The graph below shows the relationmq /*yx (fln8nship between maternal age and the incidence of non-disjunction. What relationship ismxq / n(8yl*nf suggested by the data in the graph?

  Which stage of meiosis is represented in the diagram pe zcwo qc))5d)ajy.l o6j n-1below?

  The diagram below showsokwu(wi aacq;xj)yv,,2 ,jv( chromosomes 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 q mjq q0.g zgmv58 si4xe+/9j0jkhnn6states the number of alleles of a single gene which would be present in the nucl4mj im q0g+zj.qnk 5xsv9 8 hg6nqej/0eus of a cell as a result of each process?

  Which keyword is matnz3 6-priro-9owh4 ws ched to the correct definition?

  Which statement(s) aboan: by6+dv9 wk-zcbi6ut 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 poib3b6 mwpne wv.;x4i;1h1rgqh nts to a cell in anaphase?

  During which stage of mitosis does the nuclear 91(gzv6zdgj u envelope break down?

  Which one of the following transport proteins only carries out active oxv -4rf x*gm /-k)dvu l9q;sqtransport?) -o-ugv/q xlvfm94qxrd;sk*

  Which process does no8: 08yoqz rzmxt happen in the shoot apex?

  Which type/s of membrane transport dv;dkdy(ng :f5o/does not require energy expenditure?
I. Facilitated diffusion
II. Active transport
III. Osmosis

  The diagram below represents a cell with a diploid number of 4. Whsdlt (hbrya +qj i98;2d(ef/xich stage of cell division is the cell current( arix29lfesd8/qh + (jdybt;ly undergoing?

  The photomicrograph below shows a root tip meriste,u5epoi nq p +zoq894wm. Which of the following sentences correctly defines a meristem?wpuoi q8o9p qnz,+ 4e5

  When does the random orientation of homologous chromosome pair+7cz x ev9z8wcs occur?

  Which process does not occur duriqar 7ua mko4i;67ig7dng meiosis?

  If a cell with a diploid number of 36 undergoes mitosis, how mann la7j3k,z1 ryy chromosomes willnzyr,137lj k a be present in each daughter cell after cytokinesis?

  The image shows a micrograph of a cell.6aem,ev 3xdtr5a buz/zz44t 5


What explains the appearance of the cell in the micrograph?

  Which statement(s) about homologous chromosomes is/are not tw+t l).nvau e5dzq9 n-rue?
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* (+7f holjr)zjhfs*02or8pi(zbm: i x*adv c Down syndrome.

Which statement is not correct?

  In the cells of a horse (E. 2zxvbnm 8l)x*caballus) during prophase I of meiosis I there are 64 chromosomes. Wh8 2x xnm*vz)lbat is the haploid number of chromosomes?

  Which arrow is pointing to a chiasma4*w 3ssv s7p,- b7gnxg u)yu9iboq4xp?

  The diagram below represents the structure of a 0d.lk0zww wl.u;a 1nf shoot apical meristem. Which row in the ta0fn.;1 k0 wdz.ul wawlble correctly identifies the processes occuring in the structures labeled in the diagram?

  How does meiosis promote var .vicqq4:g(hjiation?

  Which of the following statem*xk ovkd ma957 gw.2qt im6n)jents 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 game4e)7 klxk)z -b n:-lvi fte7aftes produced 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 tekz-;s3*v bum tuzswq 4 m67v)umours from primary tumours as a re t *qz mb)m-u43 ;zvw7vusks6esult of the movement of cells?

  How many chiasmata are present in the diagszqm6 50f8,mxny td o y60g:xqram?

  Which statement is a similarity between cyj6h):2 y)4u y-ocvmhcqi *kfwtokinesis in animal and plant cells?

  Which stage of meiosis is r m0xd *uqq-/yvsf4, / mpd ui,e6db6bmatched to the correct description?

  Which statement(s) arqkclk h zgk(cwkn:3y5 p4 q).dty-3 j,e 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 first meiotic division. This resul93pr 91k,gj0db *l c 1(lmaqliflqm2pts in the format0 jk(l l9rmi3p1mqdcq* fp1bl2g,l9aion of one large cell and one small cell. What is the fate of the large cell?

  Which row correctly describes dipifro*.e d8.e wloid and haploid cells in humans?

  The following table showyo7)4jil f 5n vj.8g -y.rlpcds the diploid chromosome number of a range of species.


Which of these statements is correct?

  What conclusion can be drawn from the karyogram below 2c l*(4w3*. a1phuul hvvluek?

  Which of the following processes is characteristic of the meiotic a4qx h9;vpd uk)nd not the mitotic cell cycled )qu4x9pk;h v?

  The diagram represents a bud p3/ gzayd*9mm 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 tt7jbt b2zsu59 he chimpanzee (Pan troglodytes) is 48. Which row shows the tsu5tb7 bzj29correct chromosome number for different cell types and cell division stages?.

