The graph below shows the relan u61s6 gvni cl8o l, al2m0ysn+nw7 t;qxmy1/tionship between maternal age and the incidence of non-disjunction. What relationship is suggested by the datcnmv 1lx 6i1s 68nol,;nan+/7t qly2sgymu0wa in the graph?

  Which stage of meiosis is represented in thm5.+czz e8e)6:inzv nj q/nite diagram below?

  The diagram below shows chromosomes during meiosis2r).hz 4trc3 7iib 5qvdgypz,.


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 alleles of a single gene whicu, 5mz+iem)r q3 z3etuh would be present in the nucleus of a cell as a eq3 tu) mimuz5,e+3 zrresult of each process?

  Which keyword is matched to the 8yx:s. j 1vdjtt.-gfa9ds-s t correct definition?

  Which statement(s) about mitosis is//)xg mu5mgx,q 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 pxez2-xn xrxnxd:4l4 4oints to a cell in anaphase?

  During which stage of mitosis does the nuclear eli /ur*f/m2 pdnvelope break down?

  Which one of the following transport proteins only carries ou9p mz2i.mv+(ms -gs2zmaas+lt active transport? mz l(+mgs-m+ivmsz9a as.p 22

  Which process does not happen in the shoot apex -6r79xjrpag c?

  Which type/s of membrane transport do/does not require energy expenditure? 2qimk*wdc9i zv+g kn2 et/ by 2xl*66o
I. Facilitated diffusion
II. Active transport
III. Osmosis

  The diagram below represents a cew a,jm5s8f wj0b(4u eqll with a diploid number of 4. Which stage of cell divisjf4u b 5q8mwa(s0 e,wjion is the cell currently undergoing?

  The photomicrograph below shows a root tip meristem. Which of 7.rllr.:zrs78uj2l j.zmfvc 5 c nh*gthe following sentences cor7.j .lgv7m2: u8 rsjlrc rzh. cfnlz5*rectly defines a meristem?

  When does the random o *( +ne-.yqkgf9wlpf wrientation of homologous chromosome pairs occur?

  Which process does not occur during meiowbp 1kh q;wcvdw; p ril(u(4f*:anj2k h/; tc:sis?

  If a cell with a diploid numbe lod2)b)yh 5myhl0 g )jod(z6dny3bl-r of 36 undergoes mitosis, how many chromosomes will be present in each daughter cell after 5dmyh 2 j)olz03d)b()y6hbn oyg-lld cytokinesis?

  The image shows a micro7a. kpc l-dd*,1 x0y htluyg:ggraph of a cell.


What explains the appearance of the cell in the micrograph?

  Which statement(s) about homologous chromosomes9o;1u/gj;:kq c dccia 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 indies5md 1 nxd0zmpfz0 x27g1g f/vidual with Down syndrome.

Which statement is not correct?

  In the cells of a horse (E. caballus) during prophase I of meiosis cr sf(87 h2 kerdas8s6I there are 64 chromosomes. What is the26r s8cs fsk8r7 dhea( haploid number of chromosomes?

  Which arrow is pointing to a p6(79yt9g; dis yjg9kttdk s-chiasma?

  The diagram below represents the structure of a shoot apical meristem. Wg7t9zsa d*f*8 /tmuux z2(jymhich row in the table correctly identifies the processes occuring in the structures labeled inz/ 78z* t2yf(juam9xm sg*udt the diagram?

  How does meiosis promote va- sjgqk 4bspdao+ p,o++p14wlriation?

  Which of the following statements is/are correct for meir xspbf3//rk3osis?
I. It is a reduction division
II. It involves random orientation
III. It produces genetically identical cells

  The diagram shows gametes produced from two homologous chromosomes. zq,nj2x;qq6r s - 9upj


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 p 5 /qayel3v2plrimary tumours as aa2q ly5p lev3/ result of the movement of cells?

  How many chiasmata are present in the diagr(4gc9k:6 mj rybofc r -w5*sevam?

  Which statement is a similarity between cytokinesis in animav5)(yx 7vdlk wl and plant cells?

  Which stage of meiosis is matched to thefz1 i,ika ymb:uwyk,e 6j h.r970pcc+ correct description?

  Which statement(s) are true of meiosis I but 1 yz-c m( xm4g3hcat;vnot 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 fi4 tprc-kn(d431u-9 e x5iv3mbqjlvc krst meiotic division. This results in the formation of one large cell andr 4c( m3px 94tj-enc-vdk1vkq5li3bu one small cell. What is the fate of the large cell?

  Which row correctly describes diploid and haploid cells dl* ;nw-toe ,zin humans?

  The following table showsm:uq a(ut( xr+yxc v7: the diploid chromosome number of a range of species.


Which of these statements is correct?

  What conclusion can be drawn from the karyogrfu:)+h q7nm 4dna gjpz b/q2:ram below?

