The graph below shows the relationship bet0+ea.r vbx +k;x m)7kkk rgopz9oi:c0ween maternal age and the incidence of none)px00omc+zrboa. vk;k kk:i9 7x+g r-disjunction. What relationship is suggested by the data in the graph?

  Which stage of meiosis is represehbhx qf1-g g,s/3i 2azh)hsg21 ukam)nted in the diagram below?

  The diagram below shows chromosomes during meiosisbxcr- 4 +(,qm0;kja-v (hsgvxg9tmkx.


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 which w pf 3yh5efg r)h-xcy4q+ mu61uould be present in the nucleusm5ff-)6yy+uep1u4h x 3crq g h of a cell as a result of each process?

  Which keyword is matched to the co+dy 1(zou (i v5c3cqevxw i;blubk /6*rrect definition?

  Which statement(s) abow3mlqb/kz w 35s;sn1ht zj6*tut 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 points th77mq /rywbk,o a cell in anaphase?

  During which stage of mitosis does the nuclear envelope break down3iz,b+1b vnr y?

  Which one of the following tra wsvsl y+l7vz; p97/cll71lo dnsport proteins only carries out active transport?ls1vd ; 7zl v+ slwp977lcoyl/

  Which process does n t4ahsx+ /6we)-ceoq iot happen in the shoot apex?

  Which type/s of membrane transport do/does not require energy expendituribp 9tk iwu b:,.a9ab.e?
I. Facilitated diffusion
II. Active transport
III. Osmosis

  The diagram below represents a cell witq,6 -lmbcxeh 8h a diploid number of 4. Which stage of cell division is the cell currently unde-lmq c ,xb68ehrgoing?

  The photomicrograph below shows a root tip meristem. Which of the following sent1ew/ch9xv7o hxl9x zrl k:+,l ences correctly defines a meristem?ze9:w, xlvl1h+l/ xor9kx7hc

  When does the random orientation of ho 1wteo 20cd) f8ymfiy.mologous chromosome pairs occur?

  Which process does not occur during me* u-4+ic7s0kwvb: x/ ozyq bfgiosis?

  If a cell with a diploid number of 36 lem2hc z;awr)z*t +f.m ,qy2mundergoes mitosis, how many chromosomes will be present in each daughter cell afyre,;wmzmf2cmlt 2qa+)* zh . ter cytokinesis?

  The image shows a microryg +lylpta-uv5h ;y 6:w0 r/pgraph of a cell.


What explains the appearance of the cell in the micrograph?

  Which statement(s) axo(tko-h2pd 1m ez+15uz1rvjl 0d pr/n0x*imbout 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 Down syndr+ *lflqao b/l5l j1ws,ome.

Which statement is not correct?

  In the cells of a horse (E. caballus0xmi.xeg h/o -) during prophase I of meiosis I there are 64 chromosomes. What is the haploid number of chromosxmeox0 - /hig.omes?

  Which arrow is pointingq9o; t 1j z (1ujkwkoe;qj *8wt6+pnzz to a chiasma?

  The diagram below represents the structure of a shoot apicvnwx/m5) wtj0 al meristem. Which row in the table correctly identifies the proce xmnw0 j/tw5)vsses occuring in the structures labeled in the diagram?

  How does meiosis promot,no* /bu qyf5bb40gz ue variation?

  Which of the following statements isln8 i;;eruc6w d:uexx z58a ss.9jcf8/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 from two homolog6-od x bz94u/qva7vnoous 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 )ms; 54 sjv1pq-jv 8rm3ndzp/usd+f w primary tumours as a result of t q+3 vrdj8zp/ ;jnws54fmv ps1m-s)duhe movement of cells?

  How many chiasmata are present in the di.rx yvx), lo9z4f -ujlagram?

  Which statement is a similarity r7l* w:zabq;ri8u )dubetween cytokinesis in animal and plant cells?

  Which stage of meiosis is matched to the d -:ww .3q7vjh x)3siv xu*foov y4:yqcorrect description?

  Which statement(s) are true of meiosis I but not meiosis xk (e*u2szu9jII?
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 afterg548s af dj7)lubbd )z the first meiotic division. This results in the formation of one large cell and one small cell. What is the fateju7dg d4fs)bl a)zb 85 of the large cell?

  Which row correctly dnh t/equ6:sroy6m0 m -escribes diploid and haploid cells in humans?

  The following table shows the diploixwrv qq.vbv-l-n *:h 9d chromosome number of a range of species.


Which of these statements is correct?

  What conclusion can be drawn from ajjt;8 us.+it(obt.p the karyogram below?

  Which of the following processes is characteristic k9vfdr-+,ld,cygpl:mw 1 oj3of the meiotic and not the mitotivy+goc:,l,fd 3mj1l rp kw 9d-c cell cycle?

