MITOSIS

1.

The cell cycle

Name and state the purpose of each of these sub phases

P1 : ………………………..

……………………………………………………………………………………………

Q : ………………………..

……………………………………………………………………………………………

P2 : ………………………..

……………………………………………………………………………………………

R : ………………………..

……………………………………………………………………………………………

S : ………………………..

……………………………………………………………………………………………

2. State the definition of Mitosis.

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P 1

P 2

Q

R S

3. Rearrange the jumbled words .

The importance of mitosis is :

a. W O T H G R _____________________

b. ELLC E C A L P N E T E R M _____________________

c. G E T O I R E N E N A _____________________

d. X E S A A U L D U T C I N E R R O P _____________________

4. Label the diagram below.

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MITOSIS Process by which a nucleus divides to produce _____________ daughter cells, each containing the __________ number of chromosomes as the parental cells.

i.

ii.

iii.

5. Underline the correct words in the bracket.

Cytokinesis in eukaryotes occurs ( just prior to , after ) mitosis; cell division in

prokaryotes occurs by a ( simpler, more complex ) process called, binary ( fission ,

fusion ). Between divisions, eukaryotic cells are in ( dormant-phase , interphase ) , an

active period during which chromosomal DNA is duplicated, the cell mass ( increases,

decreases) and new organelles are produced. Nuclear DNA is replicated only during S

phase. The process of mitosis occurs in the following order : prophase, ( anaphase ,

metaphase ) , ( anaphase , metaphase ) and telophase. The mitotic spindle is a

complex of ( microtubules , microfilaments ) that ( prevents , assists ) chromosome

movement. The spindle is attached to each chromosome at a site called the

( connector , centromere ). Following nuclear division, the cytosol of the cells is divided.

The soon-to-be daughter cells are separated by the cleavage ( plane , furrow ) in

animals cells and the cell ( plate , furrow ) in the plant cells.

6. How does mitosis in plant cells differ from mitosis in animal cells ?

Cell division in plant and animal cells differs in two ways : (1) animal cells have

…………………………… , whereas plants cells ……………………. , and (2) animal cells

have ………………………………….. , whereas plant cells have ………………………..

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8. Complete the flow chart below

Tissue Culture Technique

…………. of carrot

Transverse section of root

Cell ( …..n )

Fragments cultured in ……………..

Cell division ………………. to form …………

Callus cultured on ……….. medium and transferred to ………….

Adult plant

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9. Explain briefly how Dolly the sheep was produced by cloning. Give your answer in the

form of a diagram which shows the successive steps with explanatory notes for each

step.

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10. ADVANTAGES AND DISADVANTAGES OF CLONING

Advantage Disadvantage

Cloned plant are ……………………… is

size and shape

Clones are …………………… to new

diseases

Plants can be produced ………… the year Clones are easily destroyed if there is a

…………………. in the environment

Plant maintain the …………….. designed

characteristics of the mother plants

Tissue culture techniques are cost

……………………

Clones can be produced in ………………..

numbers in a short time

MEIOSIS

11.

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MEIOSIS Process by which a nucleus divides to produce ____________ daughter cells, each containing ___________ the number of chromosomes of the parental cell.

12. Fill in the blank using the words provided.

1. At __________ phase of meiosis are these two cells, each with sister chromatids

aligned at the spindle equator.

2. The meiotic process by which homologues are paired during prophase I is called

__________ .

3. Crossing occurs during ________ .

4. Meiosis consists of __________ nuclear divisions, producing ___________

haploid cells.

5. The function of meiosis I is to separate _________ . The function of meiosis II is

to separate _____________ .

6. Meiosis I produces two ____________ cells.

7. Meiosis II produces four ______________ cells.

13. By using two different colours show the result of crossing-over.

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Synapsis Sister Chromatids Metaphase II four

Haploid Haploid Homologous chromosomes

Two Diploid Prophase I Diploid

14. Complete the table below.

Name of Phase Description

1. Homologous chromosomes pair up and form tetrad

2.Spindle fibers move homologous chromosomes to opposite

sides

3. Nuclear membrane reforms, cytoplasm divides, 4 daughter

cells formed

4. Chromosomes line up along equator, not in homologous pairs

5. Crossing-over occurs

6. Chromatids separate

7. Homologs line up alone equator

8. Cytoplasm divides, 2 daughter cells are formed

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15. Name the stages in the figures above .

