The graph below shows the relationship between maternal age and+mv pwcfkyyi2* g* g/mmbm++5y;nqn/ the incidence of non-disjunction. What relatgb+/mfyn*2v/yg *k+m y qnc 5imwp+ ;mionship is suggested by the data in the graph?

  Which stage of meiosis g.sa.kqi b(n5.2ou6g1wz8mo m( eeoq is represented in the diagram below?

  The diagram below shows chromoszlssxv/lg:6gi6zmm l1+t8 4 k omes 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 the number of/qxh*dj*/1 yneqyx ; q alleles of a single gene which would be present in the nq*enxqyxd*/; jy /1qhucleus of a cell as a result of each process?

  Which keyword is matched to t.m4w.lt 8hutut vz .0the correct definition?

  Which statement(s) about mitosis *1env(/zoy(m wipj a-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 ;yl:f;+y tap;b)pl r( sc3roiletter points to a cell in anaphase?

  During which stage of mitosis does the nl7 pntq: z9gu3uclear envelope break down?

  Which one of the following transport po 0y6d2us,, ;.slza3iqcxm.1 ;skj df5izjz kroteins only carries out active transport?5z ds; y;zj0 mil,fk1zq i63. kasouxsj, d2c.

  Which process does not happen in the shoot atne7xj 0vts(;vgg4 o;q.a4ae pex?

  Which type/s of membrane transport do/does not )ikbdyo9x1g(9lhlv bklb5 ) 6 require energy expenditure?
I. Facilitated diffusion
II. Active transport
III. Osmosis

  The diagram below represents a cell with a diploid num*av;0( /h9 e5d ygjyy8qew redber of 4. Which stage of cell division is theagy ye h 8j5/*v;r0w9qed( dye cell currently undergoing?

  The photomicrograph below shows a root tip meristem. Which of the fo k5q2bx; o.o))mo wligllowing senten.)gm)52; bqoo ixlw okces correctly defines a meristem?

  When does the random orientation of homologous chromosome pairs rrh *n /uw5by 9yb ,,az:2zkuvvk:8wjoccur?

  Which process does not occur during mei0f )a/vr rnu)posis?

  If a cell with a diploid number of 36 undergoes mitosis, how many chr(qu njzl i83)zomosomes will be present in each d3z)n8 zu(qli jaughter cell after cytokinesis?

  The image shows a micrograph ol 2hq r/a0axw+ ckd.8mf a cell.


What explains the appearance of the cell in the micrograph?

  Which statement(s) about homologous chromosomes icc3;jsgnlomk1 yx) y+k 4 5 6p qyxrfr*a000cws/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.eo0cg7bmlm 0*

Which statement is not correct?

  In the cells of a horse (E. cab (ttpd e+)y8tsallus) during prophase I of meiosis I there are 64 chromosomes. What is t t+ pte(y)ds8the haploid number of chromosomes?

  Which arrow is pointing to a chiasma?21 kqq9jrjkhq q;0o 5h

  The diagram below represents the s e4 nur2i3,mg/i*p ps;znx.tstructure of a shoot apical meristem. Which row in the table correctly identifies the processes occuring in the strucpu. n/ pir;ni4s2*emztx3, sgtures labeled in the diagram?

  How does meiosis promote vari5/hub91gbnp zation?

  Which of the following statements is/q;pwfn2nq:)kz.y +ra e5k: jn 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 prgtkb 53 j)z5kboduced 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 e id) avb qof50y109taof secondary tumours from primary tumours as a result of the movement of cee1od0 v0ta9y a iq5)fblls?

  How many chiasmata are present in the diagram?.xs4zpgm;gv+

  Which statement is a similarity between cytokinesis in 6/pn d.ukt;dnanimal and plant cells?

  Which stage of meiosis is matched to the correct d fd/5*biot/ujescription?

  Which statement(s) a r9zxzqcv1 0m8:lfr l7re true of meiosis I 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 oocyte after the first meioticp;a(c(ifjjhkw2hl*5 v 94e+y /t twb d division. This results in the formation of one large cell and one small cell. What is the fyd;cht4efv wti (bw25 *hklja/9+jp (ate of the large cell?

  Which row correctly desc7t opa 0h)ca 6ykz6d9dribes diploid and haploid cells in humans?

  The following table shows the diploid chromosome number:bn 3.e)u d-jv ;dicu e9 v2dp04wxwtr of a range of species.


Which of these statements is correct?

  What conclusion can be drawn from the karyogram bel9*kw.bg .o pu9ricwj)ow?

  Which of the followin7vms11gi- lw ug processes is characteristic of the meiotic and not the mitoti1 smlu71g iv-wc cell cycle?

  The diagram represents a bud with a shoot apicaq7p9o , bd0kwwtt71yvl 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 troglodytes) is 48. Which row shows th,b qt(prs c 2ekep/ice -p2h5*e correct chromosome number for epp ce(e,i2pr*q c/tk2h sb5- different cell types and cell division stages?.