  At the end of which phase8hi3j 87( c*+6ayghixfks kmtn- k*uz of meiosis I does crossing over occur, and what is the outcome of crossing o3kkz7i- f8+uyx k*ng (8t imj*hchsa6 ver?

  Which of the followingh1baygplk5i6 s x+sv+-j -fv6 statements does not describe a step in the sodium-potassium pump--kas 5 v1vbpli hfj xg+6+sy6 cycle in the neuronal cells?

  Which row in the table below is trued*839g9o:b t wvddhrq:dv q7e of meiosis?

Membrane transport is important for allowing particles to move across 4vq-f. 8eysgz the cell membrane and respond to changes in the che8ev zysqfg.-4 mical 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 icz2u:,3xhp,, 0j8lbl mb.e xe jw8quhs 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 concentrations of different cyclins during ;cabxn6)l41j ob 6 9;2k hoxeltph sz/the cell cycle. Which cyclin is involved in preparing for DNA replicat;4x6skoe n9clhh2 /bx lo japb)z; 61tion?

The diagram below shows chl6gxzknbb k e.s--r2 *romosomes 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 caifs/fv4 xen j-3l g6 r,:d1ba8c(yl ohromosomes?

  The mitotic index of throat tis zvq +1 *eagkzx 9ew:.te08vuwsues taken from 4 different patients is shown below. Whi:w8 e+av90gkxwv *ze 1eut zq.ch patient is most likely to have cancerous throat tissue?

1.Draw a labelled diagram to represent the process tz x:d6mc0u0r bmiw 11)bsq8sk;8ckw of crossing over.

2.Compare and contrast random orientation and crossing over.

3.Outline the stages of meiosis.

  The image shows an abnormal human kary ;zd1afrr(o j3otype.


What is the abnormality in this karyotype and its cause?

The graph below shows the relative amount of D: kmue8b vj48eNA in one cell during one complete cmj4e vkbe :u88ell cycle. 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 a cross between a male cat that is homozygous for bcsq p/48 0y;nw/sp5:uvu jrdjrown, long hair and a female cat that hadjwpu 0pjv8/us4s/5n ; qc yr:s black, short hair.


Which of the offspring has a recombinant genotype?

1.Outline how polygenic trbkr +)3vza 9ynaits 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 result from the crossing over of non-sistmpfabq9,6;pmvk u*)der chromatids shown in the vkp f,p)9u;q6a*mmbd diagram below?

  The photomicrograph shows a pollen grain from L. candidum (Lily).s30 8n4b dth78ynghy e Which stage of meiosis 04synb hty8 ng38d 7ehis shown?

1.Outline the events we4hi7(i a /av3avewx)2 p7ty3arg2ojhich would lead to an individual being born with Down syndrome, which is characterised by the presence of three copies of chromosome 21.aa43h7e i/j273 y xgoaewav t2v pr)i(

2.Explain how meiosis increases variation.

3.Outline the stages of meiosis.

The mitotic index is an indirect way of;dm2e+hj4xm 9jxc s5t measuring plant growth. A study was conducted on white onions (Allium cepa), under controlled conditions in a lab, to invehd c2xsmt9; jmj+x5e4 stigate 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. The diagra+6tnje(7)qll:a u8 x5gvgl4 c ikb/m yms below show two cells from an organism with a diploit 4gmce)8y7(/ln qxv 6gbulil+ :j5a kd 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 iif, o f(vb3n:yuga5 r-n 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 different).wdpb : xv/bv stages of meiosis. Which row correctly n :bdbxw.vvp/ )ames each stage?

  The micrographs show four phases of meiosis I in a plant. In what order do thes,tj5hdvv* :f zts a/8g(a/ 9t qwttl7fewt8f:(9j*tstg vt af /v7 qzl5a th,/d phases occur?

Mitochondria are respo+ht3du:5yw bg nsible 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 yut3d:ghbw5+ 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 3 yo6b7z6hdbwtch 7kk 7y5f:rin four samples of lung tissue from four patients. Which tissue has the lowest mi7zkh7h:dybo6k73 ct wb y6f5rtotic index?

  The diagram shows the domi - pm5 hrpp;ew zl/stv;g)ji90bw2iv+nant cyclin/CDK complexes at different time points in the cell cycle. Which h+ps0 vg;;-vj ml/peb w ip w5it2z9r)cyclin/CDK complex activates DNA replication machinery?

  Studies have shown that genes such as Cyclin Dependent Kinase 3 (CDKN3cw(fu;,s6y ous 6 65,vgkqwd u) are highly overexpressed in cervical tuodku;u,fqv, 5cs y6us6 g(6ww mours.


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 upf1wzth+q 2)m1zq.d the highest during the cell cycle ?