The graph below shows the relationship between maternal age and the incidka 7/kpahkp)p(h .oh ,ence of non-disjunction. What relationship is suggested by the data in the graph(.h,/kk pp)aho k7p ah?

  Which stage of meiosis is re 2l ul q+qxqgeqjfypi/:t*g. ( 0wp78ppresented in the diagram below?

  The diagram below shows chromosomes duw bge7m d-::earing 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 nx l3cs8)gxsu hnl +amd z)n53), 8pyvnumber of alleles of a single gene which would be present in the nucleus of a cell as)8lc s xnz538d nu g)+hypnax ms)3,lv a result of each process?

  Which keyword is matched tp j 5o/d9k 1:jhzobq;go the correct definition?

  Which statement(s) about mitosis:-e,ub ),ejy ur dhn,c 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, whic3 pzqow 16t, h1 vin,5yknib.,vd0kzzh letter points to a cell in anaphase?

  During which stage of mi;jt 0zsg-u kx+tosis does the nuclear envelope break down?

  Which one of the fol20tqpg( i-qtu8v2b ean+z/hs7) j yaqlowing transport proteins only carries out active transport?ajt+t2b 780u(ni2pqeqy ah-zsq)/ v g

  Which process does not hpa1d-xmdafsvz i4og;s+ -/ a :appen in the shoot apex?

  Which type/s of membrane transport do/does not require energy expenditurmye88v 7c/l-t wxn 5rgdj;z0ge?
I. Facilitated diffusion
II. Active transport
III. Osmosis

  The diagram below repres,sbp-ytp8ka3cvy2;s39 q x zaents a cell with a diploid number of 4. Which stage of cell division is the cell currently unpv 2pyztas ,9 3qabk83xc-;sydergoing?

  The photomicrograph below shows a root tip m1e8e0k(-qv p vya p-p65pon iceristem. Which of the following sentences corkn- v-pe8 016epoaiyv(pp q5 crectly defines a meristem?

  When does the random orientation of homologous chrom-bx7rn8oxg w w )laa;a8l k,m8osome pairs occur?

  Which process does not occur cs+r nb,ht u8-during meiosis?

  If a cell with a diploid numbpxa+v p/rp7yby4kpk - owm-30er of 36 undergoes mitosis, how many chromosomes will be present in each daughp/ v3bprxkwy4 -o yp0mkp -+a7ter cell after cytokinesis?

  The image shows a microgra kji;)r1 q4htkjctv1/ ph of a cell.


What explains the appearance of the cell in the micrograph?

  Which statement(s) abv 54-gwjn +x-i0l/occlgf1go o0 g)nzout homologous 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 Dop8f2pd 0xx uy;qpa7 (rz54kng wn syndrome.

Which statement is not correct?

  In the cells of a horsezcbz5q)b3it 5 (E. caballus) during prophase I of meiosis I there are 64 chromosomes. What is the haploid number of chr5 5zqzbtbc3i)omosomes?

  Which arrow is pointi8hzv 13 uzpy-)sgwda.i uh)+v6oa,o ing to a chiasma?

  The diagram below represents the structure of a shoot apical meriste7 e z q:xx;)szyomix;-m. Which row in the table corymze; : 7sxx zxiqo);-rectly identifies the processes occuring in the structures labeled in the diagram?

  How does meiosis promou3d7/ mzxl t 4pk/baqci5v -e;te variation?

  Which of the following stalrksw.-3f dk2 tements 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 gametes produced fh 2g;.emi 9xvb c cnmz+ e8bzk11b0 vf59mto2grom 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 4g ya0(xy:dy rsecondary tumours from primary tumours as a result of the move ad4(x0:y yyrgment of cells?

  How many chiasmata are present i( t.;1c svnz *:itaoxin the diagram?

  Which statement is a similarity between cytokinesis in animal qd+jj m nn3drj;lx/-)and plant cells?

  Which stage of meiosis is matched to tq el1z5 hrb9wh*vc4) yhe correct description?

  Which statement(s) are true of meiosis I but n6m8x9i * ebyeq l z525jdfv*s0g0fxvsot 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 diviso/s rjn;p7nb /5go(8j fu5dun.zkm)n ion. This results in the formation of one large cell and one small cell. What is the fate of the larg /go;s. nn n58u om5(uj7rb)/fzpkndje cell?

  Which row correctly descr*2db67j-sb* slc rrxjc pz94jibes diploid and haploid cells in humans?

  The following table shows the diploid chromosome number olc9l6orkilt 2iv v) d.i (ev:8f a range of species.


Which of these statements is correct?

  What conclusion can be ed6hn.m :)pfl daata/h2 5c w6drawn from the karyogram below?

  Which of the following processes is characteristij/q/9k)pr emic of the meiotic and not the mitotimk i/re/9 )qpjc cell cycle?

