Upload
matkas
View
213
Download
0
Tags:
Embed Size (px)
DESCRIPTION
biology
Citation preview
Biology Teaching and Learning Module Cell Division
Chapter 5 : Cell Division(ANSWERS)
Theme : Investigating Cell As a Basic Unit of Life
LS Understanding Mitosis
5.1.1 The necessity for the production of new cells in organisms
List down the need for producing new cells in life (significance of mitosis)
1. produces new cells for growth2. repair and replaces cells that are dead or damage.3. to increase the number of unicellular organisms4. ensure that the offspring/new cells are genetically identical to the parent5. mitosis preserves the diploid number of chromosomes
5.1.2 The necessity for the production of new cells identical to parent cells
List down the necessity for the production of new cell identical to parent cells
1. Species survival2. preserve the diploid number of chromosomes3. preserve the genetic information 4. to preserve the parent characteristics
5.1.3 Definition of Mitosis
A type of cell division which involves the division of the nucleus to produce two daughter cells, each contain same number and same kind of chromosomes as the parent cells.
Operational-definition – based on observationThe produce of two daughter cells which is a look like the parent cell with the division of nucleus
Places where the mitosis occur during the division of cell - all somatic (in animal) cells which are all body cells except gametes- meristem cells ( in plant) at the end of the shoots, the end of roots and cambium
1
Biology Teaching and Learning Module Cell Division
5.1.4 The cell cycle
The cell cycle is the period that extends from the time a new cell is produced until the time the cell completes a cell division. The cell cycle can be divided into two major phases : interphase and mitotic cell division or the M phase. Mitotic cell division consists of mitosis (nucleus division) and cytokinensis (cytoplasmic division)
On the cell cycle diagram below, identify the phases and explain what happen during each phase.
2
(G2) Fasa 2 : Tenaga dihasilkan
(S) Synthesis phase : DNA replication occur
(1) Phase 1 : Organelle are synthesized and biochemical substances (enzymes) are produced
(M) Mitosis
(G2) Phase 2 : Energy is produced
Biology Teaching and Learning Module Cell Division
5.1.5 Mitosis Process
Mitosis involved of division of nucleus from the parent cell to produced two new daughter cells which are genetically identical to the parent. Before mitosis occur cell is in the interphase level and after mitosis the cytokinesis occur.
Cell cycle = Interphase + Mitosis + Cytokinesis
Activity 1 : Watching the animation phases in mitosisActivity 2 : Identify phases of mitosis
On the diagram below, identify phases of mitosis which have been labeled
K : Early prophase
L : Metaphase
M : Interphase
N : Late telophase
O : Early anaphase
P : Late anaphase
Q : Late prophase
R : Early telophase
3
Biology Teaching and Learning Module Cell Division
Activity 3 : Arrange the various stages of mitosis in the correct sequence and explain the mitosis and cytokinesis
Stages of cell division of mitosis process.
Instruction : Cut the phases of division cell of mitosis above and paste the appropriate pictures in the box provided in the next page in correct order. Explain what happen during each stage in the boxes provided.
Anaphase
Interfasa
Metaphase
Prophase Metaphase
Late TelophaseEarly Telophase
Anaphase
4
Biology Teaching and Learning Module Cell Division
Stages of cell division of mitosis process.
Diagram Explanation
Interphase
The chromosomes are not visible but appear as thread-like structures called chromatin
Nucleus is large and prominent
Involves synthesis of protein and organelles, replication of DNA,
Prophase
Chromosomes in the nucleus condense and become more tightly coiled. The chromosomes appear shorter and thicker and are visible.
Each chromosome now consists of a pair of sister chromatids joined together at the centromere.
The spindle fibres begin to form and extend between the centrioles.
The chromatids are attached to the spindle fibres by their centrioles
At the end of the prophase, the nucleolus disappears and the nuclear membrane disintegrate.
Metaphase
Begins when the centromeres of all chromosomes are lined up on the metaphase plate.
Ends when the centromeres divide
5
Biology Teaching and Learning Module Cell Division
Diagram Explanation
AnaphaseTwo sister chromatids of each chromosome separate at the centromere.
The sister chromatids are pulled apart to the opposite poles by the shortening of the spindle fibres
Once separated, the chromatids are referred to as daughter chromosomes
By the end of anaphase, the two poles of the cell have complete and equivalent sets of chromosomes
Early Telophase
Begin when the two sets of chromosomes reach the opposite poles of the cell.
The chromosomes start to uncoil and revert to their extended state (chromatin).
The chromosomes become less visible under the microscope.
