The graph below shows the relationship be)b;39jdl c .rj g)x(iobq 7toftween maternal age and the incidence of non drbi ;oj9x)q3)(f.cb7oglt j-disjunction. What relationship is suggested by the data in the graph?

  Which stage of meiosis is represented in the diagram kj 2 :.kv5+zelvrvqp /below?

  The diagram below shows chromosomeslaze4w,ysl3;zenoc7 q2 4 ; gr 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 o0 s 4u;ha/jv9 (dhcp.fte kf3gs;z yu-f alleles of a single gene which would be present in av .uz st;hcg 09skf y/d4 eu3;p(-jfhthe nucleus of a cell as a result of each process?

  Which keyword is matched to the correct defit lvahw c zp c,p*w:o+*10i 4s64zkvblnition?

  Which statement(s) about miton4y690gpj r uesis 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 to a cell r +x(jrecom ylc0kza*i : p07qnm4q27in anaphase?

  During which stage of mitosis does the nuclear envelopb.sjf6-)9w7tmkcqyw ew2fc tf3r 6 sr lr)5c2e break down?

  Which one of the following transport proteins only carries out a5u yf icat,)j(ctive transport?(a fju5 )cyi,t

  Which process does not happen in5-mq fdk8dq *39sz-d *ntqpi v tp8ll4 the shoot apex?

  Which type/s of membrane transport do/does not require energy expends aif-z v;y:q-iture?
I. Facilitated diffusion
II. Active transport
III. Osmosis

  The diagram below reprezmn)f(a hrb d9;s(q/ zsgj2w/sents a cell with a diploid number of 4. Which stage of ce ;/)w9qbrj/mgas(z z2 (n dfhsll division is the cell currently undergoing?

  The photomicrograph belo; ,6tlnkx b3cow shows a root tip meristem. Which of the following sentences correctlo3 t;kc ,nbxl6y defines a meristem?

  When does the random orientation of homologous chromn u8og5n7jwv6mt + 1(bxlz /orosome pairs occur?

  Which process does not occur during me-b-u7 atb( hfliosis?

  If a cell with a diploid number of 36 undergoes mitosis, how many chromosomesd6188 c/bjnhp ::l3y yci yapk will be present in each daughter cell af6jy :dni3b8y 18cca: hkypp /lter cytokinesis?

  The image shows a micrograph of 6 gj3zb8q9 jrl2fe5hrn3 xx)c a cell.


What explains the appearance of the cell in the micrograph?

  Which statement(s) about homologous chromosomes is/are noa ;gm k9qxfb8.zrj8 1zt 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.o 6 y(/;uk6x 0qmnciql1h51 m6 ewfqbg

Which statement is not correct?

  In the cells of a horse u3s:2af4bxz yr jb:3 vhbn3k5(E. caballus) during prophase I of meiosis I there are 64 chromosomes. What is the haplvn ::zafkr uj3y4b s b323bx5hoid number of chromosomes?

  Which arrow is pointing to a 9mg4f 9xan;m 6gsg.4ktkhd, uchiasma?

  The diagram below represents the st 9l j/6q,qsc(9f v5 jxuclp0wmructure of a shoot apical meristem. Which row in the table correctly identifies the processes occuring in the structures labeled in t9(9l5cusxw 0q,j/v f mplj6qche diagram?

  How does meiosis promote variati4)gnixu k7y3 iqa;1j nj da3/jon?

  Which of the following stabkuha )1sv.n ,v ozdhfxc+,;0tements 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 homologous chromosome2nr44sl k ;g1dbvb4 chs.


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 primary tad.4 :ogjd3k bumours as a resultdgd4 a3:bj.ko of the movement of cells?

  How many chiasmata are present i8ij62himc e w4n the diagram?

  Which statement is a similarity between cedr*9l fpal0mg/ark1vque r7;m, 7 ij1 7b.gsytokinesis in animal and plant cells?

  Which stage of meiosis is matched to the corr pi*8hme3 op,rect description?

  Which statement(s) are true of meiosis I but not meit9 yitn wjze/c9z+*2a osis 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.9uceak*; 1dp-t0cd9zr31 q bkjrzgg- This results in the formation of one br;k99-*pk 1czdg -u0rtace qgd1j z3large cell and one small cell. What is the fate of the large cell?

  Which row correctly describes diploid 4vk(ux y zwwny05n9 vp3z(p c(and haploid cells in humans?

  The following table shows the dipl ac)l5x 71eo oteot/j5oid chromosome number of a range of species.


Which of these statements is correct?

  What conclusion can be x6ez/ itni*4o c+a;s21 bnyw8bvmxoy+7mn0z drawn from the karyogram below?

  Which of the followino j27 kq3h03e pc;rjgcg processes is characteristic of the meiotic and not the mitotic cg hr70 j3qjpckoe;c 32ell cycle?

