The graph below shows the relationship between maternal a nu.qj v/mmk65a0 ju(ige and the incidence of non-disjun6kmuaq u(jn0 miv5./jction. What relationship is suggested by the data in the graph?

  Which stage of meiosis is repr;qs5riiv brd( 62cobk0czm; 4esented in the diagram below?

  The diagram below shows chrc3s1p4b cdd1 ;5qfqiiomosomes 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 thk3pc;t(hh ;p umym; la,87g y2n+wifye number of alleles of a single gene which would be present in the nucleus of a cell as a result of each prgmck2n;yl; ,p7w 3hy8phf t;m(yu+iaocess?

  Which keyword is matched to the correct dhill-sfr41 j3if a*. s,b yp9definition?

  Which statement(s) about mitosis is/are truu/a-u6yfr q ze/b ctyx1oz 5/ mh0,-tre?
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 in 9yls +m sypsev+ 3v:vk )gv:cem f)34uanaphase?

  During which stage of mitosis does the nuclear envelope break doy. cyp oh5py/elycc u;:bdil6gl 1f *0na .4c1wn?

  Which one of the followi3dpa;xcfs4 xm ali1sx kv4 (8*ng transport proteins only carries out active transport?dkpims3alv1*4( ;c xf axsx4 8

  Which process does not happx ndfdj)* 5njtp*/7a (a9 liosen in the shoot apex?

  Which type/s of membrane transport do/do na09xgl0aq/m es not require energy expenditure?
I. Facilitated diffusion
II. Active transport
III. Osmosis

  The diagram below represents a cell with a diploid number khwe9tke5 9g cm36,l 2l2 tuuiof 4. Which stage of cell divi5ceul92 gl 2,we tu93ki6khtmsion is the cell currently undergoing?

  The photomicrograph below shows a root tip meristem. Which69hdr,e yy(c y*5p*voeuhc 7e of the following sentences correctly d(5perc*yhe,7 e9udc6voy *yh efines a meristem?

  When does the random orientation of homxd.5+jwfnel+sycld y.,:l7 tologous chromosome pairs occur?

  Which process does not occur durin o,c5dct3-l7a/tv t xmg meiosis?

  If a cell with a diploid number of 36 undergoepw*t5rzkq*7atloo7 +sa 1s8f s mitosis, how many chromosomes will be pra81 qoso+atfzk *l*w7 sp5t7r esent in each daughter cell after cytokinesis?

  The image shows a micrograph of a cell; frpk-i p):ko.


What explains the appearance of the cell in the micrograph?

  Which statement(s) about homologous chjq6j0 g9. ih04inctmbk d k )kdbpy6e3 ;aw+q0romosomes 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 wi1 5ai4;w/lo x3qogwq tth Down syndrome.

Which statement is not correct?

  In the cells of a horse (E. ca)fwu.6simf)57 c kfb qvhail 9iln:5o-b*p :aballus) during prophase I of meiosis I there are 64 chromosomes. What is the haploid number of chromoso6)i5*lpb vk)-95 iamhcl.7 s: uwn q:o ibafffmes?

  Which arrow is pointing to a chiu2v5qwp .rg yqq 1g+m:asma?

  The diagram below represents the structure ,uto1l;a c1coy+st2+ os 7zgn of a shoot apical meristem. Which row in the table correctly identifies the processes occuring in the str27o zs,stt+1+ 1 n;yagcclououctures labeled in the diagram?

  How does meiosis promote varim0jq b8k2xq:t fm ssp91sc* c+ation?

  Which of the following statemen76l2vrv;ysdr ih;xsm q1;nypp 6;bv7ts 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 homologouk :ntzlpf4ht yn 05d+mya x*+0s 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 secondar;fpzor5d(05sk0jpbg )u jl f8y tumours from primary tumours as a resus(rz5 ) 8p05kb j0 gl;dujffpolt of the movement of cells?

  How many chiasmata are present in thcr7/w - fz9qtze diagram?

  Which statement is a similg+k.q vcqmx)lmd8-t 3arity between cytokinesis in animal and plant cells?

  Which stage of meiosis is matched to the correct descrip(xd)q cpe ,lv(1ey*r f,s ,edction?

  Which statement(s) are true of meiosis vuu f 2:wc4i):c8pjz6rcp jc6 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. Thj/7t4i jt m.stis results in the formation of one large cell and one small ctmj/7i4 j .tstell. What is the fate of the large cell?

  Which row correctly describes diploid and haploid cells in humansbo/ jchvomg*w -33u/z ?

  The following table shows the diploid chromosome number of a rang 6petxv;+ hrz)e of species.


Which of these statements is correct?

  What conclusion can be drawn from the karyograma5hu h7zc2 xv . sy*vo55l.keo, wa)na no*6il below?

  Which of the following processes is characteristic of tl+n; dpgyvi/ p9,sm5a he meiotic and not the mi/ys dv9;pgplm,na +5itotic cell cycle?