Late Telophase
The spindle fibres disappear and a new nuclear membrane forms around each set of chromosomes
The nucleolus also re-forms in each nucleus.
6
Biology Teaching and Learning Module Cell Division
Cytokinesis is the division of the cytoplasm. In animal cell a cleavage furrow is formed while in plant cell a cell plate is formed.
Explain the cytokinesis process in the table below.
Diagram ExplanationAnimal cell
In animal cell, actin filaments in the cytoplasm contracts to pull a ring of plasma membrane inwards
Forming a groove called a cleavage furrow
Plant cell
In plant cell, membrane-enclosed vesicles gather at a plant cell’s equator between the two nuclei
The vesicles fuse to form a cell plate.
The cell plate grows outwards until its edges with the plasma membrane of the parent cell.
7
Biology Teaching and Learning Module Cell Division
5.1.6 Application of Knowledge on Mitosis
Activity : Collect information. Do an article about the application of knowledge mitosis according to the topic below. In your article you can include tabled data, picture and other suitable technique which is necessary.
a) Tissue culture
Diagram
Explanation
1. Wash the tomato plant tissue with hypochloric solution.2. Tomato tissue are cultured in a sterile medium rich in nutrients3. After the callus is formed, transfer the tissue culture to a new sterile medium rich in nutrients
which contain growth hormone.4. After the shoots is formed, transfer them into the plant pod
Tomato plant tissue
Callus
root
Shoots
8
Biology Teaching and Learning Module Cell Division
b) Cloning : Advantages and Disadvantages
Advantages Disadvantages
Ensure the continuity of hereditary traits from the parent to the clones.
Increase the rate of production and the quality of the products
Good qualities of the plants and animals can be selected and maintained in the clones
Many clones are produced in a short time Can be carried out any time of the year.
The resistance of the clones towards diseases and pests is the same. If a clone is infected with a disease or attacked by pests then all the clones will also affected and die.
9
Biology Teaching and Learning Module Cell Division
5.1.7 The Importance of Controlled Mitosis
Explain the importance of controlled mitosis.
1. mitosis – increase the number of cells and repair damage cells. It happens in animal and plant in growth, preserve the normal body tissues for survival of life.
2. meiosis – produce haploid gametes to maintain the number of chromosomes in organisms
5.1.8 The Affect of Uncontrolled mitosis in living things
Explain the affect of uncontrolled mitosis (cancer)
1. Mitosis occur because the changes of gene which control the cell cycle. 2. This condition happen because of certain virus, toxic chemical substances, expose to the
direct and strong ultra violate rays.3. The cells divide very fast and unregulated. This abnormal cell are called tumour.
Benign tumour – abnormal cells remain at the original site. Do not cause serious problems and can be removed by surgery.Malignant tumour – the tumour becomes invasive and spread to neighbouring tissues. This is cancer.
10
Biology Teaching and Learning Module Cell Division LS 2 : Understanding Meiosis
5.2.1 Inheritance in offspring
Process of producing new individuals is celled sexual reproduction. Sexual reproduction involved two parents male and female. Male and female produce
gametes. Each gamete has half the number of chromosome compare to the parent. Gamete is produced during meiosis process.
Male gamete (haploid) and female gamete (haploid) will combined to form a zygote (diploid) and grow to form a new individual.
The new individual which is produced will inherit the characteristic from both parents. The number of chromosomes diploid must be maintained from one generation to another
generation so that the characteristic of the species and the number of chromosome can be maintained. Any changes regarding the number of chromosome will effect the healthy growth (syndrome)
Each species has different number of chromosomes diploid.
5.2.2 Definition of Meiosis
Meiosis is the process of nuclear division that reduces the number of chromosomes in new cells to half the number of chromosomes in the parent cell and produce four daughter cell.
Places where the meiosis occur :In the testes (male) –produce sperms and ovaries (female) – produce ovumAnther of flowers – produce male gamete in pollen and ovaries of the flowers – produce egg cell as ovules
5.2.3 The Stages of Meiosis
Meiosis consist of two separate divisions. They are Meiosis I and Meiosis II.Each stage include the prophase, metaphase, anaphase and telophase.
Activity 1: Arrange the stages of meiosis process and explain each stage.
11
Biology Teaching and Learning Module Cell Division
Stages of Meiosis Process.
Instruction : Cut the phases of division cell of mitosis above and paste the appropriate pictures in the box provided in the next page in correct order. Explain what happen during each stage in the boxes provided.
