The graph below shows the relatvt3 5tuj)tv*rup58sx;ew 3,0fos a s1gehfh 5ionship between maternal age and the incidence of non-disjunxjv5htg)r,p3s18a v3hftfs;wu ot0see *u55 ction. What relationship is suggested by the data in the graph?

  Which stage of meiosis is repres: 1 h5ixkly+ayented in the diagram below?

  The diagram below shows chromoso*+jlv m32; h pg5kts0qd y7rvymes 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 numbet c xg)zv:9w8kr of alleles of a single gene which would be present in the nucleus of a cell as a re9v8xg c) z:kwtsult of each process?

  Which keyword is matched to the corre0. jb7wso5rkhe pi2:ijxsws5f;jg8- ct definition?

  Which statement(s) about mitosis is/are hv, j. qy wupxs790 el/v;)i0ecub z8ltrue?
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 to*73*zj/ul bi vq(oer*cua ee- a cell in anaphase?

  During which stage of mitosis does the fw. 2f-)g ydvynuclear envelope break down?

  Which one of the following transport proteins only carries out act97+xst97qg3kezh8xu w1d8i 6k i f pkmive transport?z6hwxgdf9 q tmikixs+ 7u1k 883 ke9p7

  Which process does nr; z1 sn2yiik(ot happen in the shoot apex?

  Which type/s of membrane transport do/does not require energy jtjhrk17 )-kx expenditure?
I. Facilitated diffusion
II. Active transport
III. Osmosis

  The diagram below represents a cell with a di lq jldesm//c ev8 0:zjfc2j)mj (oz90ploid number of 4. Which stage of cell divi0 ojjmj) ecz8d z09s/fm:jlc/qve(2lsion is the cell currently undergoing?

  The photomicrograph belfguq3(/ 4tsh mow shows a root tip meristem. Which of the following sentenc4shgfmt3 uq(/es correctly defines a meristem?

  When does the random orientation of homologous chromosome paizg2 vra7e n+z9rs occur?

  Which process does not occur during meiosisjtb j, 9c2r(isoq8s7c jjc:b/5j hkc9?

  If a cell with a diploid num1.uwe k 5neonxlc+1 9rber of 36 undergoes mitosis, how many chromosomes will be present in each daughter cell af511wn ckxurl n9 ee.+oter cytokinesis?

  The image shows a micrograph of a ce7acr 6+x*oa+ *dolays4d: ukz ll.


What explains the appearance of the cell in the micrograph?

  Which statement(s) about homologous chromosomes is/are not true?g/(ba)xi k d(fc5owo 9
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 in mh f1y*ql-k -iw9:ghjdividual with Down syndrome.

Which statement is not correct?

  In the cells of a horse (E. caballus) during prophase I of meiobry nolyiw0 b6d65(;d sis I there are 64 chromosomes. What is the haplodyi50 (;bl yrd6nwbo 6id number of chromosomes?

  Which arrow is pointing ck/q g1;gs0 f;emx*avto a chiasma?

  The diagram below represents the structure of a shoot apical meyma7+iffqu**m u1la;5wyx 2 z ristem. Which row in the table correctly identifies the processes occuring in the structures labeled in thexw1im7fa 2*u *; ayyq ml+5zfu diagram?

  How does meiosis promote variatio dj 5crm4gem0r/d+rmrw04wrvku i ;95n?

  Which of the following statemep+3pgdgq4v9 qxq,p r2nts 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 from two homot fbq lpb3 l0z;/b6yr.logous 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 tumouahepx75:8( cvttf* pqrs from primary tumours as a result of the mapc7xt5:8qpf( * th veovement of cells?

  How many chiasmata are present in the diagram6usgcbi,c+r m zq: die 3b0m--?

  Which statement is a similarity between 8 fh7ffk n/dfec54 e8fcytokinesis in animal and plant cells?

  Which stage of meiosis is matched to thev6rq1b6ss/ k tm 3d:tf correct description?

  Which statement(s) are true py-e x36ajx1vo )naos 8zu(5uof 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 meiotic division. Thisw08;m,blt b pi results in the formation of one large cell and one small cell. What is t0ipbb 8 w,l;tmhe fate of the large cell?

  Which row correctly describes1tohn)rb vf/ ,7zkeug68a5y b diploid and haploid cells in humans?

  The following table shows the diploid chromosome number of a range of specizc) :) rjm ;s wj8ttintkhmn d74,0i:ces.


Which of these statements is correct?

  What conclusion can b (:njq(rlan1 ;a,de xutz3w5ie drawn from the karyogram below?

