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== ;)

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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

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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

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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

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Reptiles

• First true land living vertebrates

• Cold blooded

• Covered with dry scales for protection

• Breathe through lungs

• Internal fertilization; lay eggs

  

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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

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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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