)n0/etdv), 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 can divide. Thx(e0nqxjh,;6 w3 fej)tgo t:ue diagrams below show two cells from an ;e 3x) t,nj(fq :je w0gt6uxohorganism 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 express/nk m/,q .rgw0 c/8ynis(zkt fion 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, 3 p8)v1 rbqs/ovmi)xdin different stages of m) 8irb/ s)d31qompvvxeiosis. Which row correctly names each stage?

  The micrographs show four phases of meiosis I:b6p+w lglbqh btj 82(lf0k t6 in a plant. In what order do these phases2bbwhg 6 l6klft:t +qpb0(lj8 occur?

Mitochondria are responsible for supplying metabolic ecs q(1k tzm.a;3 m)sdrnergy 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 or(.; tmz rkcsqdas)m31 ganisms, 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 different stages of the cell a+osh 2pb f;*;+v axeecycle in four samples of lung tissue from foup ovbf;e*h+x ea; +sa2r patients. Which tissue has the lowest mitotic index?

  The diagram shows the dominantl/-7zhfgef: atucrn5 wx4)8 v cyclin/CDK complexes at different time points in the cell cycle. Which cyclin/CDK cov - /z4u8)ga5t7:hflfnwe crxmplex activates DNA replication machinery?

  Studies have shown that genes such as Cyclin c;nyj(7 t(f o dvhst2ln xcvng85,-v-Dependent Kinase 3 (CDKN3) are highly nnfv vn- ,-(5(ycg2hvc8sj l x7tot;d 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 g. udowg3)pi 8ack- s89k-miahighest during the cell cycle ?