The graph below shows the relationship beyt ri:/ n4pi*p,7 ftagtween maternal age and the incidence of non-disjunction. What relationship is suggeste7/ *i pgnty,a4tf:pr id by the data in the graph?

  Which stage of meiosis is represented in the5n 0dn rtx3+fit;zqq- .njj 8+eh)lql diagram below?

  The diagram below shows chromoso5f8 f1m+2* sog )4 ;olbtn fmgwiqua0bmes 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 num60ea3fos9dh.s i/vpyp +d4jm ber of alleles of a single gene which would be present in the nucleus of a cell as a resul.pfe+i0 mp s a9ohs/v j3d4d6yt of each process?

  Which keyword is matched to the c2g,fcm jxij2a+:2 biw6) t tnlorrect definition?

  Which statement(s) about mitu34qntns)(rzb9qgo6d hp0n1 osis 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 anaphase l56 .;*-p tylyb s(a vlxppbqx4scz8(?

  During which stage of mitosisga/aty 2f bte20 -ufn9 does the nuclear envelope break down?

  Which one of the following transport proteins only carries out active transp0z/noh:j wzr 4qn:6fkort?:o qhrz4nnw6/z:0fkj

  Which process does not happen in the shoot 7.tv o53lzabf apex?

  Which type/s of membr6h9:g.2 vpjaedx;k sb ane transport do/does not require energy expenditure?
I. Facilitated diffusion
II. Active transport
III. Osmosis

  The diagram below represents a cell with a diploid number of cs ah)b (:av39ne fe/x4. Which stage of cell division is the cell currently se:/)vhcneb x3(a9 fa undergoing?

  The photomicrograph below shows a root tip meristem. Whi -9wgxu3ffc7mhxvk6+o2u h6m,k8uq och of the following sentenc3hx7o+fu26xkqhof6muwv,9mg 8k u- c es correctly defines a meristem?

  When does the random orientation4.) a/ fcr sdh4rmgjnf+)mrt9 of homologous chromosome pairs occur?

  Which process does not occur during meiomkc (-a6sj j0 j3tv;tosis?

  If a cell with a diploid number of 36 undergoes mitosis, howjzbb2/ -nw 5f2l qvi)jsun/4j many chromosomes will be present in each daughter cell after b q b5j24j/-fswl znn/)u2ivjcytokinesis?

  The image shows a micrograph of aq9ukp t:+95a qfpu7y ai;cm)q cell.


What explains the appearance of the cell in the micrograph?

  Which statement(s) about homologous chromosomesx+gzjn:8qq :ot vz8g/ 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; 4yi fz k:)l:63dxq,w0 ykm fq u8k*6eclgiqs with Down syndrome.

Which statement is not correct?

  In the cells of a horse (E. caballus) during k48mmt6/pcd0h1sg gz prophase I of meiosis I there are 64 chromosomes. What is the haploid num8 s46/g hct1 pgm0mdkzber of chromosomes?

  Which arrow is pointing cbm *y+q7 -mozto a chiasma?

  The diagram below represents the strucalu hgg 4k)/x77dfqqvg b,zl 2)q0l7cture of a shoot apical meristem. Which row in the table correctly identifies the processes occuring in the structures labeledquq)2l, ka cd4ghlgb )7q7f 7vg0x/lz in the diagram?

  How does meiosis promote varia6va,,mvjr+z / sz;xpktion?

  Which of the following statements is/are correct for meiosis?6q;iz6w-y(f3rzkki s
I. It is a reduction division
II. It involves random orientation
III. It produces genetically identical cells

  The diagram shows gametes produced from twosuboby/ gdi0as2(w,c ( ex7l3 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 prb8qf4g/rmhxl5 fkoczx sszp/0- .q: 3imary tumours as a result of the movement of ce/0zhb-rk8/sfz: 4c q3.lxsgqop5xm f lls?

  How many chiasmata are present in t y0mi:fy/+by1uc (hro he diagram?

  Which statement is a similarity between cytokaen 4+bhj kxhz,.--tje(o a2fi ci86winesis in animal and plant cells?

  Which stage of meiosis is matched:smm9khtti 4tr( m3 )f to the correct description?

  Which statement(s) are true of meiosis I but not meiou7 uy,;ozkovo4 b2 n2gsis 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 ifdrbr7htoxdd/,+ 7+q jg +e3division. This results in the formation of one large cell and one small cell. What is the fate of the large celrx+b, o gth+q7ef/ d7i3dr +jdl?

  Which row correctly describes dm evoh7 gq ji-l76 i2h9)pboi)iploid and haploid cells in humans?

  The following table shows the diploid chromosome numb-u lj:iij7ec0 er of a range of species.


Which of these statements is correct?

  What conclusion can be drawn from the karyogram bel: 8ylzamg(:pn+yz vd0ow?

  Which of the following processes is characteristic of the meiotic ;*ww jn9su5hyo 44 0iyer m/upand not the mito sm;p njr4hi9uoy wwu0e4*y5/tic cell cycle?

