The graph below shows the relationship between maternatcp9;*xl, z)aaq 6 kval age and the incidence of non-disjunction. What relationship is suggested by the data in the graphavzap* a )klctxq, 9;6?

  Which stage of meiosis is r 14vor.a: ful x97jaxy2a )asrepresented in the diagram below?

  The diagram below shows chromosomes during meiosis. f:lkcu919ve b*fze c ,


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 th 79 0b:jje xv5ektegu*e number of alleles of a single gene which would be present in the nucleus of a cell as a result of e7exekgbj vu*5jt 0e9:ach process?

  Which keyword is matched ztchx*62jsm :zsc7t3 c0) jmv to the correct definition?

  Which statement(s) about mitosi,.g mpsgpq94 qs 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 ldd)u)y, qb3q yetter points to a cell in anaphase?

  During which stage of mitosis does the nuclear envelope break m t:oy 7vbv b0900 6ttjmrktibd8+g0vdown?

  Which one of the following transport proteins only carries ouc vyo n ua;+csaq30v(,r +i/iut active transport?/;virq(a o+yaucci 3nu0s, +v

  Which process does not happen in the shas odrcruz )/le7 0w33oot apex?

  Which type/s of membrane transport do/does not require energy expendit2p /2ypqkxr r4p2myz6ure?
I. Facilitated diffusion
II. Active transport
III. Osmosis

  The diagram below represents a cell with a auxt;aef . ;.jdiploid number of 4. Which stage of cell division is the cell cujteua;;afx .. rrently undergoing?

  The photomicrograph below shows a root tip meristem. Which of the following -q v.x .l- 7orrcxu3agsentences correctly definesr.uq-.o l-x gaxcr7v3 a meristem?

  When does the random orientati3xdt e x*br9l6ih4f9 ef*4-ht6ylo mqon of homologous chromosome pairs occur?

  Which process does not occur durw0 f:k:g,x lqjing meiosis?

  If a cell with a diploid number of 36 2i 86/vg ov-svr8zfhn undergoes mitosis, how many chromosomes will be presentg r vvf28s-z6i n8hv/o in each daughter cell after cytokinesis?

  The image shows a microg8 5hptys4yl 7graph of a cell.


What explains the appearance of the cell in the micrograph?

  Which statement(s) about homologous chromoso tm9 x zkv- o8ezejvhuh)c4.:*mes 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;cmkmro;iv4:;uwm 4 gome.

Which statement is not correct?

  In the cells of a horse (E. caballus) during prophase I of meiosis I there artvu-0n8s)z; cin5z ueze5 sdt2e4k3o6j8n as e 64 chromosomes. What is the haplo2;id58a 4 8noune-zc jss50etu)3 z vsze6ktnid number of chromosomes?

  Which arrow is pointing to a chiaty4) ,kd 28dr7uyri6yt9 t +pbua(whvsma?

  The diagram below represents the strmj) /wff:y +hxucture of a shoot apical meristem. Which row in the table correctly identifies the processes occuring in the structurf/hwx)m: j+fyes labeled in the diagram?

  How does meiosis promote var4lq).u8 f/oy sc/ilixiation?

  Which of the following statements is/are correctyb: al4pn)/ac77z d ln for meiosis?
I. It is a reduction division
II. It involves random orientation
III. It produces genetically identical cells

  The diagram shows gametes pro.p:sxov fh: lx/ dy6)uduced from 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 h tqw2w u8hpf1/tma.ll) hgt/ qg+w(*tumours from primary tumours as a p hwt+fu 1*.g/q hht8ta2m)qwgll (/wresult of the movement of cells?

  How many chiasmata are presenj )u fucsq- y8 -)1)lt2zpcxrot in the diagram?

  Which statement is a similarity between cytokinesis in animal and plantjdwsplzgxy 929 ;g q** cells?

  Which stage of meiosis is matched to the correct djf; jfb1 y;cis88+3n ipwtx(le- 3eqdescription?

  Which statement(s) are true of meiosis Ive+1pk g*agytav9o ti+;+ *)ic,yq kmq3 /pa b but not 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 oocyib(i0*pr2 ab xyx:mo6te after the first meiotic division. This results in the formation of one larg(062:ymx*iobpa bri xe cell and one small cell. What is the fate of the large cell?

  Which row correctly describel ejf5, 43fylws diploid and haploid cells in humans?

  The following table sho;j3b 5+e4sp c +)xovoed +mnvwws the diploid chromosome number of a range of species.


Which of these statements is correct?

  What conclusion can be drawn from the karyh6;ds2zttx1mwf*t ; uogram below?

  Which of the following processesk2 t jh.4b12:gmhuwqv is characteristic of the meiotic and not the mitoth2bwv:j gt1 .4qmhuk2 ic cell cycle?

  The diagram represents a bud with a shoot apical merista,: -qc fzmdzpu-q5: jem.

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 (Pajnezu8k12 . .u*qbpjt n troglodytes) is 48. Which row shows the correct chrj jn *uuepq .1bk.28ztomosome number for different cell types and cell division stages?.

