The graph below shows the r3vyz7ut7 zdcj 3buz 7* lcsdrk+98x*eelationship between maternal age and the incidence of non-disjunction. What relationship is suggested by the data ubk *7 *8tsezzj3c7ldczur3 +y7 v9dxin the graph?

  Which stage of meiosis is represented in the m-hg6a eo.rm9diagram below?

  The diagram below shows chromosomes during ia+f,f qb+9cz6s t;ehs:yk g*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 axs4r*s oo1hr/rpda:5k.et .u lleles of a single gene which would be present in the nucleus of a cell as a result o/rdo.r hasou54 xt :kr1p*s.ef each process?

  Which keyword is matched to the correct definmv c7ssh9abjm; 4gojy5 1:rn0ition?

  Which statement(s) about mitosve 8ah6 w,2p uao: wi8:z5mkidis 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 tg7rqi) 0ipgk;f c.qvx0+2v aho a cell in anaphase?

  During which stage of mitosis does the nuclm(a f+,qlyfl/ ear envelope break down?

  Which one of the following transport proteins only carries out activ 8rrk5 )fu)qg.tqwhrk-s b92le transport?g5r-q) r8b)kqwh rukf.9 lt2s

  Which process does not happen ( 6 m(d.yw)yw; vhdgkw;bgqu-in the shoot apex?

  Which type/s of membrane transport do/does lq9 ts4z7qt d7e: ak28 qv0dgqnot 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 3ndl:7z rup :eb83syvof celle7r zy : v3n:3uspdl8b division is the cell currently undergoing?

  The photomicrograph below shows a root tip meristem. Which of the follow t8zw7narc6u 3ing sentences correctly defines ac8wn6u 3 aztr7 meristem?

  When does the random orientation of homologous c1faj8;oa4 ufe hromosome pairs occur?

  Which process does not occur during meiosis 7o baz,r) x.aj:3jcus?

  If a cell with a diploid number of 3a,cfnu 6y f 3ujwgx-+26 undergoes mitosis, how many chromosomes will be present in eacx,gjufy36+w u ca-2nfh daughter cell after cytokinesis?

  The image shows a mi63(f djbmtno/6 wk:wp .h(ltp crograph of a cell.


What explains the appearance of the cell in the micrograph?

  Which statement(s) about homolog2l; 6ab :zzxslous 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 wi/u0t*omhpls : j+ )rvzth Down syndrome.

Which statement is not correct?

  In the cells of a horse (E. caballus) during prophase I of meiosis I thebuu kvl5d9zo9r1o 061 v5 kbmyre are 64 chromosomes. What is the haploid number of v6z1ukbr9oy 51lvd om5u9 kb0chromosomes?

  Which arrow is pointing/t*u pz .t9k/ufc9xp6g i- dydgz :rw: to a chiasma?

  The diagram below represents the strucp w.)t2srd1t eture of a shoot apical meristem. Which row in the table correctly identifies the processes occuring in the structurese r2t1)p.sw td labeled in the diagram?

  How does meiosis promote variatioa92g79rq. 9vu4twn w bb4m dcxn?

  Which of the following statements is/are correct for mfd em34+7 s8i veg:orieiosis?
I. It is a reduction division
II. It involves random orientation
III. It produces genetically identical cells

  The diagram shows gametes produ ;h( +lj jvm8pdxlr8 sob4sm7v(e; c3lced 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 describes the formation u q,/b.ed0 desof secondary tumours from primary tumours as a result of the movement of ces0qd eeb ,/.dulls?

  How many chiasmata are present in the diagramkibx p 2 f7gjmd3-kq6;u g8m+q?

  Which statement is a4tx-.6zec nydnmh fe+b:3i i : similarity between cytokinesis in animal and plant cells?

  Which stage of meiosis is match4z6h2 wm 5i qvu()ppnzs*7 q.-q(ete0 unbxwqed to the correct description?

  Which statement(s) are true of meio8xg x4kmt 3 2m9zg1g0t(qcn lusis 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 division. This results 0 plr 8yrv--r ;kj h*prva0s1uin the formation of one large celv1rpy08r*jvr r a-sp lu h0k-;l and one small cell. What is the fate of the large cell?

  Which row correctly descrpnzko)t46 o -kibes diploid and haploid cells in humans?

  The following table shows tbhkz :.dw ;v 8bow4wdx4-:cco he diploid chromosome number of a range of species.


Which of these statements is correct?

  What conclusion can be drawd su)z g57n/hvn from the karyogram below?

  Which of the following prof 09*vhrovgi l*z2njg 7iqbj. 5 0j9vlcesses is characteristic of the meiotic and not the mitotic 97bg* ii oj vn0qjz5 rjvvfh.9l*l02g cell cycle?

