The graph below shows the relationship between maternal age and t,cgh83 (d(; mhol*tio7hl1 zut6lbdy.zo )tche incidence of non-disjunction. What relationship is suggesly hm7ct6 *z odgh8dz u)t1c tbol,3;oh.li((ted by the data in the graph?

  Which stage of meiosis is represented in the diag1o3zo. ldw.4h u7pw4xzosz )ux 2tlh3ram below?

  The diagram below show/pyb a68chw:*cwmv0 ts 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 states t(xu 9c) w7rp 7sfsorn:n/,bk3ms ndg6he number of alleles of a single gene which would be present in the nucleus of7s,: 7nsx)96srgdw 3/cmbkunf opn(r a cell as a result of each process?

  Which keyword is matched rv62g/6 ihdl( 8xwvrl to the correct definition?

  Which statement(s) about y1heync:3mb 6mitosis 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, whw3xr)a,u n-so ich letter points to a cell in anaphase?

  During which stage of mitosis does the nuclear env4 3f:zs rqwye7v3 ybltt /a78welope break down?

  Which one of the following transotp4o , d 8kpfe,ztsu ;x:09t;ai:uzgport proteins only carries out active transport?iutto ta4uz,px:efp gd8o;:,z 0s ;k9

  Which process does not happen 8rvy9 oq3j:l yin the shoot apex?

  Which type/s of membrane transport do/does not require energy 6a./6si fxgvb expenditure?
I. Facilitated diffusion
II. Active transport
III. Osmosis

  The diagram below represents a cell with a diploid number of q wat:+mb0 l)l4. Which stage of cell division is the cell currently undergoing?: ba )0mw+lqlt

  The photomicrograph below shows a root;zqq5aws:/)r u xlv6j tip meristem. Which of the following sentej6:x5r wa;lqqv/us )z nces correctly defines a meristem?

  When does the random orientation of homologous chromod sdp/a 6mk anxs84(qy wlz280some pairs occur?

  Which process does not occu-bm:a18akvtq i gyes-+ m*gbyb-9ut/r during meiosis?

  If a cell with a diploid number of 36 undergoes mit s6onml8c*7g.gp t*tvsr+cw; osis, how many chromosomes will be present in each daughter cell after cyto*spgttw;7csg rlcv*+8n. 6o mkinesis?

  The image shows a micrograph of a cekjm al6j0rq-hp; y32bll.


What explains the appearance of the cell in the micrograph?

  Which statement(s) about ho motd .+s66 06vzvqbvrmologous 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 with Down syndrome. d -(-zl sepy(9 8ektfjik;r6n

Which statement is not correct?

  In the cells of a horse (E. caballus) during prophase I of meiosis I the3qmnseb-)1 j v8 kh7jere are 64 chromosomes. What is the haploid)n-137v bjq8shmje ke number of chromosomes?

  Which arrow is pointing to 4i) a;v3r irmha chiasma?

  The diagram below represent )y(j*kkca y(rkog3v1s the structure of a shoot apical meristem. Which row in the table correctly identifies the processes occuring in the strucvk1)j kk ao*g(ry3c(ytures labeled in the diagram?

  How does meiosis promo6u mwg p)4sdv2mu02vste variation?

  Which of the following statements is/are correct for 3sa pl8eig67i meiosis?
I. It is a reduction division
II. It involves random orientation
III. It produces genetically identical cells

  The diagram shows gametes produced from acp)thj .d fvp qi+;7g0x7 yp.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 tum85 xx g2o w:v gum*1fr5td2rfwours from primary tumours as a result o :udg2 5m w*fwr2g8forx15vx tf the movement of cells?

  How many chiasmata are presentvcip, 0i 4i:1s acvdg: in the diagram?

  Which statement is a similarity betweeny( tgat;kr)4 t cytokinesis in animal and plant cells?

  Which stage of meiosis is matched thp 5: ;bhvjg1 1nk-vhmo the correct description?

  Which statement(s) are true of meiosis I but not meiositu-,jp; ekz -xgwssrn0k. x8 :s 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 resug63 gkbwv/u4 tlts in the formation of one large cell and one twvb36/ku4 gg small cell. What is the fate of the large cell?

  Which row correctly describes diploid an6ex/ dd:moq 4p-kxil(ju x0x 0d haploid cells in humans?

  The following table shows the diploid chromosome number of a range ,n dk6 y a7h.p(umog7s2dq;ruof species.


Which of these statements is correct?

  What conclusion can be drawn f3j .1s-h;zb m2bukhhe rom the karyogram below?

  Which of the following proce/gg)n2c5av o y6yj js5ysi:n* sses is characteristic of the meiotic and not the mitotic cel yog*gn s25v6/ ny)jc:ja5syil cycle?

  The diagram represents a bud with a shoot apical merist dl8l qq*dbp0 6.kb9pcem.