  At the end of which phase of meiosis I does crossing over occur, ann tul8r2ip8f:wgy 6dsfga( *+d what is the( 8f w:yaugfg68d2n p *ri+lts outcome of crossing over?

  Which of the following statements does not describe a step in the sodium-potassp;oc 40 boff,hcc8 b,:8hxlbgium pump cycofl, 4,f cb;8gb 0cbxpho8c: hle in the neuronal cells?

  Which row in the table bellr h1h**1li 3.uf puujow is true of meiosis?

Membrane transport is important for ach+n gusug t.) (alev79tcf/6llowing particles to move across the cell membrane and respond to changes in the chemical composition of the extracellular fg)agcft.+c he/7 ( v ulns6tu9luid.

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(ppzh*9o8xsmc:h0 4bykn 1 0bou d7bk is 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 concentrations of different cyclins during t82mnfe:p7gy- hkgdet75 /ikjhe cell cycle. Which cyclin is involveip/t7nk8 f j 2h ggdeme-5y:k7d in preparing for DNA replication?

The diagram below shows chromosomes during meios7l kagbw /3/ om(xzt;wis.

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 homologoc8l5pf l nwr3tt8s4d,9yhq+dv0 r;scus chromosomes?

  The mitotic index of throat37 2 7towgoidhf e)rr) tissues taken from 4 different patients is shown below. Which patient is )gf2r wdh 3o7e i7ot)rmost likely to have cancerous throat tissue?

1.Draw a labelled diagram to represent the process of crossing ovyz()q16m. n hqcf m)-k-zqzaqer.

2.Compare and contrast random orientation and crossing over.

3.Outline the stages of meiosis.

  The image shows an abnormal hum eky ;7ly;qf fb(zy:k3an karyotype.


What is the abnormality in this karyotype and its cause?

The graph below shows t gvml:gt3)ves3*pjx8: z elel9es:9i he relative amount of DNA in one cell during one complete cell cycle. Each letter represent3:x:j ggslpl)elte983e e* im9 sz vv:s 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 homozygous for brown2oct4/::xw0 sculjmx , long hair and a female cat that has black, short hair.x:xj c2c/ 4m:0stulow


Which of the offspring has a recombinant genotype?

1.Outline how polygenic traits can show jbt2iwy( 7kkv4vu 8j-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 result from thtk5m9 bs( hh+kje+x4w:8 o pgyv/ (sghe crossing over of non-sister chromatids shown in thsps8gv t/(gem wkhxy+ohb j 5+(kh:49e diagram below?

  The photomicrograph shows a;o/p 9vn99f(emocnu1vs loj73 .wlr -b xb; rw pollen grain from L. candidum (Lily). Which stage of(vlopon /.f;9jvbo9 le; b9m wu-wr1crxn 7s3 meiosis is shown?

1.Outline the events which wou97cv7sr s06id,5xnvzwh d a9 uld lead to an individual being born with Down syndrome, which is characterised by the prexacd979nzv5uh is7 6rv0w ds,sence of three copies of chromosome 21.

2.Explain how meiosis increases variation.

3.Outline the stages of meiosis.

The mitotic index is an indirewbpw0 k(y ;q) ml:/gmw i2pkga(k/wrbd e-3e3ct way of measuring plant growth. A study was conducted on white onions (Allium cepa), under controlled conditions in a lab, to investigate the er/2 b 3kgy;a mwlwwegp:(wk pi0/qm)d b-ek3(ffect 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 diarqhj)8dk; sk ;grams below show two celhkrdsq;; )kj8ls from 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 stem groyhy5w0) zvgh) wth.

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 dipug( z lxe; k48* grz,s)dspi-ploid number of 8, in different stages of meiosis. i,egzg;kxdp (s 8l-4)r p us*zWhich row correctly names each stage?

  The micrographs show four phases of cy-ym ad r;2/ dzqia/fk/- dq3meiosis I in a plant. In what order do these phases occurz/myd23/fqd/ar i c a-k-yq ;d?

Mitochondria are respp--qebvmky . 7onsible for supplying metabolic energy in eukaryotic cells. In most eukaryotes, which reproduce by sexual reproduction, mitochy-vbpe. 7-m kqondrial 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 lu4i wc68:r: 6djoltmin different stages of the cell cycle in four samples of lunmwi:l: uolt8j6 4d6r cg tissue from four patients. Which tissue has the lowest mitotic index?

  The diagram shows the dominant cyclin/CDK complexes at differenthd/t tcy lk.k)o 7+ irj)h(qh/ time points in the cell cycle. Which cyclin/CDK complex activates Dt kih)jyl /.tc(q o7)+rdhhk/NA replication machinery?

  Studies have shown that genes such as Cyclin Dependent Kinase 3 cqq4n da.h;5g (CDKN3) are highly ove.hn4c dqgaq5 ;rexpressed 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 concentration of cyclin E the highest3k1e o4 :,y :y* kdoecuf;imdv during the cell cycle ?