Biology Module 2010 Seratas

Biology Form 4 module with the content of notes, Power Point notes, PowerPoint courseware and question bank. This module is suitable to be use by teachers and students as aid learning material to compliment the textbook.

Nurul Azuwin bt YazidBiology Form 4

Learning Objective:

Understanding mitosisUnderstanding meiosisappreciating the movement of chromosomes during mitosis and meiosis

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Chapter 5: Cell Division5.1 Mitosis

Do you still remember what the basic of living thing is? Do you ever think how you can growth from a baby into an adult? What happen to your body or maybe to your cell?

_______________________________

Most of our cells are continuously growing, dividing and dying. The dead cells must be replaced with new cells. The cells undergo cell division to produce the new cells.

Necessity for cell division in living organism

The new cell formation allows:

replacement of dead cell body repair damaged tissue body growth and development reproduction in unicellular organism eg.

binary fission of Amoeba sp.

Stages of cell division

nuclear division- mitosis or meiosis cytoplasmic division- cytokinesis

What is DNA and Chromosome?

Types of cells:

1.Somatic cell- all body cell (except reproductive cell) form trough mitosis

2.Gametic cell- reproductive cell that formed trough meiosis

Chromosome contain DNA which carries genes (genetic material)

The nucleus of cell contain chromosomes

DNA is tightly wrapped with histone to form chromatin.

Chromosome--the chromatin then coils up even tighter to form short fat bundles during division

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Homologous chromosomes and karyotype

Different species have different number of chromosomes, but all members of the same species have the same number. Example: Humans have 46 chromosomal numbers.

Each chromosome has a characteristic size, shape and banding pattern, which allows it to be identified and numbered

Humans have 22 pairs of autosomes, and 1 pair of sex chromosomes.

Diploid and haploid

Ploidy – refers to the number of sets of homologous chromosomes in a cell

Diploid organisms receive one of each type of chromosome from maternal and paternal chromosomes

Haploid – one copy of each chromosome – designated as “n”

Diploid – two copies (= pair) of each chromosome – designated as “2n”

Significance of mitosis

Produce from replication of DNA. Have identical genetic contain

Pairs of same size, shape and banding patterns chromosome

Homo= same

Karyotype=arrangement of homologous pairs of chromosome

Trivia?

A monkey sperm cell have 24 chromosomes, how many pairs of chromosomes does the cheek cells of the monkey have?

Answer:

2set (2n/diploid): ___ chromosomes (somatic cell)

1set (n/haploid): ___ chromosomes (gametic cell)

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Significance

growth- the number of cell

within organism increases by

mitosis.

cell replacement- replacement

damaged cells and tissue

Regeneration –star fish

regenerate whole part of the body such

asexual reproduction -binary fission


Each daughter formed through mitosis carries genetic material (DNA) inherited from the parent cell.

This genetic information is passed on to new cells during division to produce two identical nuclei.

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Cell cycle

2 major phases:

i) interphase (3 stages: G1,S and G2)

– DNA uncondense (= chromatin)

- 90% of cell cycle

ii) Mitotic phase (4 stages + cytokinesis)

- Nuclear division & cytoplasm division

- DNA condensed (= chromosomes)

cytokinesis

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Interphase

chromatin not visible DNA replicated

Prophase chromosomes condensed and visible centrioles at opposite poles of cell phase ends with the breakdown of the nuclear membrane

Metaphase chromosomes align along equator of cell spindle fibres (microtubules) connect centrioles to chromosomes

Anaphase

centromeres split, allowing chromatids to separate chromatids move towards poles

Telophase

spindle fibres disperse nuclear membranes form

Sub phase of mitosis

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Cytokinesis

(division of cytoplasm)

In animals, a groove called the cleavage furrow forms pinching the parent cell in two

In plants, a cell plate forms down the middle of the cell where the new cell wall will be

? Find the differences of cytokinesis in animal and plant cell.

Controlled and uncontrolled mitosis

Importance of controlled mitosis Effect of uncontrolled mitosis

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Ability of cell to divide by its own rate and timing Controlled by genes Enables growth and development occur at right time Important for normal growth, development and maintenance

example-division of human skin throughout life- division of nerve cell and muscles cell stop after cells mature

Causes cell divide repeatedly without control and regulation

lead to formation of benign and malignant tumor

Benign- abnormal cell remains at original site. Remove by surgery

malignant- cancer which spread to other tissues through blood or lymph circulatory

Cause by mutation of gene- exposure to ultraviolet, carcinogenic chemical or virus.

