The graph below shows the relationship between maternal age and :r n4,jjqoi1j the incidence of non-dj4q,rno1j: j iisjunction. What relationship is suggested by the data in the graph?

  Which stage of meiosis is reprl(sr, e )6.-zhrbtuo os0pt7 lesented in the diagram below?

  The diagram below shows chromosomes dly-i x.3r-vxj:b 59fmiwbak;uring 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 alleles of a single gene which would k3gf/om2uh;b6 bm pv4be present in the nucleus of a h bpf /mbo64vk3u;mg2cell as a result of each process?

  Which keyword is matched to thef6s:8sq4 e rbm correct definition?

  Which statement(s) about mitosi .axd-fezfa+ 6s 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 cel k8i fptx:mui8fg)-t tx9t1/ nl in anaphase?

  During which stage of min :h;t/mc;n ny gwuwmy+ 8hz,9 7gc-o,k hbr0vtosis does the nuclear envelope break down?

  Which one of the following transport proteins only carries out act +i:1n 9azla(,wu gbbdive transport? bz9i lw:(du1,baga+n

  Which process does not haqj 1qf*n97kzeppen in the shoot apex?

  Which type/s of membrzczo. di f3;r3kh)xc7ane transport do/does not require energy expenditure?
I. Facilitated diffusion
II. Active transport
III. Osmosis

  The diagram below represents a cell with a diploid number of 4. Whic rz 3j3xm ae/(6itycd.h stage of cell division is the cell currently undym/rdeit 6. xj3zc 3a(ergoing?

  The photomicrograph below shows a root tip meristem. Which of thexchtm jb:e4m0gq6 )m3 v8,hyg following sentences8 : gjm)6,vqxme c0b4 yhh3gtm correctly defines a meristem?

  When does the random orientation of homologous chromosome pairs occuszoef0 -r5 ykm*.5joer?

  Which process does nun dj95ak6u.3uzmxxf3 bf5v ,ot occur during meiosis?

  If a cell with a diploid number of 36 undergoes mu/w(8j gfa3v0zwhfo)1l9 i sfitosis, how many chromosomes will beo( uaf3sf8v9z/ji0f)w g lh1 w present in each daughter cell after cytokinesis?

  The image shows a micrograph 376.rjn0udfi 1lm r uwof a cell.


What explains the appearance of the cell in the micrograph?

  Which statement(s) about homologous chrowu1ap;i)g i+4ct jb. oy 3stw1mosomes 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 individuaqlan3 ;:attj:q a *byb8(1e vwl with Down syndrome.

Which statement is not correct?

  In the cells of a horse (E a8y:a glxzfyz v16+6w. caballus) during prophase I of meiosis I there are 64 chrow gy:6zx1v fla6 yz+a8mosomes. What is the haploid number of chromosomes?

  Which arrow is pointing to a chiasm61q9yq -ywi-fvz,70oj dsf ima?

  The diagram below represents the structure of a shoot apical meristem. Wh(* pke0l0.c5sagz xg dich row in the table correctly identifies the processes occuring in the strlg0cx . p0s 5gz(k*edauctures labeled in the diagram?

  How does meiosis promote variatio*7z brxokgj:w 4y e(n;n?

  Which of the following statements ik 7cm*y0un vdfdxu0j* z/0(w xs/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 homo;1rr ddzg efow) 1,r6xlogous 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 secondarik3s:b8etb q+zgn o/6 y tumours from primary tumours as a result of the move k/zst :g63q8bobni+ement of cells?

  How many chiasmata ars:3 i;gps6.o usx r1vke present in the diagram?

  Which statement is a /-amc *+uyfzusimilarity between cytokinesis in animal and plant cells?

  Which stage of meiosis is matchevrn- e qxo7rwu z-8e(+d to the correct description?

  Which statement(s) are true of meiosis I bhm bev *ukz1mjn( sb,ugm2/3 s2z5( beut 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. This resd+mznlmfp*fl)u 3+eu :w,i1 uults in the formation of one large cell and one small cell. Whatm+,ud: )1+uewmin3* lzpu flf is the fate of the large cell?

  Which row correctly describes diploid and haploid cells in humans1d(tye .sl ;vohr6y::g/mjz h7u3 tbx?

  The following table shows ff,n sq4),tjm the diploid chromosome number of a range of species.


Which of these statements is correct?

  What conclusion can be dm+8u(zgo*rsj t(j 1zp5u e p2frawn from the karyogram below?

  Which of the following processes isp/dwt8np2f wu ah 02+s characteristic of the meiotic and not the mitotic cell cyn02 2dtwuh+f 8ps/wap cle?

  The diagram represents a bud with a shoot apr h;dq6qhvnjp l..z1:nu 6o j5ical 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. Whichn*: d u+afxqi*j2(wyi row shows the correct chromosome number for different cell types* aw 2uini:y*jd+fqx ( and cell division stages?.

