Characteristics of Living Organisms (1.1-1.5)

All living organisms undergo:

• %%M%%ovement: when an organism or part of it changes its place/position
• %%R%%espiration: Biochemical reaction in cells that breakdown nutrient molecules for (energy) metabolism
• %%S%%ensitivity: Detection of a stimulus and ability to respond
• %%G%%rowth: Permanent increase in cell size, number or complexity
• %%R%%eproduction: Creation of offspring of the same species as the parents
• %%E%%xcretion: Removal of toxic materials, waste products from metabolic processes or substances in excess
• %%N%%utrition: Intake of substances required for growth and to provide energy

%%MRS GREN%% will help you remember!

• $Viruses are NOT considered living organisims$ because they do not complete these processes   * Viruses are non-cellular and consist of genetic material surrounded by a protein coat   * They reach target cell and inject this genetic material into the cell, which will then replicate to reproduce the virus harming the target cell

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Classification systems

• ==Classification is used to group species==   * Species==:== group of organisms that can be bred to reproduce fertile offspring   * Organisms are divided based on MORPHOLOGY and ANATOMY     * Morphology: Study of external characteristics     * Anatomy: Study of internal characteristics
• ==DNA sequencing studies give a more accurate comparison==
• DNA of each species is mapped and compared; species with similar ancestors will have closer DNA base seqences

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• Binomial Nomenclature: a system of nomenclature in which each species of animal or plant receives a name of two terms   * Second part is the SPECIES and is all in lowercase letters   * First part of the name is the GENUS and will always start with an uppercase letter
• The order of classification of organsims is: ==K==ingdom, ==P==hylum, ==C==lass, ==O==rder, ==F==amily, ==G==enus, ==S==pecies

==KING PHILIP CAME OVER FOR GRAN’S SPAGHETTI== ;)

\ The Five Kingoms:

1. Animal
2. Plant
3. Fungus
4. Prokaryote
5. Protoctista

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Cell Structures

• Cells of all living organisms contain:

1. Cytomplasm
2. Cell membrane
3. DNA as genetic material

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Kingdom: Plants

• %%Autotrophs%%: Living organisms that synthesize organic molecules from simple inorganic substances (through photosynthesis)   * %%Photosynthesis:%% Carbon Dioxide + Water → Glucose + Oxygen     * 6CO2 + 6H2O → C6H12O6 + 6O2

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Classifying Plants

• Algae: No leaves, roots or stem and contains chlorophyl   * It is photosynthetic; using the energy of the sun to change carbon dioxide and water into food and oxygen.
• Ferns: Do not produce flowers   * No true roots, stems or leaves but have ‘fronds’ instead   * Reproduces through spores
• Mosses: No vascularisation (xylem/phloem)   * No true leaves but have phyllids instead, no roots or stems (anchored by rhizoid)   * Reproduces by spores and sporangia
• Gymnosperms: Has vascularisation   * Has (true) leaves, roots and stems   * Reproduces through cones
• %%Angiosperms:%% Has vascularisation   * Has (true) leaves, roots and stems   * Reproduces through flowers   * Angiosperms can be further divided into monocots and dicots

\ \ \ Least developed →Most developed

Algae → Mosses → Ferns → Gymnosperms → Angiosperms

Kigdom: Fungi

• Either unicellular (eg. yeat) or multicellular (eg. dandruff, mushroom or mould)
• Structure of fungi:   * Grow as thread like filaments called hypha which intertwine to make up the mycelium   * Cell wall is made of chitin (or cellulose)   * Reproduce asexually by producing spores which can be dispersed by water, wind or other organisms OR can be shot out by sporangia   * Feed on dead decaying organic matter; saprophytic

Kingdom: Animals

• All animals are ^^heterotrophs:^^ ^^feed on organic molecules^^
• The animal kingdom is divided into VERTEBRATES ( have a backbone) & INVERTEBRATES (no backbone)

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Invertebrates

• Arthropods

  ^^Common features of arthropods^^   * Segmented body   * Hard exostkeleton   * Many pairs of jointed legs

• Arthropods are divided into : Crustacea , Insects, Arachnids, Myriapods

1. Crustacea:    * Many Body segments    * Stalked compound eyes    * 2 pairs of antennae as sense organs
2. Insects    * Divided into 3: head, abdomen, and thorax    * 1 Pair of antennae as sense organ    * Pair of compound eyes; wider vision    * 3 Pairs of jointed legs
3. Arachnids    * 2 body segments: Clepathorax and abdomen    * No antennae; Pair of pincers to hold food    * 4 Pairs of legs    * No compound eyes
4. Myriapods    * Centipedes are carnivorous- 1 pair of legs per segment    * Millipedes are herbivorous- 2 pairs of legs per segment

Nematodes

• No body segements
• Moves by wrigglign but lives in one place
• Parasitic; organism that lives on or in a host organism and gets its food from or at the expense of its host
• Soft bodied

Annelids

• Long segmented body covered in mucus
• Chaete (bristles) on each segment for movement
• Hard, waterproof body covering
• Herbivorous

Molluscs

• Have a shell that protects soft body
• Eyes on tentacles
• Mouth part to scrape vegetation
• Foot muscle with slimy covering for movement

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Vertebrates

Fish (Pisces)

• All are aquatic
• Cold blooded
• Scales for protection
• Lateral Line as sense organ and used for balance
• Movement through fins
• Breathing through gills; covered by operculum
• Skeleton is bone or cartillage
• External fertilisation; Female lays eggs in water, male sheds sperm over eggs to form zygote that develops into a young fish
• Stream lined to facilitate easier swimming

\ Amphibians

• Smooth, Slimy, Naked skin
• Cold blooded
• Moves using legs/limbs with their hind legs end in webbed feet for swimming under water
• External fertilisation
• Can live in both land and water
• Breathe through skin, mouth and lungs

\ Reptiles

• First true land living vertebrates
• Cold blooded
• Covered with dry scales for protection
• Breathe through lungs
• Internal fertilization; lay eggs

\ Birds/Aves

• Warm blooded
• Bodies covered by feathers   * To trap warm air and provide protection   * Quill feathers for wings and plume for the rest of the body
• Scales on legs which are tipped with claws
• Jaws modified into toothless beaks
• Forelegs modified into wings
• Hollow bones to decrease body weight and facilitate flying
• Internal fertilisation; reproduce through laying eggs
• Breathe through lungs; Have extra air sacs to store oxygen

\ Mammals

• Warm blooded
• Body covered by hair/fur
• Presence of external ear (pinna) to collect sound waves
• Females have mammary glands to secrete milk to feed their offspring
• Internal fertilization; give birth to live offspring

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Kingdom: Prokaryote

• Microscopic and unicellular
• Some have flagella for movement
• No nucleus BUT have circular DNA strands instead
• Plasmids and extra chromosomal DNA
• Composed of: Outer cell wall made of murien, a cell membrane and cytoplasm
• Reproduces asexually by binary fission

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Dichotomous keys

• @@Used to identify species based on a series of questions about their features@@
• A user is presented with @@2 questions at a time (hence the name DIchotomous)@@ and is supposed to chose one that correlates with the species
• This leads to a pair of other questions
• In order to successfully navigate a key, you need to pick a single organism to start with and @@follow the statements from the beginning@@ until you find the name
• You then pick another organism and start at the beginning of the key again, repeating until all organisms are named

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