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16. If a diploid cell has two chromosomes ( 2n = 4 ) , Draw and describe the events that

occur in each stage in mitosis and meiosis.

Mitosis Prophase Meiosis I Prophase Meiosis II Prophase

Chromosome

behaviour

Mitosis Metaphase Meiosis I Metaphase Meiosis II Metaphase

Chromosome

behaviour

o o

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Mitosis Anaphase Meiosis I Anaphase Meiosis II Anaphase

Chromosome

behaviour

o o

Mitosis Telophase Meiosis I Telophase Meiosis II

Telophase

Chromosome

behaviour

o o

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17. COMPARE AND CONTRAST

1. Complete the table below.

Meiosis I Similarities Meiosis II

1. The chromosomes become …………………………. and …………………….

during prophase.

2. The chromosomes are arranged at the …………………………. plate.

MEIOSIS I Aspect compared MEIOSIS II

Homologous chromosomes pair

up and …………………………...

between non-sister chromatids

occurs.

Prophase Synapsis of homologous

chromosomes and

………………………….between

non- sister chromatids does not

take place

…………………………………….

align at the metaphase plate of

the cell

Metaphase ………………………. align at

the metaphase plate ( equator)

of the cell

Homologous chromosomes

…………………… and move to

opposite poles. Sister

chromatids are still attached

together and move as a unit.

Anaphase Sister chromatids

…………………………becoming

daughter chromosomes that

move to opposite poles.

……….. haploid daughter cells

are formed.

Telophase …………. haploid daughter are

formed.

Each daughter cell has only

…………. of each type of

chromosome : either the

paternal or the maternal

chromosome.

Set of chromosome Each daughter cell has the

……………. number of

chromosome as the haploid cell

produced in meiosis I but each

cell has only one of the sister

chromatids.

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18. Complete the table below.

Mitosis Similarities Meiosis

1. A nuclear division process

2. Nuclear division occur

MITOSIS Aspect compared MEIOSIS

Place occur

Role

Number of

sitokinesis

Synapsis of

homologous

chromosomes

Number of

daughter cells

Set of

chromosomes

Genetic

composition of

daughter cells

Variation

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EXERCISES

1. Figure 1.1 shows phases M and N during meiosis I.

M phase : N phase :

Description : Description :

a. In the space provided,

i. State the both stages in M and N

ii. Describe the behaviour of both chromosomes in above stages.

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b. Figure 1.2 shows the chromosome behaviour during Prophase I in meiosis.

i. State the M process

……………………………..

ii. State the part of chromatid where the M process occurs.

……………………………...

c. Based on figure 1.2, draw the chromosome behaviour during Prophase II.

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UV ray

d. Based on the above statement, explain how the situation happens.

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e. Figure 1.3 shows the formation of cancer cell in epithelium .

Based on figure 1.3 , explain how the cancer happens.

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Statement :

Meiosis is a process to produce gametes that take place in sex organ .

Case :

In a family, there are variability occurs in offspring.

UV ray

Epithelium cell Cancer cells

2. Meiosis is involved in the production of gametes for sexual reproduction. Offspring

produced by sexual reproduction differ genetically from one another and from the

parents. Draw a diagram and explain briefly how meiosis makes genetic variation

possible.

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3. Figure shows the differences that occur in a family member.

Based on figure 8, identify the differences among the family members. Discuss how

the differences are inherited.

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4. Diagram 2.1 shows phase X and phase Y in the cell cycle of an organism.

Phase X consists of three sub-phase, P, Q and R. Phase Y involves two

processes, U and Y.

Diagram 2.1

(a) (i) Name process U.

……………………………………………

(ii) State two roles of process U in an organism.

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(b) Diagram 2.2 shows the various stages in process U.

Diagram 2.2

(i) Based on Diagram 2.2 complete the correct sequence of stages in

process U.

Stage → Stage → Stage → Stage

IV ………… ……… ………

(ii) Name the stages in process U.

Stage Name of stage

I

II

III

IV

(c) (i) Name phase X in Diagram 2.1.

…………………………………

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(ii) Describe what happens in the cell during phase X.

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(d) A technique which involves the cell cycle shown in Diagram 2.1 could

used in cattle farming. A researcher to use the technique to increase the

number of beef cattle. Describe the technique.

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