  The diagram represents a bud r;u82j 6q)avl ufofx6 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 (Pan troglodytes) is 48. 5lb3w fw7b+xw7 v mk8eWhich row shows the correct chromosome number for different cell types awbx8wbwm 5l7 3kvf +e7nd cell division stages?.

  At the end of which phase of meiosis I does crossing over occur, fs +eb.. dus+rj4mjx 1i0fwozh 88qj( and what is the o8ufe(w4 dio+0 q r1fsj.m8jh +b.xszjutcome of crossing over?

  Which of the following statements does not describe-ulykpmgzm2jh07 j :5ow 4/sf a step in the sodium-potassium pump cycle in the neuronal cuj7f y/4-swzm2p:johkl mg05ells?

  Which row in the table below i)djn.v znv(4 ss true of meiosis?

Membrane transport is importantfpz*,u nlgb t:2b6m c+ for allowing particles to move across the cell membrane and respocn2*m:u bpg6+tflbz, nd 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 mitosis is regulated in cells*f ;03rlf5z ,me ujzkg.

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 du8 .pqkns6c0 0wxifv2q ring the cell cycle. Which cyclin is involved in preparing for DNA replics0q 0.wxn pqvk62fi8cation?

The diagram below shows chromosomes dusc2cz2 x/ j(iiring 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 homologous c6nmd5ehjv/ .:wjf )rkz 4 bdb.hromosomes?

  The mitotic index of throat tissues taken fw wpa3r:yfozv a8rrw0 +r;; z51)jjs arom 4 different patients is shown below. Which patient is most likely to have cancerouszojvr1raj w pf :w5rz;+;a )w0s8 3rya throat tissue?

1.Draw a labelled diagram to represent the process of ct na*) c ;q;n+af-zjy8 cs:qchrossing over.

2.Compare and contrast random orientation and crossing over.

3.Outline the stages of meiosis.

  The image shows an abnormal human karyotypg rj +6a- xhj8+sbin+p)pno+de.


What is the abnormality in this karyotype and its cause?

The graph below shows the relatitn0yp2 jiv:a4d djwq hgo, 9:*ve amount of DNA in one cell during one complete cell cycle. Each letter represents on4gq0 d92j:*hj: a n towipv,dye 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 225r0d/xcabil*x e cmcross between a male cat that is homozygous for brown, long hair and a female 5 adl2*/iecxmb02 xrccat that has black, short hair.


Which of the offspring has a recombinant genotype?

1.Outline how polygenic traits can show ,dqfjw x1eo qbioo:/ i9: (2pxa normal distribution.

2.Outline the differences and similarities between homologous chromosomes.

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

  Which gamete can resuej9bt4 dg +x*zlt from the crossing over of non-sister chromatids shown in the diagratb*+e4j9g d zxm below?

  The photomicrograph shows a pollen grain from L. candidum (Lily).z up *lz/uyu -i)-)ike Which stage of meiosis iu lu*uekz i-p)/iz) y-s shown?

1.Outline the events which would lead to an individual being born wik, 3ce fm v+q3 ;sesw6p*ogj/fzf .h)nth Down syndr;v+,z)3jmhs nfpe sc.k*3/ o gq e6ffwome, which is characterised by the 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 plant wf d p2ureo: tor4r)t8.b2n9egrowth. A study was conducted on white onions (Allium cepa), under controlled conditions in a lab, to investigate the effect of soil pH on there294o8wpdentb2 : tof.urr) 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 diagrams below plyo4 e8( hkmy3) p.ea nt49oushow two cells from an organism with a diploid number (2n) ap t e494o3(yke.uolyp) n8 hmof 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 zu 8a/a llis ju* 6rs2;.7v;zn.jmhgkexpression 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 8, in differentaookl;b* n5dma * 9c va9x*6vsfe;7cr stages of meiosis. kv65*vr7m*xadceb l ;9 af c; 9anos*oWhich row correctly names each stage?

  The micrographs show four phases of 7 xzit-zk/:;j(fnuka meiosis I in a plant. In what order do these phast-(7 zfua/knk ;xi: zjes occur?

Mitochondria are respons5bx qjp0bgtexsk* *3 :l nf(t:ible 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 mother in the case of humans. This is in contrast to nuclear DNt(nx3: *sx qkbglfbj pt:5e0*A 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 cell8lsez t;tz00h*06i 0bh/vmi kf0aq yy cycle in four samples of lung tissue from four patients. Which tissue has the lowest m fai*8es;zthy0ztq 00lyhm/0ibv60k itotic index?

  The diagram shows the dominant cyclin/CDK complexes at different timep dkul5 xotu3 e4:z3r) points in the cell cycou)ed3rzl k t5 4xp3u:le. Which cyclin/CDK complex activates DNA replication machinery?

  Studies have shown that genes such as Cyclin Dependent Kinase 3 (CDKN3) j vgo n h,c zeo2rs36pq5:3 nmpq,.3zeare highly overexpressed 2v6qz3spqnnhg:33p zjor5,om e, c.e 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 higv9 l81t3f, rqpaf* mukhest during the cell cycle ?