  The diagram represents a bud with a sxo3(eubpw/p5 k7u:4h b qpk940e9pm *qnu fbb hoot 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 chimpax) q n)w2ncg fc*ztc09nzee (Pan troglodytes) is 48. Which row shows the correct chromosome number for different cell typg2xzn9* n ) ft)cqc0wces and cell division stages?.

  At the end of which phase of meiosis I does crossing over occcz5o qw2lj- 1aur, and what is the outcome of crossing ooczj2lq a-5w 1ver?

  Which of the following statements does not describe a stepnq3 dds/hf,9e i im:q9 in the sodium-potassium pump cycln s q:i9/fh3ddq,i9eme in the neuronal cells?

  Which row in the table belnli/j6e6at/hm 7 ;*biet;ns xow is true of meiosis?

Membrane transport is important for allowing particles to move 4xygq lhsf a9i 17b i2vr:ji/*across the cell membrane and respond to changes in the iqvy ji21 :7ah*sx9fri/glb 4 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 o (,r-xehn eg- 77swtyregulated 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 cz vw vsmqbl3at pq9sl6 3i3f4x5e14 .gell cycle. Whicp4 mf9e3v i1z4ql wa6s3tg l35x.v qsbh cyclin is involved in preparing for DNA replication?

The diagram below shows chromosomes during meiosis.i /jaxmjgca6 ..g -b-z

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 chromosome* zwb qkie.w5y 9**3mus 6j;;pwrobdfs?

  The mitotic index of throat tissues tak w hu.bus *e x/xf7r*uia2-sk+i+kx1sen from 4 different patients is shown below. Which patient is most likely to have ca s*xfu7/++su uix b1-xrkk2 seh*iaw .ncerous throat tissue?

1.Draw a labelled diagram to represey;8r 0hur+/ ues y-(d dgcxfc;nt the process of crossing over.

2.Compare and contrast random orientation and crossing over.

3.Outline the stages of meiosis.

  The image shows an abnormal8afc8n:t.4 g70tn jaq 5cczyd human karyotype.


What is the abnormality in this karyotype and its cause?

The graph below shows the relative amount of DNA in o-;wx9dpd8 tqfne cell during one complete cell cycle. Each letter represents one stage of thd 9xp8twfd;-qe 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 - un pj:8xtj:to7wc4 tcat that is homozygous for brown, long hair a 4: j-nt78xw ct:jputond a female cat that has black, short hair.


Which of the offspring has a recombinant genotype?

1.Outline how polygenic traits can show a normal distribu5b0k33x t :xwove(.ie;yil ujx .v9xu tion.

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-suk1z*un jmrfk0 i9)m6 7eqq 3r (jg+dui;w. kbister chromatids shown in the diagram belowfm )(riukkkjjg*.qzd u+bnw;0q96ir u 3 e71m ?

  The photomicrograph shows a pollen grain from L. candidum (Lily). Which znvl h t+6d1 +7 llje+lkgz+,ostage of meiosis is s+1+nljg hl le76zd zo,t+lkv+ hown?

1.Outline the events which would lead to an ilz uz21p0mhr:r(kdpsj;pk e2t 13 p7 mndividual being born with Down syndrome, which is characterised by the presentpup2pj7splkmz :z rm0e2dk113( r;hce of three copies of chromosome 21.

2.Explain how meiosis increases variation.

3.Outline the stages of meiosis.

The mitotic index is an indirecup e+z0ln( ey t+p9:rvt way of measuring plant growth. A study was conducted on white onions (Allium:n(erlt+ p9ypu+e v z0 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 diagramsgijn1 i nbw /ntq)9v8b cp/0rr :xv2o; below show two cells frox /;b)r1ig:i2n98nojb n pc/vwt vqr0m an organism with a diploid 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 in s-woat4 hv2mgt ra p/) (e:ds3pbh73kytem 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 numberj50mcf 4jq js 8q.hmb0 of 8, in different stages of meiosis. Which row correctly names each stage?m jsqcmf bh500 j4.qj8

  The micrographs show48o5mawubb p 9 four phases of meiosis I in a plant. In what order do these pow4 mub95a8bphases occur?

Mitochondria are responsibledn5 i* bh; r1m-jdfl6f for supplying metabolic energy in eukaryotic cells. In most eu h*- mj56rblfn;1 iddfkaryotes, 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 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 difsw6 1nqm xso-b : qlci3(1ed.aferent stages of the cell cycle in four samples of lung tissue from four p6s1axl-n.q1 qe3wbs i(c :dmoatients. Which tissue has the lowest mitotic index?

  The diagram shows the dominant cyclin/C0rvo .xi qn(6kDK complexes at different time points in the cell cycle. Which cyclin/CDK complex activates DNA replication machinery?i qo0nkvr. 6x(

  Studies have shown that genes such as Cyclin Dependent Kinase 3 (C0aqp 8-w zppe6mm7)9/0 bqvwrlvs) cqDKN3) are highly overexpressed l rvpm9v q0)wqqab0-)76w/zc8m ppes in cervical 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 concentrat rvm .n:h8hnn0ion of cyclin E the highest during the cell cycle ?