The graph below shows th-vx,a4(z2qlmfd +c ahe relationship between maternal age and the incidence of non-disjunction. l+, a(4d q -vx2mhcfzaWhat relationship is suggested by the data in the graph?

  Which stage of meiosis is represented in the /;d/7ue fqhuddiagram below?

  The diagram below shows chromosomes during :tl zo/;r9 qkrgfie6 -3 kyut1meiosis.


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 singleue)0 ,pbtdh3b gene which would be present in the nucleus0dtb u,hp e)3b of a cell as a result of each process?

  Which keyword is matchej, vtevca*f/ (d to the correct definition?

  Which statement(s) about mitosis is/are tfpbq b 2g*h yh2+r)j cd16v2fyrue?
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 anapha0k/.mk re 3qp5jiivip/w7;c lse?

  During which stage of mitosis does the no z9eot.lm6b,uclear envelope break down?

  Which one of the following transport protein )xa1j*akob,,l a ctg+fg zi:-s only carries out active transport?gb, *-+ f g,iojcxaat:1 )lzka

  Which process does not happen in the shoot apex?tpvkt9u c)gdy7+ h :a3

  Which type/s of membrane transport do/does not require energy1i-d6 guyc)t s8gnh2/rp39g leg)hbo expenditure?
I. Facilitated diffusion
II. Active transport
III. Osmosis

  The diagram below repf3cbt2liz86 / , nqosuresents a cell with a diploid number of 4. Which stage of cell division is the cell currentlyoq2/b cf,6ltnuz8 i s3 undergoing?

  The photomicrograph below shows a root tip meristem. Which of hz;9x4 y :elzjooyf:l7x (pm6 the following sentences correctly defines a meristemeo(z px6xo : j;z:4f7ll9hyym?

  When does the random orientatio3;:e:j* dso/pdwtl fcn of homologous chromosome pairs occur?

  Which process does not occur dkd tcurd 4ydj/*/ 6g0b w(6gcpuring meiosis?

  If a cell with a diploid number of 36 undergoes ma6pqykt(bh )qmdc)k :/2la4 vitosis, how many chromosomes will be present in each da ka4:hky2)abc6lmqqt)/p d(v ughter cell after cytokinesis?

  The image shows a micrograph of a jmup9;wao /s 4cell.


What explains the appearance of the cell in the micrograph?

  Which statement(s) about homologous chromosomes is8osmxsp pi;;-jxgx/ ( 9cy;ca/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 individua00toej k3y(jz*4m. a9(uvi ar rlokj+l with Down syndrome.

Which statement is not correct?

  In the cells of a horse ( 3dq,lyit9lc:fixm l2uqq223a4 vx *mE. caballus) during prophase I of meiosis I there are 64 chromosomes. What is the ha:23 qvqim2ilu 9x,lmqc4tax l d*2y3fploid number of chromosomes?

  Which arrow is pointing to a chiasm )hqedi. 4h7bnp;xfb4a?

  The diagram below represents the structure of a shoot apical vyjs s ty7 8/vlmq,x;;meristem. Which row in the table correctly identifies the processes occuring in the structures la, v y t;/vys7l;8qxjmsbeled in the diagram?

  How does meiosis promot:qlm;* h od-cbln5/e t7pl4h(hw y k.ke variation?

  Which of the following statements is/are corbpnd411 pvn.; t wc p:lc9b5nerect 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 chromosome,klcne0o pv-*s.


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 secondaw sg 96r/koh:gbc5il(ry tumours from primary tumours as a result of bwg lh o 9:gsk(/ic5r6the movement of cells?

  How many chiasmata are present in the diaga r,g;ghorq0 4ram?

  Which statement is a similarity betweensna, e +x(3r. l7 sx*8qeh2qb. ozblcgv6l-ej cytokinesis in animal and plant cells?

  Which stage of meiosis is matched to the correct xpudq u o)v16o52ums +description?

  Which statement(s) are true of meiosis I but not meiosi*e *zsg s6b 76avb oax1n)pbj1s 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 meioc8o/9fduz2 f z+jf v hmmq6,:htic division. This results in the formation of one large cell8uq/: 6cmzh jh o+d, zffm29vf and one small cell. What is the fate of the large cell?

  Which row correctly deshbg30 4 6oa:wmx r6dbmcribes diploid and haploid cells in humans?

  The following table shows the diploid chromosome number of a range of species. 52 ,+ evsj*j+/bxcll 8aeegd y


Which of these statements is correct?

  What conclusion can b yq6 hyww,1/3rip.xl ;rcpru0e drawn from the karyogram below?

