Contents
1 Characteristics and classification of living organisms
2 Organisation of the organism
3 Movement into and out of cells
4 Biological molecules
5 Enzymes
6 Plant nutrition
7 Human nutrition
8 Transport in plants
9 Transport in animals
10 Diseases and immunity
11 Gas exchange in humans
12 Respiration
13 Excretion in humans
14 Coordination and response
15 Drugs
16 Reproduction
17 Inheritance
18 Variation and selection
19 Organisms and their environment
20 Human influences on ecosystems
21 Biotechnology and genetic modification
1
,1. Characteristics and classification of living organisms
1.1 Characteristics of living organisms
7 Characteristics of living things (MRS GREN):
● Movement - an action by an organism or part of an organism causing a change of
position or place.
● Respiration - the chemical reactions in cells that break down nutrient molecules and
release energy for metabolism.
● Sensitivity - the ability to detect and respond to changes in the internal or external
environment.
● Growth - a permanent increase in size and dry mass.
● Reproduction - the processes that make more of the same kind of organism.
● Excretion - the removal of the waste products of metabolism and substances in
excess of requirements.
● Nutrition - the taking in of materials for energy, growth and development.
1.2 Concept and uses of classification systems
Organisms can be classified into groups by the features that they share.
Classification - systems aim to reflect evolutionary relationships
● Sequences of bases in DNA are used for classification.
● They classify organisms by using their genetics to trace their evolutionary
relationships.
● Many species have similar features that allow us to put them into groups.
● Organisms who share a more recent ancestor (i.e. more closely related) have DNA
base sequences that are more similar than those who only share a distant ancestor.
Species - A group of organisms that can reproduce to produce fertile offspring (with
organisms sharing similar characteristics and living space.)
Binomial Naming - an internationally agreed system in which the scientific name of an
organism is made up of two parts showing the genus and species. E.g. homo (genus)
sapiens (species)
Dichotomous key - used to classify animals based on their visible characteristics
2
,1.3 Features of Organism
Kingdom -> phylum -> class -> order -> family -> genus -> species
All living things are classified into five kingdoms:
● Plants - multicellular, contains nucleus, chloroplasts & cell walls.
● Animals - multicellular, contains nucleus, no chloroplasts/cell wall.
● Fungi - multicellular, contains nucleus & cell walls.
● Protoctists - unicellular, contains nucleus.
● Prokaryotes - unicellular, contain cell walls, no nucleus.
Animal kingdom
Main groups of vertebrates (animals with a backbone): mammals birds, reptiles, amphibians,
fish
Vertebrate Body Movement Reproduction Sense Blood Examples
class organs
Fish Scales Fins Jelly-covered Eyes Cold Herring
eggs blooded Shark
Amphibians Moist 4 limbs Jelly-covered Eyes Cold Frog
skin Webbed feet eggs in water Ears blooded Newt
Reptiles Dry 4 legs (apart Rubbery-shelled Eyes Cold Lizard
scales from snake) eggs Ears blooded Snake
Birds Feathers 2 wings Hard shelled Eyes Warm Chicken
2 legs eggs, laid on Ears blooded Penguins
land
Mammals Fur 4 limbs Produce live Eyes Warm Cow
young Ears blooded Cat
with
pinna
3
, Main groups of arthropods (invertebrates — animals with no backbone): myriapods, insects,
arachnids, crustaceans
Traits:
● Most have a firm/hard external skeleton made up of chitin.
● Jointed limbs
○ Arachnid: 8 legs
○ Crustaceans: 10 legs
○ Insects: 6 legs
○ Myriapods: uncountable
● Body segmentation (2 or 3).
- Arachnid and Crustaceans: cephalothorax, abdomen.
- Insects: head, thorax and abdomen.
- Myriapods: not obviously divided.
● Eyes
- Arachnids & Myriapods: simple eyes.
- Insects & Crustaceans: compound eyes.
Plant kingdom
● Ferns - the first plants to adapt to living on land. They have evolved to have roots,
stems, complex leaves and vascular tissues.
● Angiosperms - plants with flowers and seeds. They have evolved most recently.
Monocotyledon Features Dicotyledon
Narrow & elongated Leaf shape Round / broad
Parallel Leaf vein Net - like, reticulate,
branching
Only one seed leaf Cotyledon (seed leaf) Double
3 Grouping of flower parts 5
Fibrous / branched Roots Tap (one main root)
Viruses
● Viruses are not considered as living things.
● They DO NOT display the 7 characteristics of living things.