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) isr7-d 55a p/jkcbd 9g) fpqbz2a 48. Which row shows the correct chromosome number for different cell types and cell division5qgdadp97ba/ prbk- cj )f52z stages?.

  At the end of which phase of+tj * 8cq4yyrq meiosis I does crossing over occur, and what is the outcome of crossing over?4rtc*8 q yqj+y

  Which of the followin8sv c 16jgt aly 2suvtikm1*9.g statements does not describe a step in the sodium-potassium pl1y9kt*vtmsa 2i6sg v.8u1c jump cycle in the neuronal cells?

  Which row in the table belcg.idq+v enhg)v34b7pw94uh tbo07epd i:3 low is true of meiosis?

Membrane transport is important for allowing particles to move acro.mrcu (;,ww lrss the cell membrane and respond to changes in the chemical composition of the extracellular flrw.rm ul(w; ,cuid.

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 regw :cb kam: zhl-8.6oetulated 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 the cells6s:p-tpcp ;aj4vs a:f/xzj+ cycle. Which cyclin is involpj: /vpj ;ts a+zca xpsf4-6:sved in preparing for DNA replication?

The diagram below shows chromosomes during meiosim3ygh* s7e xx:s.

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 meiosisv4z vmm7 j,ya 97pa9bt*yw1cb involves the separation of homologous chromosomes?

  The mitotic index of throat tissues taken from 4 different patienj/c o5o6,5wwhw ( ajctts is shown below. Which patient is most likely to have cancerous ,htoowwj w/ 5cc( a5j6throat tissue?

1.Draw a labelled diagram to represent the process of crossing ove 0fjn;*3vbx3ic0cw kw2g .(a .ys npusr.

2.Compare and contrast random orientation and crossing over.

3.Outline the stages of meiosis.

  The image shows an abnormal human karyotvsh7fiw f,f a0)u9l5kype.


What is the abnormality in this karyotype and its cause?

The graph below shows the sc ;9sg,pis6jptk 3q)relative amount of DNA in one cell during one complete cell cycle. Each letter represents one stage of the celjc3,tksg p;pq s69s) il 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 cro-+7p5 kjv ds5sec qix3ss between a male cat that is homozygous for brown, long hair and a female capq 53scvj5- +7ikx esdt that has black, short hair.


Which of the offspring has a recombinant genotype?

1.Outline how polygenic traits can show a normal distrir p uz(6kmda5z 3zc1ycj-i5o*bution.

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 crswz4h3q p6xwn)(jg u -ossing over of non-sister chromatids shown in the diagram beloqux h3g64zw-wnp sj)( w?

  The photomicrograph shows a pollen grain from L. 6q4 8tph*g si;new60yi tgb2ecandidum (Lily). Which stage oft s*pienwbeqi24;6tyg8g 60 h meiosis is shown?

1.Outline the events whi z:s /-wn6n qepxh2i/bch would lead to an individual being born with Down syndrome, which is characterised by the presenwiznx-nq p2 s/b h6/:ece 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 0qf.8 :,wtjw -bb lqolstudy was conducted on white onions (Allium cepa), fbwt, qb:.lj08l owq-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 wht0w6bkmm . jx4ich cells can divide. The diagrams below show two cells from an organism with a diploidb6xj.kt mw04 m 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 gem 3 xl.bzh7m-8 zeg4ubne 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 ( hi3yh;g9ltzio.laa4z wac5 +xr :0ucell, with a diploid number of 8, in different stages ofl.g: ; 9(autlhzzix 4ichwr 305a+ayo meiosis. Which row correctly names each stage?

  The micrographs show four phases of meiosis I in .9xns *w.d 3wwgp;xd da plant. In what order do these phases occu.x wx ;9ns*dgddpww.3r?

Mitochondria are responsible for supplying metabolic energy in euk4gmykw p- ,ix,cn; c:p)w7 fi;xtxd3daryotic 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 gen); ;tx,ppw,cf-wx 3cxkynig7 dmid4:etic 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 6vong7pm30ie 2o ) fdpagzs zxc4)+1pcycle in four samples of lung tissue from four patients. Which tissue has the lowest g mv76zopsi4d+)xcpa 10ef32ng)z pomitotic index?

  The diagram shows the dominant cyclin/CDK comple-qf(tevz4g/nkm; c x3xes at different time points in the cell cycle. Which cyclin/CDK complex activates3zf x( mck/eg-q vtn;4 DNA replication machinery?

  Studies have shown that genes such as Cyclin De r7a7xd3ar rtem28q q-gad i l,n:g(+fpendent Kinase 3 (CDKN3) are highly overexpressed in cervic qegm3-,f + tliq8nrdr7aar(xa2d7g:al 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 hige ,/lxfc cf(ldjn b:ewj0-. ;b3 pvm6hhest during the cell cycle ?