The characteristics of life: 2.1.1 Define nutrition, excretion, respiration, sensitivity, reproduction, growth, and movement.

The seven characteristics of living organisms are: MRS GREN… movement, reproduction, sensitivity, growth, respiration, excretion, and nutrition

Movement: being able to change position or place Reproduction: being able to duplicate an organism that looks like the

parent Sensitivity: being able to pick up stimuli from the environment and

responding to it Growth: being able to make a permanent increase in size and dry mass by

an increase in cell size or number of cells Respiration: being able to break down nutrients/organic molecules in

living cells to release usable energy for the cell Excretion: being able to get rid of toxic waste produced from metabolism

and excess substances not used during metabolism in cells Nutrition: taking in of nutrients, and minerals which are the building

blocks to assimilate into species specific polymers for growth, maintenance, and repair

ClassificationLinnaean Classification

Developed by Carl Linnaeus (1707 – 1778) a Swedish botanist & taxonomist. Most of his classifications of organisms, based on physical traits, for example, ____________________________ are still accurate and still used today.

Taxonomy: the branch of science concerned with classification or a scheme of classification

Domains and Kingdoms

There are different ways to organise all the groups of organisms. The most commonly used systems, and the ones in your textbooks, is of three domains and five kingdoms. The bacteria and archea are all prokaryotes. The protoctista, plantae, fungi, and animalia are all in the eurkarya domain.

The three domain system

bacteria archea Eukarya

The (old) five kingdom system

prokaryotes protoctista plantae fungi animalia

When classifying organisms we go from general characteristics to specific, so from Domain down to species. A good way remembering the order is to remember this mnemonic.

King

Philip

Came

Over

For

Good

Spaghetti

Binomial nomenclatureA formal system of naming species of organisms. Each species is assigned a scientific name made from two parts: Genus and species. The names are usually written in italics. The Genus has a capital letter and the species is in lower case, e.g.Common name : KoalaScientific name: Phascolarctos cinereus

Kingdom AnimaliaRemember that there are very many more Phyla, classes etc. than we will study. We will study 7 different phyla: porifera, cnidaria, platyhelminthes, mollusca, annelida, arthropoda, chordata and 5 classes of chordata: bony fish, amphibians, reptiles, birds and mammalsPorifera, e.g. sponges

2 cell layers No clear symmetry Attached to a surface Pores through body No mouth or anus No coelom No true organs

Cnidaria, e.g. jellyfish, corals, hydra

2 cell layers Radially symmetric Tentacles with stinging cells (nematocyst -

cnidocytes) Mouth but no anus No coelom Primitive nervous system (nerve net)

Platyhelminthes, (flatworms): e.g. tapeworm, planaria

3 cell layers Bilateral symmetry Flat bodies Unsegmented Mouth but no anus (waste comes of out

mouth) No coelom Primitive symmetrical nervous system

Mollusca, e.g. snails, octopi, gastropods, mussels, slugs…

3 cell layers Bilateral symmetry Soft bodied May have calcium carbonate shell Muscular foot and mantle Often excellent vision Shell usually present Segmentation not visible Mouth and anus

Coelom – body cavity

Annelida, e.g. earthworms Bilateral symmetry Bristles often present Segmented Mouth and anus Coelom – body cavity

Arthropoda, e.g. insects, arachnids (spiders, scorpions), crustaceans (crabs & shrimps), millipedes

Bilaterally symmetric exoskeleton segmented jointed appendages (“legs”)

Chordata

notochord – flexible rod made of cartilage (bone) which supports the nervous system

dorsal nerve cord pharyngeal gill slits post-anal tail

Subphylum VertebratesThe five major classes of vertebrates are mammals, bony fish, birds, reptiles, amphibians. You should know the main features of each.

Bony fish scales grow from the skin gills with a single gill slit fins supported by rays swim bladder for buoyancy external fertilization (eggs laid in water)

Amphibia soft moist permeable skin lungs with small internal folds Cold blooded (ectothermic) Dependent on water for reproduction Cold blooded (ectothermic) protective gel around eggs larval stages in water Tadpole with 2 chambered heart; adult with 3-chambered heart Tadpole with gills; adult with lungs

Reptiles dry scaly impermeable skin

lungs with extensive folding Cold blooded Scaly skin internal fertilisation one type of teeth Amniote egg [hard outer covering but softer than bird eggs] Dependent on land for reproduction Claws on toes 3 ½ chambered heart

Birds feathers growing from skin warm blooded (endothermic) 4-chambered heart lungs with parabronchial tubes front legs adapted into wings hard shell around their eggs beak but no teeth

Mammals hairs growing from the skin (may be fur) lungs with alveoli (air sacs) diaphragm separated thorax and abdomen give birth to live young mammary glands secret milk 4 chambered heart teeth of different types warm blooded (endothermic)

Kingdom plantaeThere are many different plant divisions. We will study four: bryophytes, filiconphytes, coniferophyta, angiospermatophyta

Roots, stems and leaves Reproductive structuresBryophyta(mosses)

Structures similar to root hairs called rhizoids but no roots.Mosses have simple leaves and stems.Liverworts have a flattened thallus (green “leaf” part)No vascular tissue

Spores are produced in a capsule. The capsule develops at the end of the stalk

Filiconphyta(ferns)

Roots, leaves and short n0n-woody stems.Leaves are called fronds.Vascular tissue is present

Spores are produced in a sporangia, usually on the underside of the leaves.

Coniferophyta(conifers)

Shrubs or tress with roots, leaves and woody stems.Leaves often narrow with a thick waxy cuticleVascular tissue is present

Seeds which develop from ovules on the surface of the scales of female cones.Male cones produce pollen.

Angiospermatophyta(Flowering plants)

Very variable, but usually have roots, leaves and stems.Stems of shrubs and tress are woody.Vascular tissue is present.

Seeds which develop from ovules inside ovaries in flowers.Fruits develop from the ovaries to disperse seeds.