  The diagram represents a 2mjyfdu o- c0 h8rk8l6bud with 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 troglodytes) is 48. Whichy 3. cepzj+z0bn+m:mm row shows the correct chromosome number for different cell types and cell diviszm ben :jc0m3pyz.++m ion stages?.

  At the end of which phase of meiosis I does crossing over occur, and wh h yb pr3ncrmn)4.1 :4hoqisy7at is the outcome of crossing b:p73m4nyrn1chrsoh 4yi . q)over?

  Which of the following statements does hz+ +yyrs69 jwnot describe a step in the sodium-potassium pump cycle ijryh++ w96zys n the neuronal cells?

  Which row in the table p01(q bunitvurj-qr;a r rh8/7:,iyq below is true of meiosis?

Membrane transport is important for allowing particles to movefb pf oyga7 q*mti/ 79+kx:5k73exeei across the cell membrane and respond to changes in the chemical composition of the extracellulg +oe:f k7f7k 3ey5*79meax tx/iibq par 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.gd ..3wtm kqz1

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 different c-eaorjj w8g03rw- v ,zyclins during the cell cycle. Which cyclin is involved in preparing for DNA replicatior3 ajgowr 8-0v,j e-zwn?

The diagram below shows chroouen h0 4qf+0gmosomes 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 separation of homologous chromof 3+da/t 5xavii.mde53 ewi v;somes?

  The mitotic index of throat tissues taken from 4 6tle3 :lqr. ;-osqkxt6 zdcx )different patients is shown below. Which patient is most likely to havesc qlo)l3kr 6:q6;ztdxx -. te cancerous throat tissue?

1.Draw a labelled diagram to represent the process of crossing cwog1oe) w8r +over.

2.Compare and contrast random orientation and crossing over.

3.Outline the stages of meiosis.

  The image shows an abnormal hbn u 148vd70i pzjnqi(uman karyotype.


What is the abnormality in this karyotype and its cause?

The graph below shows the relative amount of DNA i1dp3 -; t 8*hzxe)j6mbkudlr fn one cell during one complete cell cycle. Each letter represents one j h )z31mde u;l68-f bkxdt*rpstage 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 that is homozygous for brooi7 xbjv 2y5wu2s1uy p 6e l0,nrdjy/6wn, loox5 vjur2,yyl7db 2 1 /06pun6eiswjyng hair and a female cat that has black, short hair.


Which of the offspring has a recombinant genotype?

1.Outline how polygenic traits can 9gn6q10s jhu/kn i.de 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 dhnqf o 6.3vc8.e)d x.c/pxcpnon-sister chromatids shown in the diag3pcch )nd .6xeod8/.x.qcfv pram below?

  The photomicrograph shows a pollen grain from L. candidum (Lily). Whe325ch )tyye zich stage of meiosis i2eyct e) z35yhs shown?

1.Outline the events which would z9/b e nhul7.-bznt -dlead to an individual being born with Down syndrome,n/7ztb-bue zhl n -.9d 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 indirectz 9sym8:c rg/j way of measuring plant growth. A study was conducted on: zjrm c9ysg8/ white onions (Allium cepa), 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 t(98h8y+t+ 9i*azlr gxk up xrqwo ways in which cells can divide. The diagrams below show two cel8p+ (+zr8t*axxgyrhik9ql9 u ls 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 r3l5/ ufl0lip7o ctw* gene expression 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, if *egp)z9.cmsod0 6)t k3thepn different stages of meiosis. Which row cez6mc .o*g tks)ppt9d)f3 e0horrectly names each stage?

  The micrographs show f+ pa*t;n*sdfz our phases of meiosis I in a plant. In what order do these phasesdpnt*z *s; fa+ occur?

Mitochondria are responsible for supplying meta9v0su(;f2wsjchw) d y mvn-gk;(v r, wbolic 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 reproductios,hrunv ( -w j2k) dymfg0v;9vs ww;c(n 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 cycle in 4c6,hy9p5 ii qrxrp3tfour samples of lung tissue from four patientp, q4 yc rpi6ti3rx59hs. Which tissue has the lowest mitotic index?

  The diagram shows the 7w4j tyv6i qm66*mzbtdominant cyclin/CDK complexes at different time points in the cell cycle. Which citm4 vb7w*66 m6jytzqyclin/CDK complex activates DNA replication machinery?

  Studies have shown that genes such asc: b oa08vsv) u)3qu)q rcr+lj Cyclin Dependent Kinase 3 (CDKN3) are highly overexpresse as)+jo):rr cl0)vbqv cu8q3 ud 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 hig 6s.bhs: 7susihest during the cell cycle ?