The graph below shows the relationship between mater0s ai:ndvh68a nal age and the incidence of non-disjunctionvsaha:d86i 0n . What relationship is suggested by the data in the graph?

  Which stage of meiosis is represente6t/rha zj qp0 w9u40ynd in the diagram below?

  The diagram below shows chromosomes during x. 3iwsvd0 kz9meiosis.


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 alle g)g +7u1pjffzles of a single gene which would be present in the nucleus of a cell as a res)u7 +1zggjffpult of each process?

  Which keyword is matched to the correct definitioxl4q :zhgo15ln bwm+osp;l:(p35i enn?

  Which statement(s) about mitosis issi0:odp(0 q:7a(+xz pbp b5g rnr.ct m/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 l 9 ,tps6uent 8u-pbf1hd8 4itietter points to a cell in anaphase?

  During which stage of mitosis does the nu3 2mrhr ibh .v8df 6.mqt5g)t-mlzyh7clear envelope break down?

  Which one of the following transport proteins only carries oubv 6v-rio9 qq,t active transport?r-vqv,qi69 ob

  Which process does not happen in bm +0 i *7mggx)pjfjk;the shoot apex?

  Which type/s of membrane transport do/does not require energy expeybjh2he knqjdrm * hm*oh*/i2v.4; ; qnditure?
I. Facilitated diffusion
II. Active transport
III. Osmosis

  The diagram below represents a cell with a diploid number of 4. Whicbdz/8g8vjd . wh stage of cell division is the cell currently undergoin8g/ zd wj8vb.dg?

  The photomicrograph below shows a root tip meristem. Which of the following )yicv8p38 rei/6 qkj0w 3rs prsentences correctly defines a meriste 8rsje 0iwkrppy)3 8ci/r3q6v m?

  When does the random orientation of )6*pxj y 7hwv)xzrbw;homologous chromosome pairs occur?

  Which process does not occur duribi(5r98x a,7r1 bdvtxz cdnd0 ng meiosis?

  If a cell with a diploid number of 36 undergoes mitosq ouqf:8m):e )x0vofpis, how many chromosomes will be present in each daugh:mqoe)f)vx :8 upfo q0ter cell after cytokinesis?

  The image shows a micrograph of a ch 8lss;jqs+ /s0v i3slell.


What explains the appearance of the cell in the micrograph?

  Which statement(s) about homologous chromosomes is/are nsva:hjcj9(c kf/nw; ag - y13s6 s0epoot 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 syndrw297 )-gpigb lq0pyspome.

Which statement is not correct?

  In the cells of a horse (E. caballus) during prophase I ge9 ;xx*1 rgpduln)t8cjl. f) of meiosis I there are 64 ;. t 1xlpgg*dl)8 jnucf)e 9xrchromosomes. What is the haploid number of chromosomes?

  Which arrow is pointing to a chiasma?ft2u0 p mi9/znxso52t

  The diagram below represents the structure of a shox1kne ko7-4:q.bp ihl atbc/t:;fb b 2ot apical meristem. Which row in the table correctly identifies the processes occuring in the structures labeled in th:1 t t7eco 4hfqb.apb;ibkx l:k/b2n -e diagram?

  How does meiosis promote vari9j f hd4p1sae8ke*/otfu /5sgation?

  Which of the following statements is/are correct for meiosis?ws-e dqu lb;y g.98z31zonb( e
I. It is a reduction division
II. It involves random orientation
III. It produces genetically identical cells

  The diagram shows gametes *k o(7by9aowzproduced 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 of secondary tumours from primaqc (o8sg dw,:g ;rgl0r)vqq8r ry tumours as a result of the8:0sv ;qgqwg,r g)ror ql(8dc movement of cells?

  How many chiasmata arek- (oec /6oeda present in the diagram?

  Which statement is a si mmlvl88 t/+tft)swk8milarity between cytokinesis in animal and plant cells?

  Which stage of meiosj0sx4 eudouhgvf hfc759 d7)4is is matched to the correct description?

  Which statement(s) aregt7x /l:r 0yts true of meiosis 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 fw1yvo8 fe 1l6first meiotic division. This results in the formation of one large cell and one smal 1fye61ow 8flvl cell. What is the fate of the large cell?

  Which row correctly describes diploid and haploid cj 285z2svd)egb c0pvuells in humans?

  The following table shows the diploid chromosome nu.5c5v ug*5y: *nj d rcss/wugember of a range of species.


Which of these statements is correct?

  What conclusion can be dr,hk6n,vnp d ikqq:,h5hs3f s-awn from the karyogram below?

  Which of the following prx 26wpvuf ,5dx9n. yov5ek8zkocesses is characteristic of the meiotic and not the mitoticv6y2n xkp5vxukf 9wz ,de.5o8 cell cycle?