  At the end of which phase of meiosis I does crossig:smevo2vaf8 z u.; u4ng over occur, and what is the outcome of crossing ovf:v u8 gu;2a s4.zmoever?

  Which of the following statements does not describe a stepbh2y+qzd:s +dt p+0jh rv+. rt in the sodium-potassium pud dz.h vjq+s+t2pbh0++r y:rtmp cycle in the neuronal cells?

  Which row in the table bext65mknfgz.*j v 4cn:wjrd +8y eke,+low is true of meiosis?

Membrane transport is important for allowing particles to move across the celc c)n*5d6 2otgwl r-mll membrane and respond to changes in the chemi2ctgo6lw-nr mdc) 5l* cal 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 reguli9bi,s+5ql ja l r9u:sated 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 concentrationsrm28:j 0iliof 4l(, nmjgen(w of different cyclins during the cell cn jifm:w,2 4mjl0ielo8n(r( gycle. Which cyclin is involved in preparing for DNA replication?

The diagram below shows chromosomes during meiosis.5 f,kh rol+co*

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 ;gwj5(bchb g2 homologous chromosomes?

  The mitotic index of th(. qugx v-bxv8roat tissues taken from 4 different patients is shown below. Which patient is most likely to have cancerous throat -vxb .qg vxu8(tissue?

1.Draw a labelled diagram to represent the process o,wxmxb9sp)-xx 9 92pxc x wf3jr-9 a0n;mbttgf crossing over.

2.Compare and contrast random orientation and crossing over.

3.Outline the stages of meiosis.

  The image shows an abno6phuekh7*avedu2 5 3 vb g3g6mrmal human karyotype.


What is the abnormality in this karyotype and its cause?

The graph below shows the relative amount of; s)yc 8s,szov DNA in one cell during one complete cell cycle. Each letter represents one stage of t s)ocss z;8,yvhe 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 cagpy1t- q g7xh aa /7zdrg /8dym9ffn42t that is homozygous for brown, long hair and a female cat that has blaca8h2/ndzm y 1rg9tafg74/ gpq7x-ydf k, short hair.


Which of the offspring has a recombinant genotype?

1.Outline how polygenic traits can show a normal distribution 9yja5/gbxv/-oxidxuk* 8 e1p.

2.Outline the differences and similarities between homologous chromosomes.

3.Explain why expected and observed Mendelian ratios may differ.

  Which gamete can result fr:ck,+6ux) n;l z ogrqsom the crossing over of non-sister chromatids shown in the diagram below? +,;qs l go)uncz :rkx6

  The photomicrograph shows a pollen gr a65zqivo* j7yain from L. candidum (Lily). Which stage of meiosis 67v q*jai5yzo is shown?

1.Outline the events which would lead to an individual being born wie03h b:os e)erth Down syndrome, which is characterised by the presence of three copies of chromosome 21.3e0s: oeehb)r

2.Explain how meiosis increases variation.

3.Outline the stages of meiosis.

The mitotic index is an indirect way of measurig6du v6,j d1xvvg x;m;ng plant growth. A study was conducted on white onions (Allium cepa), under controlled conditions in a lab, to investigate the effect of soil pH on the mitotivum;g j,dx6vx ;g6vd 1c 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 t2;gl.1btl ct o xls0:kwo ways in which cells can divide. The diagrams below show two cells from an organism with a diplxl1kol :blgc0 ;.2st toid 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 g 8zj1m3b/h :ics2d vc7)z olxxrowth.

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 +b0- y :sasi gr2p7r(r2tijmqof 8, in different stages of meiosis. Which row correctly names ea i i- g0:jmsq r2t(+rsb7py2rach stage?

  The micrographs show four phaayf+)l+gwcf0 .kxca-;l ncf 5ses of meiosis I in a plant. In what order do these phases occurk)-cwlf lnf f+c+5g ;y.c0aax?

Mitochondria are responsibleyrs 8+gyzy mdw. y4vi) x2/lhjpkv,5, for supplying metabolic energy in eukaryotic cells. In most eukaryotes, which reproduce by sexual reproduction, mitochondrial DNA (mtDNA) is inherited from only one of the parents: the motvrj i ,48)mg,/ . h2wlypvz5kxdy+syyher 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 di(6+f0or2kl u fh89a4 sn ylxqefferent stages of the cell cycle in four samples of lung tissue from four patients. Which tissue has the lowest mitotic iyul 9roqf( 20x48nh6f+klsaendex?

  The diagram shows the dominant cyclin/CDK complexes at di.lvv4)qdvf14s2 v xoifferent time points in the cell cycle. Which cyclin/CDK compl42ivlqs1 vxv.v) 4f odex activates DNA replication machinery?

  Studies have shown thayff dffl. x7kd)awk1+ orzh bf-;3-inb72x7kt genes such as Cyclin Dependent Kinase 3 (CDKN3) are highfrno7)xki -h f2-d.7kfw 7aylf +zxb3;d1kf bly overexpressed 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 cycliq3 j-od ((n.rl )pfp b1wacx4xn E the highest during the cell cycle ?