Application of mitosis

Asexual reproduction is the production of offspring from a single parent using mitosis. Therefore the offspring are genetically identical to each other and to their "parent"- i.e. they are clones.

METHODS OF ASEXUAL REPRODUCTION

Natural Methods Artificial Methods

MICROBES

binary fission, budding, spores, fragmentation

cell culture, fermenters

PLANTSvegetative propagation, parthenogenesis

cuttings, grafting, tissue culture

ANIMALS

budding, fragmentation, parthenogenesis

embryo splitting, somatic cell cloning

i) Tissue culture

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Explain the steps of tissue culture base on the diagram.

ii) animal cloning

Activity

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5.2 Meiosis

Importance of meiosis

After fertilization of male and female gametes, the offspring will have twice number of chromosomes

Hence, in order to maintain the same chromosomal number of the offspring, the cell must undergo meiosis.

Each gametes receive one chromosomes from every pair of homologous .So, gametes contain haploid (n) number of chromosomes Meiosis comprises two successive nuclear divisions with only one round of DNA replication.

Dolly-1st cloning mammal CC-cat clone in 2001

Find about these clone on internet.

Internet research

Meiosis is process of nuclear division that reduces number of chromosome in new cells to the half number of chromosome in parent cells

Meiosis I

Meiosis II

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Where does meiosis occur?

Animal Plant

sex Male female Male female

organ

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How to count chromosome?

This I single chromosome

or chroma

tid

The number

of chromo

some can

count by the

number of the

centromere

Sister chromatid

centromere

Tetrad


Gametes

sperm ovum pollen ovum

Meiosis stages

Synapsis and crossing over

During

prophase I, homologous chromosomes come

together form bivalent through synapsis. The bivalent

visible as four-part structure known as tetrad

Crossing over occur between non sister chromatid

to change genetic material

Chiasma (plural: chiasmata) is site at crossing over occur

Crossing over

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Meiosis I: Separate the Homologues

Meiosis II:

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daughter cells are formed = eggs or sperm. Each contains half as many chromosomes as the parent cell (n); each cell is genetically different from its parents and from its "siblings". Fertilization of an egg by a sperm restores the chromosome number to 2n.

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Comparison of meiosis and mitosis

Meiosis I Differences Meiosis II

- Homologous chromosome pairs up –

- crossing over between non sister chromatid

PROPHASE -no synapsis of homologous chromosome

- No crossing over

- Homologous chromosomes align at equator

METAPHASE -chromosomes align at equator

- Homologous chromosome separate and move to opposite poles

- siser chromatid attach at centromere

ANAPHASE -sister chromatid separate becoming daughter chromosome

-Produce 2 haploid daughter cell

-each daughter cell has only one of each type of chromosome

TELOPHASE 4 haploid daughter cell produced

each cell have only one of the sister chromatid

Have same number of chromosome with haploid cell from meiosis I

Compare meiosis and mitosis

Mitosis Aspect Meiosis

- similarities

- Place -

- role -

Number of division

Synapsis and crossing over

Number of daughter cell

Genetic composition in daughter cell

Genetic variation

Ploidy level

5.3 Appreciating the movement of chromosomes during mitosis and meiosis

Activity

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What will happen if the chromosome not move in proper position during the division?

Make internet research about:

-Downs Syndrome

-Turner syndrome

-Edwards Syndrome

Internet research What happen to chromosome which cause these syndromes occur in human?

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Chapter 8: DYNAMIC ECOSYSTEM

Learning Objective:

Understanding the abiotic and biotic components of environmentUnderstanding the processes of colonization and succession in an ecosystem Synthesizing ideas on population ecologyUnderstanding the concept of biodiversity Understanding the impact of microorganism on lifeAppreciating biodiversity

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Grass (producer)grasshoppers (primary consumer)frog (secondary consumer)snakes (tertiary consumer)


8.1 The Abiotic and Biotic Component of the Environment

Food chain, food web and trophic levels

Food

chain - sequence of organisms through which energy is transferred.

