Cells and Classification of Living Things: notes

Living things

• Seven life processes: movement, respiration, sensitivity, growth, reproduction, excretion and nutrition.

Cells

• Animal cell: nucleus, cytoplasm, cell membrane, mitochondria.
• Plant cell: the same, plus a cellulose cell wall, a large vacuole and chloroplasts.
• Specialised cells: red blood cells carry oxygen; root hair cells absorb water; nerve cells carry impulses.
• Organisation: cells form tissues, tissues form organs, organs form systems.
• Magnification: image size divided by actual size.

Classification

• Dichotomous key: a series of two-way questions used to name an organism.
• Vertebrate groups: fish, amphibians, reptiles, birds and mammals. Mammals have hair and feed young on milk.
• Arthropods: insects (6 legs), arachnids (8 legs), crustaceans and myriapods.