  Which of the following processes is characteristic of the meiotic and not the mi (z ebzaj(dtv ;7y h-u651asmn+;lkwqdn uje vwl+6;(h z maak7zyt 15b;qs-(totic cell cycle?

  The diagram represents a bud with a shoot apical merirodtq ;;8dm)xme o)b7stem.

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(my-pxqiaiwwn/3 l5d rtgwv. 3m ,0:w) is 48. Which row shows the correct chromosommli3(:nr-0dp mwvi 5,. gwa wty /qwx3e number for different cell types and cell division stages?.

  At the end of which phase of meiosis I do0g/a :jpg;yuar:* f xzes crossing over occur, and what is the outcome of cro/rgp:;0a*y zjg:a u fxssing over?

  Which of the following statements does not describe a step 0f, hyr1qn hxnf2:-xmin the sodium-potassium pump cycle in the neuronalxhqh 1n,mr yxf0:2n-f cells?

  Which row in the table below is true unt8q h-nyvo2+afs kmx5-,43 9 rrmo eof meiosis?

Membrane transport is importanwe; 87g6p.gw6fby0rg *jbup3lo as 3bt for allowing particles to move across the cell meb*a8b sj.3gwr lb7 e;g oufpw 66ypg30mbrane 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 mitosis is regulated in cellskg083noe brk,mal dy .j6 05iy.

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 v4 2be-esdky (7thf )/bujksag 3r5,lduring the cell cycle. Which cyclin is involved ie4 bj(,72uyelas h)kg5 3-/s tvbfdrkn preparing for DNA replication?

The diagram below shows chromosomes during meios : vpf)(abgy /qg*efy7is.

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 involvo;bs (.jl (eijes the separation of homologous chromosomes?

  The mitotic index of throat tissues tq)4lqn.d c us)aken from 4 different patients is shown belo qqcnl4)d.su )w. Which patient is most likely to have cancerous throat tissue?

1.Draw a labelled diag 2bbyuc68n4rvd eu o/9ram 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 human karyoty 6ps87csh-swx pe.


What is the abnormality in this karyotype and its cause?

The graph below shows the relative i/a);jtz ee+uamount of DNA in one cell during one complete cell cycle. Each letter represents one stage of ;ez)eta/uij+ 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 cat that is homozygous fouv2s)sfcsc49x98+5dr q jg zdr brown, long hair and a female cat that has blas9jz rcv2 xf ucs+)qd854sg9 dck, short hair.


Which of the offspring has a recombinant genotype?

1.Outline how polygenic tr11 ljd /vx09mk4o8brxnht (hiaits 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 crossingakb )jr v6c5nlfg201q over of non-sister chromatids shown in the diagram below? fk 1lgq6b0c)n 5jr2av

  The photomicrograph shows a pollen grain from t *dh5h,75 knnygihg)L. candidum (Lily). Which stage of meiosis d h i,hkg5*gyhtn7)5nis shown?

1.Outline the events which would lead w 7ro,g ryd.v he1z(x5to an individual being born with Down syndrome, which is chary o vgwr,1 x7eh(5zr.dacterised 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 growth. A stux/i oz)knlm/ n(z(fs *7zsl q+dy was conducted on white onions (Allium cepa), under controllq /( ( mx7fz)on*z nlss+il/kzed 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 bef fy*tgl;l :)xlow show two cells from an organism with a diploid number (2n) of 8l*txffgl; y :).


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 ih8g5jlwj5)yw3pa+3q tq cff *n 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 dipl1e/uiym)60r4vy kbto8c5 xx b oid number of 8, in different stages of meiosis. Whi16yo)bemxr 08utviy b x/4 c5kch row correctly names each stage?

  The micrographs show four /r ;,9bxjp gd31ahk, ei qd:hdphases of meiosis I in a plant. In what order do these 1ia ,h,;/p 39: rxddkjbd gehqphases occur?

Mitochondria are responsible for supplying metabolic energy in eukaryotic cd;.x,, kdyrocells. 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 found in hybrid cells, which are the result of sexual reproduction between two different yeast sdy.;d,, xorckpecies, 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 staq8v elabq 12/cges of the cell cycle in four sampllqv2ac e q1b8/es of lung tissue from four patients. Which tissue has the lowest mitotic index?

  The diagram shows the dominant cyclin/CDK complexes at different time ltu13mnn mjz3w9k;e(points in the cell cycle. Which cyclinlmeu(wt1 9kn z3n3;jm/CDK complex activates DNA replication machinery?

  Studies have shown that genes such as Cyclin Dependent Kinasemofja-)rthgsf 31 9*c 3 (CDKN3) are highly overexpressed in)tm* h -a9fs1 rg3cojf 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 the c--11w g78:fifxmxphl)h 0gj / j vsoctell cycle ?