Explain what is :

1. producer-

2.primary consumer-

3. Secondary consumer-

4. tertiary consumer-

5 decomposer-

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The abiotic component The biotic component

The non-living components such as The living organisms in the environment such as

1.pH value – soil and water2.Light intensity – as source of energy3.Temperature4.Humidity – amount of water vapour present in the air5.Topography – physical features of land (altitude, gradient and aspect of region)6.Microclimate – climate in a microhabitat

1. Producers – synthesise organic substances (plants)

2. Consumers – eat other organisms (primary consumer, secondary consumer, tertiary consumer)

3. Decomposers – microorganisms that break down waste products and dead bodies (bacteria and fungi)


Food web – food chain interconnected.

Energy flows through food web and lost when it transferred from one level to another level of the trophic levels in the form of heat

Label the producer and consumer in the food web

Activity

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The interaction between biotic component in relation to feeding

Organisms interact with one another in various ways such as

(a)Symbiosis

close relationship between two or more different species which live closely together and interact with each otherthree categories:

(b) Prey-predator

Relationship where an organism which is smaller, called the prey, is haunted and eaten by a stronger animal, the predatorE.g. an owl (predator) and a rat (prey)The interaction takes place in a cycle that keeps the populations of both organisms in a dynamic equilibrium

(c)The interaction between biotic components in relation to competition

Competition – interaction between organisms living together in a habitat and competing for the same resources that are limited supplyTwo types:

a) Intraspecific – competition between the same speciesb) Interspecific – competition between different species

Commensalism

One species (the commensal) benefits, the other (the host) don’t get benefits nor is harmedE.g. epiphytes grows on branches of trees

MutualismRelationship between two species of organisms in which both benefitE.g. bacteria in the digestive system of human

ParasitismRelationship between two organisms in which one organism (the parasites) benefits from the other organism (the host)Two types:a) Ectoparasites – live on the surface of the host (e.g. ticks and fleas)b) Endoparasites – live inside the body of the host (e.g. tapeworms)

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8.2 Colonisation and Succession in an Ecosystem

Ecosystem

A community of organisms which interact with their non-living environment & function as unit.Vary in size-Have level of organisation:

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a group of organisms that have similar characterisitics, share the same roles in an ecosystem and are capable of interbreeding.Speci

es

Popu

lationseveral different species living in the same habitat in an ecosystemC

ommun

it

y

r o le o f a n o r gan i sm in e cos yst e m

Niche

Colonisation

Colonisation takes place in a newly formed areas where no life previously existed.The first organism occupy a newly formed area are called pioneer species.Characteristics:i.Hardy plant that have dense root system (grass)ii.Short life-cycleThey modify and creating more conducive condition to other organisms

Second species

Second species came after the pioneer species are the successor species.Characteristics:i. Bigger than pioneer species (herbs)ii.Have small wind-dispersal seeds (to spread and grow rapidly)They change the structure and quality of the soil and creating more conducive condition for larger plants to grow.

Third and permanent species

Third and permanent species are the dominant species (shrub).Modify the environment for larger trees to grow.

Succesion

Succession – the gradual process through which one community changes its environment to be replaced by another community.

Climax community

ecological succession leads to relatively stable community (equilibrium with its environment)


Colonisation and succession

Make research or field trip to mangrove to study the succession and plant species at the mangrove

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The quadrat sampling techniqueUsed in estimating the size of plant population and immobile animal.A quadrat – metal, wooden frame or PVC pipe frame which form a square of a known area (1 m2).placed randomly in an ecosystem where sampling is carried outFrequency – number of times a particular species is found present when a quadrat is thrown a certain number of timeDensity – the mean number of individuals of species per unit areaPercentage coverage – an indication of how much the area of quadrat is occupied by a species

The capture, mark, release and recapture techniqueUsed to estimate mobile animals (small mammals, butterflies, birds and insects)Procedure:1.Animal sample is captured2.Marked3.Released4. Second sample captured & number of marked animal recorded


8.3 Population Ecology

A branch of ecology that studies the structure and dynamics of population.Population density – number of organism per unit area of habitatAffected by abiotic and biotic factors, birth rate, death rate, immigration and emigration.

Determine population density

Direct counting – method to estimate the size and density of population (impractical due to the size of ecosystem, the number of plants involved and the movement of the animal).Sampling technique – more practical way, enable us to estimate the total population size of the organism.