  The diagram represents a bu:pyfma1pd*m5 d 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 (Paj;d3j jsth-c8y8y ak: y+ zh1mn troglodytes) is 48. Which row shows the correct chromosome number for different cell types and cell dijt3jy8 m s1zhy-ja :d8+chk;yvision stages?.

  At the end of which phase of meiosis I does crossing over r l fe6105ldvfzx5pd5occur, and what is the outcome of crossi0lz rxpdl5 d 1fv565feng over?

  Which of the following statements does not describe a step in the sodium-p-ns r ezyb7x9np94pq f e:p,o8otassium pump s8p p4r9penz,o:9bnyq - xef 7cycle in the neuronal cells?

  Which row in the table below is true offlhj:jj,+u 3 s 25cjnv meiosis?

Membrane transport is important fgfr b q3c/;mr uik 918seth4,qor allowing particles to move across the cell membrane and respond to changes in the chemical co ;4b tqiqe9 sr,gu31kchrf /8mmposition 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 is1eut8eoh f d;9 :j7zr- up;ycs 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 concentro(n/3(c j0 gppj0 aetiations of different cyclins during the cell cycle. Which cyclin is invol(nj030etp pa cj/oig( ved in preparing for DNA replication?

The diagram below shows chromosomes during meiosi)hj vc gd8rkb)-a c6jsgw 7./rs.

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 iuk - ;m)tip1ypnvolves the separation of homologous chromosomes?

  The mitotic index of throat tissuaai ki,ejo.ganyh93q 9;pk* 3es taken from 4 different patients is shown below. Whi3k,o 9e.a nqk aa;y9j3hig ip*ch patient is most likely to have cancerous throat tissue?

1.Draw a labelled diagram to represent the process of crossing :o+vc7tinykvk).h;z over.

2.Compare and contrast random orientation and crossing over.

3.Outline the stages of meiosis.

  The image shows an abnormal human b 2wzcvhm+; e3karyotype.


What is the abnormality in this karyotype and its cause?

The graph below shows the relative amount of DNA in one cell during one comple zj.zvu j/zjp4;t.cq1te cell cyclc .41qpzz.;vjut jj/ze. 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 git) 9-1rykcc dvk jf)8 /qtq(homozygous for brown, long hair and a female cat-8ciq1ktr/9v(yc))gtf kq d j that has black, short hair.


Which of the offspring has a recombinant genotype?

1.Outline how polygenic traits can show a normal distribu )zdp. uin5/wntion.

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-sister chromatids p/ ch(kh:bgy/shown ing b/h ypchk:(/ the diagram below?

  The photomicrograph shows a pollen grait;u pspt8;b )pn from L. candidum (Lily). Which stage of m8u b ;ptp;pst)eiosis is shown?

1.Outline the events which would lead to an individual being born s 6s tte)0+ppswith Down syndrome, which is characterised by the presence of three copies of chromosome 216)sp0t pts+es .

2.Explain how meiosis increases variation.

3.Outline the stages of meiosis.

The mitotic index is an indirect way of measuring plant growz *z .a)sb8 3- i epucdri991burqphf8th. A study was conducted uzhb zarp1cp-i u.99 sq*df8i )r 8be3on white onions (Allium 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 -f.au1u -,f ;u lsl(kptg.g obare two ways in which cells can divide. The diagrams below show two cells from a(-,p ku- b.u;u1 sl.g ltfogfan 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 expressiond 30euvn/ yuh6 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 8xmugzvd /-t , h(3d1iq, in different stages of meiosis. Whic (3,g vqt d/z-mixudh1h row correctly names each stage?

  The micrographs show four phases bh9 t (hp r0vnunh/oqm+5x2;s of meiosis I in a plant. In what order do these phases occurn hsr5/;q0nm 2 ( +tu9pvhxhob?

Mitochondria are responsible for supplying metabolic energy in eqk(4higg) ey9d 9lt7 aukaryotic cells. In most eukaryotes, which reproduce by sexual reproduction, mitochondrial DNA (mtDNA) is inherited from only one of the parents: the mother in th ( 7ktqheaigd)9g94y le 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, h/tq)u p)san cells in different stages of the cell cycle in four samples of lung tissue from four patients. Which tissue has the lowestsp /quh) n,a)t mitotic index?

  The diagram shows the dominant cyclin/CDK complexes at dil c7s2 vfzoppqfr66*.p,)q nyfferent time points in the cell cycle. Which cyclin/CDK complex activates DNA ,qorpy vf7 2 6fspqp.*6)nzlcreplication machinery?

  Studies have shown that genes such as Cyclin Dependent Kinase 3 (Cxd b o;9i,o3,gptji h.DKN3) are highly overexpressed in cervical tumours.;bph.39,x,oo t jid gi


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 during th0 cumx ; a*e.dwgxhn1)d0k4qnaj (2a ne cell cycle ?