  Which of the following processes is characteristic of the meio. ohvqjq -*6tbx6i;wotic and not the mitovjthq 6o*w-xb q6.;o itic cell cycle?

  The diagram represents a -wtr:5zufp2 ro;4hthbud 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 b0r u8js1lao+ae0 rt5troglodytes) is 48. Which row shows the correct chromoso ja0at10e8 rbs5l+orume number for different cell types and cell division stages?.

  At the end of which phase of p :w-g:epxwi ,meiosis I does crossing over occur, and what is the outcome, wiw-:exp:p g of crossing over?

  Which of the following statements does not describe a sw12c)w7+ h2c zz4/y hquuekwwtep in the sodium-potassium pump cycle in the neuronal c 4chy /zw+72huqw2kwu) ce1zwells?

  Which row in the table scdr+x4( lt dn3znv8*l+l:gl below is true of meiosis?

Membrane transport is important for allowing particlese2 zf6crc1s e0 to move across the cell memrecsc612 zf0e brane 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 itd w3)y-,z mjks 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 tq8d9 . z6uvzqohe concentrations of different cyclins during the cell cycle. Which cyclin is involved in prepauvod9q6zzq. 8ring for DNA replication?

The diagram below shows chr/etev*ak d3tu38c*tp rjz g3la8(e t;omosomes 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 meiosij3 m-p kok0j0gs involves the separation of homologous chromosomes?

  The mitotic index of throat tissues taknj0 )h sucjv5+en from 4 different patients is shown below. Which patientn cvu5+sjhj )0 is most likely to have cancerous throat tissue?

1.Draw a labelled diagram to reprn/ar,+ap xr4d esent the process of crossing over.

2.Compare and contrast random orientation and crossing over.

3.Outline the stages of meiosis.

  The image shows an abnormal human karyoty 1.ams67q2g/mpdcr2j0h3 epy qbf*sbpe.


What is the abnormality in this karyotype and its cause?

The graph below shows the relative amount of DNA in one cell during one compx46k+h+0wc khvi -ele,/af zxlete cell cycle. Each lettere+/0ax cf w,6lk4xh-e+ivz hk 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 bed4 a dyud5y:g45b-yd htween a male cat that is homozygous for brown, long hair and a female cat that has black, shoradg :hdd45ydy u 5y4-bt hair.


Which of the offspring has a recombinant genotype?

1.Outline how polygenic traits can show a normal distribution)7cjnzc( ng+it7q6 df.

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-sisted*w2c8-d3 tljk43eav cgq1 bcr chromatids shown in the diagram23cb* 1e4wvgkdqc 3-la dtc8j below?

  The photomicrograph shows a pollen grain .akyd,ut,bw: 1 5yobk 0zx3yzfrom L. candidum (Lily). Which stage of meiosis is shoxobwzdy5ut :b1ak,zk,3y .y 0wn?

1.Outline the events which would lead to an individ8 he2x2c l3axw/o 0p-0w q7g(j iwzdheual being born with Down syndrome, which is characterised by the presence of three /aoh2c0w2xqzw3e gi-h07dw(jl8xp e 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 pdqamyr0 .g d:.rma/r2r f9b2rlant growth. A study was conducted on white onions (A ad92.2r/mbygdaq 0r.f rrm: rllium 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 two ways in which cells can divide. The diagrw+ x gzyx1za51ams below show two cells from an organism with a diploid yx z1a1xw+ zg5number (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 expressx uk8/ u4kf4)vqop 0arion 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 different saih(:zswud /y44+2ib )u-uhr v hra9 ltages of meiosis4h/ubhur2 s wra-: i+hul( 4)dzv y9ai. Which row correctly names each stage?

  The micrographs show four phases of meiosis cfqq gci(i3 7-I in a plant. In what order do these phases occur? i(qci3 q-7 cfg

Mitochondria are responsible for supplying metabolic energyvy1 vtb 3+eq eyhx:v8 nau/t,2snxj;d09ux9p in eukaryotic cells. In most eukaryotes, which reproduce by sex9q u0euy,x/xt2e 1dyn ;s tb83n9vhx:j+ va vpual 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 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 ceunkg**f3 g,vfll cycle in four samples of lung tissuev ,*gnfku3gf * from four patients. Which tissue has the lowest mitotic index?

  The diagram shows the dominant cyclin/CDK complexes xrz +0*bm;kup at different time points in the cell cycle. Which cyclix0mb+p; k z*urn/CDK complex activates DNA replication machinery?

  Studies have shown that genes such as Cyclin Dependent-du p(h5 x:1,ylib bly.ph,d w Kinase 3 (CDKN3) are highly overexpressed in cervicalp5:,i uhpd.dh( y1bl yx,bl-w 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 ty+g x)u+w b)lqaa(g0ysj:+c5r j: s ishe highest during the cell cycle ?