  The diagram represents a bud w a/.:ck9ad oddith 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 tr mzx*8nkzfne2+e gy-9oglodytes) is 48. Which row shows the correct chromosome number for differen mg 2yneez-zk9fx8*n+t cell types and cell division stages?.

  At the end of which phase of meiosis I does crossing over occur, and wha.4uo 6 ng .lhw6+morjdt is the outcome of crosn .mgwl6dru .o 6j+ho4sing over?

  Which of the following stanub.0qpy2kmzv;/ ; r k*cq yj;tements does not describe a step in the sodium-potassium pump cycle in the neuronal cel*;cz.b0 2;upmqjq ;nryv/ky kls?

  Which row in the table below is true btt ,ghrhd .w5f63t x-mvog*, of meiosis?

Membrane transport is important for allowing particles to move acrosso/umkko((xg hv.p 60 w the cell membrane and respond to changes in moop. 60wkvux g((h/kthe 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 re3 4r.tb p-cipoghv uyck/l65pf 36q,h gulated 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 concentrationsnx:vzdfi:txe/q(rgqd8 4f ) no/7.sc wvy1 .n of different cyclins during the cell cycle. Which c 8cnyfgiqnxv fed1o4rz )d. /t/.(7n:qv:s xwyclin is involved in preparing for DNA replication?

The diagram below shows chromosomes de9-j usmk.z/ry49 d0srt jp4curing 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 ch)r+vwn ldmu5lglf (5or a7o5-romosomes?

  The mitotic index of throat tissues taken from 4 diffb:7 ko1 ynroh+r; jf*werent patients is shown below. Which patient is most likely to have cancerous thr* ;nbrhf+jy1 7 kowr:ooat tissue?

1.Draw a labelled diagram to represent the process of crossing over.;o96nvj9(l zgwq 6 kg8u9fqk x

2.Compare and contrast random orientation and crossing over.

3.Outline the stages of meiosis.

  The image shows an abnormal human karyotarj i9i*+ki z+ype.


What is the abnormality in this karyotype and its cause?

The graph below shows the relative amount of DNA in on7g7nt3qn- (dmjpx z -re cell during one complete cell cycle. Each letter represents one -pz 7 3jx7grqm-tn(ndstage 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 thanv0wi 9f y,gga0 0y)crt is homozygous for brown, long hair and) 0,argcyi y00 gfv9nw a female cat that has black, short hair.


Which of the offspring has a recombinant genotype?

1.Outline how polygenic traits can show a)m k llqn i2k9:mh0 d7z,fy2nm 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 chromatids shown in.pel0 sb,pfaf og;2r2 the diagram bf0;lg pr foa sb,22.epelow?

  The photomicrograph shows a pollen grain from L. caw 2+g20cnr)r 9 xizxwlndidum (Lily). Which stage of meiosis iswxn2 lg 0w)9+xrr ciz2 shown?

1.Outline the events which would lead to an individual being bo 16sn,qchu7j m7 owix4opge:zqi:0p.rn with Down syndrome, which is characterised by the presence of t.mz shg0woix7:pn q76e:jup ioc1,4 qhree 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 study w q1 aoo1b7id x3n(fwg7)gs8e aas conducted on white onions (Allium cepa), under controlled conditions in a lab, to investigate the effect of soilgf1a(o83xw abn 7sgi7 oe1q )d 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 can6vz5:l+hs.6op/wjs 0b 1ffa7dz17p e xjvyjk divide. The diagrams below show two cells from an organism with a diploid number (2n) z1:apj 0y7bv6jh7xe.w j5s6/+o dfs kflpv1zof 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 k xnrt3l pe,vc:se c,wx87* z2growth.

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 nm t*8r ntj(/ynumber of 8, in different stages of meiosis. Which row correctly names each stag 8rtj*tyn nm(/e?

  The micrographs show four phases of meiosis I wwuh*o5 fmi..f; oz)r in a plant. In what order do these phases occur? o)hor.*u . wfzw5 f;im

Mitochondria are responsible for supplying metabolic energy iny4f -oenme(ufx 0:t +u y4l9fs eukaryotic cells. In most eukaryotes, which reproduce by sexual resf+m4u0t:nefleu y 4 (f y-o9xproduction, 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 difpo+i 8bfi/k 6mferent stages of the cell cycle in four samples of lko8p/+bi6 mfi ung tissue from four patients. Which tissue has the lowest mitotic index?

  The diagram shows the dominant cyclin/CDK complexes at different tim5du8b axo9ps0ui)2s3 ibmg-,0 txk/end-dgme points in the cell cycle. Which cyclin/CDK com s98b ku d/n)0-xam- e0igbmo23d ,stdg5up ixplex activates DNA replication machinery?

  Studies have shown that genes such aa6i/afpm p1)n)x br 5is Cyclin Dependent Kinase 3 (CDKN3) are highly overexpressed in ca p1) 5 ap/inf6m)ixbrervical 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 highe7tu,cja7rt 4 ast during the cell cycle ?