Metaphase I
Anaphase II Metaphase II Telophase II
Prophase I
Late Prophase I
Anaphase I
Prophase II
12
Biology Teaching and Learning Module Cell Division The Stages of Meiosis Process
MEIOSIS I
Figure Explanation
Early Prophase I
Late Prophase I
Chromosomes begin to condense and shorterHomologous chromosomes come together to form bivalents through a process called synapsis.
Non-sister chromatids exchange segments of DNA in a process known as crossing over.
The points at which segments of chromatids cross over are called chiasmata
Nucleolus and nuclear membrane disappear
Centrioles migrate to the opposite poles of the cells
Spindle fibres strate to form.
Matephase I
The homologous chromosomes are lined up side by side on the metaphase plate.
13
Biology Teaching and Learning Module Cell Division
14
Biology Teaching and Learning Module Cell Division
Figure Explanation
Anaphase I
Homologous chromosomes move to the opposite poles of the cell.
Telophase IChromosomes arrive at the poles
Each pole now has haploid daughter nucleus because it contains only one set of chromosomes.
Spindle fibres disappear
Nuclear membrane nucleolus reappears
MEIOSIS II
Prophase II
Nuclear membranes of the daughter cells disintegrate again.
The spindle fibres reform in each daughter cell.
15
Biology Teaching and Learning Module Cell Division
16
Biology Teaching and Learning Module Cell Division
Figure Explanation
Metaphase II
Chromosomes are lined up on the metaphase plate
Anaphase II
The centromeres of the sister chromatids finally separated and move towards the opposite poles of the cell.
Telophase IIThe nucleoli and nuclear membranes re-form
The spindle fibres disappear
Cytokinesis occur and four haploid daughter cells are formed
Each contain half the number of chromosomes and it genetically different from the parent diploid cell.
It will develop into gametes
17
Biology Teaching and Learning Module Cell Division
5.2.4 Comparison Between Meiosis I and Meiosis II
Complete the table below regarding the similarities and differences between Meiosis I and Meiosis II.
Stage Meiosis I Melosis IIProphase
Similarities :- Spindle fibres are formed- End when chromosomes reach the metaphase plate.
Differences :- Synapsis occur- Crossing over occur
MetaphaseSimilarities :
- Chromosomes are lined up on the metaphase plate
Differences :- Homologous
chromosomes are lined up on the metaphase plate.
Differences :- Chromosomes are lined up
on the metaphase plate.
Anaphase Similarities :- Chromosomes / chromatids move to the opposite poles started
with the centromere
Difference - Paired homologous
chromosomes separate and move to the opposite poles.
- No separation of centromere
Difference - Separation of chromatids - Have separation of
centromere
Telophase Similarities - Nuclear membrane appear
Difference - The chromosomes of
daughter cell are double helix bond
- Two daughter cells are formed
Difference :- The chromosomes of
daughter cell are single helix bond
- Four daughter cells are formed
18
Biology Teaching and Learning Module Cell Division
5.2.5 Comparison Between Mitosis and Meiosis
- Occur in M phase in cell cycle- The division involved nucleus and cytoplsm
For growth, maintenance and repair of body tissue
Somatic cell
No cross over
Daugther cells are genetically identical to the parent
2
Synapsis occur
Has same number of chromosomes as the parent cell (diploid)
Has half the number of chromosomes of the parent cell (haploid)
Synapsis occur
4
Daugther cells are genetically non-identical to the parent
Cross over occur
Produce gamete
Reproductive organ
Similarities
Differences
Place occur
The role of cell division
Crossing over happen or not ?
Genetic composition of daugther cells
Number of daugther cell
Synapsis of homologous chromosomes
Number of chromosomes in daugther cells
19
Biology Teaching and Learning Module Cell Division
5.2.6 The movement of Chromosomes during Mitosis and Meiosis
a) Why the movement of chromosomes during mitosis and meiosis should be regulated in a precise manner?
1. Meiosis – to ensure gametes are haploid and each gametes genetically different from each other
2. Mitosis – to ensure daughter cells has the same number of chromosomes as the parent cell.
b) There are many substances which can interrupt the movement of chromosomes during mitosis and meiosis. Name the substances and the effect of the process
Substances which can interrupt the movement of chromosomes 1. Radioactive rays 2. X rays3. UV rays4. Carcinogens
Affect 1. Cause gene mutation – cancer 2. homologous chromosomes fail to separate – produce abnormal chromosomes
c) How can we avoid the interruption of movement of chromosomes during mitosis and meiosis.
1. Healthy way of life – not smoking 2. Have a balanced diet 3. Practise healthy social activities4. avoid exposure to carcinogenic substances
20