All living organisms undergo:

• Movement: when an organism or part of it changes its place/position

• Respiration: Biochemical reaction in cells that breakdown nutrient molecules for (energy) metabolism

• Sensitivity: Detection of a stimulus and ability to respond

• Growth: Permanent increase in cell size, number or complexity

• Reproduction: Creation of offspring of the same species as the parents

• Excretion: Removal of toxic materials, waste products from metabolic processes or substances in excess

• Nutrition: 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

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

• 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: Kingdom, Phylum, Class, Order, Family, Genus, Species

KING PHILIP CAME OVER FOR GRAN’S SPAGHETTI ;)

The Five Kingoms:

1. Animal

2. Plant

3. Fungus

4. Prokaryote

5. Protoctista

Cell Structures

• Cells of all living organisms contain:

1. Cytomplasm

2. Cell membrane

3. DNA as genetic material

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

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)

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

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

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

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