1. Characteristics and
classification of living organisms
Objectives
• To list, describe and define the
characteristics of living things
Characteristics of living things
• All living things have the following
properties
Characteristic Definition
Movement The chemical reactions that break down nutrient molecules in living cells to release energy
Reproduction A permanent increase in size and dry mass by an increase in cell number, cell size or both
Sensitivity An action by an organism or part of an organism to change position or place
Growth Removal of toxic materials, the waste products of metabolism (chemical reactions that occur in cells) and substances in excess of requirements
Respiration The processes that make more of the same kind of organism
Excretion The ability to detect or sense changes in the environment (stimuli) and make responses
Nutrition Taking in of nutrients which are organic substances and mineral ions, containing raw materials or energy for growth and tissue repair and absorbing and
Characteristic Definition
Movement An action by an organism or part of an organism to change position or place
Reproduction The processes that make more of the same kind of organism
Sensitivity The ability to detect or sense changes in the environment (stimuli) and make responses
Growth A permanent increase in size and dry mass by an increase in cell number, cell size or both
Respiration The chemical reactions that break down nutrient molecules in living cells to release energy
Excretion Removal of toxic materials, the waste products of metabolism (chemical reactions that occur in cells) and substances in excess of requirements
Nutrition Taking in of nutrients which are organic substances and mineral ions, containing raw materials or energy for growth and tissue repair and absorbing and
Objectives
• Use the binomial system and know 2
examples
• Define
species
• Know the main features of the 5 vertebrate
groups
Identification and discussion
• Before you can study living things, it helps if you know what living things you are
studying
• In your native
language, what is this?
Binomial nomenclature
• To aid international co-operation
scientists agree to
use a common name for this sort of
organism
A close relative
• The leopard shares many characteristics with the tiger and
belongs to the same group, or genus, as the tiger but it is a different species.
• Its scientific name is
Why do we need to classify?
•
BrainPOP | Classification
• Explain why scientists classify species into
groups
• Give the binomial names for two species.
• Explain what is meant by a “species”.
• BrainPOP | Classification | Quiz
Vertebrate species
• BrainPOP | Vertebrates
Fish
• Breathes through gills • Skin made of fine scales • Move with fins
• Lives and breeds in water • Lays thousands of soft
eggs
• No/little parental care • Cold blooded
Amphibians
• Breathes with lungs and through skin
• Breeds in water but can live on land
• Lays hundreds of soft eggs in water
• Moist skin
• Little/no parental care • Cold blooded
Reptiles
• Breathes using lungs • Usually lives on land
(some exceptions) but breeds on land
• Lays lots of soft shelled eggs
• Some parental care • Dry, scaly skin
Birds
• Breath through lungs • Live (a few exceptions)
and breed on land
• Lay a few hard-shelled eggs
• Parents feed young
• Scales adapted to form feathers
• Wings
• Warm blooded
Mammals
• Breath with lungs • Live and breed on
land (some exceptions!)
• Covered in hair
• Few young carried inside mother and then fed with milk • Warm blooded
Micro-organisms
Other Kingdoms
Arthropods
• All have a jointed exoskeleton and legs
• Bodies are divided into segments
Insects
• Jointed exoskeleton • 3 body segments
• 3 pairs of legs
• One pair antennae • Wings (usually)
• Waterproof cuticle • E.g. blue morpho
Crustaceans
• Chalky exoskeleton • No wings – nearly all
live in water
• 2 pairs of antennae • Variable number of
pairs of legs >4 but <20
Arachnids
• 2 body segments • 4 pairs of legs
• No wings
• No antennae
Cladistics
• Cladistics uses a comparison of DNA/RNA
sequences to classify organisms
• Richard Dawkins: Comparing the Human
and Chimpanzee Genomes
Other classification systems
• Other systems of classification exist e.g.
cladistics which uses DNA or RNA
Micro-organisms
• Research the features used in the
classification of viruses, bacteria and fungi
using p10-11 of Complete Biology.
Other organisms
• Design an educational poster illustrating the feature used in the classification of one of the following groups
• Flowering plants
• Arthropods – insects, arachnids, crustaceans or myriapods
• Annelids
• Nematodes • Molluscs
