Notesale: Turn your study into money

Document Preview

Extracts from the notes are below, to see the PDF you'll receive please use the links above

---

IGCSE BIOLOGY NOTES by DR
...
Characteristics of living organisms
Movement: an action by an organism or part of an organism causing a change of position, place, or aspect
Respiration: the chemical reactions that break down nutrient molecules in living cells to release energy
Sensitivity: the ability to detect or sense changes in the environment (stimuli) and to make responses
Growth: a permanent increase in size and dry mass by an increase in cell number or cell size or both
Reproduction: the processes that make more of the same kind of organism
Excretion: removal from organisms of toxic materials, the waste products of metabolism (chemical reactions in cells
including respiration) 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, absorbing and assimilating them
2
...
1 Concept and use of a classificatory system
binomial system: a system of naming species in which the scientific name of an organism is made up of two parts
showing the genus (starting with a capitol letter) and species (starting with a lower case letter), written in italics when
printed (therefore underlined when handwritten) e
...
Homo sapiens

Bony fish
Amphibians
Birds
Reptiles
Mammals

Skin
Scales
Moist
Scales on legs,
feathers
Scales
Fur/Hair

Habitat
Water
Land/Water
Land

Legs
Fins
4
2 legs & 2 wings

Breathing
Gills
Gills/Lungs
Lungs

Birth Method
Soft Eggs
Soft Eggs
Hard Eggs

Land
Land/Water

usually 4
4

Lungs
Lungs

Hard Eggs
Live birth

Viruses and bacteria:
Virus
Covered by
Protein coat
Cell membrane No
Cytoplasm
No
Genetic material DNA or RNA – only a few genes
Living or not?
Non-living unless in host

Notes by Dr
...
Anila Arshad

Page 2

There are other classification systems e
...
cladistics (based on RNA/DNA sequencing data)
The five kingdoms:
Animal: Multi-cellular ingestive heterotrophs (eat living organisms)
Plant: Multi-cellular photosynthetic autotrophic (make their own food) organism with a cellulose cell wall
...
2 Adaptations of organisms to their environment
Types of flowering plants:
Monocotyledons: one cotyledon in seed, parallel veins in leaves, elongated leaves, flower parts often in multiples of three
(stamens, petals, ovary) e
...
tulip
...
g
...


Notes by Dr
...
Insects: 6 legs, 3 body parts (head, thorax and abdomen), made of many segments, and two antennae e
...

bees
...
Crustaceans: many legs, 4 antennae, 2 body parts (head-thorax and abdomen), made of many segments
e
...
crabs
...
Arachnids: 8 legs, no antennae, 2 body parts (head-thorax and abdomen) e
...
spiders
...
Myriapods: many legs, many segments, 2 antennae e
...
centipede
 Annelids: ringed worms, no legs, chaetae (bristles) e
...
earthworms
...
g
...

 Molluscs: un-segmented, have gills and one muscular foot e
...
snails
...
Simple Keys
Dichotomous key: uses visible features to classify organisms
...


Notes by Dr

---