The World of Plants Variety Use Commercial exploitation Need for maintaining variety

Living Things Plant Kingdom Do not produce seedsProduce seeds Gymnosperms Angiosperms AlgaeFungiMossesFerns Conifers MonocotyledonDicotyledon Variety of plants

Advantages of having a wide variety of plants Food Medicine Poppy Foxglove Mandrake Rosy periwinkle

Medicinal plants common name poppyfoxglovemandrake rosy periwinkle scientific name drug extracted use of drug Papaver somniferum Digitalis lanata Mandragora officinarum Catharanthus roseus morphine digitoxinhyosycaminevincristine relief of pain treatment of heart disease sedation of patient before operation treatment of leukaemia

plant Plant organ eaten Protein (g) Fat(g) Carbo- hydrate (g)Calcium(mg)Iron(g) Vit A (mg) Vit C (mg) cabbageleaf carrotroot orangefruit peaseed potatotuber soya bean seed wheat seed grain Class of food (all values per 100g of edible food

Possible consequences to man and other animals of a reduction in the variety of species Ecological loss Tropical rain forest Loss of rainforest due to logging Plantations e.g. pineapple

Destruction of the rainforest leads to loss of habitat

Tropical rain forests cover 6% of Earth’s land They are estimated to contain half or more of all existing species of plants, animals and micro-organisms When cleared, the ecosystem and its wide variety of interdependent species are lost forever For every plant species that becomes extinct through man’s activities, several animal species that were dependent on the plant for food and habitat are threatened and may become extinct

Animals nearing extinction Brazil’s muriqui monkey Kagu bird of New Caledonia Birdwing butterfly of Papua New Guinea

Possible solutions ‘ debt-payment-for-nature’ exchange donations from conservationists being used to settle developing countries’ international debts in exchange for binding promises that these countries will create permanent reserves of tropical rain forest

Loss of future applications of plants Medicinal plants More than 40 species of flowering plants have already provided mankind with medicines Tropical rain forests are the Earth’s main source of plants containing chemicals of possible medicinal use in the future It is thought that at least 2000 different plant species may contain anti-cancer properties Most of these plants have not been studied in detail Clearing rain forests and the subsequent loss in the variety of species means losing forever these plants and their potential medicinal value in combating disease

Genetic storehouse Over 70% of present day American maize plants are genetically identical If a new disease arrives they could all be affected American Maize Plants

A wild form of maize has been discovered in Mexico that is perennial and is resistant to many diseases Mexican Maize plants Geneticists are trying to introduce these useful characteristics into modern maize by cross-breeding In future it will not be possible to introduce new beneficial characteristics into crop plants from wild varieties if they are lost by people destroying their habitats for quick commercial gain

It is essential that we conserve a wide variety of strains of each plant species to provide a genetic storehouse

Specialised uses of plants Edible oils from plants Olive oil Corn oil Sunflower oil

Specialised uses of plants The rape plant is a member of the cabbage family. Its leaves provide forage for farm animals such as sheep. Its tiny black seeds contain oil used in lubricants, metal tempering, and foodstuffs Rapeseed oil

Specialised uses of plantsCotton A cotton seed bears a mass of ‘hairy’ fibres which act like a parachute during wind dispersal of the seed A group of seeds with their fibres entangled in a fibrous mass is called a cotton boll The seeds are separated from their fibres Oil and protein for animal feed are extracted from the seeds. The fibres are spun (twisted to give strength) into yarn (thread) The yarn is then woven into cloth (cotton) Cotton is a cheap, hardwearing absorbent material. It is particularly useful for mixing with synthetic fibres to make a wide variety of useful fabrics

many uses alginates Large brown seaweed film forming gelling and binding emulsifying and stabilising thickening toothpaste shampoo Hand cream Ice cream polish emulsion paint jelly tablets dental impressions sausage casings transparent film washable wall papers