  Which of the following processes is characteristic d l;w8kr*8gbzof the meiotic and not the mitotic cell cycle?rd 8gbw; lz*8k

  The diagram represents a bud with a shoot apical meristem. cc 0doe w*3rfo(7v*q g

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 ohix o13)l26z9cdx*kmei1a(bx vm-kb;7 k ar) is 48. Which row shows the correct chx1bzh;k-xikob6la ic93o ax e1*7vr2(mk d)mromosome number for different cell types and cell division stages?.

  At the end of which phase of meiosis I does crossing over occur, and what is thqx2ccp es0mlu,c .9; xe outcp;qclxxce2muc.0s, 9ome of crossing over?

  Which of the following statements does not des kb +2pcn,z+12fho*9ytfj kozcribe a step in the sodium-potassium pump cyclep fzth2ncjk b+*zofk+, o y291 in the neuronal cells?

  Which row in the table bel::ysx8btuo4 low is true of meiosis?

Membrane transport is important for allowing particles d9m8tdw7a/cg* l:sk/v 9 w ehlyv7dw+ to move across the cell memdw9 t w8:k+7w/9vm 7cavly hdls/d*egbrane 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 mitosisoy- uw /shguu.0ad*(e 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 (up uyf*.v:d117io t/en jgv jthe concentrations of different cyclins during the cell cycle. Which cyclin is involved in preparing for DNA replication? .j* y1juou7ve : t v/n(fip1gd

The diagram below shows chromoaf6xe pme:/1t5z*ac s somes 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 meiosis involves the separation of homologouso a9 y)ifxaj:) chromosomes?

  The mitotic index of wmkqwj0);a 3hthroat tissues taken from 4 different patients is shown below. Which patient is most likely to have canj 0qa;hwwm k)3cerous throat tissue?

1.Draw a labelled diagracm r rve10fk .9ltw -ye:kyr o 4q4k.okrn0s+5m to represent 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 x aa,cv,yvh35,dzly . human karyotype.


What is the abnormality in this karyotype and its cause?

The graph below shows the relative amount squt56 s*+ blwrxy8. aof DNA in one cell during one complete cell cycle. Each letter represents one stage of the cell cycle.aslur6tw.sby5+q 8x *


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 brown,avil.my8bgd4l)sjf q t ; *9q7 long hair and 4mgy q.a ls)ljfqtvd;8b*i 79a female cat that has black, short hair.


Which of the offspring has a recombinant genotype?

1.Outline how polygep1w9hbvn 1cc s,0hf d i8esb8.nic traits can show 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 the crossing over of non-soebf jcn :+ u37yy5,qgister chromatids shown in 3:eoqj7+ybuc gn f,5ythe diagram below?

  The photomicrograph shows a po2yhr; i7swbpixg)i:dg ) 5w. pk. o+lgsw-n/ ollen grain from L. candidum (Lily). Which stage of meiosis is showd;g )g2x.kg/ihs.lwpw5r b i7)oipoy+ s-:wnn?

1.Outline the events which would lead to an in47k 1c5m :uon86yw9muko aqpz dividual being born with Down syndrome, which is characterised by the pr49ykq kc1m56:puuwz7 8o namoesence of three copies of chromosome 21.

2.Explain how meiosis increases variation.

3.Outline the stages of meiosis.

The mitotic index isj*8hw2r cgpe:9w9f u z an indirect way of measuring 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 mitotic indu:jc9 gf9h* 2rezpw 8wex 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 ce-es q:c mhjs1b* ry*9klls can divide. The diagrams below show two cells from an oqr*mej*by c-1 s:9ksh rganism 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 steovpc(q x6jk( tro,(1h:ni x z4m 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 (w, 9miab )dihstages of meiosis. Which row correct iw9hb)(da,imly names each stage?

  The micrographs show four phases of mei4awm0 )i /avivoq/ ,s45cn:upsx .pug osis I in a plant. In what order do these phasesgv xw,a/ip50oucn4p/.m ssi4aq:v ) u occur?

Mitochondria are responsible for supplying metabolic energy in e*v4h2j -efj)doq )ml/r dk6l qukaryotic cells. In most eukaryotes, 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 iq)) lj-rkhfdvqldo4e */6m j2n 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 twe qyqi+h5ma5byqw81 , xrd/(he cell cycle in four samples of lung tissue from four patients. y18i 5e/qw 5qwryhbmq(,a+dx Which tissue has the lowest mitotic index?

  The diagram shows the dominant cyclin/CDK complexes at diffe :td 59wnif0:f lgahbh;7 c)scrent time points in the cell cycle. Which cyclin/CDK complex activates DNA replication mhs 90:af:7nhb5 )lf it ;wccgdachinery?

  Studies have shown that genes sucteny;0 i:q0fph as Cyclin Dependent Kinase 3 (CDKN3) are highly overeie;0y0q f:p ntxpressed 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 highest during tameooa- 79( xn2iel 1s.t.ozv(fhn7hhe cell cycle ?