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Monera / Prokaryotaeunicellularno true nucleus - prokaryote (genetic material scattered and not enclosed by a membrane)examples - bacteria, blue-green bacteria (cyanobacteria)

Protistaunicellularhave a true nucleus - eukaryoteexamples - amoeba, diatom, euglena, paramecium, some algae (unicellular)

Fungimulticellularhave nucleimainly do not move from place to placeheterotrophic (food is digested outside of fungus)examples - mushroom, mold, puffball, shelf/bracket fungus, yeast,Plantaemulticellular, have nucleido not moveautotrophicexamples - multicellular algae, mosses, ferns, flowering plants (dandelions, roses, etc.), trees

Animaliamulticellular, nucleido moveheterotrophicexamples - sponge, jellyfish, insect, fish, frog, bird, man


1.Do the quadrat sampling technique at the field of your school to estimated the population of Mimosa pudica.2. Apply the capture recapture method using beads in laboratory.

8.4 Biodiversity

What is meant by biodiversity…o The diverse species of plants and animal interacting with one another on Earth.

Need to be classified because there are many organisms in this world.

Classification of OrganismsTaxonomy – branch of Biology concerned with identifying, describing and naming organisms.Systematic method of classifying plants and animal based on the similarities in their characteristics.Classification of OrganismsOrganisms can be classified into 5 major kingdom:

Activity

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The hierarchy in the classification of organisms

7 hierarchy levels

The number of organisms at each levels decreasesNaming of organisms is based on Linnaeus binomial system.Each organism has two names in Latin –a) first name is the name of genus (begins with capital letter) & b) second name is the name of species (begins with small letter)

E.g. Mimosa pudica – Mimosa refers to the genus and pudica refers to the species.c) Specific names are written in italic or underline.

E.g. Mimosa pudica or Mimosa pudica

The importance of biodiversity

Provide various biological products – food, medicine, timber, etc.Provide many environmental services – nutrient cycle, pollination, etc.Give diversity in the genetic pool.

http://schools.utah.gov/curr/science/sciber00/7th/classify/sciber/5king2.htm

species

genus

family

order

Class

Phylum

kingdom

On line

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8.5 The impact of Microorganisms on Life

Microorganism

Tiny living things that only can be seen using microscope Classified based on their characteristics (appearance, shape, size, method of reproduction, nutrition and habitat)Classified into 5 groups:

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Viruses smallest microorganisms, not a living cell and must use living cells to reproduce. E.g. HIV, Influenza virus

Bacteria unicellular organisms, have cell wall, form spores under unfavourable conditionhave 3 common shape : spherical, rod-shaped and spiral. E.g. Lactobacillus sp.Straphyloccous sp.

Protozoa unicellular organism, have plasma membrane and can carry out living processes. E.g. Amoeba sp.,Paramecium sp.

Algae have chlorophyl and chloroplast, can undergoes photosynthesis process. (E.g. Spirogyra sp.)

Fungiheterotrophic microorganisms,feeds by secreting enzymes that break down the surrounding organic material into simple molecule before absorb them. E.g. Mucor sp.,yeast


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The role of useful microorganisms in the ecosystem

1. Decomposition 2. The nitrogen cycle3. Digesting animal’s food4. Digesting human’s food

The harmful microorganisms

Microorganisms that cause diseases are called pathogensPathogens are classified as parasites or saprophytesThey cause diseases in two ways:

1.Produce poisonous chemical

2.Attack and destroy host cells and body tissues

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Production of antibiotics, vaccines and hormones

Waste treatment

Production of biodegradable plastic (bioplastic)

Cleaning of oil spills

Production of energy from biomass

Food processing


Controlling pathogen

Do library and internet research how to control the pathogen.

Present your research in the form of mind map

The uses of microorganisms in biotechnology

Biotechnology – application of biological processes in the manufacturing and servicing industries

TRANSMISSION OF DISEASES

Air

Water

FoodVectors

Direct Contact

Indirect Contact

Activity

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Appreciating Biodiversity

Through conservation and preservation.

List your idea how we can applying conservation and preservationActivity

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Learning Objective:

Evaluating human activities that endanger an ecosystem Understanding greenhouse effect and thinning of ozone layerRealising the importance of proper management of development activities and ecosystem

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Documents

Biology Module 2010 Seratas