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Prokaryoteo No membrane bound nucleuso Has nucleoid, (plasmids)o Has enzymes, ribosomes,

food storage granules

o No endoplasmic reticulum,Glogi body, mitochondria,

chloroplast

o (Mesosome for respiration,chlorophyll, flagellum)

Eukaryotico Has internal membraneso Has organelles and ultrastructureo Nucleus: double nuclear membrane (has holes/pores)o Chromosome -> network (chromatin) stain + gently heatingo

1+ nucleoli (manufacture of ribosomes) stain + gently heatingo Mitochondria

Rod-shaped/cylindrical organelles Muscle fibres & hormone-secreting cells Making ATP Matrix cristae Outer + inner membrane = stalked particles

o Centrioles Pull apart to produce a spindle of microtubules

o Cytoskeleton 3D web-like structure Microfilaments (protein fibres) ~ actin, myosin Microtubules (tiny protein tubes) ~ globular protein

(tubulin)

Functions Gives the cytoplasm structure Keeps the organelles in place Contractile proteins in muscle Cytoskeleton ~ cell movements and transport within

cellso Vacuole

Not permanent in animal cell Contractile vacuole: control water content Supporting plant cell, storage of minerals

o Smooth endoplasmic reticulum Have cisternae No ribosomes Making and transporting lipids, steroids Voluntary muscle fibres: storage of calcium -> contraction

oRough endoplasmic reticulum

Have cisternae

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Ribosomes attached Making proteins Storing and transporting proteins Packing proteins in vesicles

o Golgi apparatus No cisternae Vesicles fuse with Golgi Modifying proteins

Adding glycoprotein Trimming of carbohydrate

Remove water to concentrate the vesicles Produce lysosomes Stack of flattened membranous sacs

o Chloroplast thylakoid membrane -> granum Membrane has chlorophyll Soaked in stroma Double membrane

o Sap vacuole Tonoplast Turgid => maximum hydrostatic strength Flaccid

Starcho Amylose (helix) + amylopectin (branched)o 1-4 glycoside bond between glucose (~cis)o 1-6 bondo Monomers in same orientation

o Cellulose

o 1-4 glycoside bond between glucose(~trans)

o Straight chaino MANY hydrogen bond between OH groupso Every other monomer inverted

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o Make microfibrils(x50-80) -> plant fibre functions Tensile strength /inelastic Parallel arrangement Hydrogen bonding Several layers of fibres Net like arrangement of microfibrils

Ciliated epithelia often contain goblet cells that produce mucuso Skin: compound epitheliao Artery walls: nervous, collagen, elastin tissueo Glandular tissue secretes substances from inside the cellso Connective tissue: main supporting tissue in the body: e.g. bond,

cartilage, packing tissue

Squamous epithelium: blood vessels, capillaries, alveoli Cuboidal, columnar cell: other tubes in the body Plant

o

Ca2+: -> calcium pectate -> 1cell wallo Mg2+, Fe2+: chlorophyllo Sclerenchyma (fibres dead empty cells with tapering interlocking

walls + cellulose), xylem, phloem

Mitosiso Asexual reproductiono Sexual reproduction: after fusedo 2 daughter cellso The cell cycle

Interphase (G1, S, G2) DNA produced as chromosome replicate New protein, organelles, cytoplasm ATP steps up

Mitosis Prophase

o Chromatids attach 2 daughter chromatidso Nucleolus breaks downo Centrioles begin to pull apart to form the

spindle

o Nucleus and nucleolus disappear Metaphase

o Nuclear membrane broken downo Centrioles move to opposite poleso Formation of a set of microtubules

spindle

o Chromatids jostle about for position on theequator (metaphase) and line up

o Each centromere associated with amicrotubule of the spindle

Anaphaseo Centromeres linked the two identical

chromatids split-> new chromosomes

o Chromatids from each pair -> opposite polesof the cell (~minutes)

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o => 2 set of chromatids at opposite ends Telophase

o Early: Spindle fibres break downo Nuclear envelopes from around the two sets

of chromosomes

o Nucleoli and centrioles re-formed => visibleo Final: Chromosomes unravel => less denseo Observations

Chromosomes uncoiling -> invisible Nucleus visible Nucleolus may be present Spindle has broken down 2 separate nuclei visible Evidence of cell plate formation

Cytokinesis: division of cytoplasm

Control by chemical signals Cyclins (CYCLe) Attach to cyclin-dependent kinases (CDKs) Cyclin/CDK complex: add a phosphate group to

other proteins -> change shape -> next stage

Meiosiso

Gene locus: location of gene on a chromosome Haploid number: number of chromosome of body cell Higher mean number of different alleles per gene locus

o Larger genetic variationo Larger gene poolo Genotype may give a selective advantage for changeso More likely to survive and breedo Pass on favorable allele combinationso Natural selection -> most best adoptedo Change in allele over generations

Cloneso Not reply on finding mateo Can give rise of many offspring rapidlyo Almost all genetically identical

Stem Cell: undifferentiated cell -> rise to other type of cells; no limit todivision; toti/plurio Embryonic stem cell

4-8 cell stage = totipotent Blastocyst stage: pluripotent fetus, inner cell mass) ->

implantation

Totipotent: can differentiate to form all cell type, no geneswitched off, unspecialized

Pluripotent: e.g. blood stem cell -> blood cell Potential life Right starts at fertilization Viable => discard?