  The diagram represents a bud.pfx:4 5bi2wrycxgb/;o /kdc 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 chimpanzejdzkn ) /olzogg;uajh +8 qe8p480x x0e (Pan troglodytes) is 48. Which row shows the correct chromosome le/ 8n og;djog0z4+qak8u0 xjh8pzx) number for different cell types and cell division stages?.

  At the end of which phase of mfmf i(ga46 ;up l9gs,qeiosis I does crossing over occur, and what is the outcome of pq g,afufg4isl(;6m 9 crossing over?

  Which of the following statements does not describj7 (txz)p64 /p+ jn6odbouffy e a step in the sodium-potassium pump cycle in thnd b (p)u664tzfjo/7+ pyjfoxe neuronal cells?

  Which row in the table bergj1a8nkz2fs c -l1 d0low is true of meiosis?

Membrane transport is important advl-o:qo;o*mk3 s dx* *m4h gfor allowing particles to move across the cell membrk43g:dm;* ad hx*m oqoolv-*s ane and respond to changes in the 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 ihnt a1lp.yh, dx376k fs 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 concentrugi wu7 t (b-h*/6bnplations of different cyclins during the cell cycle. Which cyclin is involved in preparing forbth6np(luigu-*7/ b w DNA replication?

The diagram below shows 6khc bgr p 8sg3tm0 jih3n*p6(chromosomes 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 sdl hu.2fp +9z 4vid8xleparation of homologous chromosomes?

  The mitotic index of throat tissues taken from 4 different patients is sho-b6ns*ht whr xa( oq5yt6b o,9wn below. Which pa6 ty q*b(5 -rosht6, wbn9hoaxtient is most likely to have cancerous throat tissue?

1.Draw a labelled diagram to represent the process of crossf 7:rh7;p elxoz/ah,w ing over.

2.Compare and contrast random orientation and crossing over.

3.Outline the stages of meiosis.

  The image shows an abnormal human karyj 6z0e(c s/cscotype.


What is the abnormality in this karyotype and its cause?

The graph below shows the relative amount ofs,1o0 )j*d lkkg;ledd DNA in one cell during one complete cell cycle. Each letter represents one stage of j*0dldok,);e skdlg1 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 brown,i5vpiji7p0 hr(kv,:c v zd- 3u long hair and a feii: uz(r,kdp-ivhv j05c3 p7vmale cat that has black, short hair.


Which of the offspring has a recombinant genotype?

1.Outline how polygenic t*lna*ags 07cz lh )gr35vs ps(nd9e8nraits 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 resul*bsz3tjdba,cyt(*: ,d jprd +t from the crossing over of non-sister chromatids shown in the diajadc, dy*r d+, spbt*:zjt(3bgram below?

  The photomicrograph sh+j6f2 ;kg 3rfif noyvew r1+,oows a pollen grain from L. candidum (Lily). Which stage of meiosis is6e3rf2o i+rgf1 v k+joyf,;wn shown?

1.Outline the events which would lead to an individual being born with Down syndnp+;9(d he7ntybze8c fbej1)iux . :zrome, which is characterised by tf7z1ebyhc p)jne;.(b8+nz edx ui:t 9 he 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. A study was coyjp/k )glfh134f lcv6nducted on white onions (Allium cepa), under controlled conditions in a lab, to investigate the effect of soil pH on the mitotic index of they ck3ll 1pv)gj4/6h ff 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 cel4(* o dhtgwqap;m94; w,ribaqrc2 0 lkls can divide. The diagrams below show two cells from an organism with a dipl9ch0 b,pw4l2t4qrmqoi ( gk;a* dr ;awoid 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 expmsa ac,1 +krd+zj-c/qin+ue s3i69 yc ression 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 1b.hnc: uz l cdx3k3o ia j p2q*x7*def)9azs0different stages of meiosis. Which rows)b1c daonl. p3 qfai3c0jkz*zu :7xe h*9dx 2 correctly names each stage?

  The micrographs show four phases of meiosis I i+ewzwc)2-ciwm wn 5g:a(8yd m n a plant. In what order do these phases 8 g w2cnwcde-+:zwam y5m(wi) occur?

Mitochondria are responsible for supplying k-y+xy jem(o2r) ur)xmetabolic energy in eukaryotic cells. In most eukaryotes, which reproduce by sexual reproduction, mitochondrial DNA (mm2-rr)) uo xkeyyx(j+tDNA) 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 numb7m koow8 iak2*er of cells in different stages of the cell cycle in four samples of lung tissue from four patients. Which tissue has i7o omw8ak*k2the lowest mitotic index?

  The diagram shows the dominant cyclin/CDK complexes at different time poi z(hhb9kdae (g:*p 7pbnts in the cell cycle. 9 khbghdp a:p*b(( ez7Which cyclin/CDK complex activates DNA replication machinery?

  Studies have shown that genes such as Cyclin Dependent Kinaseb2*6g 8zvu:v xz0r*tka is5n k 3 (CDKN3) are highly overexpressed in cer zt *kiuv *n6r8asgkb025vzx:vical 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 dutsd+f - 5 la/-poqp9lp-vk3tf ring the cell cycle ?