Think about the following statements carefully. Are they true or false? Check the answers at thebook to get rid of any misconceptions.

1 lf the parent cell has 46 chromosomes, then each daughter cell from mitosis will haveonly 23 chromosomes.

2 ln G1 and G2, the cell synthesises DNA, and builds more proteins and organelles.

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3 Meiosis produces four diploid gametes.

4 ln meiosis. the chromosomes replicate twice.

5 At the end of meiosis l, two diploid daughter cells are formed.

2 What is the stage of cell division shown in thediagram below?

A Prophase I

C Prophase ll

3 The table below shows four events, E O, R andS, that occur in meiosis.

P - Nucleolus disintegratesQ - Nuclear membrane disintegratesR - Chromosomes separateS - Homologous chromosomes line up at the

equator of the cell

Which of the following occur(s) in metaphase l?

A Ronly B SonlyC PandOonly D RandSonly ( )

4 The diagram below shows a cell of an animalin the process of meiosis.

How many chromosomes are there in thegametes of the animal?

416

5 Which of the following are the differencesbetween mitosis and meiosis?

I Produces two Produces fourdaughter cells gametes

ll Conserves the Conserves thenumber of diploid number of

chromosomes chromosomes

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PAPER 1 Multiple Choice Auestions

lnstruction: Answer all questions. For each questionthere are four possible answers, A, B, C and D.Ghoose the one you consider correct and record yourchoice in the bracket.

1 A cell which has 24 chromosomes divides bymitosis. What is the result?

A Two nuclei, each having 12 chromosomesB Two nuclei, each having 24 chromosomesC Two nuclei, each having 46 chromosomesD Four nuclei, each having 12 chromosomes

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ll! Cytokinesis occurs Cytokinesis occurs .

once only twiceIV Daughter cells are Daughter cells are

haploid diptoid

A I and lll onlyB ll and lV onlyC l, ll and lll onlyD l, ll, lll and lV ( )

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6 The diagrams below show the stages of cell

division in an animal cell (2n = 4). Which of thefollowing stages occur in meiosis ll?

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A I and lll only B ll and lV onlYC l, ll and lll only D l, ll, lll and lV

7 The diagram below shows the cell division of acell with diploid number of 4.

Which of the following cells is/are produced in

the stage shown?

P-Sperms O-SkincellR - Urethra cell S - Root meristem

A P onlyB PandRonlyC OandRonlyD O, R and S only

8 The diagram below shows the nucleus of a

somatic cell in an animal.

Which of the following nuclei is not the nucleus

of a gamete from the animal?

A B

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9 The diagram below shows a few stages in thecell division of an animal cell.The time takenfor the process is 24 hours.

cell R cell S

cell P cell Q

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Which of the following statements are true?

I Cell S has the same genetic material as cell Pll Cell R is produced from cytokinesis which

occurs after division of the nucleus.lll The number of cell S produced after 48 hours

is four.!V Cell O is haploid.

A I and ll onlyB l, ll and lll onlyC l, lll and lV onlyD ll, lll and lV only ( )

10 The diagram below shows a stage in the celldivision of meristem cells in a plant.

Which of the following is true about the cell atthe end of cell division?

A At the end of telophase, four gametes areproduced with each having eight structure O.

B At the end of telophase, four gametes areproduced with each having two structure O.

C At the end of telophase, two somatic cells areproduced with each having eight structure O.

D At the end of telophase, two somatic cells areproduced with each having four structure O.

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11 lf the somatic cell of an insect is diploid(2n = ql, which of the following shows thecorrect number of chromosomes in the somaticcells of the insect before mitosis and aftermeiosis?

Before mitosis After meiosisA

12 The diagram below shows a stage in the celldivision of an animal cell.

Which is the correct chromosome number ofthe daughter cell after cell division?

A n=2 C n=8B n=4 D n=16 (

13 The graph below shows the changes in thenumber of chromosomes of cell.

Chromosomecontent

Which of the following stage occurs at X?

A Metaphase C Death of cellB Telophase D lnterphase (

Total chromosomes

4n

2n

Time

Which stage occurs at t?

A lnterphaseB ProphaseC MetaphaseD Telophase

15 The process shown in the diagram belowcauses genetic variation.

Name the process and an example of thegenetic variation caused by it.

Feftilisation

Meiosis

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Crossing over Eye colour

Mitosis Hair colour

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14 The graph below shows the changes in thenumber of chromosomes in a single cell fromthe meristem of the plant.

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PAPER 2 Structured and Free-response auestions

Section A Structured O,uestions

1 The diagram below shows the cell cycle of an animal cell

<JCell division

(a) (i) Name the phase labelled R in the cell cycle.(ii) What are phases K, L and M known as?

(b)Explain the changes which occur in phases K, L and M.(c) What is the cell division process that occurs in N?(d)The diagram below shows the sequence of the stages in one type of cell division

(i) Draw stages O and S to complete the diagram.

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(ii) Label the diagram at stage S.(iii) Name stage U and describe the process that occurs at this stage.

2 The diagram below shows a somatic cell of a male insect with diploid number 2n = 4.

(a) (i) State the number of chromosomes in the somatic cell of the insect.(ii) Draw a diagram of the daughter cell if the cell carries out mitosis.

(b) (i) Another insect has a gamete produced from a cell as shown in the diagram. Draw the diagrams

of the cell showing the behaviour of chromosomes in prophase l, metaphase l, anaphase I and

telophase I during meiosis. Describe briefly the events at each stage.(ii) Draw two daughter cells that can be produced from meiosis.

(c) Based on your answer, state two differences between daughter cells from mitosis and meiosis.

(d) Explain how meiosis maintains the diploid number of chromosomes in the insect.

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3 The diagram below shows the nucleus of a somatic cell in an organism

(a) (i) State the function of O.(ii) State the component of O which carries out this function.(iii) Draw the components of O which carry out this function.

(b) Draw a diagram to show the behaviour of the chromosomes during(i) early prophase in mitosis.(ii) prophase I in meiosis.

(c) (i) Name two types of cells produced through meiosis.(ii) How many chromosomes are there in each cell named in (c)(i)?

4 Mitosis plays a significant role in the growth and development of an organism. Describe the importanceof mitosis in

(a)growth;(b) repair;(c) asexual reproduction.

Section B Free-response Ouestions

5 (a) Meiosis I reduces the number of chromosomes by half, that is, from diploid to haploid.Explain this statement if the diploid number is 2n = 4.

(b)Meiosis ll is similar to mitosis. Explain this statement using a cell with diploid number 2n = 4.(c) (i) Explain how crossing over occurs.

(ii) What is the significance of crossing over?

6 Cell division results in the growth of an organism. Describe the stages of cell division which will result ingrowth at the shoot and root tips.

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