o Umbilical cord stem cell

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Pluripotent: give raise to most specialized cell, some geneswitched off, unspecialized

Precursor cells of leukemia may already presento Adult stem cells

Somatic stem cells In white bone marrow: white blood cell stem cell Multipotent

Differentiationo Deactivate some geneo mRNA from activated gene translate to different proteino protein modify cello changes is permanent

Strategy of asexual reproductiono Binary Fission

Mitosis + splitting of an individualo

Sporulation (producing spore) Mitosis + asexual spore E.g. fungi, plants like mosses and ferns

o Regeneration E.g. regeneration oflizards tail Fragmentation -> new individuals

E.g. starfisho Budding

~Binary fission Parent cell > bud

Chromosome: a mass of coiled threads of DNA and proteins Histones (+ charged proteins)

o DNA winds around it to form dense cluster: nucleosomeso Supercoiled areas: genes not available to be copied => different

type of cells

Karyotype: chromosome Meiosis in the formation of gametes

o Halve chromosomes numbero Restore to diploid after fertilizationo Allow genetic variation

Through independent assortment Through crossing over

Phenotypeo Appearance of genotypeo Somehow affected by environment

Genotypeo the genetic makeup of a cell, an organism, or an individual

Alleleo Alternative form of gene

Spermatozoao Many, mini, motileo Tasks

Remain in suspension in semen: transport through femalereproductive tract

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Penetrate the protective barrier around ovum Deliver male haploid genome

o Microtubules: whip-like movement in suspension + swim to ovum

Acrosin in acrosomeo Enzyme to help sperm nucleus to get in to the egg through zonao Stimulus: contact with zona and present of chemicalso Acrosome swellso Acrosome fuses with sperm cell surface membraneo Exocytosis

Historic drug testing vs contemporary drug testing (both find suitabledoes; on patients; extract drugs from plants)

1. C usesanimals2. C tests on healthy people3. C pay volunteers4. C may involve double-blind trials;5. C use statistical analysis / phase 3 / use large number6. C more regulation;7. Controlling {factors/variables/eq} in tested cohort e.g. age, lifestyle;

Sexual reproduction of flowing plantso Stamen = anthers + filamento Carpels = ovary + stigma + styleo Pollination: the transfer of pollen from a mature anther to a

receptive stigma

Self-pollination / cross-pollination Nectar, colourful -> insect Feather like, hanging out -> wind Fertilization

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After pollination + germination Pollen grain produces a pollen tube -> style ->ovule 2 male nuclei delivered by the pollen tube 1 fuses with the egg nucleus in the embryo sac =>

diploid zygote

1 fuses with a nucleus which triggers formation ofthe food store for the developing embryo

Double fertilization Independent assortment

o Random aligningo New combinations of alleles

Crossing overo Breaking and rejoining of DNAo On same chromosome pairo Recombines genes

Genetic Diversity: size of gene pool in a species; genotype/ allele Species richness: number of species / within a habitat Store seed from several individual plants

o Less chance of inbreedingo Less chance that many seeds stored are disease seedso Larger genetic variety

Species: a group of closely related organisms that are all potentiallycapable of interbreeding to produce fertile offspring.

Morphology Molecular phylogeny

Ecological species: based on the ecological niche occupied Anatomical adaption: inner organ

o E.g. thick later of bladder in whales and seals Behavioral adaption

o E.g. hunting as a team Evolution; selection pressure; change of conditions

o Mutation -> different physical appearance e.g.o If in advantage -> more likely to survive and reproduceo If in disadvantage -> removal from gene poolo If neutral -> remain by chance

Small populationo Chance of losing an allele by bad luck is large => smaller gene

pool

Maintain biodiversity need large population Founder effect

o Allele is a random selection of gene poolo Not include all the alleles at the same f as in the original populationo Unusual genes become amplified as the population grows

Directional Selection -> one phenotype Diversifying Selection -> diverse (extreme) phenotype Balancing Selection -> allele seemed disadvantage remain

o Heterozygote advantage / hybrid vigour

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Endemismo Selective pressure (condition unlike home)o Founder effect (limited gene)o New species in a small area (endemic organisms)

Planto Where rain fallo How water runs off from soilo Transpiration

Keystone species: important impact on the environment Extinction: permanent loss of all member of a species Captive breeding programmes: endanger species are bred in zoos and

parks in attempt to save the species from extinction

o Problems Insufficient space and recourses for all endanger species Difficulty in providing a condition of breeding Unless reasons for endanger removed, unsuccessful to

reintroduce

Animal have problem in adjusting to unsupported life inwild

Small gene pool in zoos Costly and time-consuming and may not success

Captive breeding programmeso Increase population

Condition and food Predators

o Maintain genetic diversity Selection of mate DNA profiling

Reintroduction programmeso Select habitato Reinforcing wild behaviouro Raise awareness

Cross-species cloningo Closely related surrogate mother

Biodiversity = variety of organisms Simpson Diversity Index

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Seed savingo X-ray: check for healthy, fully-developed embryoo Some seed do not store well

E.g. crop plants like mango, cacao, coconuto Dryingo Freezingo Low oxygeno Low humidityo Absences of lighto Sterilization

Control groupo Ensure difference of result due to independent var oro Show the situation without ___ for comparison

Stain: orcein, toluidine

Observe mitosiso Root tipo Break open tipo Acido Staino Warm to internsify stainingo Mount in staino Squash under coverslip

Tensile strength: Ability to resist stretching

Cell wall Plasmodesmata