  The diagram represents a bud with; ew)r 3qrkeu0 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 (Pan troglodytes) is 48 i4gvhc1 ;ih8-on ch zpq-*0mb. Which row shows the correct chromosome number for different cell types and cell division stage8 zio1gnmc*0-; bcvhhq4pi- hs?.

  At the end of which phase of meiosis I does crossing over occur, and w2dixdieadp1- 72jxece q(a*e2ed d 0/hat is the outcome of / de- e2dieia 1p ea*x7xqjdedd2c0( 2crossing over?

  Which of the following statements does not describe a ste,ccvn ku(o r+/p in the sodium-potassium pump cycle in the neuronal cells? /rn(kv ouc+c,

  Which row in the table below is true o),mt agcn f;4nf meiosis?

Membrane transport is important for , k3 snsojny4-allowing particles to move across the cell membrane and respond to changes in the chemical composition of,- 3nsno yskj4 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 regulat6w : jqrwx*/zbed 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 duh6c/tvzw1-06 rdhh uhring the cell cycle. Which cyclin is involved in preparhhd6 v/ w06th1uhzc -ring for DNA replication?

The diagram below shows chromo ygbyftk- 88 drt1y x 3o+.hn.3aywk,p ,ee,fvsomes 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 invo;az/9 avhtyz .w5bm+w lves the separation of homologous chromosomes?

  The mitotic index of throat tisoko l73l qe8yow 5uz0)sues taken from 4 different patients is shown below. ywz uo l35kol87) oeq0Which patient is most likely to have cancerous throat tissue?

1.Draw a labelled diagram to represent hrb k f+n9/bs/ h9/+qht2:eu nvqq7pxthe process of crossing over.

2.Compare and contrast random orientation and crossing over.

3.Outline the stages of meiosis.

  The image shows an abnormal human karyotype. ;tw -ea9txik tp7hf6 t n78s,hi03-z:jwnjfu


What is the abnormality in this karyotype and its cause?

The graph below shows the relwyth1+n4ko a 8ative amount of DNA in one cell during one complete cell cycle. Each l41nkt howay8 +etter 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 cathemb 1v/df 5v7. 9zrcm that is homozygous for brown, long hair and a female cat that has black, short hf7rdm5c b /e 9z.v1hmvair.


Which of the offspring has a recombinant genotype?

1.Outline how polygenic trait.i+-6 vn ojqlos 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-sister chromatidgrx/s6u6u0t0x l mw. rs shown in t6mutx.u6l0 rx sr/w0 ghe diagram below?

  The photomicrograph shows a pollen grain from L. candidum (Lily). Which stage ofhl,eh7msf(u 5 meiosis is showsh5 fel(,umh 7n?

1.Outline the events which would lead9)e :/badd t-a*jt nph to an individual being born with Down syndrome, which is characterised by t n-)h tpeajadb9d/t:*he presence of three copies of chromosome 21.

2.Explain how meiosis increases variation.

3.Outline the stages of meiosis.

The mitotic index is an indirect way of measuring plant3yvqt a73sx p3 growth. A study was conducted on white onions (Allium cepa), under controlled conditions in a lab, to invesq7 ya33xts p3vtigate 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 cadp :/a1a)dpg+a/it9jr2w k j/fruka 8n divide. The diagrams below show two cells from an oprr/9pj8 a+dauk g2i:j/dtf a/wak ) 1rganism 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 st dnx*dx.w4fyql t26d/s ytp:9 em 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 stau6 3rw xdeabuv21*mf) ges of meiosis. Which row cor2me*6v fu)aub 1 xd3wrrectly names each stage?

  The micrographs show four phases of meiosis I in a plant. Inglaqe, * c7w1f4a),f7o jg xsf what order do these phases7acf ,1,f4ws ejq7lga*ogf x) occur?

Mitochondria are responsible for supplying metabolic ener(9 k k8 o:.kgjihtk:nfbawu/9gy in eukaryotic cells. Ih/bo:9w8tfa.kk(gik nj : k9u n 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 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 different stages of the cell cpo*jr6d6hde, ycle in four samples of lung tissue from four patients. Which tissue has the loo6d,ed6hrj p *west mitotic index?

  The diagram shows the dominant cyclin/CDK complexes at different a(dg- puh8in u: b)4vqtime points in the cell cycle. Which cyclin/CDK ca b8d:ugn-quhv()p 4i omplex activates DNA replication machinery?

  Studies have shown that genes 42by(u a1k7tnyh;up a i0v +4s lrd*ytsuch as Cyclin Dependent Kinase 3 (CDKN3) are high17ib ldk +artatuy40vupy;hn( 2y4 s*ly 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 oey);qjxaxf(o : 5 sqt;f cyclin E the highest during the cell cycle ?