  At the end of which phase of meiosis I does crossing over occur, and w40m46. k:tbkcoppvh lhat is the outcome h ckl.6v4pp: 0kmbt4o of crossing over?

  Which of the following statements does not describe a step in t yjx:8 n1eizcajxb / am87)g ckxd2t-)he sodium-potassium puxgn8c :8xkbz 1j7dxy2m-cjia)t /a e)mp cycle in the neuronal cells?

  Which row in the table below is true of meiosqel25 03xrdfgis?

Membrane transport is important fort4em fi; ( e;3q/gh:rerjsn 9c allowing particles to move across the cell membrane and respond to chact 9fn(4 ;/:rqsie r3gmh; jeenges 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 ro l9.b.dkgm s;o4hlb6/ vd3q legulated 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 ourd,7 g *jupvag gocrek)--m(20q4jjf different cyclins during the cell cycle. Which cyclin is involved in prepavg-pog*rgj0jmk)4ur,uj7ea- 2(q c dring for DNA replication?

The diagram below shows chromosomes during meioy/ze( a8std e8sis.

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 separat(yx9 2n j0s;va-ltx gjion of homologous chromosomes?

  The mitotic index of throat tissues taken from 4 different patients is shown.1f ,f 1 n7wnomx wma k:(xxcv7yghv0aq.dl09 below. Which patient is most likely to have cancqv(nw1xha7 .ffw x0yg: cd 91,mv 0n7klo.m xaerous throat tissue?

1.Draw a labelled diagram tc8) 4svl2zcqj o 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 hg.ish bd0pf ,9j9+nhhuman karyotype.


What is the abnormality in this karyotype and its cause?

The graph below shows the relatjyv::pnl g/n (kvdda/3 ,u 8chive amount of DNA in one cell during one complete cell cycle. Each letter represents one stage of the cell cycle. :uk,pg:a(vd//8nj 3nc hl vyd


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 d-/)ksd5o0fa lc g q+vcross between a male cat that is homozygous for brown, long hair and a- aod)v+q/f5k d0l scg female cat that has black, short hair.


Which of the offspring has a recombinant genotype?

1.Outline how polygenic traits can show a normal distrila +jxjn)3o28qdg5yv.-s r mtbution.

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 chromatidje48 qzl*nv: is shown in the d ilez4jv: *8qniagram below?

  The photomicrograph shows a pollen grain from L. candidum (Lilye0teq0l -fpkngb5 ;r7b p l9.d). Which stage of fbbel79p le. d5rq-;0 p0gk ntmeiosis is shown?

1.Outline the events frz,h x3)a;cx4x0g hywhich would lead to an individual being born with Down syndrome, which is characterised by the presence of thrc4xxf3ax0rgz)h , y;hee 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 growth. A studybuyvhz267 e0i )e1efp was conducted on white onions (Allium cepa), under cf2i0ubz16 )hyepeev7ontrolled conditions in a lab, to investigate 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 can divide. The diagrams below 44 6()tvct7jybi,obl+u iema+ pbb f.show two cells from an organism with a diploid number (2n) of bi4bai)b f4+ 7,6b pttojecyv+m ul(.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 ste 5dfkgke xpi19hg2 3)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 cell1dl0(, ysc jw-y tvor,j fench8;3g2f:yh. cr, with a diploid number of 8, in different stages of meiosis. Which row coy3f;j2-hn ehs w gy(j0: ct8flvr co.1r ydc,,rrectly names each stage?

  The micrographs show four phases of meiosis I in a plant. Isd /o/ q4b 4*u.bl -ogmnou1bnn what order do these .n s-/u l4ub1qondbbgom/o4*phases occur?

Mitochondria are responsible for supplyin7 zni4gq *svedp)ol7 *)8laakg 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 DNA which is inherited from both parents. It has been suggested that, in some eukaryotic organisms, inheritance patterns of mtDNA foundg)i*oell vpd 8q7) *7zas kn4a 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 cycle6akpqfp df r7 ;68txw/va18tl dsn2w 5 in four samples of lung tissue from four patients. Which tissue has ta7x6 spw1dn5k d2fatt qr lp/88fv;6w he lowest mitotic index?

  The diagram shows the dominant *9 bw:u )kvpuhb* g+xpcyclin/CDK complexes at different time points in the cell cycle. Which cyclin/CDK complex activates DNA replication *+*kbgh9pwvxupb) : umachinery?

  Studies have shown that genes such as Cyclin Dependent Kinase 3 (CDKN3 kxgepe- 5.w 0cyl1(yw) are highly overexpressed in cervicagpe (c05y e1 ylxk.w-wl 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 cycl7j xh5hh)c 5nsin E the highest during the cell cycle ?