4
1 Characteristics and classification of living organisms
2 Organisation of the organism
3 Movement into and out of cells
4 Biological molecules
5 Enzymes
6 Plant nutrition
7 Human nutrition
8 Transport in plants
9 Transport in animals
10 Diseases and immunity
11 Gas exchange in humans
12 Respiration
13 Excretion in humans
14 Coordination and response
15 Drugs
16 Reproduction
17 Inheritance
18 Variation and selection
19 Organisms and their environment
20 Human influences on ecosystems
21 Biotechnology and genetic modification
1
,1. Characteristics and classification of living organisms
1.1 Characteristics of living organisms
7 Characteristics of living things (MRS GREN):
● Movement - an action by an organism or part of an organism causing a change of
position or place.
● Respiration - the chemical reactions in cells that break down nutrient molecules and
release energy for metabolism.
● Sensitivity - the ability to detect and respond to changes in the internal or external
environment.
● Growth - a permanent increase in size and dry mass.
● Reproduction - the processes that make more of the same kind of organism.
● Excretion - the removal of the waste products of metabolism and substances in
excess of requirements.
● Nutrition - the taking in of materials for energy, growth and development.
1.2 Concept and uses of classification systems
Organisms can be classified into groups by the features that they share.
Classification - systems aim to reflect evolutionary relationships
● Sequences of bases in DNA are used for classification.
● They classify organisms by using their genetics to trace their evolutionary
relationships.
● Many species have similar features that allow us to put them into groups.
● Organisms who share a more recent ancestor (i.e. more closely related) have DNA
base sequences that are more similar than those who only share a distant ancestor.
Species - A group of organisms that can reproduce to produce fertile offspring (with
organisms sharing similar characteristics and living space.)
Binomial Naming - an internationally agreed system in which the scientific name of an
organism is made up of two parts showing the genus and species. E.g. homo (genus)
sapiens (species)
Dichotomous key - used to classify animals based on their visible characteristics
2
,1.3 Features of Organism
Kingdom -> phylum -> class -> order -> family -> genus -> species
All living things are classified into five kingdoms:
● Plants - multicellular, contains nucleus, chloroplasts & cell walls.
● Animals - multicellular, contains nucleus, no chloroplasts/cell wall.
● Fungi - multicellular, contains nucleus & cell walls.
● Protoctists - unicellular, contains nucleus.
● Prokaryotes - unicellular, contain cell walls, no nucleus.
Animal kingdom
Main groups of vertebrates (animals with a backbone): mammals birds, reptiles, amphibians,
fish
Vertebrate Body Movement Reproduction Sense Blood Examples
class organs
Fish Scales Fins Jelly-covered Eyes Cold Herring
eggs blooded Shark
Amphibians Moist 4 limbs Jelly-covered Eyes Cold Frog
skin Webbed feet eggs in water Ears blooded Newt
Reptiles Dry 4 legs (apart Rubbery-shelled Eyes Cold Lizard
scales from snake) eggs Ears blooded Snake
Birds Feathers 2 wings Hard shelled Eyes Warm Chicken
2 legs eggs, laid on Ears blooded Penguins
land
Mammals Fur 4 limbs Produce live Eyes Warm Cow
young Ears blooded Cat
with
pinna
3
, Main groups of arthropods (invertebrates — animals with no backbone): myriapods, insects,
arachnids, crustaceans
Traits:
● Most have a firm/hard external skeleton made up of chitin.
● Jointed limbs
○ Arachnid: 8 legs
○ Crustaceans: 10 legs
○ Insects: 6 legs
○ Myriapods: uncountable
● Body segmentation (2 or 3).
- Arachnid and Crustaceans: cephalothorax, abdomen.
- Insects: head, thorax and abdomen.
- Myriapods: not obviously divided.
● Eyes
- Arachnids & Myriapods: simple eyes.
- Insects & Crustaceans: compound eyes.
Plant kingdom
● Ferns - the first plants to adapt to living on land. They have evolved to have roots,
stems, complex leaves and vascular tissues.
● Angiosperms - plants with flowers and seeds. They have evolved most recently.
Monocotyledon Features Dicotyledon
Narrow & elongated Leaf shape Round / broad
Parallel Leaf vein Net - like, reticulate,
branching
Only one seed leaf Cotyledon (seed leaf) Double
3 Grouping of flower parts 5
Fibrous / branched Roots Tap (one main root)
Viruses
● Viruses are not considered as living things.
● They DO NOT display the 7 characteristics of living things.
4
